Science.gov

Sample records for severe sliding conditions

  1. Tribological Behaviour of PTFE Under Variable Loading Dry Sliding Condition

    NASA Astrophysics Data System (ADS)

    Patil, S. M.; Ahuja, B. B.

    2014-04-01

    To study the tribological behaviour of materials subjected to variable and constant loading the pin-on-disk tribometer has been modified. This paper discusses the wear and friction behaviour of Poly Tetra Fluoro Ethylene (PTFE) operating under variable loading dry unidirectional sliding condition using the modified tribometer. The results under variable loading are compared with corresponding maximum, minimum and mean constant load situations. Wear and specific wear rate of PTFE subjected to variable loading under dry unidirectional sliding condition lies above those of corresponding mean constant load but no such comparative behaviour was observed for coefficient of friction.

  2. Frictional sliding of biotite gouge under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Lu, Z.; He, C.

    2012-12-01

    In order to understand the origin of compositionally-weak fault and the mechanical behavior of fault zone composed of biotite-rich rocks in general, this work investigated the frictional sliding behavior of biotite gouge under hydrothermal conditions by shearing 1-mm-thick biotite gouge layers sandwiched between saw-cut driver blocks, using a triaxial testing system with argon gas as confining medium. Experiments were conducted under effective normal stress of 200MPa, with pore pressure of 30MPa, temperatures from room temperature to 600°C, and shear displacement rate were stepped with our standard (0.0001-0.001mm/s) and slow velocity steps (0.00004-0.0002mm/s). The results show that the coefficient of friction of biotite is on the order of 0.29 in the low temperature range (25 to 100°C), and varies around 0.35 for temperatures over 200°C. The overall average of friction coefficient from room temperature up to 600°C is ca. 0.33, evidently weaker than framework minerals such as quartz and feldspar and also weaker than muscovite in the mica group. Within the sliding displacement up to 4mm in our experiments, velocity strengthening occurred at temperatures of 25-200°C, with steady-state rate dependence ranging from 0.001 to 0.006. Weak velocity weakening was found at 300°C, with steady-state rate dependence similar to neutral. At 400°C, the deformation behavior changed radically and very strong velocity strengthening occurred, with steady-state rate dependence ranging from 0.012 to 0.112. At 500 and 600°C, the experiments show strong velocity dependence in the early stage of sliding, but the sliding behavior gradually evolves to stick-slip as the shearing deformation proceeds, indicating strong velocity-weakening behavior. The strongest velocity dependence occurred at 400°C in the early stage of sliding, with stress exponent similar to that of power-law creep, but the confining pressure dependence of shear strength suggests that such a behavior is semi

  3. Effect of starvation on film thickness and traction under elastohydrodynamic rolling and sliding conditions

    NASA Technical Reports Server (NTRS)

    Wedeven, L. D.

    1975-01-01

    Traction measurements under starved elastohydrodynamic conditions were obtained for a point-contact geometry. Simultaneous measurements of the film thickness and the location of the inlet lubricant boundary were made. Optical interferometry was used to measure film thickness. The thickness of a starved film for combined rolling and sliding conditions varies with the location of the inlet boundary in the same way as previously found for pure rolling conditions. When the fluid velocity distribution is calculated in the inlet region by a Reynolds lubrication analysis, backflow is seen to occur over a portion of the inlet region. Backflow is essential for the establishment of a flooded condition. The location of certain fluid velocity conditions within the inlet region, as suggested in the literature, does not adequately describe the onset of starvation. For the same slide-roll ratio a starved film was observed to possess greater traction than a flooded film. Traction measurements under starved conditions were also compared with those under flooded conditions for equivalent shear rates in the Hertzian region. When the shear rates within the Hertzian region were low and the film was severely starved, the measured tractions were lower than expected. This may be due to large shear stresses developed by the large pressure gradients that are generated in the inlet region when it is severely starved.

  4. Scuffing initiation in metals sliding against copper under non-lubricated conditions

    SciTech Connect

    Kovalchenko, A M; Blau, Peter Julian; Qu, Jun; Danyluk, S

    2011-01-01

    Metallic components in sliding contact are sometimes subjected to high-loads with little or no lubrication. Such starved conditions can lead to a phenomenon called scuffing. Various definitions exist for this term, but in the present case, three criteria were used to signal its onset: changes in friction, vibrations, and noise, coupled with surface examination. On this basis, scuffing initiation was determined for seven technically pure metals (Al, Mo, Nb, Ta, Ti, W, Cu) and stainless steel, all rubbing against Cu. A flat-ended pin-on-disk test configuration was used with normal loads of 1-3 N, and with step-wise increases in sliding speed from 0.16 to 2.56 m/s. Al was only weakly resistant to scuffing, presumably due to its solubility in Cu, its high ductility and its relatively low elastic modulus. Niobium provided satisfactory sliding behavior at low speeds and loads, presumably due to protective oxides; however, it scuffed at higher loads when the oxide broke through. Stainless steel, Mo, and Ta had higher friction coefficients than Al and Nb, presumably because the relatively high strengths of the former prevented severe wear even when their oxide films failed. Like Al, Ti scuffs on Cu, probably because of its high relative solubility; however, Ti's higher elastic modulus resists the more severe forms of surface damage than does Al. Of all the materials slid against Cu, W displayed the least scuffing, even under maximum speed and load. Tungsten's negligible solubility in Cu may have reduced its adhesion, and W's high elastic modulus resisted shear-deformation, even at high frictional heating. Self-mated Cu couple scuffed when the speed was increased. The oxides on the Cu surface serve as solid lubricant avoiding scuffing at lower speeds.

  5. Reaction of perfluoroalkylpolyethers (PFPE) with 440C steel in vacuum under sliding conditions at room temperature

    NASA Technical Reports Server (NTRS)

    Mori, Shigeyuki; Morales, Wilfredo

    1989-01-01

    Reactions of perfluoroalkylpolyethers (PFPE: Fomblin, Demnum and Krytox) were studied during the sliding contact of stainless steel specimens under ultrahigh vacuum conditions. All three fluids reacted with the steel specimens during sliding. Fomblin, which has acetal linkages, decomposed under the sliding conditions generating gaseous products, (COF2 and fluorinated carbons) which were detected by a quadrupole mass spectrometer. Gaseous products were not detected for the Demnum and Krytox fluids. The amount of gaseous products from Fomblin increased with increasing sliding speed. At the end of the sliding experiments, the wear scar and deposits on the specimens were examined by small spot size XPS. The oxide layer on the specimen surface was removed during sliding, and metal fluorides were formed on the worn surface. The surface of the wear scar and deposits were covered with adsorbed PFPE. Based on these results, it was concluded that the decomposition reaction on Fomblin was initiated by contacting the fluid with a fresh metal surface which was formed during sliding.

  6. Decomposition of perfluoroalkylpolyethers (PFPE) in ultra-high vacuum under sliding conditions

    NASA Technical Reports Server (NTRS)

    Mori, Shigeyuki; Morales, Wilfredo

    1990-01-01

    Reactions of perfluoroalkylpolyethers (PFPE: Fomblin, Demnum and Krytox) were studied during the sliding contact of stainless steel specimens under ultrahigh vacuum conditions. All three fluids reacted with the steel specimens during sliding. Fomblin, which has acetal linkages, decomposed under the sliding conditions generating gaseous products, (COF2 and fluorinated carbons) which were detected by a quadrupole mass spectrometer. Gaseous products were not detected for the Demnum and Krytox fluids. The amount of gaseous products from Fomblin increased with increasing sliding speed. At the end of the sliding experiments, the wear scar and deposits on the specimens were examined by small spot size XPS. The oxide layer on the specimen surface was removed during sliding, and metal fluorides were formed on the worn surface. The surface of the wear scar and deposits were covered with adsorbed PFPE. Based on these results, it was concluded that the decomposition reaction on Fomblin was initiated by contacting the fluid with a fresh metal surface which was formed during sliding.

  7. Fault stability inferred from granite sliding experiments at hydrothermal conditions

    USGS Publications Warehouse

    Blanpied, M.L.; Lockner, D.A.; Byerlee, J.D.

    1991-01-01

    Seismicity on crustal faults is concentrated in the depth interval 1-3 to 12-15 km. Tse and Rice (1986) suggested that the lower bound on seismicity is due to a switch with increasing temperature from velocity weakening (destabilizing) to velocity strengthening (stabilizing) friction. New data is presented from sliding experiments on granite at elevated T (23?? to 600??C) plus elevated PH2O(100 MPa). Results show velocity strengthening at room temperature, but velocity weakening from 100?? to 350??C (except at 250??). From 350?? to 600?? there are systematic trends from velocity weakening to strong velocity strengthening, and from high to low friction; neither trend was seen in tests on dry granite. The velocity dependence data imply the potential for unstable slip in the interval 100?? to 350??. Using a geotherm to map temperature to depth, this interval closely matches the observed earthquake distribution. -from Authors

  8. XPS analysis of 440C steel surfaces lubricated with perfluoropolyethers under sliding conditions in high vacuum

    NASA Technical Reports Server (NTRS)

    Herrera-Fierro, Pilar; Masuko, Masabumi; Jones, William R., Jr.; Pepper, Stephen V.

    1994-01-01

    This work presents the results of the X-Ray Photoelectron Spectroscopy (XPS) analysis of AISI 440C ball surfaces lubricated with perfluoropolyether (PFPE) oils after friction experiments under sliding conditions at high load in air and vacuum environments. The PFPE lubricants tested were Demnum S100, Fomblin Z-25, and Krytox 143AB. It was found that all the PFPE lubricants were degraded by sliding contact causing the formation of inorganic fluorides on the metallic surfaces and a layer of organic decomposition products. KRYTOX 143AB was the least reactive of the three lubricants tested. It was also found that metal fluoride formed at off-scar areas. This suggests the formation of reactive species, such as COF2 or R(sub f)COF, during sliding experiments, which can diffuse through the lubricant film and react with the metallic surfaces away from the contact region. Comparison of reference specimens before sliding with those that had undergone the sliding tests showed that the amount of non-degraded PFPE remaining on the surface of the balls after the sliding experiments was greater than that of the balls without sliding.

  9. Impact of pavement conditions on crash severity.

    PubMed

    Li, Yingfeng; Liu, Chunxiao; Ding, Liang

    2013-10-01

    Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses.

  10. The Influence of Sliding and Contact Severity on the Generation of White Etching Cracks

    SciTech Connect

    Gould, Benjamin; Greco, Aaron

    2015-10-17

    White etching cracks (WECs) have been identified as the dominant mechanism of premature failure for bearings within wind turbine gearboxes. Though WECs have been observed in the field for over a decade, the exact mechanisms which lead to this failure are still debated, and benchtop replication has proven difficult. In previously published work, WECs have been replicated only through the use of component level test rigs, where complete bearings are tested. In these tests, the factors that are thought to drive the formation of WECs, such as slide-to-roll ratio (SRR) and lubricant film thickness, cannot not be easily altered or controlled. In this paper, WECs have been replicated on a three rings on roller, benchtop test rig, which allowed for a direct investigation into the influence that SRR magnitude, sliding direction, and the lubricant film thickness have on surface failures and WEC generation. It was determined that WEC were formed in samples that experienced -30% SRR at various lubrication conditions, however, at lower levels of negative SRR and positive SRR up to 30% no white-etching cracks were observed.

  11. Onset of frictional sliding of rubber–glass contact under dry and lubricated conditions

    PubMed Central

    Tuononen, Ari J.

    2016-01-01

    Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons’ law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements. PMID:27291939

  12. Onset of frictional sliding of rubber–glass contact under dry and lubricated conditions

    NASA Astrophysics Data System (ADS)

    Tuononen, Ari J.

    2016-06-01

    Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons’ law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements.

  13. Onset of frictional sliding of rubber-glass contact under dry and lubricated conditions.

    PubMed

    Tuononen, Ari J

    2016-01-01

    Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons' law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements. PMID:27291939

  14. Onset of frictional sliding of rubber-glass contact under dry and lubricated conditions

    NASA Astrophysics Data System (ADS)

    Tuononen, Ari J.

    2016-06-01

    Rubber friction is critical in many applications ranging from automotive tyres to cylinder seals. The process where a static rubber sample transitions to frictional sliding is particularly poorly understood. The experimental and simulation results in this paper show a completely different detachment process from the static situation to sliding motion under dry and lubricated conditions. The results underline the contribution of the rubber bulk properties to the static friction force. In fact, simple Amontons’ law is sufficient as a local friction law to produce the correct detachment pattern when the rubber material and loading conditions are modelled properly. Simulations show that micro-sliding due to vertical loading can release initial shear stresses and lead to a high static/dynamic friction coefficient ratio, as observed in the measurements.

  15. Antifriction Property of Microarc Oxidation Coating on Titanium Alloy Under Solid Lubricating Sliding Condition

    NASA Astrophysics Data System (ADS)

    Wang, Y. M.; Jiang, B. L.; Guo, L. X.; Lei, T. Q.

    Ceramic coatings were fabricated on Ti6Al4V alloy surface by microarc oxidation (MAO) in Na2SiO3-(NaPO3)6-NaAlO2 solution using an AC power supply. Microstructure and phase composition of coating were characterized by SEM and XRD, respectively. The antifriction property of the coating with and without solid lubricant sliding against SAE 52100 steel ball was investigated on a pin-on-disk friction and wear tester. The results show that the microarc oxidation coating is relatively dense and uniform, mainly composed of rutile and anatase. The coating sliding against the steel has friction coefficient as low as 0.2-0.3 at an applied load of 0.5 N and sliding cycle below 2500, which is much smaller than that of uncoated Ti6Al4V against the same counterpart. The transferring of materials from the softer steel ball onto the coating surface is the main wear event, while the microarc oxidation coating is characterized by slight abrasive wear and adhesive wear. Introducing solid graphite lubricant into the porous surface of microarc oxidation coating significantly improves the long-term antifriction property (registering friction efficient of 0.15 in the long-term sliding) under a similar sliding condition. This improvement is attributed to the reduction of materials that are transferred from the softer steel ball onto the coating surface.

  16. 76 FR 26957 - Special Conditions: Boeing, Model 747-8 Series Airplanes; Door 1 Extendable Length Escape Slide

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... most critical angle, escape slides usually exceed 25 knot performance at other than the critical angle... wind velocity is appropriate since the slide will be in an abnormal condition. Available data indicate... critical angle, with the airplane on all its landing gear, with the assistance of one person on the...

  17. Voice interactive systems in severe noise conditions

    NASA Astrophysics Data System (ADS)

    Steeneken, J. H. M.; Langhout, G.

    1987-02-01

    In a comparison of word recognition performance between human listeners and automatic speech recognition systems (ASR), the human listeners performs much better, especially in severe noise conditions. An application engineer can try to optimize the performance of an ASR system by selecting the optimal noise cancelling microphone and vocabulary for voice input. Some results from a study on the effect of signal handling and vocabulary configuration on the performance of voice input and voice output systems are discussed.

  18. Effect of Operating Conditions on Tribological Response of Al Al Sliding Electrical Interface

    SciTech Connect

    Bansal, Dinesh G; Streator, Jeffrey L

    2011-01-01

    Aluminum is widely used in electrical contacts due to its electrical properties and inexpensiveness when compared to copper. In this study, we investigate the influence of operating conditions like contact load (pressure), sliding speed, current, and surface roughness on the electrical and tribological behavior of the interface. The tests are conducted on a linear, pin-on-flat tribo-simulator specially designed to investigate electrical contacts under high contact pressures and high current densities. Control parameters include sliding speed, load, current, and surface roughness. The response of the interface is evaluated in the light of coefficient of friction, contact resistance, contact voltage, mass loss of pins, and interfacial temperature rise. As compared to sliding speed, load, and roughness, current is found to have the greatest influence on the various measured parameters. Under certain test conditions, the interface operates in a voltage saturation regime, wherein increase in current do not result in any increase in contact voltage. Within the voltage saturation regime the coefficient of friction tends to be lower, a result that is attributed to the higher temperatures associated with the higher voltage (and resulting material softening). Higher interfacial temperatures also appear to be responsible for the higher wear rates observed at higher current levels as well as lower coefficients of friction for smoother surfaces in the presence of current.

  19. Conditions for the sliding-bouncing transition for the interaction of a bubble with an inclined wall

    NASA Astrophysics Data System (ADS)

    Barbosa, C.; Legendre, D.; Zenit, R.

    2016-07-01

    In this study we analyze the interaction of a single rising bubble with an inclined wall. We conduct experiments considering different liquids and bubble sizes, to cover a wide range of Reynolds and Weber numbers, with wall angles from nearly horizontal to nearly vertical. For all cases, the bubble initially collides with the wall; after the initial interaction, in accord with previous studies, the bubble either steadily slides on the wall or ascends, colliding repeatedly with it. Considering a force balance for the bubble motion on the wall, we propose a set of conditions for the transition from sliding to bouncing that is validated with the present and previous data.

  20. Soft-sediment deformation from submarine sliding: Favourable conditions and triggering mechanisms in examples from the Eocene Sobrarbe delta (Ainsa, Spanish Pyrenees) and the mid-Cretaceous Ayabacas Formation (Andes of Peru)

    NASA Astrophysics Data System (ADS)

    Odonne, Francis; Callot, Pierre; Debroas, Elie-Jean; Sempere, Thierry; Hoareau, Guilhem; Maillard, Agnès

    2011-04-01

    Soft-sediment deformation structures resulting from submarine sliding are investigated in two natural examples: (1) the Eocene Sobrarbe delta, which covers ~ 500 km 2 of the Ainsa Basin in northern Spain, and (2) the Ayabacas Formation, which crops out over more than 80,000 km 2 in southern Andean Peru. In the Sobrarbe delta, 15% of the sediments were displaced along several slide surfaces, whereas most of the Ayabacas Formation was displaced during the giant submarine collapse of a regional carbonate platform at the Turonian-Coniacian transition. Sliding appears to have been highly favoured by conditions such as high pore-fluid pressure due to undercompaction of fine-grained sediments. High sedimentation rates in the Sobrarbe delta (70-87.5 cm/kyr) facilitated slide formation; slides may also have been controlled by the facies transition between marls and silts or sands at the delta front, as well as relative sea-level changes due to tectonic activity in the south Pyrenees foreland basin. In the Ayabacas Formation, the degree of lithification of siliciclastic materials in the lower part of the involved succession was low at the time of collapse, whereas the overlying limestone sequence had undergone some cementation starting shortly after deposition; the collapse and the different behaviour of materials resulted in an extraordinarily deformed, highly disrupted and slumped chaotic unit. Tectonic activity may have been responsible for some sliding in the Ayabacas Formation and for some seismites in the Sobrarbe delta but relationships between sliding, earthquakes and soft-sediment deformation are not unequivocally clear. In the downslope part of slides, unroofing of sediments shows that they had acquired a compaction sufficient to form mode 1 fractures. Active displacement appears to have been the most effective parameter in controlling soft-sediment deformation associated with submarine sliding. With increasing displacement, displaced rafts increasingly deformed

  1. Characterization of Wear Particles Generated from CoCrMo Alloy under Sliding Wear Conditions

    PubMed Central

    Pourzal, R.; Catelas, I.; Theissmann, R.; Kaddick, C.; Fischer, A.

    2011-01-01

    Biological effects of wear products (particles and metal ions) generated by metal-on-metal (MoM) hip replacements made of CoCrMo alloy remain a major cause of concern. Periprosthetic osteolysis, potential hypersensitivity response and pseudotumour formation are possible reactions that can lead to early revisions. To accurately analyse the biological response to wear particles from MoM implants, the exact nature of these particles needs to be characterized. Most previous studies used energy-dispersive X-ray spectroscopy (EDS) analysis for characterization. The present study used energy filtered transmission electron microscopy (TEM) and electron diffraction pattern analysis to allow for a more precise determination of the chemical composition and to gain knowledge of the crystalline structure of the wear particles. Particles were retrieved from two different test rigs: a reciprocating sliding wear tribometer (CoCrMo cylinder vs. bar) and a hip simulator according to ISO 14242-1 (CoCrMo head vs. CoCrMo cup). All tests were conducted in bovine serum. Particles were retrieved from the test medium using a previously published enzymatic digestion protocol. Particles isolated from tribometer samples had a size of 100 – 500 nm. Diffraction pattern analysis clearly revealed the lattice structure of strain induced hcp ε-martensite. Hip simulator samples revealed numerous particles of 15 – 30 nm and 30 – 80 nm size. Most of the larger particles appeared to be only partially oxidized and exhibited cobalt locally. The smallest particles were Cr2O3 with no trace of cobalt. It optically appeared that these Cr2O3 particles were flaking off the surface of larger particles that depicted a very high intensity of oxygen, as well as chromium, and only background noise of cobalt. The particle size difference between the two test rigs is likely related to the conditions of the two tribosystems, in particular the difference in the sample geometry and in the type of sliding

  2. Boundary conditions in the vicinity of a dynamic contact line: experimental investigation of viscous drops sliding down an inclined plane.

    PubMed

    Rio, E; Daerr, A; Andreotti, B; Limat, L

    2005-01-21

    To probe the microscopic balance of forces close to a moving contact line, the boundary conditions around viscous drops sliding down an inclined plane are investigated. At first, the variation of the contact angle as a function of the scale of analysis is discussed. The dynamic contact angle is measured at a scale of 6 mum all around sliding drops for different volumes and speeds. We show that it depends only on the capillary number based on the local liquid velocity, measured by particle tracking. This velocity turns out to be normal to the contact line everywhere. It indirectly proves that, in comparison with the divergence involved in the normal direction, the viscous stress is not balanced by intermolecular forces in the direction tangential to the contact line, so that any motion in this last direction gets damped.

  3. Selected Landscape Plants. Slide Script.

    ERIC Educational Resources Information Center

    McCann, Kevin

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with commercially important woody ornamental landscape plants. Included in the script are narrations for use with a total of 253 slides illustrating 92 different plants. Several slides are used to illustrate each plant: besides a view of…

  4. Effect of thickness and boundary conditions on the behavior of viscoelastic layers in sliding contact with wavy profiles

    NASA Astrophysics Data System (ADS)

    Menga, N.; Afferrante, L.; Carbone, G.

    2016-10-01

    In this work, the sliding contact of viscoelastic layers of finite thickness on rigid sinusoidal substrates is investigated within the framework of Green's functions approach. The periodic Green's functions are determined by means of a novel formalism, which can be applied, in general, to either 2D and 3D viscoelastic periodic contacts, regardless of the contact geometry and boundary conditions. Specifically, two different configurations are considered here: a free layer with a uniform pressure applied on the top, and a layer rigidly confined on the upper boundary. It is shown that the thickness affects the contact behavior differently, depending on the boundary conditions. In particular, the confined layer exhibits increasing contact stiffness when the thickness is reduced, leading to higher loads for complete contact to occur. The free layer, instead, becomes more and more compliant as thickness is reduced. We find that, in partial contact, the layer thickness and the boundary conditions significantly affect the frictional behavior. In fact, at low contact penetrations, the confined layer shows higher friction coefficients compared to the free layer case; whereas, the scenario is reversed at large contact penetrations. Furthermore, for confined layers, the sliding speed related to the friction coefficient peak is shifted as the contact penetration increases. However, once full contact is established, the friction coefficient shows a unique behavior regardless of the layer thickness and boundary conditions.

  5. Classical conditioning in patients with severe memory problems.

    PubMed Central

    Daum, I; Channon, S; Canavan, A G

    1989-01-01

    Classical conditioning is one of the most fundamental forms of learning, and yet little is known regarding the effects of brain injury on conditioning processes in humans. Three patients with temporal lobe lesions and severe memory problems were therefore assessed in terms of eyeblink conditioning, extinction, discrimination and reversal learning, and in one patient electrodermal conditioning was also investigated. The acquisition of conditioned responses was seen to be intact, but the evidence regarding extinction was ambiguous. All of the patients were impaired in discrimination learning and also reversal learning. PMID:2496204

  6. Full-length fuel rod behavior under severe accident conditions

    SciTech Connect

    Lombardo, N J; Lanning, D D; Panisko, F E

    1992-12-01

    This document presents an assessment of the severe accident phenomena observed from four Full-Length High-Temperature (FLHT) tests that were performed by the Pacific Northwest Laboratory (PNL) in the National Research Universal (NRU) reactor at Chalk River, Ontario, Canada. These tests were conducted for the US Nuclear Regulatory Commission (NRC) as part of the Severe Accident Research Program. The objectives of the test were to simulate conditions and provide information on the behavior of full-length fuel rods during hypothetical, small-break, loss-of-coolant severe accidents, in commercial light water reactors.

  7. 7 CFR 765.207 - Conditions for severance agreements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Conditions for severance agreements. 765.207 Section 765.207 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DIRECT LOAN SERVICING-REGULAR Protecting the Agency's...

  8. 24 CFR 3285.404 - Severe climatic conditions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....404 Severe climatic conditions. In frost-susceptible soil locations, ground anchor augers must be installed below the frost line, unless the foundation system is frost-protected to prevent the effects of frost heave, in accordance with acceptable engineering practice and § 3280.306 of this chapter...

  9. 24 CFR 3285.404 - Severe climatic conditions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ....404 Severe climatic conditions. In frost-susceptible soil locations, ground anchor augers must be installed below the frost line, unless the foundation system is frost-protected to prevent the effects of frost heave, in accordance with acceptable engineering practice and § 3280.306 of this chapter...

  10. 24 CFR 3285.404 - Severe climatic conditions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....404 Severe climatic conditions. In frost-susceptible soil locations, ground anchor augers must be installed below the frost line, unless the foundation system is frost-protected to prevent the effects of frost heave, in accordance with acceptable engineering practice and § 3280.306 of this chapter...

  11. 24 CFR 3285.404 - Severe climatic conditions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....404 Severe climatic conditions. In frost-susceptible soil locations, ground anchor augers must be installed below the frost line, unless the foundation system is frost-protected to prevent the effects of frost heave, in accordance with acceptable engineering practice and § 3280.306 of this chapter...

  12. 24 CFR 3285.404 - Severe climatic conditions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....404 Severe climatic conditions. In frost-susceptible soil locations, ground anchor augers must be installed below the frost line, unless the foundation system is frost-protected to prevent the effects of frost heave, in accordance with acceptable engineering practice and § 3280.306 of this chapter...

  13. Aversive Conditioning and the Severely/Profoundly Handicapped.

    ERIC Educational Resources Information Center

    Haring, Norris G.

    Research regarding the use of aversive conditioning is reviewed, ethical questions are considered, and the proper use of the procedure with the severly handicapped is examined. Cited are studies on the use of shock therapy, mild aversive, timeout procedures, overcorrection, and restraint. The importance of pairing positive with aversive stimuli is…

  14. Investigation of Wear and Friction Properties Under Sliding Conditions of Some Materials Suitable for Cages of Rolling-Contact Bearings

    NASA Technical Reports Server (NTRS)

    Johnson, Robert L; Swikert, Max A; Bisson, Edmond E

    1952-01-01

    An investigation of wear and friction properties of a number of materials sliding against SAE 52100 steel was conducted. These materials included brass, bronze, beryllium copper, monel, nichrome v, 24s-t aluminum, nodular iron, and gray cast iron. The metals investigated may be useful as possible cage (separator or retainer) materials for rolling-contact bearings of high-speed turbine engines. The ability of materials to form surface films that prevent welding is a most important factor in both dry friction and boundary lubrication. On the basis of wear and resistance to welding only, the cast irons were the most promising materials investigated; they showed the least wear and the least tendency to surface failure when run dry, and when boundary lubricated they showed the highest load capacity. On the basis of mechanical properties, nodular iron is superior to gray cast iron. Bronze had the lowest friction coefficient under dry sliding conditions. The results with brass, beryllium copper, and aluminum were poor and these materials do not appear, with regard to friction and wear, to be suitable for cages.

  15. Wear testing of total hip replacements under severe conditions.

    PubMed

    Zietz, Carmen; Fabry, Christian; Reinders, Joern; Dammer, Rebecca; Kretzer, Jan Philippe; Bader, Rainer; Sonntag, Robert

    2015-07-01

    Controlled wear testing of total hip replacements in hip joint simulators is a well-established and powerful method, giving an extensive prediction of the long-term clinical performance. To understand the wear behavior of a bearing and its limits under in vivo conditions, testing scenarios should be designed as physiologically as possible. Currently, the ISO standard protocol 14242 is the most common preclinical testing procedure for total hip replacements, based on a simplified gait cycle for normal walking conditions. However, in recent years, wear patterns have increasingly been observed on retrievals that cannot be replicated by the current standard. The purpose of this study is to review the severe testing conditions that enable the generation of clinically relevant wear rates and phenomena. These conditions include changes in loading and activity, third-body wear, surface topography, edge wear and the role of aging of the bearing materials. PMID:26048088

  16. Effect of bionic coupling units' forms on wear resistance of gray cast iron under dry linear reciprocating sliding condition

    NASA Astrophysics Data System (ADS)

    Pang, Zuobo; Zhou, Hong; Xie, Guofeng; Cong, Dalong; Meng, Chao; Ren, Luquan

    2015-07-01

    In order to get close to the wear form of guide rails, the homemade linear reciprocating wear testing machine was used for the wear test. In order to improve the wear-resistance of gray cast iron guide rail, bionic coupling units of different forms were manufactured by a laser. Wear behavior of gray-cast-iron with bionic-coupling units has been studied under dry sliding condition at room temperature using the wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that bionic coupling unit could improve the wear resistance of gray cast iron. The wear resistance of gray cast iron with reticulation bionic coupling unit is the best. When the load and speed changed, reticulation bionic coupling unit still has excellent performance in improving the wear resistance of gray cast iron.

  17. Endurance of a diffuser under severe rocket motor operating conditions

    NASA Astrophysics Data System (ADS)

    Shani, Shimon; Katz, Uri

    1993-06-01

    This paper presents the design and test results of a diffuser subjected to severe rocket motor operating conditions. High heat fluxes (over 1 (MW/sq m)) cause extremely high thermal and mechanical loads. The solution selected for the diffuser construction was based on a ductile steel structure, cooled by forced water flow through spiral channels. The paper describes the heat transfer analysis, the mechanical and water system design and post firing examination.

  18. Frictional behavior and microstructures of calcite fault gouges deformed under extreme conditions of normal stress and sliding velocity

    NASA Astrophysics Data System (ADS)

    Smith, S. A.; Billi, A.; Spagnuolo, E.; Di Toro, G.; Nielsen, S. B.; Violay, M. E.

    2011-12-01

    In recent years several experimental studies have been performed using rotary-shear apparatus to investigate the frictional behavior of gouge materials at seismic slip rates. However, because of technical difficulties confining gouge layers, a majority of these experiments were conducted at normal stresses <2-3MPa, making extrapolation to natural conditions challenging. Here, we present results from an experimental study on calcite gouges (<250μm grain size) deformed in a purpose-built sample holder and using a rotary-shear apparatus at INGV, Rome. Ring-shaped (25/45mm int./ext. diameter), 2.8mm-thick layers of gouge were deformed up to 34MPa normal stress, at slip rates of 10μm/s - 3m/s, in both room-dry and water-present conditions. A peak slip rate of 3m/s was achieved after 0.5s, and total displacements were 1-3m. CO2 emissions were monitored using a mass spectrometer connected to a capillary tube positioned approximately 1cm from the gouge sample holder. Samples were preserved in ultra-low viscosity resin for optical and Field-Emission SEM observations. At slip rates >0.3m/s frictional strength, μ, increases to a peak value of 0.6-1.0 followed by a rapid decay to a lower steady-state value, μss, before finally undergoing dynamic strength recovery during decelerating slip. CO2 starts to be liberated almost instantaneously (within 500μm of slip) during acceleration and reaches a peak value during steady-state sliding of up to 10,000ppm, before decreasing to 380-420ppm within a few seconds following the experiment. μss decreases with increasing slip rate, but in contrast to previous experiments we find that extremely low values of μss<0.2 are only achieved at a slip rate of 1m/s for normal stresses >22MPa. An unexpected result is that steady-state shear stress at slip rates >1m/s does not increase monotonically (either linearly or not, e.g. in the presence of lubrication) with normal stress, but begins to decrease above a normal stress of 15-20MPa, a

  19. EPA Field Demonstration of Innovative Condition Assessment Technologies for Water Mains at Louisville, KY - slides

    EPA Science Inventory

    This presentation will describe a series of field demonstrations of innovative leak detection/location and condition assessment technologies that was sponsored by the U.S. Environmental Protection Agency (EPA), conducted by EPA’s contractor (Battelle), and hosted by the Louisvill...

  20. Severe local convective storms in Bangladesh: Part II.: Environmental conditions

    NASA Astrophysics Data System (ADS)

    Yamane, Yusuke; Hayashi, Taiichi; Dewan, Ashraf Mahmmood; Akter, Fatima

    2010-03-01

    This paper examines the environmental conditions of severe local convective storms during the pre-monsoon season (from March to May) in Bangladesh. We compared composite soundings on severe local convective storm days (SLCSD) with those on non-severe local convective storm days (NSLCSD) using rawinsonde data at 06 Bangladesh Standard Time (BST) in Dhaka (90.3°E and 23.7°N). Temperatures are rising in the lower layer and falling in the middle layer, and the amount of water vapor is significantly increasing in the lowest layer with southerly wind intensified on SLCSD compared with NSLCSD. This situation produces great thermal instability in the atmosphere on SLCSD. Convective parameters on SLCSD are computed with the rawinsonde data at 06 BST in Dhaka and compared with those on NSLCSD. The comparison shows that while most convective parameters related to thermal instability can discriminate between SLCSD and NSLCSD with statistical significance, no convective parameters related to the vertical wind shear can distinguish between the two categories. We evaluated the forecast skill of the convective parameters using Heidke Skill Score (HSS). The evaluation shows that the HSS for the Lifted Index and Precipitable Water are better among all parameters and have great forecast ability.

  1. Tribological Behavior of Ferrous-Based APS Coatings Under Dry Sliding Conditions

    NASA Astrophysics Data System (ADS)

    Vencl, Aleksandar

    2015-04-01

    The use of Al-alloys for engine blocks production, instead of e.g., gray cast iron, results with weight savings and lower fuel consumption and therefore, reduces pollution. Possible solution for overcoming poor tribological properties of Al-alloys is the application of thermal spray coatings. In this paper, the tribological properties of two ferrous-based coatings were analyzed and compared with gray cast iron as a standard material for engine blocks. The process used for coating deposition on an Al-Si alloy substrate was atmospheric plasma spraying. In order to investigate the tribological behavior of these coatings under dominant adhesive and abrasive wear regime, two tests were applied with different test equipments and conditions. Both tribological tests showed that, for the investigated conditions, both coatings had improved wear resistance and lower coefficient of friction compared with gray cast iron.

  2. Analysis of concrete containment structures under severe accident loading conditions

    SciTech Connect

    Porter, V.L.

    1993-12-31

    One of the areas of current interest in the nuclear power industry is the response of containment buildings to internal pressures that may exceed design pressure levels. Evaluating the response of structures under these conditions requires computing beyond design load to the ultimate load of the containment. For concrete containments, this requirement means computing through severe concrete cracking and into the regime of wide-spread plastic rebar and/or tendon response. In this regime of material response, an implicit code can have trouble converging. This paper describes some of the author`s experiences with Version 5.2 of ABAQUS Standard and the ABAQUS concrete model in computing the axisymmetric response of a prestressed concrete containment to ultimate global structural failure under high internal pressures. The effects of varying the tension stiffening parameter in the concrete material model and variations of the parameters for the CONTROLS option are discussed.

  3. Hierarchically nanotextured surfaces maintaining superhydrophobicity under severely adverse conditions

    NASA Astrophysics Data System (ADS)

    Maitra, Tanmoy; Antonini, Carlo; Auf der Mauer, Matthias; Stamatopoulos, Christos; Tiwari, Manish K.; Poulikakos, Dimos

    2014-07-01

    Superhydrophobic surfaces are highly desirable for a broad range of technologies and products affecting everyday life. Despite significant progress in recent years in understanding the principles of hydrophobicity, mostly inspired by surface designs found in nature, many man-made surfaces employ readily processable materials, ideal to demonstrate principles, but with little chance of survivability outside a very limited range of well-controlled environments. Here we focus on the rational development of robust, hierarchically nanostructured, environmentally friendly, metal-based (aluminum) superhydrophobic surfaces, which maintain their performance under severely adverse conditions. Based on their functionality, we superpose selected hydrophobic layers (i.e. self-assembled monolayers, thin films, or nanofibrous coatings) on hierarchically textured aluminum surfaces, collectively imparting high level robustness of superhydrophobicity under adverse conditions. These surfaces simultaneously exhibit chemical stability, mechanical durability and droplet impalement resistance. They impressively maintained their superhydrophobicity after exposure to severely adverse chemical environments like strong alkaline (pH ~ 9-10), acidic (pH ~ 2-3), and ionic solutions (3.5 weight% of sodium chloride), and could simultaneously resist water droplet impalement up to an impact velocity of 3.2 m s-1 as well as withstand standard mechanical durability tests.Superhydrophobic surfaces are highly desirable for a broad range of technologies and products affecting everyday life. Despite significant progress in recent years in understanding the principles of hydrophobicity, mostly inspired by surface designs found in nature, many man-made surfaces employ readily processable materials, ideal to demonstrate principles, but with little chance of survivability outside a very limited range of well-controlled environments. Here we focus on the rational development of robust, hierarchically

  4. Reciprocating sliding wear behavior of alendronate sodium-loaded UHMWPE under different tribological conditions.

    PubMed

    Huang, Jie; Qu, Shuxin; Wang, Jing; Yang, Dan; Duan, Ke; Weng, Jie

    2013-07-01

    The aim of this study is to investigate the tribological behaviors and wear mechanisms of ultra-high molecular weight polyethylene (UHMWPE) loaded with alendronate sodium (ALN), a potential drug to treat osteolysis, under different normal loads and lubrication conditions. A mixture of UHMWPE powder and ALN (1.0 wt.%) solution was dried and hot pressed. The static and dynamic friction coefficients of UHMWPE-ALN were slightly higher than those of UHMWPE except under normal load as 10 N and in 25 v/v % calf serum. The specific wear rates of UHMWPE-ALN and UHMWPE were the lowest in 25 v/v % calf serum compared to those in deionized water or physiological saline. In particular, the specific wear rate of UHMWPE-ALN was lower than that of UHMWPE at 50 N in 25 v/v % calf serum. The main wear mechanisms of UHMWPE and UHMWPE-ALN in deionized water and UHMWPE in physiological saline were abrasive. The main wear mechanism of UHMWPE-ALN in physiological saline was micro-fatigue. In 25 v/v % calf serum, the main wear mechanism of UHMWPE and UHMWPE-ALN was abrasive wear accompanied with plastic deformation. The results of Micro-XRD indicated that the molecular deformation of UHMWPE-ALN and UHMWPE under the lower stress were in the amorphous region but in the crystalline region at the higher stress. These results showed that the wear of UHMWPE-ALN would be reduced under calf serum lubricated, which would be potentially applied to treat osteolysis.

  5. Failure to elicit conditioned taste aversion by severe poisoning.

    PubMed

    Ionescu, E; Buresová, O

    1977-03-01

    In an attempt to assess the universal validity of the conditioned taste aversion (CTA) paradigm, various types of poisoning (UC) were associated with the gustatory CS. Water deprived rats were habituated for two days to the drinking box, where water was available for 15 min. On Day 3, access to the CS (0.1% saccharin 15 min) was followed after 30 min by a sublethal dose of the poison (0.15 M LiCl, 4% body weight; 0.1 M sodium malonate, 1% body weight; pyrrolopyrimidine drug BW 58-271, 15 mg/kg; sodium cyanide 4 mg/kg; sodium iodoacetate 40 mg/kg; sodium fluoride 30 mg/kg; gallamine triethiodide 40 mg/kg). Rats injected with the last drug were maintained under artificial respiration until muscular paralysis disappeared. After 4 days of recovery, water deprivation schedule was resumed on Days 8 and 9. During the retention test on Day 10 saccharin consumption dropped by 60% in the LiCl poisoned rats, but not CTA developed in animals poisoned by pyrrolopyrimidine, gallamine, malonate and cyanide. CTA of intermediate intensity was evoked by iodoacetate and fluoride. The absence of CTA was not due to the amnesic effect of poisoning, since LiCl administration to NaCN poisoned rats produced CTA of usual intensity. It is concluded that CTA is not related to the overall severity of poisoning but rather to the effect of the poison on specific interoceptors.

  6. Prototype Slide Stainer

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The prototype slide staining system capable of performing both one-component Wright's staining of blood smears and eight-step Gram staining of heat fixed slides of microorganisms is described. Attention was given to liquid containment, waste handling, absence of contamination from previous staining, and stability of the staining reagents. The unit is self-contained, capable of independent operation under one- or zero-g conditions, and compatible with Skylab A.

  7. Surface Damage Characteristics and Specific Wear Rates of a New Continuous Carbon Fiber (CF) / Polyetheretherketone (PEEK) Composite under Sliding and Rolling Contact Conditions

    NASA Astrophysics Data System (ADS)

    Almajid, Abdulhakim; Friedrich, Klaus; Floeck, Joachim; Burkhart, Thomas

    2011-06-01

    The surface damage characteristics of a continuous carbon fiber reinforced composite, having a polyetheretherketone (PEEK) matrix, were investigated under sliding and rolling contact. The corresponding mechanisms were studied by the use of scanning electron microscopy (SEM) in three different fiber orientations, namely: Paralllel direction to the fibers, AntiParallel direction to the fibers, and Normal direction to the fibers. All wear tests were conducted against smooth steel surfaces for both contact conditions. Mechanical properties under tension, compression, and shear were investigated for the material at two different temperature levels, i.e. room temperature and 150 °C. The composite material under normal fiber orientation has the lowest specific wear rate in case of rolling wear while the parallel orientation has the lowest specific wear rate under sliding wear conditions. Both results were compared to wear data of the neat PEEK matrix.

  8. Preignition Characteristics of Several Fuels Under Simulated Engine Conditions

    NASA Technical Reports Server (NTRS)

    Spencer, R C

    1941-01-01

    The preignition characteristics of a number of fuels have been studied under conditions similar to those encountered in an engine. These conditions were simulated by suddenly compressing a fuel-air mixture in contact with an electrically heated hot spot in the cylinder head of the NACA combustion apparatus. Schlieren photographs and indicator cards were taken of the burning, and the hot-spot temperatures necessary to cause ignition under various conditions were determined.

  9. In-vessel flow characterization under severe accident conditions

    SciTech Connect

    Nourbakhsh, H.P.; Kim, S.B.; Khatib-Rahbar, M.

    1987-01-01

    The purpose of this study is to provide a parametric framework for characterization of flow and heat transfer regimes and their associated phenomenological uncertainties following severe accidents using a two dimensional, heterogenous, porous media formulation. This approach extends the understanding of buoyancy-induced flow characteristics in the uncovered region of the reactor core and the upper plenum of a PWR vessel. The results of this study can be used to augment the boil-off steam flow in integrated one-dimensional severe accident codes such as the Source Team Code Package (STCP).

  10. The Sensor Fish: Measuring Fish Passage in Severe Hydraulic Conditions

    SciTech Connect

    Carlson, Thomas J. ); Duncan, Joanne P. ); Gilbride, Theresa L. )

    2003-05-28

    This article describes PNNL's efforts to develop the Sensor Fish, a waterproof sensor package that travels thru the turbines of spillways of hydroelectric dam to collect pressure and acceleration data on the conditions experienced by live salmon smolts during dam passage. Sensor Fish development is sponsored by the DOE Advanced Hydropower Turbine Survival Program. The article also gave two recent examples of Sensor Fish use: turbine passage at a McNary Kaplan turbine and spill passage in topspill at Rock Island Dam.

  11. Friction and wear of Si3N4 ceramic/stainless steel sliding contacts in dry and lubricated conditions

    NASA Astrophysics Data System (ADS)

    Zhao, X. Z.; Liu, J. J.; Zhu, B. L.; Miao, H. Z.; Luo, Z. B.

    1997-04-01

    Austenitic stainless steel AISI 321 is one of the most difficult-to-cut materials. In order to investigate the wear behavior of Si3N4 ceramic when cutting the stainless steel, wear tests are carried out on a pin-ondisk tribometer, which could simulate a realistic cutting process. Test results show that the wear of Si3N4 ceramic is mainly caused by adhesion between the rubbing surfaces and that the wear increases with load and speed. When oil is used for lubrication, the friction coefficient of the sliding pairs and the wear rate of the ceramic are reduced. A scanning electron microscope (SEM), an electron probe microanalyzer (EPMA), and an energy dispersive x-ray analyzer (EDXA) are used to examine the worn surfaces. The wear mechanisms of Si3N4 ceramic sliding against the stainless steel are discussed in detail.

  12. Public Playground Equipment: Suggested Safety Requirements and Supporting Rationale for Swing Assemblies and Straight Slides.

    ERIC Educational Resources Information Center

    Mahajan, Bal; And Others

    This memorandum report proposes a safety standard to reduce the frequency and severity of children's impacts with the suspended members of swing assemblies and falls from slide surfaces, under conditions of normal use and reasonably foreseeable misuse. The standard applies to swings and straight slides intended for use as public playground…

  13. Finite-time control of DC-DC buck converters via integral terminal sliding modes

    NASA Astrophysics Data System (ADS)

    Chiu, Chian-Song; Shen, Chih-Teng

    2012-05-01

    This article presents novel terminal sliding modes for finite-time output tracking control of DC-DC buck converters. Instead of using traditional singular terminal sliding mode, two integral terminal sliding modes are introduced for robust output voltage tracking of uncertain buck converters. Different from traditional sliding mode control (SMC), the proposed controller assures finite convergence time for the tracking error and integral tracking error. Furthermore, the singular problem in traditional terminal SMC is removed from this article. When considering worse modelling, adaptive integral terminal SMC is derived to guarantee finite-time convergence under more relaxed stability conditions. In addition, several experiments show better start-up performance and robustness.

  14. Ceramic wear in indentation and sliding

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.

    1984-01-01

    The various wear mechanisms involved with single-crystal ceramic materials in indentation and in sliding contacts. Experiments simulating interfacial events have been conducted with hemispherical, conical and pyramidal indenters (riders). With spherical riders, under either abrasive or adhesive conditions, two types of fracture pits have been observed. First, spherical-shaped fracture pits and wear particles are found as a result of either indenting or sliding. These are shown to be due to a spherical-shaped fracture along the circular or spherical stress trajectories. Second, polyhedral fracture pits and debris, produced by anisotropic fracture, and also found both during indenting and sliding. These are primarily controlled by surface and subsurface cracking along cleavage planes. Several quantitative results have also been obtained from this work. For example, using a pyramidal diamond, crack length of Mn-Zn ferrite in the indentation process grows linearly with increasing normal load. Moreover, the critical load to fracture both in indentation and sliding is essentially isotropic and is found to be directly proportional to the indenter radius.

  15. T-Slide Linear Actuators

    NASA Technical Reports Server (NTRS)

    Vranish, John

    2009-01-01

    T-slide linear actuators use gear bearing differential epicyclical transmissions (GBDETs) to directly drive a linear rack, which, in turn, performs the actuation. Conventional systems use a rotary power source in conjunction with a nut and screw to provide linear motion. Non-back-drive properties of GBDETs make the new actuator more direct and simpler. Versions of this approach will serve as a long-stroke, ultra-precision, position actuator for NASA science instruments, and as a rugged, linear actuator for NASA deployment duties. The T slide can operate effectively in the presence of side forces and torques. Versions of the actuator can perform ultra-precision positioning. A basic T-slide actuator is a long-stroke, rack-and-pinion linear actuator that, typically, consists of a T-slide, several idlers, a transmission to drive the slide (powered by an electric motor) and a housing that holds the entire assembly. The actuator is driven by gear action on its top surface, and is guided and constrained by gear-bearing idlers on its other two parallel surfaces. The geometry, implemented with gear-bearing technology, is particularly effective. An electronic motor operating through a GBDET can directly drive the T slide against large loads, as a rack and pinion linear actuator, with no break and no danger of back driving. The actuator drives the slide into position and stops. The slide holes position with power off and no brake, regardless of load. With the T slide configuration, this GBDET has an entire T-gear surface on which to operate. The GB idlers coupling the other two T slide parallel surfaces to their housing counterpart surfaces provide constraints in five degrees-of-freedom and rolling friction in the direction of actuation. Multiple GB idlers provide roller bearing strength sufficient to support efficient, rolling friction movement, even in the presence of large, resisting forces. T-slide actuators can be controlled using the combination of an off

  16. Tribological study of selected ceramics versus metal sliding couples

    SciTech Connect

    Matsuhiro, K.; Sakai, H.; Soma, T.; Oda, I.

    1987-01-01

    A tribological study has been done with dry and lubricated conditions on the several selected sliding couples of ceramics vs. ceramics, ceramics vs. metal and ceramics vs. plasma sprayed metal. Sliding velocity was 2.6m/s (8.5ft/s), load was 22N and temperature was room temperature to 540/sup 0/C (1000/sup 0/F). No significant wear was observed on any sliding couples when they were lubricated. A considerably better tribological character was found in the ceramics vs. metal couple with dry condition. Especially sintered silicon nitride (SSN) vs. LiF+Cu plasma sprayed M2 steel at room temperature to 540/sup 0/C and SSN vs. M2 steel couple at 540/sup 0/C were remarkable. It is considered that the tribological character between ceramics and metal contact may be controlled by adhesion of metal to ceramics.

  17. Dust Slides

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03677 Linear Clouds

    Dust slides are common in the dust covered region called Lycus Sulci. A large fracture is also visible in this image.

    Image information: VIS instrument. Latitude 28.1N, Longitude 226.3E. 18 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 Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Electrical equipment performance under severe accident conditions (BWR/Mark 1 plant analysis): Summary report

    SciTech Connect

    Bennett, P.R.; Kolaczkowski, A.M.; Medford, G.T.

    1986-09-01

    The purpose of the Performance Evaluation of Electrical Equipment during Severe Accident States Program is to determine the performance of electrical equipment, important to safety, under severe accident conditions. In FY85, a method was devised to identify important electrical equipment and the severe accident environments in which the equipment was likely to fail. This method was used to evaluate the equipment and severe accident environments for Browns Ferry Unit 1, a BWR/Mark I. Following this work, a test plan was written in FY86 to experimentally determine the performance of one selected component to two severe accident environments.

  19. Contriving Transitive Conditioned Establishing Operations to Establish Derived Manding Skills in Adults with Severe Developmental Disabilities

    ERIC Educational Resources Information Center

    Rosales, Rocio; Rehfeldt, Ruth Anne

    2007-01-01

    The purpose of this study was to demonstrate derived manding skills in 2 adults with severe developmental disabilities and language deficits by contriving transitive conditioned establishing operations. Specifically, we evaluated whether a history of reinforced conditional discrimination learning would ultimately result in a derived mand…

  20. The Relationship of Revenue Dispersion to Several Indicators of Institutional Financial Conditions.

    ERIC Educational Resources Information Center

    Taylor, Barbara A.

    The relationship between revenue dispersion and several indicators of financial condition in four-year colleges and universities was studied. Revenue dispersion is a measure of the diversity of institutional income sources. It was hypothesized that revenue dispersion would be positively related to financial condition, since variants on…

  1. Relationship of coal severance tax allocations to coal county socio-economic conditions

    SciTech Connect

    Lenzi, R.C.

    1985-01-01

    This research study undertakes an analysis of social and economic conditions in America's coal producing counties and the relationship to and effect of coal severance tax allocations on these conditions. These conditions are examined for 188 major coal producing counties in 16 states for the period 1970-1980. Coal county conditions are analyzed in detail. Among the variables reported are income, poverty, unemployment, total employment, bank deposits, population, population density, and local government finances. Change in these conditions are compared in a quasi-experimental model that identifies coal counties receiving severance tax as the experimental group and coal counties as a control group. These counties represent a total enumeration of major coal producing counties of the United States. Eastern severance counties averaged $10 per capita while western counties averaged nearly $293 per head in coal severance allocations. Local allocations equalled about one-third of property tax collections and about 3% of per capita income nationwide. Significant differences were found in most of the five socio-economic welfare variables between severance and nonseverance counties. The factor analysis revealed a significant relationship of coal severance tax allocations to economic growth in eastern counties. A weak relationship was found in western counties, possibly due to the lateness of those allocations to the study period.

  2. Experimental results from containment piping bellows subjected to severe accident conditions: Results from bellows tested in corroded conditions. Volume 2

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1995-10-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted at Sandia National Laboratories under the sponsorship of the US Nuclear Regulatory Commission. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of nineteen bellows have been tested. Thirteen bellows were tested in ``like-new`` condition (results reported in Volume 1), and six were tested in a corroded condition. The tests showed that bellows in ``like-new`` condition are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage, while those in a corroded condition did not perform as well, depending on the amount of corrosion. The corroded bellows test program and results are presented in this report.

  3. Key Parameters for Operator Diagnosis of BWR Plant Condition during a Severe Accident

    SciTech Connect

    Clayton, Dwight A.; Poore, III, Willis P.

    2015-01-01

    The objective of this research is to examine the key information needed from nuclear power plant instrumentation to guide severe accident management and mitigation for boiling water reactor (BWR) designs (specifically, a BWR/4-Mark I), estimate environmental conditions that the instrumentation will experience during a severe accident, and identify potential gaps in existing instrumentation that may require further research and development. This report notes the key parameters that instrumentation needs to measure to help operators respond to severe accidents. A follow-up report will assess severe accident environmental conditions as estimated by severe accident simulation model analysis for a specific US BWR/4-Mark I plant for those instrumentation systems considered most important for accident management purposes.

  4. Evaluation of several non-reflecting computational boundary conditions for duct acoustics

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Zorumski, William E.; Hodge, Steve L.

    1994-01-01

    Several non-reflecting computational boundary conditions that meet certain criteria and have potential applications to duct acoustics are evaluated for their effectiveness. The same interior solution scheme, grid, and order of approximation are used to evaluate each condition. Sparse matrix solution techniques are applied to solve the matrix equation resulting from the discretization. Modal series solutions for the sound attenuation in an infinite duct are used to evaluate the accuracy of each non-reflecting boundary conditions. The evaluations are performed for sound propagation in a softwall duct, for several sources, sound frequencies, and duct lengths. It is shown that a recently developed nonlocal boundary condition leads to sound attenuation predictions considerably more accurate for short ducts. This leads to a substantial reduction in the number of grid points when compared to other non-reflecting conditions.

  5. Improving condition severity classification with an efficient active learning based framework.

    PubMed

    Nissim, Nir; Boland, Mary Regina; Tatonetti, Nicholas P; Elovici, Yuval; Hripcsak, George; Shahar, Yuval; Moskovitch, Robert

    2016-06-01

    Classification of condition severity can be useful for discriminating among sets of conditions or phenotypes, for example when prioritizing patient care or for other healthcare purposes. Electronic Health Records (EHRs) represent a rich source of labeled information that can be harnessed for severity classification. The labeling of EHRs is expensive and in many cases requires employing professionals with high level of expertise. In this study, we demonstrate the use of Active Learning (AL) techniques to decrease expert labeling efforts. We employ three AL methods and demonstrate their ability to reduce labeling efforts while effectively discriminating condition severity. We incorporate three AL methods into a new framework based on the original CAESAR (Classification Approach for Extracting Severity Automatically from Electronic Health Records) framework to create the Active Learning Enhancement framework (CAESAR-ALE). We applied CAESAR-ALE to a dataset containing 516 conditions of varying severity levels that were manually labeled by seven experts. Our dataset, called the "CAESAR dataset," was created from the medical records of 1.9 million patients treated at Columbia University Medical Center (CUMC). All three AL methods decreased labelers' efforts compared to the learning methods applied by the original CAESER framework in which the classifier was trained on the entire set of conditions; depending on the AL strategy used in the current study, the reduction ranged from 48% to 64% that can result in significant savings, both in time and money. As for the PPV (precision) measure, CAESAR-ALE achieved more than 13% absolute improvement in the predictive capabilities of the framework when classifying conditions as severe. These results demonstrate the potential of AL methods to decrease the labeling efforts of medical experts, while increasing accuracy given the same (or even a smaller) number of acquired conditions. We also demonstrated that the methods included in

  6. Improving condition severity classification with an efficient active learning based framework.

    PubMed

    Nissim, Nir; Boland, Mary Regina; Tatonetti, Nicholas P; Elovici, Yuval; Hripcsak, George; Shahar, Yuval; Moskovitch, Robert

    2016-06-01

    Classification of condition severity can be useful for discriminating among sets of conditions or phenotypes, for example when prioritizing patient care or for other healthcare purposes. Electronic Health Records (EHRs) represent a rich source of labeled information that can be harnessed for severity classification. The labeling of EHRs is expensive and in many cases requires employing professionals with high level of expertise. In this study, we demonstrate the use of Active Learning (AL) techniques to decrease expert labeling efforts. We employ three AL methods and demonstrate their ability to reduce labeling efforts while effectively discriminating condition severity. We incorporate three AL methods into a new framework based on the original CAESAR (Classification Approach for Extracting Severity Automatically from Electronic Health Records) framework to create the Active Learning Enhancement framework (CAESAR-ALE). We applied CAESAR-ALE to a dataset containing 516 conditions of varying severity levels that were manually labeled by seven experts. Our dataset, called the "CAESAR dataset," was created from the medical records of 1.9 million patients treated at Columbia University Medical Center (CUMC). All three AL methods decreased labelers' efforts compared to the learning methods applied by the original CAESER framework in which the classifier was trained on the entire set of conditions; depending on the AL strategy used in the current study, the reduction ranged from 48% to 64% that can result in significant savings, both in time and money. As for the PPV (precision) measure, CAESAR-ALE achieved more than 13% absolute improvement in the predictive capabilities of the framework when classifying conditions as severe. These results demonstrate the potential of AL methods to decrease the labeling efforts of medical experts, while increasing accuracy given the same (or even a smaller) number of acquired conditions. We also demonstrated that the methods included in

  7. 45. March 26, 1935 View of the big slide of ...

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

    45. March 26, 1935 View of the big slide of several hundred cubic yards of rock, spring of 1934. Another slide occurred at this same location on May 26, 1935. - Scotts Bluff Summit Road, Gering, Scotts Bluff County, NE

  8. Dynamical chiral symmetry breaking in sliding nanotubes.

    PubMed

    Zhang, X H; Santoro, G E; Tartaglino, U; Tosatti, E

    2009-03-27

    We discover in simulations of sliding coaxial nanotubes an unanticipated example of dynamical symmetry breaking taking place at the nanoscale. While both nanotubes are perfectly left-right symmetric and nonchiral, a nonzero angular momentum of phonon origin appears spontaneously at a series of critical sliding velocities, in correspondence with large peaks of the sliding friction. The nonlinear equations governing this phenomenon resemble the rotational instability of a forced string. However, several new elements, exquisitely "nano" appear here, with the crucial involvement of umklapp and of sliding nanofriction.

  9. Severe Pulmonary Toxicity After Myeloablative Conditioning Using Total Body Irradiation: An Assessment of Risk Factors

    SciTech Connect

    Kelsey, Chris R.; Horwitz, Mitchell E.; Chino, Junzo P.; Craciunescu, Oana; Steffey, Beverly; Folz, Rodney J.; Chao, Nelson J.; Rizzieri, David A.; Marks, Lawrence B.

    2011-11-01

    Purpose: To assess factors associated with severe pulmonary toxicity after myeloablative conditioning using total body irradiation (TBI) followed by allogeneic stem cell transplantation. Methods and Materials: A total of 101 adult patients who underwent TBI-based myeloablative conditioning for hematologic malignancies at Duke University between 1998 and 2008 were reviewed. TBI was combined with high-dose cyclophosphamide, melphalan, fludarabine, or etoposide, depending on the underlying disease. Acute pulmonary toxicity, occurring within 90 days of transplantation, was scored using Common Terminology Criteria for Adverse Events version 3.0. Actuarial overall survival and the cumulative incidence of acute pulmonary toxicity were calculated via the Kaplan-Meier method and compared using a log-rank test. A binary logistic regression analysis was performed to assess factors independently associated with acute severe pulmonary toxicity. Results: The 90-day actuarial risk of developing severe (Grade 3-5) pulmonary toxicity was 33%. Actuarial survival at 90 days was 49% in patients with severe pulmonary toxicity vs. 94% in patients without (p < 0.001). On multivariate analysis, the number of prior chemotherapy regimens was the only factor independently associated with development of severe pulmonary toxicity (odds ratio, 2.7 per regimen). Conclusions: Severe acute pulmonary toxicity is prevalent after TBI-based myeloablative conditioning regimens, occurring in approximately 33% of patients. The number of prior chemotherapy regimens appears to be an important risk factor.

  10. A Sliding Mode Control with Optimized Sliding Surface for Aircraft Pitch Axis Control System

    NASA Astrophysics Data System (ADS)

    Lee, Sangchul; Kim, Kwangjin; Kim, Youdan

    A sliding mode controller with an optimized sliding surface is proposed for an aircraft control system. The quadratic type of performance index for minimizing the angle of attack and the angular rate of the aircraft in the longitudinal motion is used to design the sliding surface. For optimization of the sliding surface, a Hamilton-Jacobi-Bellman (HJB) equation is formulated and it is solved through a numerical algorithm using a Generalized HJB (GHJB) equation and the Galerkin spectral method. The solution of this equation denotes a nonlinear sliding surface, on which the trajectory of the system approximately satisfies the optimality condition. Numerical simulation is performed for a nonlinear aircraft model with an optimized sliding surface and a simple linear sliding surface. The simulation result demonstrates that the proposed controller can be effectively applied to the longitudinal maneuver of an aircraft.

  11. Basic Environmental Control Devices for Persons with Severe Multiple Handicapping Conditions.

    ERIC Educational Resources Information Center

    Giangreco, Michael F.

    The guide presents a non-technical approach to adapting battery-operated and electrical devices for persons with severe handicapping conditions. The material was developed through Project REACH (Reconstructive Equipment Adaptations for Children with Handicaps). Chapter 1 presents rationales for the use of adapted switches and devices, including…

  12. Temperature histories of commercial flights at severe conditions from GASP data

    NASA Technical Reports Server (NTRS)

    Jasperson, W. H.; Nastrom, G. D.

    1983-01-01

    The thermal environment of commercial aircraft from a data set gathered during the Global Atmospheric Sampling Program (GASP) is studied. The data set covers a four-year period of measurements. The report presents plots of airplane location and speed and atmospheric temperature as functions of elapsed time for 35 extreme-condition flights, selected by minimum values of several temperature parameters. One of these parameters, the severity factor, is an approximation of the in-flight wing-tank temperature. Representative low-severity-factor flight histories may be useful for actual temperature-profile inputs to design and research studies. Comparison of the GASP atmospheric temperatures to interpolated temperatures from National Meteorological Center and Global Weather Central analysis fields shows that the analysis temperatures are slightly biased toward warmer than actual temperatures, particularly over oceans and at extreme conditions.

  13. Cryogenic Tunnel Pressure Measurements on a Supercritical Airfoil for Several Shock Buffet Conditions

    NASA Technical Reports Server (NTRS)

    Bartels, Robert E.; Edwards, John W.

    1997-01-01

    Steady and unsteady experimental data are presented for several fixed geometry conditions from a test in the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel. The purpose of this test was to obtain unsteady data for transonic conditions on a fixed and pitching supercritical airfoil at high Reynolds numbers. Data and brief analyses for several of the fixed geometry test conditions will be presented here. These are at Reynolds numbers from 6 x 10(exp 6) to 35 x 10(exp 6) bases on chord length, and span a limited range of Mach numbers and angles of attack just below and at the onset of shock buffet. Reynolds scaling effects appear in both the steady pressure data and in the onset of shock buffet at Reynolds numbers of 15 x 10(exp 6) and 3O x 10(exp 6) per chord length.

  14. Sliding vane geometry turbines

    DOEpatents

    Sun, Harold Huimin; Zhang, Jizhong; Hu, Liangjun; Hanna, Dave R

    2014-12-30

    Various systems and methods are described for a variable geometry turbine. In one example, a turbine nozzle comprises a central axis and a nozzle vane. The nozzle vane includes a stationary vane and a sliding vane. The sliding vane is positioned to slide in a direction substantially tangent to an inner circumference of the turbine nozzle and in contact with the stationary vane.

  15. Teach Classification with Slides.

    ERIC Educational Resources Information Center

    Franks, Deborah

    1980-01-01

    Described is a creative approach to the use of contact slides as a means of student participation in a learning unit on animal classification. The finished product is a slide presentation in which students themselves have made the slides and taped the narration. (CS)

  16. [Scoring of severity of patients' condition with acute surgical diseases and injuries of the abdominal cavity].

    PubMed

    Efimenko, N A; Lesik, P S; Kharisov, A M; Pashaev, A A

    2015-07-01

    Ten of the most frequent symptoms that do not require special methods of their determination except general clinical examinations established by any health care professional on pre-hospital stage were determined on the basis of analysis of more than one thousand records of patients with acute surgical abdominal diseases and clinical symptom load. The authors performed an assessment of each symptom depending on severity of patient's condition ranging from 1 point (satisfactory condition) till 5 points (critical condition). Information has been obtained: in case of satisfactory condition--up to 10 points, moderate--up to 20 points, heavy--up to 30 points, extremely heavy condition--up to 45 points and terminal condition--more than 45 points. Thus, conditional descriptive method of assessment of patient's condition during the clinical examination is combined with objective-scoring. The given method combines numeric expression with methods accepted in literature--"MFS-CA", "APACHE II" and allows to perform an objective assessment of the treatment process at different stages, to practice health care standards, to perform an analysis of outcomes. The article provides tables, which substantiate proposed method.

  17. Conditions of the household and peridomicile and severe dengue: a case–control study in Brazil

    PubMed Central

    Gibson, Gerusa; Souza-Santos, Reinaldo; Honório, Nildimar Alves; Pacheco, Antonio Guilherme; Moraes, Milton Ozório; Kubelka, Claire; Brasil, Patrícia; Cruz, Oswaldo; Carvalho, Marilia Sá

    2014-01-01

    Introduction The potential influence of high-vector-density environments where people are supposedly more exposed to mosquito bites may have a relation to the clinical severity of dengue fever, an association that has been poorly discussed in the literature. Objective This study aimed at analyzing the association between anthropic environmental factors, particularly those related to the conditions of domicile and peridomicile, and the occurrence of severe dengue cases during the 2008 epidemic in the state of Rio de Janeiro. Methods We conducted a retrospective case–control study with a sample of 88 severe patients aged 2–18. They were selected through chart review in four children's tertiary care centers. The 367 controls were neighbors of the cases, paired by age. Data were collected through interviews and systematic assessment of house conditions as well as peridomicile area conditions, and they were later analyzed by conditional logistic regression. Results The presence of three or more high-volume capacity containers, which were without a lid or were inadequately sealed (water tanks, wells, cisterns, cement tanks, and pools), was significantly more frequent in households with severe cases when compared with households of controls (OR=1.6; CI 95%=1.36–20.01; p=0.015). Discussion The presence of such larger reservoirs that could potentially produce more adult forms of the vector is consistent with a situation where people are more exposed to mosquito bites, and consequently are more prone to have multiple infections over a short period of time. Conclusion The emergence of severe dengue cases in a high-transmission context underpins the importance of constant vigilance and interventions in those types of reservoirs, which result from precarious household structures and irregular water supply services. PMID:24765250

  18. Study of light water reactor containments under important severe accident conditions

    SciTech Connect

    Hofmayer, C.H.; Pratt, W.T.; Bagchi, G.; Noonan, V.S.

    1985-01-01

    The US Nuclear Regulatory Commission has sponsored studies to develop a ''LEAKAGE-BEFORE-FAILURE'' model for use in severe accident risk assessments to provide a means of accounting for significant containment leakage prior to reaching the containment threshold pressure. Six containment types have been studied (large dry, subatmospheric, ice condenser, Mark I, II, and III). Potential leak paths through major containment penetration assemblies were investigated and upper-bound estimates of leak areas established. These leak areas may result from increasing internal pressure and degradation of nonmetallic seal materials due to severe accident conditions. This paper describes the approach and summarizes the results and conclusions of this study.

  19. Severe stress hormone conditions cause an extended window of excitability in the mouse basolateral amygdala.

    PubMed

    Karst, Henk; Joëls, Marian

    2016-11-01

    Shortly after stress, basolateral amygdala neurons are exposed to sequential yet partly overlapping waves of hormones. We examined how these hormonal waves can change activity of basolateral amygdala neurons such that emotional aspects of stress become so deeply ingrained. To this end, spontaneous glutamatergic transmission was recorded during and up to several hours after combined adrenergic and corticosteroid waves, targeting the time-window relevant for encoding of stress-related information. Hormonal waves mimicking moderately stressful conditions cause a transient enhancement followed by later suppression of glutamatergic transmission. However, this late phase flips from suppressed to enhanced glutamatergic transmission with conditions mimicking severe stress. Such a prolonged window of enhanced excitability may contribute to the excessively strong encoding seen after the experience of highly stressful or traumatic events.

  20. Severe stress hormone conditions cause an extended window of excitability in the mouse basolateral amygdala.

    PubMed

    Karst, Henk; Joëls, Marian

    2016-11-01

    Shortly after stress, basolateral amygdala neurons are exposed to sequential yet partly overlapping waves of hormones. We examined how these hormonal waves can change activity of basolateral amygdala neurons such that emotional aspects of stress become so deeply ingrained. To this end, spontaneous glutamatergic transmission was recorded during and up to several hours after combined adrenergic and corticosteroid waves, targeting the time-window relevant for encoding of stress-related information. Hormonal waves mimicking moderately stressful conditions cause a transient enhancement followed by later suppression of glutamatergic transmission. However, this late phase flips from suppressed to enhanced glutamatergic transmission with conditions mimicking severe stress. Such a prolonged window of enhanced excitability may contribute to the excessively strong encoding seen after the experience of highly stressful or traumatic events. PMID:27460963

  1. Estimate of radionuclide release characteristics into containment under severe accident conditions. Final report

    SciTech Connect

    Nourbakhsh, H.P.

    1993-11-01

    A detailed review of the available light water reactor source term information is presented as a technical basis for development of updated source terms into the containment under severe accident conditions. Simplified estimates of radionuclide release and transport characteristics are specified for each unique combination of the reactor coolant and containment system combinations. A quantitative uncertainty analysis in the release to the containment using NUREG-1150 methodology is also presented.

  2. Newly recognized submarine slide complexes in the southern California Bight

    NASA Astrophysics Data System (ADS)

    Conrad, J. E.; Lee, H. J.; Edwards, B. D.; McGann, M.; Sliter, R. W.

    2012-12-01

    New high-resolution bathymetric and seismic-reflection surveys have imaged large (<0.5 km3) submarine landslides offshore southern California that have not been previously recognized in the Borderland. The new data show several large slides or slide complexes that include: 1) a slide complex consisting of numerous (>7) individual overlapping slides along the western margin of Santa Cruz Basin (SCB slide); 2) a series of slumps and slide scars on the slope south of San Pedro shelf (SPS slide); and 3) a slope failure along the shelf edge in northern San Diego County, termed the Del Mar slide. The SCB slide complex extends for 30 km along the western slope of Santa Cruz Basin, with debris lobes extending 5-8 km into the basin. Head scarps of some of these slides are 50-75 m high. The SPS slide complex also appears to consist of multiple slides, which roughly parallel the Palos Verdes Fault and the San Gabriel Canyon submarine channel on the shelf edge and slope south of San Pedro shelf. Slide deposits associated with this complex are only partially mapped due to limited high-resolution bathymetric coverage, but extend to the south in the area SW of Lasuen Knoll. Seismic-reflection profiles show that some of these deposits are up to 20 m thick. The Del Mar slide is located about 10 km north of La Jolla Canyon and extends about 6 km along the shelf edge. The head scarp lies along the trend of a branch of the Rose Canyon Fault Zone. Radiocarbon ages of sediment overlying this slide indicate the Del Mar slide is approximately 12-16 ka. These large slide complexes have several characteristics in common. Nearly all occur in areas of tectonic uplift. All of the complexes show evidence of recurrent slide activity, exhibiting multiple headwall scarps and debris lobes, and where available, high-resolution seismic-reflection profiles of these slide areas provide evidence of older, buried mass transport deposits. Assuming typical sedimentation rates, the recurrence interval of

  3. A Comparison of Perturbed Initial Conditions and Multiphysics Ensembles in a Severe Weather Episode in Spain

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco; Tao, Wei-Kuo; Angelis, Carlos F.; Martinez, Miguel A.; Cecilia Marcos; Antonio Rodriguez; Hou, Arthur; Jong Shi, Jain

    2012-01-01

    Ensembles of numerical model forecasts are of interest to operational early warning forecasters as the spread of the ensemble provides an indication of the uncertainty of the alerts, and the mean value is deemed to outperform the forecasts of the individual models. This paper explores two ensembles on a severe weather episode in Spain, aiming to ascertain the relative usefulness of each one. One ensemble uses sensible choices of physical parameterizations (precipitation microphysics, land surface physics, and cumulus physics) while the other follows a perturbed initial conditions approach. The results show that, depending on the parameterizations, large differences can be expected in terms of storm location, spatial structure of the precipitation field, and rain intensity. It is also found that the spread of the perturbed initial conditions ensemble is smaller than the dispersion due to physical parameterizations. This confirms that in severe weather situations operational forecasts should address moist physics deficiencies to realize the full benefits of the ensemble approach, in addition to optimizing initial conditions. The results also provide insights into differences in simulations arising from ensembles of weather models using several combinations of different physical parameterizations.

  4. Severe dopaminergic neuron loss in rhesus monkey brain impairs morphine-induced conditioned place preference

    PubMed Central

    Yan, Ting; Rizak, Joshua Dominic; Wang, Jianhong; Yang, Shangchuan; Ma, Yuanye; Hu, Xintian

    2015-01-01

    It is well known that dopamine (DA) is critical for reward, but the precise role of DA in reward remains uncertain. The aim of this study was to determine what percentage of dopaminergic neurons in the primate brain is required for the expression of conditioned reward by measuring the performance of DA-deficient rhesus monkeys in a morphine-induced conditioned place preference (CPP) paradigm. Animals with mild Parkinsonian symptoms successfully developed and retained a morphine preference that was equivalent to control monkeys. However, these monkeys could not maintain the preference as well as controls when they retained severe Parkinsonian symptoms. On the other hand, monkeys initially in a severe Parkinsonian state developed a preference for morphine, but this preference was weaker than that of the controls. Histological results showed that the loss of dopaminergic neurons in monkeys that had severe Parkinsonian symptoms was about 80% in comparison to the control monkeys. All these data suggest that a severely impaired DA system alters rewarding-seeking behavior in non-human primates. PMID:26528155

  5. Better fear conditioning is associated with reduced symptom severity in autism spectrum disorders.

    PubMed

    South, Mikle; Larson, Michael J; White, Sarah E; Dana, Julianne; Crowley, Michael J

    2011-12-01

    Evidence from behavioral and neuroimaging studies suggest that atypical amygdala function plays a critical role in the development of autism spectrum disorders (ASD). The handful of psychophysiological studies examining amygdala function in ASD using classical fear conditioning paradigms have yielded discordant results. We recorded skin conductance response (SCR) during a simple discrimination conditioning task in 30 children and adolescents (ages 8-18) diagnosed with high-functioning ASD and 30 age- and IQ-matched, typically developing controls. SCR response in the ASD group was uniquely and positively associated with social anxiety; and negatively correlated with autism symptom severity, in particular with social functioning. Fear conditioning studies have tremendous potential to aid understanding regarding the amygdale's role in the varied symptom profile of ASD. Our data demonstrate that such studies require careful attention to task-specific factors, including task complexity; and also to contributions of dimensional, within-group factors that contribute to ASD heterogeneity.

  6. Fabrication and Wear Behavior Analysis on AlCrFeNi High Entropy Alloy Coating Under Dry Sliding and Oil Lubrication Test Conditions

    NASA Astrophysics Data System (ADS)

    Tang, Yipin; Wang, Shouren; Sun, Bin; Wang, Yan; Qiao, Yang

    2016-03-01

    In this paper, AlCrFeNi high entropy alloy coating was fabricated on the surface of Q235 steel using hot pressing sintering process. The coating has the controlled thickness size and excellent mechanical properties. Scanning electron microscopy (SEM), XRD and hardness testing method were used to study the morphology, phase structure and hardness of high entropy alloys coating. The lattice distortion plays a significant role in increasing the hardness. Coating formation mechanism caused by the element diffusion under the hot pressing effect is also discussed in the paper. Simultaneously, the dry sliding and oil lubrication wear tests, wear morphology observation and wear mechanism discussion were completed. As the result shows, AlCrFeNi high entropy alloys coating exhibits superior wear resistance either at dry sliding or oil lubrication tests owing to its hard high entropy solid solution structure.

  7. Friction and wear of Si{sub 3}N{sub 4} ceramic/stainless steel sliding contacts in dry and lubricated conditions

    SciTech Connect

    Zhao, X.Z.; Liu, J.J.; Zhu, B.L.; Miao, H.Z.; Luo, Z.B.

    1997-04-01

    Austenitic stainless steel AISI 321 is one of the most difficult-to-cut materials. In order to investigate the wear behavior of Si{sub 2}N{sub 4} ceramic when cutting the stainless steel, wear tests are carried out on a pin-on-disk tribometer, which could simulate a realistic cutting process. Test results show that the wear of Si{sub 3}N{sub 4} ceramic is mainly caused by adhesion between the rubbing surfaces and that the wear increases with load and speed. When oil is used for lubrication, the friction coefficient of the sliding pairs and the wear rate of the ceramic are reduced. A scanning electron microscope (SEM), an electron probe microanalyzer (EPMA), and an energy dispersive x-ray analyzer (EDXA) are used to examine the worn surfaces. The wear mechanisms of Si{sub 3}N{sub 4} ceramic sliding against the stainless steel are discussed in detail.

  8. Simulated water fluxes during the growing season in semiarid grassland ecosystems under severe drought conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Na; Liu, Chengyu

    2014-05-01

    To help improve understanding of how changes in climate and land cover affect water fluxes, water budgets, and the structure and function of regional grassland ecosystems, the Grassland Landscape Productivity Model (GLPM) was used to simulate spatiotemporal variation in primary water fluxes. The study area was a semiarid region in Inner Mongolia, China, in 2002, when severe drought was experienced. For Stipa grandis steppe, Leymus chinensis steppe, shrubland, and croplands, the modeled total, daily and monthly averaged, and maximum evapotranspiration during the growing season and the modeled water deficits were similar to those measured in Inner Mongolia under similar precipitation conditions. The modeled temporal variations in daily evaporation rate, transpiration rate, and evapotranspiration rate for the typical steppes also agreed reasonably well with measured trends. The results demonstrate that water fluxes varied in response to spatiotemporal variations in environmental factors and associated changes in the phenological and physiological characteristics of plants. It was also found that transpiration and evapotranspiration (rather than precipitation) were the primary factors controlling differences in water deficit among land cover types. The results also demonstrate that specific phenomena occur under severe drought conditions; these phenomena are considerably different to those occurring under normal or well-watered conditions. The findings of the present study will be useful for evaluating day-scale water fluxes and their relationships with climate change, hydrology, land cover, and vegetation dynamics.

  9. Associations of emotional arousal, dissociation and symptom severity with operant conditioning in borderline personality disorder.

    PubMed

    Paret, Christian; Hoesterey, Steffen; Kleindienst, Nikolaus; Schmahl, Christian

    2016-10-30

    Those with borderline personality disorder (BPD) display altered evaluations regarding reward and punishment compared to others. The processing of rewards is basal for operant conditioning. However, studies addressing operant conditioning in BPD patients are rare. In the current study, an operant conditioning task combining learning acquisition and reversal was used. BPD patients and matched healthy controls (HCs) were exposed to aversive and neutral stimuli to assess the influence of emotion on learning. Picture content, dissociation, aversive tension and symptom severity were rated. Error rates were measured. Results showed no group interactions between aversive versus neutral scenes. The higher emotional arousal, dissociation and tension, the worse the acquisition, but not reversal, scores were for BPD patients. Scores from the Borderline Symptom List were associated with more errors in the reversal, but not the acquisition phase. The results are preliminary evidence for impaired acquisition learning due to increased emotional arousal, dissociation and tension in BPD patients. A failure to process punishment in the reversal phase was associated with symptom severity and may be related to neuropsychological dysfunctioning involving the ventromedial prefrontal cortex. Conclusions are limited due to the correlational study design and the small sample size. PMID:27491014

  10. Associations of emotional arousal, dissociation and symptom severity with operant conditioning in borderline personality disorder.

    PubMed

    Paret, Christian; Hoesterey, Steffen; Kleindienst, Nikolaus; Schmahl, Christian

    2016-10-30

    Those with borderline personality disorder (BPD) display altered evaluations regarding reward and punishment compared to others. The processing of rewards is basal for operant conditioning. However, studies addressing operant conditioning in BPD patients are rare. In the current study, an operant conditioning task combining learning acquisition and reversal was used. BPD patients and matched healthy controls (HCs) were exposed to aversive and neutral stimuli to assess the influence of emotion on learning. Picture content, dissociation, aversive tension and symptom severity were rated. Error rates were measured. Results showed no group interactions between aversive versus neutral scenes. The higher emotional arousal, dissociation and tension, the worse the acquisition, but not reversal, scores were for BPD patients. Scores from the Borderline Symptom List were associated with more errors in the reversal, but not the acquisition phase. The results are preliminary evidence for impaired acquisition learning due to increased emotional arousal, dissociation and tension in BPD patients. A failure to process punishment in the reversal phase was associated with symptom severity and may be related to neuropsychological dysfunctioning involving the ventromedial prefrontal cortex. Conclusions are limited due to the correlational study design and the small sample size.

  11. Predictions of structural integrity of steam generator tubes under normal operating, accident, and severe accident conditions

    SciTech Connect

    Majumdar, S.

    1996-09-01

    Available models for predicting failure of flawed and unflawed steam generator tubes under normal operating, accident, and severe accident conditions are reviewed. Tests conducted in the past, though limited, tended to show that the earlier flow-stress model for part-through-wall axial cracks overestimated the damaging influence of deep cracks. This observation is confirmed by further tests at high temperatures as well as by finite element analysis. A modified correlation for deep cracks can correct this shortcoming of the model. Recent tests have shown that lateral restraint can significantly increase the failure pressure of tubes with unsymmetrical circumferential cracks. This observation is confirmed by finite element analysis. The rate-independent flow stress models that are successful at low temperatures cannot predict the rate sensitive failure behavior of steam generator tubes at high temperatures. Therefore, a creep rupture model for predicting failure is developed and validated by tests under varying temperature and pressure loading expected during severe accidents.

  12. Fission products behaviour in UO2 submitted to nuclear severe accident conditions

    NASA Astrophysics Data System (ADS)

    Geiger, E.; Bès, R.; Martin, P.; Pontillon, Y.; Solari, P. L.; Salome, M.

    2016-05-01

    The objective of this work was to study the molybdenum chemistry in UO2 based materials, known as SIMFUELS. These materials could be used as an alternative to irradiated nuclear fuels in the study of fission products behaviour during a nuclear severe accident. UO2 samples doped with 12 stable isotopes of fission products were submitted to annealing tests in conditions representative to intermediate steps of severe accidents. Samples were characterized by SEM-EDS and XAS. It was found that Mo chemistry seems to be more complex than what is normally estimated by thermodynamic calculations: XAS spectra indicate the presence of Mo species such as metallic Mo, MoO2, MoO3 and Cs2MoO4.

  13. Experiments to evaluate behavior of containment piping bellows under severe accident conditions

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1993-11-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall. In a severe accident they may be subjected to high pressure and temperature, and a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted at Sandia National Laboratories, Albuquerque, New Mexico. Several different bellows geometries, representative of actual containment bellows, are being subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of thirteen tests have been conducted. The tests showed that withstanding relatively large bellows are capable of deformations, up to, or near, the point of full compression before developing leakage. The test data is presented and discussed.

  14. Hydrogen-control systems for severe LWR accident conditions - a state-of-technology report

    SciTech Connect

    Hilliard, R K; Postma, A K; Jeppson, D W

    1983-03-01

    This report reviews the current state of technology regarding hydrogen safety issues in light water reactor plants. Topics considered in this report relate to control systems and include combustion prevention, controlled combustion, minimization of combustion effects, combination of control concepts, and post-accident disposal. A companion report addresses hydrogen generation, distribution, and combustion. The objectives of the study were to identify the key safety issues related to hydrogen produced under severe accident conditions, to describe the state of technology for each issue, and to point out ongoing programs aimed at resolving the open issues.

  15. Residual stress analysis on tensile MMC specimens after loading/unloading tests in several conditions

    NASA Astrophysics Data System (ADS)

    Giuliani, Alessandra; Albertini, Gianni; Manescu, Adrian

    2004-07-01

    Residual stresses have been investigated in samples made of AA6061+22% Al2O3 in order to correlate microstructural characteristics with mechanical performances. In particular, the possible occurrence of a brittle fracture induced by an excessive load transfer from the matrix to the reinforcement was investigated. To this end, macrostresses and microstresses were analysed. A neutron diffraction test on 12 specimens submitted to several loading/unloading conditions at different temperatures was performed. These measurements aimed to establish the optimal temperature for the initial extruded billet in pre-heating stage, before forging the final wheel hub.

  16. Physics in water slides

    NASA Astrophysics Data System (ADS)

    Thomazo, Jean-Baptiste; Reyssat, Etienne; Fermigier, Marc

    2015-11-01

    Water slides are body-size inclined pipes fed with water to improve sliding. Water is allowed to freely flow down the slide. It forms a lubrication film that reduces friction between the slide and the body, allowing sliders to travel down at high speeds. We present the results of an experimental study on a model water slide at the scale of the laboratory. We analyze the sliding velocities of cylindrical objects of various masses and sizes sliding down an inclined gutter fed with a controlled flux of water. In the range of parameters that we have studied, we show that the speed of the model sliders is faster than the flow of the environing water. We propose a minimal model to account for the observed sliding velocities measured in our experiments. The sliding velocity is set by a balance of the apparent weight with inertial drag or viscous friction in the lubrication film under the slider. Other resisting mechanisms will also be discussed.

  17. A frictional sliding algorithm for liquid droplets

    NASA Astrophysics Data System (ADS)

    Sauer, Roger A.

    2016-08-01

    This work presents a new frictional sliding algorithm for liquid menisci in contact with solid substrates. In contrast to solid-solid contact, the liquid-solid contact behavior is governed by the contact line, where a contact angle forms and undergoes hysteresis. The new algorithm admits arbitrary meniscus shapes and arbitrary substrate roughness, heterogeneity and compliance. It is discussed and analyzed in the context of droplet contact, but it also applies to liquid films and solids with surface tension. The droplet is modeled as a stabilized membrane enclosing an incompressible medium. The contact formulation is considered rate-independent such that hydrostatic conditions apply. Three distinct contact algorithms are needed to describe the cases of frictionless surface contact, frictionless line contact and frictional line contact. For the latter, a predictor-corrector algorithm is proposed in order to enforce the contact conditions at the contact line and thus distinguish between the cases of advancing, pinning and receding. The algorithms are discretized within a monolithic finite element formulation. Several numerical examples are presented to illustrate the numerical and physical behavior of sliding droplets.

  18. Sensorimotor Difficulties Are Associated with the Severity of Autism Spectrum Conditions

    PubMed Central

    Hannant, Penelope; Cassidy, Sarah; Tavassoli, Teresa; Mann, Francesca

    2016-01-01

    Present diagnostic criteria for autism spectrum conditions (ASC) include social communication and interaction difficulties, repetitive behavior and movement, and atypical sensory responsivity. Few studies have explored the influence of motor coordination and sensory responsivity on severity of ASC symptoms. In the current study, we explore whether sensory responsivity and motor coordination differences can account for the severity of autistic behaviors in children with ASC. Thirty-six children participated: 18 (13 male, 5 female) with ASC (ages 7–16: mean age = 9.93 years) and 18 (7 male, 11 female) typically developing (TD) children (ages 6–12; mean age = 9.16 years). Both groups completed a battery of assessments that included motor coordination, sensory responsivity, receptive language, non-verbal reasoning and social communication measures. Children with ASC also completed the Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview—Revised (ADI-R). Results showed that children with ASC scored significantly lower on receptive language, coordination, sensory responsivity and a sensorimotor subscale, Modulation of Activity (MoA) compared to the TD group. In the ASC group, MoA significantly predicted ASC severity across all ASC measures; receptive language and sensory responsivity significantly predicted parental reported autism measures; and coordination significantly predicted examiner observed reported scores. Additionally, specific associations were found between the somatosensory perceptive modalities and ASC severity. The results show that sensorimotor skills are associated with severity of ASC symptoms; furthering the need to research sensorimotor integration in ASC and also implying that diagnosis of ASC should also include the assessment of both coordination deficit and atypical sensory responsivity. PMID:27582694

  19. Sensorimotor Difficulties Are Associated with the Severity of Autism Spectrum Conditions.

    PubMed

    Hannant, Penelope; Cassidy, Sarah; Tavassoli, Teresa; Mann, Francesca

    2016-01-01

    Present diagnostic criteria for autism spectrum conditions (ASC) include social communication and interaction difficulties, repetitive behavior and movement, and atypical sensory responsivity. Few studies have explored the influence of motor coordination and sensory responsivity on severity of ASC symptoms. In the current study, we explore whether sensory responsivity and motor coordination differences can account for the severity of autistic behaviors in children with ASC. Thirty-six children participated: 18 (13 male, 5 female) with ASC (ages 7-16: mean age = 9.93 years) and 18 (7 male, 11 female) typically developing (TD) children (ages 6-12; mean age = 9.16 years). Both groups completed a battery of assessments that included motor coordination, sensory responsivity, receptive language, non-verbal reasoning and social communication measures. Children with ASC also completed the Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview-Revised (ADI-R). Results showed that children with ASC scored significantly lower on receptive language, coordination, sensory responsivity and a sensorimotor subscale, Modulation of Activity (MoA) compared to the TD group. In the ASC group, MoA significantly predicted ASC severity across all ASC measures; receptive language and sensory responsivity significantly predicted parental reported autism measures; and coordination significantly predicted examiner observed reported scores. Additionally, specific associations were found between the somatosensory perceptive modalities and ASC severity. The results show that sensorimotor skills are associated with severity of ASC symptoms; furthering the need to research sensorimotor integration in ASC and also implying that diagnosis of ASC should also include the assessment of both coordination deficit and atypical sensory responsivity. PMID:27582694

  20. Evolution of the sensor fish device for measuring physical conditions in sever hydraulic environments

    SciTech Connect

    Carlson, Thomas J.; Duncan, J. P.

    2003-03-01

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new “fish-friendly” turbines, and spillway designs and operations, Pacific Northwest National Laboratory (PNNL) scientists have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. This report discusses the development and field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River, which have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  1. Effect of driver, roadway, collision, and vehicle characteristics on crash severity: a conditional logistic regression approach.

    PubMed

    Kadilar, Gamze Ozel

    2016-01-01

    The aim of the study is to examine the factors that appear to have a higher potential for serious injury or death of drivers in traffic accidents in Turkey, such as collision type, roadway surface, vehicle speed, alcohol/drug use, and restraint use. Driver crash severity is the dependent variable of this study with two categories, fatal and non-fatal. Due to the binary nature of the dependent variable, a conditional logistic regression analysis was found suitable. Of the 16 independent variables obtained from Turkish police accident reports, 11 variables were found most significantly associated with driver crash severity. They are age, education level, restraint use, roadway condition, roadway type, time of day, collision location, collision type, number and direction of vehicles, vehicle speed, and alcohol/drug use. This study found that belted drivers aged 18-25 years involving two vehicles travelling in the same direction, in an urban area, during the daytime, and on an avenue or a street have better chances of survival in traffic accidents. PMID:25087577

  2. Evolution of the Sensor Fish Device for Measuring Physical Conditions in Severe Hydraulic Environments

    SciTech Connect

    Carlson, Thomas J.; Duncan, Joanne P.

    2003-02-28

    To assist in deriving biological specifications for design of turbine rehabilitation measures, new ''fish-friendly'' turbines, and spillway designs and operations, scientists at the Pacific Northwest National Laboratory (PNNL) have developed and tested an autonomous multi-sensor device called a Sensor Fish that can acquire pressure and tri-axial linear acceleration data during passage through severe hydraulic conditions. The purpose of the Sensor Fish is to characterize physical conditions fish experience during passage through hydro turbines, spill stilling basins, high-discharge outfalls, and other dam passage routes. The Sensor Fish was developed with the support of the U.S. Department of Energy's Advanced Hydropower Turbine System program. Field tests of the Sensor Fish at Rock Island, McNary, The Dalles, Bonneville, and Wanapum dams on the Columbia River and the Prosser Irrigation District on the Yakima River have shown that the device can withstand the severe environments of turbine, spill, and fish bypass passage and provide useful environmental data that can ultimately aid in the design and operation of new and existing turbines, spill, and dam fish bypass facilities.

  3. Insights on fission products behaviour in nuclear severe accident conditions by X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Geiger, E.; Bès, R.; Martin, Ph; Pontillon, Y.; Ducros, G.; Solari, P. L.

    2016-04-01

    Many research programs have been carried out aiming to understand the fission products behaviour during a Nuclear Severe Accident. Most of these programs used highly radioactive irradiated nuclear fuel, which requires complex instrumentation. Moreover, the radioactive character of samples hinders an accurate chemical characterisation. In order to overcome these difficulties, SIMFUEL stand out as an alternative to perform complementary tests. A sample made of UO2 doped with 11 fission products was submitted to an annealing test up to 1973 K in reducing atmosphere. The sample was characterized before and after the annealing test using SEM-EDS and XAS at the MARS beam-line, SOLEIL Synchrotron. It was found that the overall behaviour of several fission products (such as Mo, Ba, Pd and Ru) was similar to that observed experimentally in irradiated fuels and consistent with thermodynamic estimations. The experimental approach presented in this work has allowed obtaining information on chemical phases evolution under nuclear severe accident conditions, that are yet difficult to obtain using irradiated nuclear fuel samples.

  4. 3D finite element modeling of sliding wear

    NASA Astrophysics Data System (ADS)

    Buentello Hernandez, Rodolfo G.

    Wear is defined as "the removal of material volume through some mechanical process between two surfaces". There are many mechanical situations that can induce wear and each can involve many wear mechanisms. This research focuses on the mechanical wear due to dry sliding between two surfaces. Currently there is a need to identify and compare materials that would endure sliding wear under severe conditions such as high velocities. The high costs associated with the field experimentation of systems subject to high-speed sliding, has prevented the collection of the necessary data required to fully characterize this phenomena. Simulating wear through Finite Elements (FE) would enable its prediction under different scenarios and would reduce experimentation costs. In the aerospace, automotive and weapon industries such a model can aid in material selection, design and/or testing of systems subjected to wear in bearings, gears, brakes, gun barrels, slippers, locomotive wheels, or even rocket test tracks. The 3D wear model presented in this dissertation allows one to reasonably predict high-speed sliding mechanical wear between two materials. The model predictions are reasonable, when compared against those measured on a sled slipper traveling over the Holloman High Speed Tests Track. This slipper traveled a distance of 5,816 meters in 8.14 seconds and reached a maximum velocity of 1,530 m/s.

  5. On the Importance of Pickup Ion Precipitation to the Martian Thermosphere Under Severe Solar Wind Conditions

    NASA Astrophysics Data System (ADS)

    Fang, X.; Bougher, S. W.; Johnson, R. E.; Luhmann, J. G.; Liemohn, M. W.; Ma, Y.

    2012-12-01

    decreased Jeans parameter, we will also evaluate the importance of pickup ion precipitation in influencing the escape of neutral heavy species when the upstream solar wind conditions are severe.

  6. Mailing microscope slides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  7. Investigating public preferences on 'severity of health' as a relevant condition for setting healthcare priorities.

    PubMed

    Green, Colin

    2009-06-01

    This study examines the preferences of a sample of the UK general public over the allocation of healthcare resources. Preferences were elicited against scenarios where alternative patient groups are competing for limited resources. Respondents were asked to make a choice between either (i) groups described according to alternative descriptions for severity of health condition, or (ii) groups described according to a broader level of disadvantage (e.g. family income). The survey used a random-location quota sampling approach, and face-to-face interview techniques. Interviews were completed with 261 people in the Southampton area of England. Results showed that the majority or respondents wanted to divide resources equally between competing groups, giving at least equal preference to the more severely affected group, and the more disadvantaged group, regardless of a stated lower potential health gain in these groups compared to alternatives. In the severity of health question 60% indicated that a unit of health gain in a severely affected patient group was of greater social value to that same unit of health gain in a moderately affected patient group, all else equal. When described by level of disadvantage, 80% of respondents stated such a preference, which indicates that they attach a greater social value to a unit of health gain in a disadvantage patient group, compared to a more advantaged group, all else equal. When given an option to 'opt out' of a difficult decision, and to 'let others choose', very few respondents (5%) took that option, suggesting that the most common stated preference of dividing resource equally between groups may be a true preference, rather than respondents avoiding difficult decisions. When interpreting the findings from the survey, results suggest that preferences reported to give priority to those more severely affected by their health, may also be a reflection of a broader preference to treat those groups classed as worse-off, in

  8. Predictions of structural integrity of steam generator tubes under normal operating, accident, an severe accident conditions

    SciTech Connect

    Majumdar, S.

    1997-02-01

    Available models for predicting failure of flawed and unflawed steam generator tubes under normal operating, accident, and severe accident conditions are reviewed. Tests conducted in the past, though limited, tended to show that the earlier flow-stress model for part-through-wall axial cracks overestimated the damaging influence of deep cracks. This observation was confirmed by further tests at high temperatures, as well as by finite-element analysis. A modified correlation for deep cracks can correct this shortcoming of the model. Recent tests have shown that lateral restraint can significantly increase the failure pressure of tubes with unsymmetrical circumferential cracks. This observation was confirmed by finite-element analysis. The rate-independent flow stress models that are successful at low temperatures cannot predict the rate-sensitive failure behavior of steam generator tubes at high temperatures. Therefore, a creep rupture model for predicting failure was developed and validated by tests under various temperature and pressure loadings that can occur during postulated severe accidents.

  9. Rhizobium-Legume Symbiosis and Nitrogen Fixation under Severe Conditions and in an Arid Climate

    PubMed Central

    Zahran, Hamdi Hussein

    1999-01-01

    Biological N2 fixation represents the major source of N input in agricultural soils including those in arid regions. The major N2-fixing systems are the symbiotic systems, which can play a significant role in improving the fertility and productivity of low-N soils. The Rhizobium-legume symbioses have received most attention and have been examined extensively. The behavior of some N2-fixing systems under severe environmental conditions such as salt stress, drought stress, acidity, alkalinity, nutrient deficiency, fertilizers, heavy metals, and pesticides is reviewed. These major stress factors suppress the growth and symbiotic characteristics of most rhizobia; however, several strains, distributed among various species of rhizobia, are tolerant to stress effects. Some strains of rhizobia form effective (N2-fixing) symbioses with their host legumes under salt, heat, and acid stresses, and can sometimes do so under the effect of heavy metals. Reclamation and improvement of the fertility of arid lands by application of organic (manure and sewage sludge) and inorganic (synthetic) fertilizers are expensive and can be a source of pollution. The Rhizobium-legume (herb or tree) symbiosis is suggested to be the ideal solution to the improvement of soil fertility and the rehabilitation of arid lands and is an important direction for future research. PMID:10585971

  10. Containment performance of prototypical reactor containments subjected to severe accident conditions

    SciTech Connect

    Klamerus, E.W.; Bohn, M.P.; Wesley, D.A.; Krishnaswamy, C.N.

    1996-12-01

    In SECY-90-016, the NTRC proposed a safety goal of a conditional containment failure probability (CCFP) of 0.1 and the alternative acceptance criteria allowed for steel containments, which specifies that the stresses should not exceed ASNE Level C allowables for severe accident pressures and temperatures. In this work, the need for an equivalent criterion for concrete containments was studied. Six surrogate containments were designed and analyzed in order to compare the margins between design pressure, pressure resulting in exceedance of Level C (or yield) stress limits, and ultimate pressure. For comparability, each containment has an identical internal volume and design pressure. Results from the analysis showed margins to yield are comparable and display a similar margin for both steel and concrete containments. In addition, the margin to failure, although slightly higher in the steel containments, were also comparable. Finally, a CCFP for code design was determined based on general membrane behavior and imposing an upper bound severe accident curve developed in the DCH studies. The resulting CCFP`s were less then 0.02 (or 2%) for all the surrogate containments studied, showing that these containment designs all achieved the NRC safety goal.

  11. The Influence of Safety, Efficacy, and Medical Condition Severity on Natural versus Synthetic Drug Preference.

    PubMed

    Meier, Brian P; Lappas, Courtney M

    2016-11-01

    Research indicates that there is a preference for natural v. synthetic products, but the influence of this preference on drug choice in the medical domain is largely unknown. We present 5 studies in which participants were asked to consider a hypothetical situation in which they had a medical issue requiring pharmacological therapy. Participants ( N = 1223) were asked to select a natural, plant-derived, or synthetic drug. In studies 1a and 1b, approximately 79% of participants selected the natural v. synthetic drug, even though the safety and efficacy of the drugs were identical. Furthermore, participants rated the natural drug as safer than the synthetic drug, and as that difference increased, the odds of choosing the natural over synthetic drug increased. In studies 2 and 3, approximately 20% of participants selected the natural drug even when they were informed that it was less safe (study 2) or less effective (study 3) than the synthetic drug. Finally, in study 4, approximately 65% of participants chose a natural over synthetic drug regardless of the severity of a specific medical condition (mild v. severe hypertension), and this choice was predicted by perceived safety and efficacy differences. Overall, these data indicate that there is a bias for natural over synthetic drugs. This bias could have implications for drug choice and usage. PMID:26683247

  12. Evaluation of oral tilmicosin efficacy against severe cryptosporidiosis in neonatal kids under field conditions.

    PubMed

    Paraud, C; Pors, I; Chartier, C

    2010-05-28

    Many compounds have been screened for their potential anti-cryptosporidial activity in ruminants but none of them has been totally efficient in controlling the disease. Macrolide antibiotics have demonstrated some activity against Cryptosporidium spp. in humans. Tilmicosin is a macrolide antibiotic, available in France in an oral form (Pulmotil AC, Lilly France). The preventive efficacy of tilmicosin was evaluated in a goat farm experiencing severe clinical cryptosporidiosis in kids. Twenty-two kids were separated from their dams just after birth and placed in a separated pen. They were divided into 3 groups: an untreated group (10 kids), group 1 (6 kids) receiving tilmicosin at 25mg/kg BW/day and group 2 (6 kids) receiving tilmicosin at 50mg/kg BW/day. Tilmicosin was individually given by oral route from day 2 of age for 10 days. Three times a week, individual faecal samples were performed to assess the oocyst output. Clinical data, i.e. diarrhea and mortality, were recorded. In control kids, the highest prevalence and intensity of excretion were observed between day 6 and day 16 of age and mortality reached 90%. Excretion dynamic and clinical consequences were similar in both treated kid groups. Finally, tilmicosin did not demonstrate any activity against severe kid cryptosporidiosis in field conditions.

  13. Sliding scale insulin use: myth or insanity?

    PubMed

    Umpierrez, Guillermo E; Palacio, Andres; Smiley, Dawn

    2007-07-01

    Inpatient hyperglycemia in people with or without diabetes is associated with an increased risk of complications and mortality, a longer hospital stay, a higher admission rate to the intensive care unit, and higher hospitalization costs. Despite increasing evidence that supports intensive glycemic control in hospitalized patients, blood glucose control continues to be challenging, and sliding scale insulin coverage, a practice associated with limited therapeutic success, continues to be the most frequent insulin regimen in hospitalized patients. Sliding scale insulin has been in use for more than 80 years without much evidence to support its use as the standard of care. Several studies have revealed evidence of poor glycemic control and deleterious effects in sliding scale insulin use. To understand its wide use and acceptance, we reviewed the origin, advantages, and disadvantages of sliding scale insulin in the inpatient setting.

  14. Sliding wear studies using acoustic emission

    NASA Astrophysics Data System (ADS)

    Lingard, S.; Yu, C. W.; Yau, C. F.

    1993-04-01

    Deformation processes in solids, such as dislocation movements under plastic flow, crack propagation and void crushing, produce stress waves at ultrasonic frequencies, usually described as acoustic emission (AE), which can be detected by sensitive instruments and which are related to the severity and nature of the deformations. The paper discusses the characteristics of the stress waves and their variation with wear rates, wear regimes, and friction forces, as determined during laboratory experiments on metallic specimens in relative sliding motion, both unlubricated and with elastohydrodynamic lubrication. It is shown that there are systematic relationships between the acoustic emissions, the wear rates, the frictional work inputs and established tribological contact variables. The predominant frequencies of the emissions are also evaluated and considered in relation to the materials and wear conditions.

  15. Thermochemistry of Ruthenium Oxyhydroxide Species and Their Impact on Volatile Speciations in Severe Nuclear Accident Conditions.

    PubMed

    Miradji, Faoulat; Virot, François; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2016-02-01

    Literature thermodynamic data of ruthenium oxyhydroxides reveal large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. Reaction energies leading to the formation of all possible oxyhydroxide species RuOx(OH)y(H2O)z have been calculated for a series of reactions combining DFT (TPSSh-5%HF) geometries and partition functions, CCSD(T) energies extrapolated to the complete basis set limits. The highly accurate ab initio thermodynamic data were used as input data of thermodynamic equilibrium computations to derive the speciation of gaseous ruthenium species in the temperature, pressure and concentration conditions of severe nuclear accidents occurring in pressurized water reactors. At temperatures lower than 1000 K, gaseous ruthenium tetraoxide is the dominating species, between 1000 and 2000 K ruthenium trioxide becomes preponderant, whereas at higher temperatures gaseous ruthenium oxide, dioxide and even Ru in gaseous phase are formed. Although earlier studies predicted the formation of oxyhydroxides in significant quantities, the use of highly accurate ab initio thermodynamic data for ruthenium gaseous species leads to a more reliable inventory of gaseous ruthenium species in which gaseous oxyhydroxide ruthenium molecules are formed only in negligible amounts.

  16. Luteinizing hormone secretion in hemidecorticate female rats under several experimental conditions.

    PubMed

    Fernandes, G A; Antunes-Rodrigues, J; Covian, M R

    1978-01-01

    Luteinizing hormone (LH) secretion by the anterior pituitary gland was investigated in hemidecorticate (HD) rats under several conditions. Higher plasma and lower pituitary LH levels were observed in HD rats in the afternoon of proestrus, after unilateral ovariectomy, and at the 7th and 14th days after bilateral castration. The ovarian hypertrophy observed in HD rats did not differ from control. When hormonal substitutive therapy was started 3 days after bilateral ovariectomy, larger doses of estradiol benzoate (EB) were required to reduce plasma LH levels in control than in HD animals. The increase in pituitary weight was, however, significantly higher in the HD castrated group. When substitutive therapy started at the 7th and 14th days after castration no significant differences between the 2 experimental groups were observed. The results of substitutive therapy suggest that hemidecortication induces an increase in the sensitivity of hypothalamic-pituitary axis to estrogen negative feedback. This change in sensitivity is clearly seen in HD rats during the first few days after castration. These results suggest that hemidecortication may release the hypothalamus from inhibitory influences coming from rhinencephalic or cortical structures, thus rendering the preoptic-suprachiasmatic complex (POA-SCH) more sensitive to LH-releasing mechanisms.

  17. Thermochemistry of Ruthenium Oxyhydroxide Species and Their Impact on Volatile Speciations in Severe Nuclear Accident Conditions.

    PubMed

    Miradji, Faoulat; Virot, François; Souvi, Sidi; Cantrel, Laurent; Louis, Florent; Vallet, Valérie

    2016-02-01

    Literature thermodynamic data of ruthenium oxyhydroxides reveal large uncertainties in some of the standard enthalpies of formation, motivating the use of high-level relativistic correlated quantum chemical methods to reduce the level of discrepancies. Reaction energies leading to the formation of all possible oxyhydroxide species RuOx(OH)y(H2O)z have been calculated for a series of reactions combining DFT (TPSSh-5%HF) geometries and partition functions, CCSD(T) energies extrapolated to the complete basis set limits. The highly accurate ab initio thermodynamic data were used as input data of thermodynamic equilibrium computations to derive the speciation of gaseous ruthenium species in the temperature, pressure and concentration conditions of severe nuclear accidents occurring in pressurized water reactors. At temperatures lower than 1000 K, gaseous ruthenium tetraoxide is the dominating species, between 1000 and 2000 K ruthenium trioxide becomes preponderant, whereas at higher temperatures gaseous ruthenium oxide, dioxide and even Ru in gaseous phase are formed. Although earlier studies predicted the formation of oxyhydroxides in significant quantities, the use of highly accurate ab initio thermodynamic data for ruthenium gaseous species leads to a more reliable inventory of gaseous ruthenium species in which gaseous oxyhydroxide ruthenium molecules are formed only in negligible amounts. PMID:26789932

  18. Nuclear waste shipping container response to severe accident conditions, A brief critique of the modal study

    SciTech Connect

    Audin, L.

    1990-12-01

    The Modal Study (NUREG/CR-4829) attempts to upgrade the analysis of spent nuclear fuel transportation accidents, and to verify the validity of the present regulatory scheme of cask performance standards as a means to minimize risk. While an improvement over many prior efforts in this area (such as NUREG-0170), it unfortunately fails to create a realistic simulation either of a shipping cask, the severe conditions to which it could be subjected, or the potential damage to the spent fuel cargo during an accident. There are too many deficiencies in its analysis to allow acceptance of its results for the presumed cask design, and many pending changes in new containers, cargoes and shipping patterns will limit applicability of the Modal Study to future shipments. In essence, the Modal Study is a good start, but is too simplistic, incomplete, outdated and open to serious question to be used as the basis for any present-day environmental or risk assessment of spent fuel transportation. It needs to be redone, with peer review during its production and experimental verification of its assumptions, before it has any relevance to the shipments planned to Yucca Mountain. Finally, it must be expanded into a full risk assessment by inputing its radiological release fractions and probabilities into a valid dispersal simulation to properly determine the impact of its results. 51 refs.

  19. Slides, Swings and Science.

    ERIC Educational Resources Information Center

    Dreyer, Kay Jardon; Bryte, Janelle

    1990-01-01

    Described are eight science activities that may take place on a school playground using a parachute, balls, swings, slides, and a balance beam. Procedures and questions for each activity are included. (CW)

  20. Water-slide alopecia.

    PubMed

    Adams, B B

    2001-05-01

    A 29-year-old male presented with large, symmetric, alopecic patches on the posterolateral aspects of both calves. A detailed history revealed that the individual had recently attended a water-slide amusement park. Repeated frictional trauma between the legs and the slide resulted in these alopecic patches. Friction, especially when encountered during sports-related and recreational activities, should be included in the differential diagnosis of well-defined alopecic patches.

  1. Fundamentals of the Slide Library.

    ERIC Educational Resources Information Center

    Boerner, Susan Zee

    This paper is an introduction to the fundamentals of the art (including architecture) slide library, with some emphasis on basic procedures of the science slide library. Information in this paper is particularly relevant to the college, university, and museum slide library. Topics addressed include: (1) history of the slide library; (2) duties of…

  2. Ornamental Landscape Grasses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven M.; Adams, Denise W.

    This slide script to accompany the slide series, Ornamental Landscape Grasses, contains photographs of the 167 slides and accompanying narrative text intended for use in the study and identification of commercially important ornamental grasses and grasslike plants. Narrative text is provided for slides of 62 different perennial and annual species…

  3. Aerosol Properties and Radiative Forcing over Kanpur during Severe Aerosol Loading Conditions

    SciTech Connect

    Kaskaoutis, D. G.; Sinha, P. R.; Vinoj, V.; Kosmopoulos, P. G.; Tripathi, S. N.; Misra, Amit; Sharma, M.; Singh, R. P.

    2013-11-01

    Atmospheric aerosols over India exhibit large spatio-temporal fluctuation driven by the local monsoon system, emission rates and seasonally-changed air masses. The northern part of India is well-known for its high aerosol loading throughout the year due to anthropogenic emissions, dust influence and biomass burning. On certain circumstances and, under favorable weather conditions, the aerosol load can be severe, causing significant health concerns and climate implications. The present work analyzes the aerosol episode (AE) days and examines the modification in aerosol properties and radiative forcing during the period 2001-2010 based on Kanpur-AERONET sun photometer data. As AEs are considered the days having daily-mean aerosol optical depth (AOD) above the decadal mean + 1 STD (standard deviation); the threshold value is defined at 0.928. The results identify 277 out of 2095 days (13.2%) of AEs over Kanpur, which are most frequently observed during post-monsoon (78 cases, 18.6%) and monsoon (76, 14.7%) seasons due to biomass-burning episodes and dust influence, respectively. On the other hand, the AEs in winter and pre-monsoon are lower in both absolute and percentage values (65, 12.5% and 58, 9.1%, respectively). The modification in aerosol properties on the AE days is strongly related to season. Thus, in post-monsoon and winter the AEs are associated with enhanced presence of fine-mode aerosols and Black Carbon from anthropogenic pollution and any kind of burning, while in pre-monsoon and monsoon seasons they are mostly associated with transported dust. Aerosol radiative forcing (ARF) calculated using SBDART shows much more surface (~-69 to -97 Wm-2) and Top of Atmosphere cooling (-20 to -30 Wm-2) as well as atmospheric heating (~43 to 71 Wm-2) during the AE days compared to seasonal means. These forcing values are mainly controlled by the higher AODs and the modified aerosol characteristics (Angstrom α, SSA) during the AE days in each season and may cause

  4. Severity of chronic Lyme disease compared to other chronic conditions: a quality of life survey.

    PubMed

    Johnson, Lorraine; Wilcox, Spencer; Mankoff, Jennifer; Stricker, Raphael B

    2014-01-01

    Overview. The Centers for Disease Control and Prevention (CDC) health-related quality of life (HRQoL) indicators are widely used in the general population to determine the burden of disease, identify health needs, and direct public health policy. These indicators also allow the burden of illness to be compared across different diseases. Although Lyme disease has recently been acknowledged as a major health threat in the USA with more than 300,000 new cases per year, no comprehensive assessment of the health burden of this tickborne disease is available. This study assesses the HRQoL of patients with chronic Lyme disease (CLD) and compares the severity of CLD to other chronic conditions. Methods. Of 5,357 subjects who responded to an online survey, 3,090 were selected for the study. Respondents were characterized as having CLD if they were clinically diagnosed with Lyme disease and had persisting symptoms lasting more than 6 months following antibiotic treatment. HRQoL of CLD patients was assessed using the CDC 9-item metric. The HRQoL analysis for CLD was compared to published analyses for the general population and other chronic illnesses using standard statistical methods. Results. Compared to the general population and patients with other chronic diseases reviewed here, patients with CLD reported significantly lower health quality status, more bad mental and physical health days, a significant symptom disease burden, and greater activity limitations. They also reported impairment in their ability to work, increased utilization of healthcare services, and greater out of pocket medical costs. Conclusions. CLD patients have significantly impaired HRQoL and greater healthcare utilization compared to the general population and patients with other chronic diseases. The heavy burden of illness associated with CLD highlights the need for earlier diagnosis and innovative treatment approaches that may reduce the burden of illness and concomitant costs posed by this

  5. Extended survival of several organisms and amino acids under simulated martian surface conditions

    NASA Astrophysics Data System (ADS)

    Johnson, A. P.; Pratt, L. M.; Vishnivetskaya, T.; Pfiffner, S.; Bryan, R. A.; Dadachova, E.; Whyte, L.; Radtke, K.; Chan, E.; Tronick, S.; Borgonie, G.; Mancinelli, R. L.; Rothschild, L. J.; Rogoff, D. A.; Horikawa, D. D.; Onstott, T. C.

    2011-02-01

    Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40 days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms' survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical

  6. Severity of chronic Lyme disease compared to other chronic conditions: a quality of life survey

    PubMed Central

    Johnson, Lorraine; Wilcox, Spencer; Mankoff, Jennifer

    2014-01-01

    Overview. The Centers for Disease Control and Prevention (CDC) health-related quality of life (HRQoL) indicators are widely used in the general population to determine the burden of disease, identify health needs, and direct public health policy. These indicators also allow the burden of illness to be compared across different diseases. Although Lyme disease has recently been acknowledged as a major health threat in the USA with more than 300,000 new cases per year, no comprehensive assessment of the health burden of this tickborne disease is available. This study assesses the HRQoL of patients with chronic Lyme disease (CLD) and compares the severity of CLD to other chronic conditions. Methods. Of 5,357 subjects who responded to an online survey, 3,090 were selected for the study. Respondents were characterized as having CLD if they were clinically diagnosed with Lyme disease and had persisting symptoms lasting more than 6 months following antibiotic treatment. HRQoL of CLD patients was assessed using the CDC 9-item metric. The HRQoL analysis for CLD was compared to published analyses for the general population and other chronic illnesses using standard statistical methods. Results. Compared to the general population and patients with other chronic diseases reviewed here, patients with CLD reported significantly lower health quality status, more bad mental and physical health days, a significant symptom disease burden, and greater activity limitations. They also reported impairment in their ability to work, increased utilization of healthcare services, and greater out of pocket medical costs. Conclusions. CLD patients have significantly impaired HRQoL and greater healthcare utilization compared to the general population and patients with other chronic diseases. The heavy burden of illness associated with CLD highlights the need for earlier diagnosis and innovative treatment approaches that may reduce the burden of illness and concomitant costs posed by this

  7. Severity of chronic Lyme disease compared to other chronic conditions: a quality of life survey.

    PubMed

    Johnson, Lorraine; Wilcox, Spencer; Mankoff, Jennifer; Stricker, Raphael B

    2014-01-01

    Overview. The Centers for Disease Control and Prevention (CDC) health-related quality of life (HRQoL) indicators are widely used in the general population to determine the burden of disease, identify health needs, and direct public health policy. These indicators also allow the burden of illness to be compared across different diseases. Although Lyme disease has recently been acknowledged as a major health threat in the USA with more than 300,000 new cases per year, no comprehensive assessment of the health burden of this tickborne disease is available. This study assesses the HRQoL of patients with chronic Lyme disease (CLD) and compares the severity of CLD to other chronic conditions. Methods. Of 5,357 subjects who responded to an online survey, 3,090 were selected for the study. Respondents were characterized as having CLD if they were clinically diagnosed with Lyme disease and had persisting symptoms lasting more than 6 months following antibiotic treatment. HRQoL of CLD patients was assessed using the CDC 9-item metric. The HRQoL analysis for CLD was compared to published analyses for the general population and other chronic illnesses using standard statistical methods. Results. Compared to the general population and patients with other chronic diseases reviewed here, patients with CLD reported significantly lower health quality status, more bad mental and physical health days, a significant symptom disease burden, and greater activity limitations. They also reported impairment in their ability to work, increased utilization of healthcare services, and greater out of pocket medical costs. Conclusions. CLD patients have significantly impaired HRQoL and greater healthcare utilization compared to the general population and patients with other chronic diseases. The heavy burden of illness associated with CLD highlights the need for earlier diagnosis and innovative treatment approaches that may reduce the burden of illness and concomitant costs posed by this

  8. Analysis of slide exploration strategy of cytologists when reading digital slides

    NASA Astrophysics Data System (ADS)

    Pantanowitz, Liron; Parwani, Anil; Tseytlin, Eugene; Mello-Thoms, Claudia

    2012-02-01

    Cytology is the sub-domain of Pathology that deals mainly with the diagnosis of cellular changes caused by disease. Current clinical practice involves a cytotechnologist that manually screens glass slides containing fixed cytology material using a light microscope. Screened slides are then forwarded to a specialized pathologist, a cytopathologist, for microscopic review and final diagnostic interpretation. If no abnormalities are detected, the specimen is interpreted as "normal", otherwise the abnormalities are marked with a pen on the glass slide by the cytotechnologist and then are used to render a diagnosis. As Pathology is migrating towards a digital environment it is important to determine whether these crucial screening and diagnostic tasks can be performed as well using digital slides as the current practice with glass slides. The purpose of this work is to make this assessment, by using a set of digital slides depicting cytological materials of different disease processes in several organs, and then to analyze how different cytologists including cytotechnologists, cytopathologists and cytotechnology-trainees explored the digital slides. We will (1) collect visual search data from the cytologists as they navigate the digital slides, as well as record any electronic marks (annotations) made by the cytologists; (2) convert the dynamic visual search data into a static representation of the observers' exploration strategy using 'search maps'; and (3) determine slide coverage, per viewing magnification range, for each group. We have developed a virtual microscope to collect this data, and this interface allows for interactive navigation of the virtual slide (including panning and zooming), as well as annotation of reportable findings. Furthermore, all interactions with the interface are time stamped, which allows us to recreate the cytologists' search strategy.

  9. The Effect of Sliding Speed on Film Thickness and Pressure Supporting Ability of a Point Contact Under Zero Entrainment Velocity Conditions

    NASA Technical Reports Server (NTRS)

    Thompson, Peter M.; Jones, William R., Jr.; Jansen, Mark J.; Prahl, Joseph M.

    2000-01-01

    A unique tribometer is used to study film forming and pressure supporting abilities of point contacts at zero entrainment velocity (ZEV). Film thickness is determined using a capacitance technique, verified through comparisons of experimental results and theoretical elastohydrodynamic lubrication (EHL) predictions for rolling contacts. Experiments are conducted using through hardened AISI 52 100 steel balls, Polyalphaolefin (PAO) 182 and Pentaerythritol Tetraheptanoate (PT) lubricants, and sliding speeds between 2.0 to 12.0 m/s. PAO 182 and PT are found to support pressures up to 1. 1 GPa and 0.67 GPa respectively. Protective lubricant films ranging in thickness between 90 to 2 10 nm for PAO 182 and 220 to 340 nm for PT are formed. Lubricants experience shear stresses between 14 to 22 MPa for PAO 182 and 7 to 16 MPa for PT at shear rates of 10(exp 7)/sec. The lubricant's pressure supporting ability most likely results from the combination of immobile films and its transition to a glassy solid at high pressures.

  10. Spatial distribution of thermodynamic conditions of severe storms in southwestern Europe

    NASA Astrophysics Data System (ADS)

    Gascón, E.; Merino, A.; Sánchez, J. L.; Fernández-González, S.; García-Ortega, E.; López, L.; Hermida, L.

    2015-10-01

    The Mid-Ebro Valley (MEV) is an area of the northeast Iberian Peninsula with a large number of hailstorms throughout the year. Therefore, new forecasting tools are required to improve the spatiotemporal detection of such storms. Using a database of 100 days with severe storms (SSs) over a 13-year period between 2001 and 2013, we obtained vertical profiles predicted by the WRF mesoscale model. A total of 31 indexes describing conditions of humidity, stability, helicity or precipitable water were obtained from the profiles and input to a binary logistic regression model. The regression model was applied using the forward stepwise method, which indicated that the stability indexes were the most accurate for SS in the study area. Of the 31 indexes, 5 were selected: Showalter index (SI), wind speed at 500 hPa (SPD500), dew point temperature at 850 hPa (Td850), relative helicity between 0 and 3 km (SREH3km), and wet bulb zero height (WBZ). Combination of these indexes in a logistic equation gives the probability of SS risk/no risk in the study area. Results of the logistic equation show a Probability of Detection (POD) of 0.94 and a False Alarm Ratio (FAR) of 0.22. The second part of the article describes regionalization of the study area by SS spatial distribution according to the logistic equation. Thus, using multivariate techniques, we used principal component analysis (PCA) in T-mode and posterior cluster analysis, getting four clusters according to the spatial distribution of SS thermodynamic behavior and the distribution of storms observed via radar data. Clusters 1 and 2 showed probabilities of hail occurrence that were lower than Clusters 3 and 4, mainly affecting the MEV and the eastern end of the study area. Likewise, the predicted hail area was more extensive in those last two clusters. These results provide a new tool that complements those previously developed for this study area, toward improving SS prediction and pinpointing these storms in space and in

  11. Cross-polarization microwave radar return at severe wind conditions: laboratory model and geophysical model function.

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Abramov, Victor; Ermoshkin, Alexey; Zuikova, Emma; Kazakov, Vassily; Sergeev, Daniil; Kandaurov, Alexandr

    2014-05-01

    Satellite remote sensing is one of the main techniques of monitoring severe weather conditions over the ocean. The principal difficulty of the existing algorithms of retrieving wind based on dependence of microwave backscattering cross-section on wind speed (Geophysical Model Function, GMF) is due to its saturation at winds exceeding 25 - 30 m/s. Recently analysis of dual- and quad-polarization C-band radar return measured from satellite Radarsat-2 suggested that the cross-polarized radar return has much higher sensitivity to the wind speed than co-polarized back scattering [1] and conserved sensitivity to wind speed at hurricane conditions [2]. Since complete collocation of these data was not possible and time difference in flight legs and SAR images acquisition was up to 3 hours, these two sets of data were compared in [2] only statistically. The main purpose of this paper is investigation of the functional dependence of cross-polarized radar cross-section on the wind speed in laboratory experiment. Since cross-polarized radar return is formed due to scattering at small-scale structures of the air-sea interface (short-crested waves, foam, sprays, etc), which are well reproduced in laboratory conditions, then the approach based on laboratory experiment on radar scattering of microwaves at the water surface under hurricane wind looks feasible. The experiments were performed in the Wind-wave flume located on top of the Large Thermostratified Tank of the Institute of Applied Physics, where the airflow was produced in the flume with the straight working part of 10 m and operating cross section 0.40?0.40 sq. m, the axis velocity can be varied from 5 to 25 m/s. Microwave measurements were carried out by a coherent Doppler X-band (3.2 cm) scatterometer with the consequent receive of linear polarizations. Experiments confirmed higher sensitivity to the wind speed of the cross-polarized radar return. Simultaneously parameters of the air flow in the turbulent boundary layer

  12. Discriminative evaluative conditioning in the long-term after severe accidental injury.

    PubMed

    Oe, Misari; Schumacher, Sonja; Schnyder, Ulrich; Mueller-Pfeiffer, Christoph; Wilhelm, Frank H; Kuelen, Eveline; Martin-Soelch, Chantal

    2016-06-30

    Impairments in classical fear conditioning and deficits in discriminative learning are observed in posttraumatic stress disorder (PTSD). However, it is unknown whether similar impairments can be found with types of discriminative learning other than classical conditioning, such as evaluative conditioning (EC), in which the valence of a stimulus can be transferred to other stimuli. In this study, we investigated whether EC is also influenced by traumatic experiences independently of presence of PTSD. We tested 14 accident survivors with remitted PTSD, 14 survivors without PTSD, and 16 non-trauma controls. We used behavioral measures, psychophysiological indicators, and subjective ratings for tasks. General effects of learning were observed across groups and conditioning/extinction. Trauma controls had slower reaction times (RTs) to the aversive conditioned stimulus compared to appetitive conditioned and neutral stimuli, as well as slower RTs and increased accuracy during conditioning than during extinction. Remitted PTSD participants showed opposite results, demonstrating decreased accuracy and slower RTs during conditioning as compared to during extinction. No discriminative effect was found in the non-trauma controls and the remitted PTSD participants. These results suggest that a traumatic experience influences EC, and that this influence differs between individuals who have and have not developed PTSD after traumatic exposure. PMID:27107667

  13. Discriminative evaluative conditioning in the long-term after severe accidental injury.

    PubMed

    Oe, Misari; Schumacher, Sonja; Schnyder, Ulrich; Mueller-Pfeiffer, Christoph; Wilhelm, Frank H; Kuelen, Eveline; Martin-Soelch, Chantal

    2016-06-30

    Impairments in classical fear conditioning and deficits in discriminative learning are observed in posttraumatic stress disorder (PTSD). However, it is unknown whether similar impairments can be found with types of discriminative learning other than classical conditioning, such as evaluative conditioning (EC), in which the valence of a stimulus can be transferred to other stimuli. In this study, we investigated whether EC is also influenced by traumatic experiences independently of presence of PTSD. We tested 14 accident survivors with remitted PTSD, 14 survivors without PTSD, and 16 non-trauma controls. We used behavioral measures, psychophysiological indicators, and subjective ratings for tasks. General effects of learning were observed across groups and conditioning/extinction. Trauma controls had slower reaction times (RTs) to the aversive conditioned stimulus compared to appetitive conditioned and neutral stimuli, as well as slower RTs and increased accuracy during conditioning than during extinction. Remitted PTSD participants showed opposite results, demonstrating decreased accuracy and slower RTs during conditioning as compared to during extinction. No discriminative effect was found in the non-trauma controls and the remitted PTSD participants. These results suggest that a traumatic experience influences EC, and that this influence differs between individuals who have and have not developed PTSD after traumatic exposure.

  14. Laboratory modeling of air-sea interaction under severe wind conditions

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Vasiliy, Kazakov; Nicolay, Bogatov; Olga, Ermakova; Mikhail, Salin; Daniil, Sergeev; Maxim, Vdovin

    2010-05-01

    velocity profile was measured by WindSonic ultrasonic wind sensor. The water elevation was measured by the three-channel wave-gauge. Top and side views of the water surface were fixed by CCD-camera. Wind friction velocity and surface drag coefficients were retrieved from the measurements by the profile method. Obtained values are in good agreement with the data of measurements by Donelan et al (2004). The directional frequency-wave-number spectra of surface waves were retrieved by the wavelet directional method (Donelan et al, 1996). The obtained dependencies of parameters of the wind waves indicate existing of two regimes of the waves with the critical wind speed Ucr about 30 m/s. For U10Ucr the dependencies of peak wave period, peak wavelength, significant wave height on the wind speed tend to saturation, in the same time the peak wave slope has the maximum at approximately Ucr and then decreases with the tendency to saturation. The surface drag also tends to saturation for U10>Ucr similarly to (Donelan et al, 2004). Video filming indicates onset of wave breaking with white-capping and spray generation at wind speeds approximately equal to Ucr. We compared the obtained experimental dependencies with the predictions of the quasi-linear model of the turbulent boundary layer over the waved water surface (Reutov&Troitskaya, 1995). Comparing shows that theoretical predictions give low estimates for the measured drag coefficient and wave fields. Taking into account momentum flux associated with the spray generation yields theoretical estimations in good agreement with the experimental data. Basing on the experimental data a possible physical mechanism of the drag is suggested. Tearing of the wave crests at severe wind conditions leads to the effective smoothing (decreasing wave

  15. Shipping container response to severe highway and railway accident conditions: Appendices

    SciTech Connect

    Fischer, L.E.; Chou, C.K.; Gerhard, M.A.; Kimura, C.Y.; Martin, R.W.; Mensing, R.W.; Mount, M.E.; Witte, M.C.

    1987-02-01

    Volume 2 contains the following appendices: Severe accident data; truck accident data; railroad accident data; highway survey data and bridge column properties; structural analysis; thermal analysis; probability estimation techniques; and benchmarking for computer codes used in impact analysis. (LN)

  16. Influence of normal loads and sliding velocities on friction properties of engineering plastics sliding against rough counterfaces

    NASA Astrophysics Data System (ADS)

    Nuruzzaman, D. M.; Chowdhury, M. A.; Rahaman, M. L.; Oumer, A. N.

    2016-02-01

    Friction properties of plastic materials are very important under dry sliding contact conditions for bearing applications. In the present research, friction properties of engineering plastics such as polytetrafluoroethylene (PTFE) and nylon are investigated under dry sliding contact conditions. In the experiments, PTFE and nylon slide against different rough counterfaces such as mild steel and stainless steel 316 (SS 316). Frictional tests are carried out at low loads 5, 7.5 and 10 N, low sliding velocities 0.5, 0.75 and 1 m/s and relative humidity 70%. The obtained results reveal that friction coefficient of PTFE increases with the increase in normal loads and sliding velocities within the observed range. On the other hand, frictional values of nylon decrease with the increase in normal loads and sliding velocities. It is observed that in general, these polymers show higher frictional values when sliding against SS 316 rather than mild steel. During running-in process, friction coefficient of PTFE and nylon steadily increases with the increase in rubbing time and after certain duration of rubbing, it remains at steady level. At identical operating conditions, the frictional values are significantly different depending on normal load, sliding velocity and material pair. It is also observed that in general, the influence of normal load on the friction properties of PTFE and nylon is greater than that of sliding velocity.

  17. Sliding wear and friction behaviour of zircaloy-4 in water

    NASA Astrophysics Data System (ADS)

    Sharma, Garima; Limaye, P. K.; Jadhav, D. T.

    2009-11-01

    In water cooled nuclear reactors, the sliding of fuel bundles in fuel channel handling system can lead to severe wear and it is an important topic to study. In the present study, sliding wear behaviour of zircaloy-4 was investigated in water (pH ˜ 10.5) using ball-on-plate sliding wear tester. Sliding wear resistance zircaloy-4 against SS 316 was examined at room temperature. Sliding wear tests were carried out at different load and sliding frequencies. The coefficient of friction of zircaloy-4 was also measured during each tests and it was found to decrease slightly with the increase in applied load. The micro-mechanisms responsible for wear in zircaloy-4 were identified to be microcutting, micropitting and microcracking of deformed subsurface zones in water.

  18. An assessment of benthic condition in several small watersheds of the Chesapeake Bay, USA.

    PubMed

    Leight, Andrew K; Slacum, Ward H; Wirth, Ed F; Fulton, Mike H

    2011-05-01

    We examined benthic condition in three small watersheds in the Chesapeake Bay. Characterization of benthic condition was based on the combined measurements of benthic fauna, sediment toxicity, and sediment contaminant loads. Significant differences between watersheds were detected for sediment contaminant concentrations and water quality. The intensity of benthic impairment was greatest in the river surrounded by the most developed watershed. Spatial patterns of benthic condition were detected within all three watersheds. In contrast to current, intense focus on nutrient pollution in the Chesapeake Bay, qualitative comparison of our findings to land-use patterns supports findings of other studies that suggest benthic condition in tributaries of the Chesapeake Bay may more closely relate to urbanization than agricultural land uses.

  19. Underwater Sliding Properties: Effect of Slider Shape and Surface Wettability

    NASA Astrophysics Data System (ADS)

    Kirveslahti, A.; Mielonen, K.; Ikonen, K.; Cui, W.; Suvanto, M.; Pakkanen, T. A.

    2016-04-01

    A dynamic test method for the measurement of the underwater sliding properties of model boats has been developed. Surface-modified model boats were examined to assess how the surface wettability properties affect sliding. Along with the surface properties, the influence of the boat shape was considered. We studied various coatings in the contact angle range of 3-162∘ with two model boat shapes. The hydrophobicity of the surfaces influenced the sliding speed of the model boat depending on the boat shape. The method is applicable to study sliding properties of model boats with different surfaces in variable flow conditions.

  20. The Parent's Manual: A Manual of Supplementary Activities for Homebound Children with Severely Handicapping Conditions.

    ERIC Educational Resources Information Center

    Shrensky, Joan; And Others

    Designed for parents of homebound severely handicapped children, the manual presents games and activities for teaching preliminary skills (including body awareness), self help skills (such as washing hands, eating with a spoon, and brushing teeth), visual skills, language skills, and mathmatics skills. An introduction to each series of activities…

  1. Dry Sliding Wear Characteristics of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Alloy at Various Sliding Speeds

    NASA Astrophysics Data System (ADS)

    Li, X. X.; Zhou, Y.; Li, Y. X.; Ji, X. L.; Wang, S. Q.

    2015-09-01

    Dry sliding wear behavior of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si (hereafter called TC11) alloy was investigated under various sliding speeds and distances. TC11 alloy presented marked variations of the wear rate with an increase of sliding speed from 0.5 to 4 m/s. Especially at high loads, a severe-to-mild wear transition occurred with the climax at 2.68 m/s, the lower values were at 0.5 to 1.5 m/s, and the lowest point was at 4 m/s. TC11 alloy also presented a mild-to-severe wear transition at 2.68 m/s with an increase of sliding distance, but not at the others. With a thorough examination for worn surfaces, subsurfaces and wear debris, the distinct characteristics were noticed to correspond to the wear behavior in various conditions. The highest wear rate at 2.68 m/s and the lowest wear rate at 4 m/s, respectively, corresponded to no oxides and large wear debris particles as well as more oxides and small wear debris particles. The tribo-oxides formed at room temperature were suggested to be protective, which seemed to be contradictory to the popular view that tribo-oxides of titanium alloys possess no wear-reducing effect.

  2. EVALUATION OF SEVERAL ASSESSMENT METHODS AS INDICATORS OF ESTUARINE ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

    Researchers from U.S. EPA's Gulf Ecology Division have conducted a multi-year evaluation of the environmental condition of near-coastal areas affected by different types of stressors. Areas of study have included coastal rivers, transportation canals, residential canals and estua...

  3. The severe hailstorm in Germany on 28 July 2013: Characteristics and meteorological conditions

    NASA Astrophysics Data System (ADS)

    Kunz, Michael; Blahak, Ulrich; Handwerker, Jan; Schmidberger, Manuel; Mohr, Susanna; Jürgen Punge, Heinz; Fluck, Elody; Mühr, Bernhard

    2015-04-01

    At the end of July 2013, a series of violent thunderstorms with large hail, severe gusts and heavy rain affected several parts of Germany. These storms were triggered by pre-frontal convergence zones that formed within unstable air masses ahead of a low pressure system named Andreas. They marked the end of a short, but intense heat wave with temperatures up to 38°C. On 28 July, two supercell thunderstorms formed in the Rhine valley upstream of the Black Forest Mountains and moved almost parallel over the Swabian Jura and Bavaria. While the northern cell was weaker, the southern cell substantially intensified in the first hours and created hailstones with diameters of up to 8 cm. The hail fell mainly over a heavily populated region between the cities of Reutlingen and Tübingen with a high concentration of exposed assets. The track of that supercell ended in the north of Czech Republic and had a length of 500 km. Approximately 80,000 buildings were severely damaged by this major hailstorm. In total, insured loss was estimated to amount around 2 bn EURO, which is even higher than that related to the June flood in Germany in the same year. In this paper we investigate the temporal evolution and the characteristics of the most damaging supercell on 28 July by combining different data from remote sensing instruments such as radar, satellite, and lightning detection systems with ground-based observations and reports from eye-witnesses and a crop insurance company. Additional simulations with the Consortium for Small Scale Modelling COSMO-DE model with different setups reveal the important role of the cold pool for the triggering of the most severe hail cell. It will be shown that a major problem for simulating the storm was its initiation, while, once triggered artificially by 'warm bubbles', its track could be simulated rather well over several hours. Moreover, the operational COSMO version has some problems to simulate the observed reflectivity structure of the

  4. Slowing the Summer Slide

    ERIC Educational Resources Information Center

    Smith, Lorna

    2012-01-01

    Research shows that summer slide--the loss of learning over the summer break--is a huge contributor to the achievement gap between low-income students and their higher-income peers. In fact, some researchers have concluded that two-thirds of the 9th-grade reading achievement gap can be explained by unequal access to summer learning opportunities…

  5. Reversing the Slide

    ERIC Educational Resources Information Center

    Gallagher, Michael

    2005-01-01

    The Government is embarking on a grand market-based vision for the sector just at the moment when university enrolments will begin a long and perhaps inexorable slide. And according to Michael Gallagher, higher education is becoming a less attractive investment for the private sector even as the Government is pushing the sector towards ever higher…

  6. A data-driven feature extraction framework for predicting the severity of condition of congestive heart failure patients.

    PubMed

    Sideris, Costas; Alshurafa, Nabil; Pourhomayoun, Mohammad; Shahmohammadi, Farhad; Samy, Lauren; Sarrafzadeh, Majid

    2015-01-01

    In this paper, we propose a novel methodology for utilizing disease diagnostic information to predict severity of condition for Congestive Heart Failure (CHF) patients. Our methodology relies on a novel, clustering-based, feature extraction framework using disease diagnostic information. To reduce the dimensionality we identify disease clusters using cooccurence frequencies. We then utilize these clusters as features to predict patient severity of condition. We build our clustering and feature extraction algorithm using the 2012 National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP) which contains 7 million discharge records and ICD-9-CM codes. The proposed framework is tested on Ronald Reagan UCLA Medical Center Electronic Health Records (EHR) from 3041 patients. We compare our cluster-based feature set with another that incorporates the Charlson comorbidity score as a feature and demonstrate an accuracy improvement of up to 14% in the predictability of the severity of condition. PMID:26736808

  7. Dynamic Sliding Analysis of a Gravity Dam with Fluid-Structure-Foundation Interaction Using Finite Elements and Newmark's Sliding Block Analysis

    NASA Astrophysics Data System (ADS)

    Goldgruber, Markus; Shahriari, Shervin; Zenz, Gerald

    2015-11-01

    To reduce the natural hazard risks—due to, e.g., earthquake excitation—seismic safety assessments are carried out. Especially under severe loading, due to maximum credible or the so-called safety evaluation earthquake, critical infrastructure, as these are high dams, must not fail. However, under high loading local failure might be allowed as long as the entire structure does not collapse. Hence, for a dam, the loss of sliding stability during a short time period might be acceptable if the cumulative displacements after an event are below an acceptable value. This performance is not only valid for gravity dams but also for rock blocks as sliding is even more imminent in zones with higher seismic activity. Sliding modes cannot only occur in the dam-foundation contact, but also in sliding planes formed due to geological conditions. This work compares the qualitative possible and critical displacements for two methods, the well-known Newmark's sliding block analysis and a Fluid-Foundation-Structure Interaction simulation with the finite elements method. The results comparison of the maximum displacements at the end of the seismic event of the two methods depicts that for high friction angles, they are fairly close. For low friction angles, the results are differing more. The conclusion is that the commonly used Newmark's sliding block analysis and the finite elements simulation are only comparable for high friction angles, where this factor dominates the behaviour of the structure. Worth to mention is that the proposed simulation methods are also applicable to dynamic rock wedge problems and not only to dams.

  8. Severe PPR infection in gazelles kept under semi-free range conditions.

    PubMed

    Elzein, E M E Abu; Housawi, F M T; Bashareek, Y; Gameel, A A; Al-Afaleq, A I; Anderson, E

    2004-03-01

    By the end of March 2002, a collection of some 200 gazelles, kept under semi range conditions in Saudi Arabia, was hit by a highly fatal peracute disease. The morbidity rate was 51% while the case mortality rate was 100%. Clinico-pathological and virological investigations were carried out. A virus was isolated from the ailing gazelles which was identified as Peste des Petits Ruminants virus (PPRV). Epidemiology of the disease in the Arabian peninsula is discussed. PMID:15030603

  9. Railgun rail gouging by hypervelocity sliding contact

    SciTech Connect

    Barker, L.M.; Trucano, T.G. ); Susoeff, A.R. )

    1989-01-01

    A description is given of a recently resolved mechanisms of gouging which occurs during hypervelocity sliding contact between two materials. A parameter study based on computer modeling of the gouging mechanism is presented in which gouging velocity thresholds are determined for several combinations of sliding materials. Materials which can gouge each other are found to do so only within a certain range of velocities. Related calculations of gaseous material ahead of railgun projectiles are also presented. Gun bore gouging experience with the Lawrence Livermore National Laboratory railgun project is reviewed.

  10. Railgun rail gouging by hypervelocity sliding contact

    SciTech Connect

    Barker, L.M.; Trucano, T.G.; Susoeff, A.R.

    1988-01-01

    A description is given of a recently resolved mechanism of gouging which occurs during hypervelocity sliding contact between two materials. A parameter study based on computer modelling of the gouging mechanism is presented in which gouging velocity thresholds are determined for several combinations of sliding materials. Materials which can gouge each other are found to do so only within a certain range of velocities. Related calculations of gaseous material ahead of railgun projectiles are also presented. Gun bore gouging experience with the Lawrence Livermore National Laboratory railgun project is reviewed.

  11. Floral resource limitation severely reduces butterfly survival, condition and flight activity in simplified agricultural landscapes.

    PubMed

    Lebeau, Julie; Wesselingh, Renate A; Van Dyck, Hans

    2016-02-01

    Agricultural intensification has a strong negative impact on farmland biodiversity (including flower-visiting insects), but understanding the mechanisms involved in this requires experimental work. We document the impact of nectar limitation on the performance of a flower-visiting insect, the meadow brown butterfly Maniola jurtina. We conducted two types of experiments: a field experiment in agricultural landscapes with grasslands of different management intensity and an experiment in outdoor flight cages in which the nectar supply was simulated. For the field experiment, we introduced an array of nectar resources in intensively managed, nectar-poor meadows and in extensively managed, flower-rich grasslands and counted flower visitors. Despite higher butterfly abundance in the extensive meadows, our introduced nectar sources were more frequently visited in intensive meadows, indicating the lack of floral resources. The 48-h confinement under nectar-poor conditions in the flight cages had a strong negative effect on body condition, flight activity and lifetime survival compared to butterflies under nectar-rich conditions. Female lifespan was reduced by 22% and male lifespan even by 43%. Agricultural landscapes that provide limited amounts of floral nectar, and no high-quality, preferred nectar sources relative to the needs of the flower-visiting species, may create ecological sinks. Regards an insect's performance, the simple presence of nectar is not necessarily functionally adequate. The effectiveness of agri-environmental schemes for flower-visiting insects (e.g. flower strips) could be improved based on ecological and evolutionary insights on the effects of specific nectar quantities and qualities.

  12. CFD Analysis of Mixing Characteristics of Several Fuel Injectors at Hypervelocity Flow Conditions

    NASA Technical Reports Server (NTRS)

    Drozda, Tomasz G.; Drummond, J. Philip; Baurle, Robert A.

    2016-01-01

    CFD analysis is presented of the mixing characteristics and performance of three fuel injectors at hypervelocity flow conditions. The calculations were carried out using the VULCAN-CFD solver and Reynolds-Averaged Simulations (RAS). The high Mach number flow conditions match those proposed for the planned experiments conducted as a part of the Enhanced Injection and Mixing Project (EIMP) at the NASA Langley Research Center. The EIMP aims to investigate scramjet fuel injection and mixing physics, improve the understanding of underlying physical processes, and develop enhancement strategies and functional relationships relevant to flight Mach numbers greater than eight. Because of the high Mach number flow considered, the injectors consist of a fuel placement device, a strut; and a fluidic vortical mixer, a ramp. These devices accomplish the necessary task of distributing and mixing fuel into the supersonic cross-flow albeit via different strategies. Both of these devices were previously studied at lower flight Mach numbers where they exhibited promising performance in terms of mixing efficiency and total pressure recovery. For comparison, a flush-wall injector is also included. This type of injector generally represents the simplest method of introducing fuel into a scramjet combustor, however, at high flight Mach number conditions, the dynamic pressure needed to induce sufficient fuel penetration may be difficult to achieve along with other requirements such as achieving desired levels of fuel-to-air mixing at the required equivalence ratio. The three injectors represent the baseline configurations planned for the experiments. The current work discusses the mixing flow field behavior and differences among the three fuel injectors, mixing performance as described by the mixing efficiency and the total pressure recovery, and performance considerations based on the thrust potential.

  13. The contribution of woody plant materials on the several conditions in a space environment

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Baba, Keiichi; Suzuki, Toshisada; Kimura, Shunta; Sato, Seigo; Katoh, Hiroshi; Abe, Yusuke; Katayama, Takeshi

    Woody plant materials have several utilization elements in our habitation environment on earth. The studies of woody plants under a space-environment in the vegetable kingdom have a high contribution to the study of various and exotic environmental responses, too. Woody plants can produce an excess oxygen, woody materials for the living cabin, and provide a biomass by cultivating crops and other species of creatures. Tree material would become to be a tool in closed bio-ecosystems such as an environment in a space. We named the trees used as material for the experiment related to space environments “CosmoBon”, small tree bonsai. Japanese cherry tree, “Sakura”, is famous and lovely tree in Japan. One species of “Sakura”, “Mamezakura, Prunus incisa”, is not only lovely tree species, but also suitable tree for the model tree of our purpose. The species of Prunus incisa is originally grown in volcano environment. That species of Sakura is originally grown on Mt. Fuji aria, oligotrophic place. We will try to build the best utilization usage of woody plant under the space environment by “Mamezakura” as a model tree. Here, we will show the importance of uniformity of materials when we will use the tree materials in a space environment. We will also discuss that tree has a high possibility of utilization under the space environments by using our several results related to this research.

  14. Metatarsal-slide lengthening without bone grafting.

    PubMed

    Tabak, B; Lefkowitz, H; Steiner, I

    1986-01-01

    Brachymetatarsia is a condition of premature closure of the epiphyseal plate of a metatarsal. The authors present a case of brachymetatarsia of the second metatarsal. Utilizing a review of the literature, various surgical procedures are discussed. Treatment in this case consisted of a metatarsal-slide lengthening osteotomy, a modification of the Giannestras step-down procedure. PMID:3950333

  15. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions

    SciTech Connect

    Heames, T.J. ); Williams, D.A.; Johns, N.A.; Chown, N.M. ); Bixler, N.E.; Grimley, A.J. ); Wheatley, C.J. )

    1990-10-01

    This document provides a description of a model of the radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident. This document serves as the user's manual for the computer code called VICTORIA, based upon the model. The VICTORIA code predicts fission product release from the fuel, chemical reactions between fission products and structural materials, vapor and aerosol behavior, and fission product decay heating. This document provides a detailed description of each part of the implementation of the model into VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided. The VICTORIA code was developed upon a CRAY-XMP at Sandia National Laboratories in the USA and a CRAY-2 and various SUN workstations at the Winfrith Technology Centre in England. 60 refs.

  16. The emergence of separation protest is robust under conditions of severe developmental stress in rural Bangladesh.

    PubMed

    Super, Charles M; Guldan, Georgia S; Ahmed, Nasar; Zeitlin, Marian

    2012-06-01

    The response of 185 infants to their mothers' departure was assessed in a rural area of Bangladesh. Despite their poor health and nutritional status, this group of infants showed the same peak in separation protest around the end of the first year that has been documented for healthier samples in several cultural contexts; correlational analysis suggests that the healthier infants were more likely to display protest. In addition, there was an earlier rise and decline in distress at maternal departure in the first half year of life, not seen in other reports. In this case, poor health appeared to dispose toward upset, indicating that the most fragile infants were least able to cope with the regulatory demands imposed by maternal departure. Overall, the results are evidence for a very strongly canalized transformation of cognitive and emotional functioning toward the end of the first year of life. PMID:22721739

  17. Effect of Maize Hybrid and Foliar Fungicides on Yield Under Low Foliar Disease Severity Conditions.

    PubMed

    Mallowa, Sally O; Esker, Paul D; Paul, Pierce A; Bradley, Carl A; Chapara, Venkata R; Conley, Shawn P; Robertson, Alison E

    2015-08-01

    Foliar fungicide use in the U.S. Corn Belt increased in the last decade; however, questions persist pertaining to its value and sustainability. Multistate field trials were established from 2010 to 2012 in Illinois, Iowa, Ohio, and Wisconsin to examine how hybrid and foliar fungicide influenced disease intensity and yield. The experimental design was in a split-split plot with main plots consisting of hybrids varying in resistance to gray leaf spot (caused by Cercospora zeae-maydis) and northern corn leaf blight (caused by Setosphaera turcica), subplots corresponding to four application timings of the fungicide pyraclostrobin, and sub-subplots represented by inoculations with either C. zeae-maydis, S. turcica, or both at two vegetative growth stages. Fungicide application (VT/R1) significantly reduced total disease severity relative to the control in five of eight site-years (P<0.05). Disease was reduced by approximately 30% at Wisconsin in 2011, 20% at Illinois in 2010, 29% at Iowa in 2010, and 32 and 30% at Ohio in 2010 and 2012, respectively. These disease severities ranged from 0.2 to 0.3% in Wisconsin in 2011 to 16.7 to 22.1% in Illinois in 2010. The untreated control had significantly lower yield (P<0.05) than the fungicide-treated in three site-years. Fungicide application increased the yield by approximately 6% at Ohio in 2010, 5% at Wisconsin in 2010 and 6% in 2011. Yield differences ranged from 8,403 to 8,890 kg/ha in Wisconsin 2011 to 11,362 to 11,919 kg/ha in Wisconsin 2010. Results suggest susceptibility to disease and prevailing environment are important drivers of observed differences. Yield increases as a result of the physiological benefits of plant health benefits under low disease were not consistent. PMID:25760523

  18. Effect of Maize Hybrid and Foliar Fungicides on Yield Under Low Foliar Disease Severity Conditions.

    PubMed

    Mallowa, Sally O; Esker, Paul D; Paul, Pierce A; Bradley, Carl A; Chapara, Venkata R; Conley, Shawn P; Robertson, Alison E

    2015-08-01

    Foliar fungicide use in the U.S. Corn Belt increased in the last decade; however, questions persist pertaining to its value and sustainability. Multistate field trials were established from 2010 to 2012 in Illinois, Iowa, Ohio, and Wisconsin to examine how hybrid and foliar fungicide influenced disease intensity and yield. The experimental design was in a split-split plot with main plots consisting of hybrids varying in resistance to gray leaf spot (caused by Cercospora zeae-maydis) and northern corn leaf blight (caused by Setosphaera turcica), subplots corresponding to four application timings of the fungicide pyraclostrobin, and sub-subplots represented by inoculations with either C. zeae-maydis, S. turcica, or both at two vegetative growth stages. Fungicide application (VT/R1) significantly reduced total disease severity relative to the control in five of eight site-years (P<0.05). Disease was reduced by approximately 30% at Wisconsin in 2011, 20% at Illinois in 2010, 29% at Iowa in 2010, and 32 and 30% at Ohio in 2010 and 2012, respectively. These disease severities ranged from 0.2 to 0.3% in Wisconsin in 2011 to 16.7 to 22.1% in Illinois in 2010. The untreated control had significantly lower yield (P<0.05) than the fungicide-treated in three site-years. Fungicide application increased the yield by approximately 6% at Ohio in 2010, 5% at Wisconsin in 2010 and 6% in 2011. Yield differences ranged from 8,403 to 8,890 kg/ha in Wisconsin 2011 to 11,362 to 11,919 kg/ha in Wisconsin 2010. Results suggest susceptibility to disease and prevailing environment are important drivers of observed differences. Yield increases as a result of the physiological benefits of plant health benefits under low disease were not consistent.

  19. Bioactivity of Several Herbicides on the Nanogram Level Under Different Soil Moisture Conditions.

    PubMed

    Jung, S C; Kuk, Y I; Senseman, S A; Ahn, H G; Seong, C N; Lee, D J

    2015-01-01

    In this study, a double-tube centrifuge method was employed to determine the effects of soil moisture on the bioactivity of cafenstrole, pretilachlor, benfuresate, oxyfluorfen and simetryn. In general, the available herbicide concentration in soil solution (ACSS) showed little change as soil moisture increased for herbicides. The total available herbicide in soil solution (TASS) typically increased as soil moisture increased for all herbicides. The relationship between TASS and % growth rate based on dry weight showed strong linear relationships for both cafenstrole and pretilachlor, with r2 values of 0.95 and 0.84, respectively. Increasing TASS values were consistent with increasing herbicide water solubility, with the exception of the ionizable herbicide simetryn. Plant absorption and % growth rate exhibited a strong linear relationship with TASS. According to the results suggested that TASS was a better predictor of herbicidal bioactivity than ACSS for all herbicides under unsaturated soil moisture conditions. PMID:26328425

  20. Bioactivity of Several Herbicides on the Nanogram Level Under Different Soil Moisture Conditions.

    PubMed

    Jung, S C; Kuk, Y I; Senseman, S A; Ahn, H G; Seong, C N; Lee, D J

    2015-01-01

    In this study, a double-tube centrifuge method was employed to determine the effects of soil moisture on the bioactivity of cafenstrole, pretilachlor, benfuresate, oxyfluorfen and simetryn. In general, the available herbicide concentration in soil solution (ACSS) showed little change as soil moisture increased for herbicides. The total available herbicide in soil solution (TASS) typically increased as soil moisture increased for all herbicides. The relationship between TASS and % growth rate based on dry weight showed strong linear relationships for both cafenstrole and pretilachlor, with r2 values of 0.95 and 0.84, respectively. Increasing TASS values were consistent with increasing herbicide water solubility, with the exception of the ionizable herbicide simetryn. Plant absorption and % growth rate exhibited a strong linear relationship with TASS. According to the results suggested that TASS was a better predictor of herbicidal bioactivity than ACSS for all herbicides under unsaturated soil moisture conditions.

  1. Severe fludarabine neurotoxicity after reduced intensity conditioning regimen to allogeneic hematopoietic stem cell transplantation: a case report

    PubMed Central

    Annaloro, Claudio; Costa, Antonella; Fracchiolla, Nicola S; Mometto, Gabriella; Artuso, Silvia; Saporiti, Giorgia; Tagliaferri, Elena; Grifoni, Federica; Onida, Francesco; Cortelezzi, Agostino

    2015-01-01

    Key Clinical Message We present a case of severe, irreversible neurotoxicity in a 55-year-old-patient with myelofibrosis undergoing hematopoietic stem cell transplantation following a reduced intensity conditioning including fludarabine. The patient developed progressive sensory-motor, visual and consciousness disturbances, eventually leading to death. MRI imaging pattern was unique and attributable to fludarabine neurotoxicity. PMID:26273463

  2. Slide system for machine tools

    DOEpatents

    Douglass, Spivey S.; Green, Walter L.

    1982-01-01

    The present invention relates to a machine tool which permits the machining of nonaxisymmetric surfaces on a workpiece while rotating the workpiece about a central axis of rotation. The machine tool comprises a conventional two-slide system (X-Y) with one of these slides being provided with a relatively short travel high-speed auxiliary slide which carries the material-removing tool. The auxiliary slide is synchronized with the spindle speed and the position of the other two slides and provides a high-speed reciprocating motion required for the displacement of the cutting tool for generating a nonaxisymmetric surface at a selected location on the workpiece.

  3. Slide system for machine tools

    DOEpatents

    Douglass, S.S.; Green, W.L.

    1980-06-12

    The present invention relates to a machine tool which permits the machining of nonaxisymmetric surfaces on a workpiece while rotating the workpiece about a central axis of rotation. The machine tool comprises a conventional two-slide system (X-Y) with one of these slides being provided with a relatively short travel high-speed auxiliary slide which carries the material-removing tool. The auxiliary slide is synchronized with the spindle speed and the position of the other two slides and provides a high-speed reciprocating motion required for the displacement of the cutting tool for generating a nonaxisymmetric surface at a selected location on the workpiece.

  4. Numerical Modelling of Tsunami Generated by Deformable Submarine Slides: Parameterisation of Slide Dynamics for Coupling to Tsunami Propagation Model

    NASA Astrophysics Data System (ADS)

    Smith, R. C.; Collins, G. S.; Hill, J.; Piggott, M. D.; Mouradian, S. L.

    2015-12-01

    Numerical modelling informs risk assessment of tsunami generated by submarine slides; however, for large-scale slides modelling can be complex and computationally challenging. Many previous numerical studies have approximated slides as rigid blocks that moved according to prescribed motion. However, wave characteristics are strongly dependent on the motion of the slide and previous work has recommended that more accurate representation of slide dynamics is needed. We have used the finite-element, adaptive-mesh CFD model Fluidity, to perform multi-material simulations of deformable submarine slide-generated waves at real world scales for a 2D scenario in the Gulf of Mexico. Our high-resolution approach represents slide dynamics with good accuracy, compared to other numerical simulations of this scenario, but precludes tracking of wave propagation over large distances. To enable efficient modelling of further propagation of the waves, we investigate an approach to extract information about the slide evolution from our multi-material simulations in order to drive a single-layer wave propagation model, also using Fluidity, which is much less computationally expensive. The extracted submarine slide geometry and position as a function of time are parameterised using simple polynomial functions. The polynomial functions are used to inform a prescribed velocity boundary condition in a single-layer simulation, mimicking the effect the submarine slide motion has on the water column. The approach is verified by successful comparison of wave generation in the single-layer model with that recorded in the multi-material, multi-layer simulations. We then extend this approach to 3D for further validation of this methodology (using the Gulf of Mexico scenario proposed by Horrillo et al., 2013) and to consider the effect of lateral spreading. This methodology is then used to simulate a series of hypothetical submarine slide events in the Arctic Ocean (based on evidence of historic

  5. Association of growth, feeding practices and exercise conditions with the severity of the osteoarticular status of limbs in French foals.

    PubMed

    Lepeule, Johanna; Bareille, Nathalie; Robert, Céline; Valette, Jean-Paul; Jacquet, Sandrine; Blanchard, Géraldine; Denoix, Jean-Marie; Seegers, Henri

    2013-07-01

    The aim of this study was to identify the risk factors for the severity of Juvenile OsteoChondral Conditions (JOCC) in limbs of French foals. Twenty-one farms in Normandy, France, were sampled and enrolled in a cohort study including 378 foals from three breeds, followed from the 8th month of pregnancy of the mares until the foals were approximately 6months old. Data on growth, feeding practices and exercise conditions were regularly collected. The carpus, the front and hind digits, the hock and the stifle of the foals were radiographed at the end of follow-up. JOCC severity in each foal was described using a global appraisal of its osteoarticular status (OAS) depending on the number and the severity of radiographic findings. Of the 378 foals, 53% had a good OAS, 34% had an intermediate OAS and 13% had a poor OAS. The breed (Selle Français and French Trotter Standardbred vs. Thoroughbred), a high girth perimeter at early age and an irregular exercise were significantly associated with a poor OAS. This study contributes to the understanding of the development of JOCC. An increased growth and reduced or irregular physical activity during the first weeks of life would be responsible for more severe lesions. Growth and exercise conditions should be carefully monitored to reduce the prevalence of severe JOCC in foals.

  6. The ability of silicide coating to delay the catastrophic oxidation of vanadium under severe conditions

    NASA Astrophysics Data System (ADS)

    Chaia, N.; Mathieu, S.; Rouillard, F.; Vilasi, M.

    2015-02-01

    V-4Cr-4Ti vanadium alloy is a potential cladding material for sodium-cooled fast-neutron reactors (SFRs). However, its affinity for oxygen and the subsequent embrittlement that oxygen induces causes a need for an oxygen diffusion barrier, which can be obtained by manufacturing a multi-layered silicide coating. The present work aims to evaluate the effects of thermal cycling (using a cyclic oxidation device) and tensile and compressive stresses (using the three-point flexure test) on the coated alloy system. Tests were performed in air up to 1100 °C, which is 200 °C higher than the accidental temperature for SFR applications. The results showed that the VSi2 coating was able to protect the vanadium substrate from oxidation for more than 400 1-h cycles between 1100 °C and room temperature. The severe bending applied to the coated alloy at 950 °C using a load of 75 MPa did not lead to specimen breakage. It can be suggested that the VSi2 coating has mechanical properties compatible with the V-4Cr-4Ti alloy for SFR applications.

  7. Nonophthalmic symptoms secondary to ocular torticollis from severe blepharoptosis: an underappreciated but treatable condition.

    PubMed

    Bohnsack, Brenda L; Bhatt, Rina; Kahana, Alon

    2012-01-01

    The purpose of this case report is to describe reversible systemic symptoms associated with ocular torticollis due to blepharoptosis. A retrospective chart review identified patients with symptomatic ocular torticollis due to bilateral congenital or acquired blepharoptosis who underwent surgical correction (levator resection or frontalis sling). Preoperative and postoperative assessment of systemic symptoms in adults and developmental milestones are reported. The authors present 4 cases, 1 adult and 3 young children, all with severe bilateral upper eyelid ptosis. In the adult patient, it caused debilitating back pain that required orthopedic evaluation but was completely relieved with ptosis repair surgery. In the toddlers, subjective developmental motor delay was rapidly reversed following ptosis repair surgery. The authors suggest that primary care physicians, and spine and neuromuscular specialists, consider the possibility of ocular torticollis due to eyelid ptosis in the evaluation of patients with unexplained back and/or neck pain or with gross motor developmental delay. The authors propose that symptomatic ocular torticollis is an indication for ptosis repair.

  8. Nonophthalmic symptoms secondary to ocular torticollis from severe blepharoptosis: an underappreciated but treatable condition.

    PubMed

    Bohnsack, Brenda L; Bhatt, Rina; Kahana, Alon

    2012-01-01

    The purpose of this case report is to describe reversible systemic symptoms associated with ocular torticollis due to blepharoptosis. A retrospective chart review identified patients with symptomatic ocular torticollis due to bilateral congenital or acquired blepharoptosis who underwent surgical correction (levator resection or frontalis sling). Preoperative and postoperative assessment of systemic symptoms in adults and developmental milestones are reported. The authors present 4 cases, 1 adult and 3 young children, all with severe bilateral upper eyelid ptosis. In the adult patient, it caused debilitating back pain that required orthopedic evaluation but was completely relieved with ptosis repair surgery. In the toddlers, subjective developmental motor delay was rapidly reversed following ptosis repair surgery. The authors suggest that primary care physicians, and spine and neuromuscular specialists, consider the possibility of ocular torticollis due to eyelid ptosis in the evaluation of patients with unexplained back and/or neck pain or with gross motor developmental delay. The authors propose that symptomatic ocular torticollis is an indication for ptosis repair. PMID:21562438

  9. Severe loss of suitable climatic conditions for marsupial species in Brazil: challenges and opportunities for conservation.

    PubMed

    Loyola, Rafael D; Lemes, Priscila; Faleiro, Frederico V; Trindade-Filho, Joaquim; Machado, Ricardo B

    2012-01-01

    A wide range of evidences indicate climate change as one the greatest threats to biodiversity in the 21st century. The impacts of these changes, which may have already resulted in several recent species extinction, are species-specific and produce shifts in species phenology, ecological interactions, and geographical distributions. Here we used cutting-edge methods of species distribution models combining thousands of model projections to generate a complete and comprehensive ensemble of forecasts that shows the likely impacts of climate change in the distribution of all 55 marsupial species that occur in Brazil. Consensus projections forecasted range shifts that culminate with high species richness in the southeast of Brazil, both for the current time and for 2050. Most species had a significant range contraction and lost climate space. Turnover rates were relatively high, but vary across the country. We also mapped sites retaining climatic suitability. They can be found in all Brazilian biomes, especially in the pampas region, in the southern part of the Brazilian Atlantic Forest, in the north of the Cerrado and Caatinga, and in the northwest of the Amazon. Our results provide a general overview on the likely effects of global climate change on the distribution of marsupials in the country as well as in the patterns of species richness and turnover found in regional marsupial assemblages.

  10. Severe Loss of Suitable Climatic Conditions for Marsupial Species in Brazil: Challenges and Opportunities for Conservation

    PubMed Central

    Loyola, Rafael D.; Lemes, Priscila; Faleiro, Frederico V.; Trindade-Filho, Joaquim; Machado, Ricardo B.

    2012-01-01

    A wide range of evidences indicate climate change as one the greatest threats to biodiversity in the 21st century. The impacts of these changes, which may have already resulted in several recent species extinction, are species-specific and produce shifts in species phenology, ecological interactions, and geographical distributions. Here we used cutting-edge methods of species distribution models combining thousands of model projections to generate a complete and comprehensive ensemble of forecasts that shows the likely impacts of climate change in the distribution of all 55 marsupial species that occur in Brazil. Consensus projections forecasted range shifts that culminate with high species richness in the southeast of Brazil, both for the current time and for 2050. Most species had a significant range contraction and lost climate space. Turnover rates were relatively high, but vary across the country. We also mapped sites retaining climatic suitability. They can be found in all Brazilian biomes, especially in the pampas region, in the southern part of the Brazilian Atlantic Forest, in the north of the Cerrado and Caatinga, and in the northwest of the Amazon. Our results provide a general overview on the likely effects of global climate change on the distribution of marsupials in the country as well as in the patterns of species richness and turnover found in regional marsupial assemblages. PMID:23029452

  11. Effect of sea sprays on air-sea momentum exchange at severe wind conditions

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yu.; Ezhova, E.; Semenova, A.; Soustova, I.

    2012-04-01

    Wind-wave interaction at extreme wind speed is of special interest now in connection with the problem of explanation of the sea surface drag saturation at the wind speed exceeding 30 m/s. The idea on saturation (and even reduction) of the coefficient of aerodynamic resistance of the sea surface at hurricane wind speed was first suggested in [1] on the basis of theoretical analysis of sensitivity of maximum wind speed in a hurricane to the ratio of the enthalpy and momentum exchange coefficients. Both field [2-4] and laboratory [5] experiments confirmed that at hurricane wind speed the sea surface drag coefficient is significantly reduced in comparison with the parameterization obtained at moderate to strong wind conditions. Two groups of possible theoretical mechanisms for explanation of the effect of the sea surface drag reduction can be specified. In the first group of models developed in [6,7], the sea surface drag reduction is explained by peculiarities of the air flow over breaking waves. Another approach more appropriate for the conditions of developed sea exploits the effect of sea drops and sprays on the wind-wave momentum exchange. Papers[8,9] focused on the effect of the sea drops on stratification of the air-sea boundary layer similar to the model of turbulent boundary layer with the suspended particles [10], while papers [11-13] estimated the momentum exchange of sea drops and air-flow. A mandatory element of the spray induced momentum flux is a parameterization of the momentum exchange between droplets and air flow, which determines the "source function" in the momentum balance equation. In this paper a model describing the motion of a spume droplet, the wind tear away from the crest of a steep surface wave, and then falling into the water. We consider two models for the injection of droplets into the air flow. The first one assumes that the drop starts from the surface at the orbital velocity of the wave. In the second model we consider droplets from

  12. Passivity-based sliding mode control for a polytopic stochastic differential inclusion system.

    PubMed

    Liu, Leipo; Fu, Zhumu; Song, Xiaona

    2013-11-01

    Passivity-based sliding mode control for a polytopic stochastic differential inclusion (PSDI) system is considered. A control law is designed such that the reachability of sliding motion is guaranteed. Moreover, sufficient conditions for mean square asymptotic stability and passivity of sliding mode dynamics are obtained by linear matrix inequalities (LMIs). Finally, two examples are given to illustrate the effectiveness of the proposed method.

  13. Patterns of nocturnal rehydration in root tissues of Vaccinium corymbosum L. under severe drought conditions.

    PubMed

    Valenzuela-Estrada, Luis R; Richards, James H; Diaz, Andres; Eissensat, David M

    2009-01-01

    Although roots in dry soil layers are commonly rehydrated by internal hydraulic redistribution during the nocturnal period, patterns of tissue rehydration are poorly understood. Rates of nocturnal rehydration were examined in roots of different orders in Vaccinium corymbosum L. 'Bluecrop' (Northern highbush blueberry) grown in a split-pot system with one set of roots in relatively moist soil and the other set of roots in dry soil. Vaccinium is noted for a highly branched and extremely fine root system. It is hypothesized that nocturnal root tissue rehydration would be slow, especially in the distal root orders because of their greater hydraulic constraints (smaller vessel diameters and fewer number of vessels). Vaccinium root hydraulic properties delayed internal water movement. Even when water was readily available to roots in the wet soil and transpiration was minimal, it took a whole night-time period of 12 h for the distal finest roots (1st to 4th order) under dry soil conditions to reach the same water potentials as fine roots in moist soil (1st to 4th order). Even though roots under dry soil equilibrated with roots in moist soil, the equilibrium point reached before sunrise was about -1.2 MPa, indicating that tissues were not fully rehydrated. Using a single-branch root model, it was estimated that individual roots exhibiting the lowest water potentials in dry soil were 1st order roots (distal finest roots of the root system). However, considered at the branch level, root orders with the highest hydraulic resistances corresponded to the lowest orders of the permanent root system (3rd-, 4th-, and 5th-order roots), thus indicating possible locations of hydraulic safety control in the root system of this species. PMID:19188275

  14. Reconstitution of flagellar sliding.

    PubMed

    Alper, Joshua; Geyer, Veikko; Mukundan, Vikram; Howard, Jonathon

    2013-01-01

    The motile structure within eukaryotic cilia and flagella is the axoneme. This structure typically consists of nine doublet microtubules arranged around a pair of singlet microtubules. The axoneme contains more than 650 different proteins that have structural, force-generating, and regulatory functions. Early studies on sea urchin sperm identified the force-generating components, the dynein motors. It was shown that dynein can slide adjacent doublet microtubules in the presence of ATP. How this sliding gives rise to the beating of the axoneme is still unknown. Reconstitution assays provide a clean system, free from cellular effects, to elucidate the underlying beating mechanisms. These assays can be used to identify the components that are both necessary and sufficient for the generation of flagellar beating. PMID:23498749

  15. Reconstitution of flagellar sliding.

    PubMed

    Alper, Joshua; Geyer, Veikko; Mukundan, Vikram; Howard, Jonathon

    2013-01-01

    The motile structure within eukaryotic cilia and flagella is the axoneme. This structure typically consists of nine doublet microtubules arranged around a pair of singlet microtubules. The axoneme contains more than 650 different proteins that have structural, force-generating, and regulatory functions. Early studies on sea urchin sperm identified the force-generating components, the dynein motors. It was shown that dynein can slide adjacent doublet microtubules in the presence of ATP. How this sliding gives rise to the beating of the axoneme is still unknown. Reconstitution assays provide a clean system, free from cellular effects, to elucidate the underlying beating mechanisms. These assays can be used to identify the components that are both necessary and sufficient for the generation of flagellar beating.

  16. Behaviorally inhibited temperament is associated with severity of post-traumatic stress disorder symptoms and faster eyeblink conditioning in veterans.

    PubMed

    Myers, Catherine E; Vanmeenen, Kirsten M; McAuley, J Devin; Beck, Kevin D; Pang, Kevin C H; Servatius, Richard J

    2012-01-01

    Prior studies have sometimes demonstrated facilitated acquisition of classically conditioned responses and/or resistance to extinction in post-traumatic stress disorder (PTSD). However, it is unclear whether these behaviors are acquired as a result of PTSD or exposure to trauma, or reflect preexisting risk factors that confer vulnerability for PTSD. Here, we examined classical eyeblink conditioning and extinction in veterans self-assessed for current PTSD symptoms, exposure to combat, and the personality trait of behavioral inhibition (BI), a risk factor for PTSD. A total of 128 veterans were recruited (mean age 51.2 years; 13.3% female); 126 completed self-assessment, with 25.4% reporting a history of exposure to combat and 30.9% reporting current, severe PTSD symptoms (PTSS). The severity of PTSS was correlated with current BI (R(2) = 0.497) and PTSS status could be predicted based on current BI and combat history (80.2% correct classification). A subset of the veterans (n = 87) also completed the eyeblink conditioning study. Among veterans without PTSS, childhood BI was associated with faster acquisition; veterans with PTSS showed delayed extinction, under some conditions. These data demonstrate a relationship between current BI and PTSS, and indicate that the facilitated conditioning sometimes observed in patients with PTSD may partially reflect personality traits such as childhood BI that pre-date and contribute to vulnerability for PTSD.

  17. Microtubule sliding in reactivated flagella.

    PubMed

    Takahashi, K; Shingyoji, C; Kamimura, S

    1982-01-01

    Recent experimental studies of microtubule sliding in demembranated sea urchin sperm flagella are described. A local iontophoretic application of ATP to a Triton-extracted flagellum elicits a local bending response whose form is in exact conformity with the predictions of the sliding microtubule model. Cinematographic analysis of the microtubule sliding initiated by treating fragments of demembranated flagella with trypsin in the presence of ATP reveals that the speed of sliding is almost constant. This implies that the speed does not depend on the number of dynein arms participating in the generation of sliding force. The distribution of apparent sliding velocities indicates that there is no difference in sliding velocity among the doublets. The sliding velocity depends on MgATP concentration in a manner consistent with Michaelis-Menten kinetics. The sliding velocity of doublets in trypsin-treated axonemes is close to the maximum velocity of relative sliding taking place between adjacent doublets in beating flagella reactivated at the same MgATP concentration.

  18. Experimental testing of total knee replacements with UHMW-PE inserts: impact of severe wear test conditions.

    PubMed

    Zietz, Carmen; Reinders, Joern; Schwiesau, Jens; Paulus, Alexander; Kretzer, Jan Philippe; Grupp, Thomas; Utzschneider, Sandra; Bader, Rainer

    2015-03-01

    Aseptic implant loosening due to inflammatory reactions to wear debris is the main reason for the revision of total knee replacements (TKR). Hence, the decrease in polyethylene wear particle generation from the articulating surfaces is aimed at improving implant design and material. For preclinical testing of new TKR systems standardized wear tests are required. However, these wear tests do not reproduce the entire in vivo situation, since the pattern and amount of wear and subsequent implant failure are underestimated. Therefore, daily activity, kinematics, implant aging and position, third-body-wear and surface properties have to be considered to estimate the wear of implant components in vivo. Hence, severe test conditions are in demand for a better reproduction of the in vivo situation of TKR. In the present article an overview of different experimental wear test scenarios considering clinically relevant polyethylene wear situations using severe test conditions is presented. PMID:25716024

  19. Caring for severely ill cancer patients. A comparison of working conditions in hospital-based home care and in hospital.

    PubMed

    Beck-Friis, B; Strang, P; Sjödén, P O

    1993-05-01

    The goal of the study was to compare working conditions in a hospital with the conditions in a specialized hospital-based home care (HBHC) unit, which aims to replace hospital care for patients in need of institutional car. Staff (doctors included) in a HBHC unit (n = 35) and on three hospital wards (n = 113) participated in the study. All staff members worked regularly with severely ill cancer patients. Question about stress, job satisfaction and working conditions were asked in a self-administered questionnaire. Both groups showed a limited degree of continuous stress and a high degree of job satisfaction. Thus, the overall perception was than the working conditions were good. When significant differences were found, the responses of the HBHC staff were more positive. This included items such as more freedom to make their own decisions (P < 0.001), better co-operation between day and night shifts (P < 0.001), a more reasonable work load (P = 0.0001), fewer problems in communication with patients (P < 0.001), and fewer problems with tension (P < 0.05) and with sleeping (P < 0.05). The findings may be due to several factors: the HBHC staff were older, more often married, had more children, had worked longer in health care and were thus more experienced. Complementary explanations may be continuous education within the HBHC and an organization stimulating the staff's own initiative, but also capable of supporting when necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Experimental results from containment piping bellows subjected to severe accident conditions. Volume 1, Results from bellows tested in `like-new` conditions

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1994-09-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted under the sponsorship of the US Nuclear Regulatory Commission at Sandia National Laboratories. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of thirteen bellows have been tested, all in the `like-new` condition. (Additional tests are planned of bellows that have been subjected to corrosion.) The tests showed that bellows are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage. The test data is presented and discussed.

  1. Appearance Normalization of Histology Slides

    NASA Astrophysics Data System (ADS)

    Niethammer, Marc; Borland, David; Marron, J. S.; Woosley, John; Thomas, Nancy E.

    This paper presents a method for automatic color and intensity normalization of digitized histology slides stained with two different agents. In comparison to previous approaches, prior information on the stain vectors is used in the estimation process, resulting in improved stability of the estimates. Due to the prevalence of hematoxylin and eosin staining for histology slides, the proposed method has significant practical utility. In particular, it can be used as a first step to standardize appearances across slides, that is very effective at countering effects due to differing stain amounts and protocols, and to slide fading. The approach is validated using synthetic experiments and 13 real datasets.

  2. Temperature rise and wear of sliding contact of alloy steels

    NASA Astrophysics Data System (ADS)

    Goswami, Arindam Roy; Sardar, Santanu; Karmakar, Santanu Kumar

    2016-07-01

    The tribo-failure of machine elements under relative sliding velocities is greatly affected by frictional heating and resultant contact temperature rise. Nevertheless, the tribo-failure of automotive components is a combined effect of mechanical, thermal and chemical phenomena. Over the decades, there have been developed a number of different mathematical models for predicting surface temperature rise at sliding contact under different geometries of asperity contacts and operating conditions. The experimental investigation is still relevant today to find out the surface temperature rise at sliding contact along with the outcomes of friction and wear under various operating conditions for real time applications. The present work aims at finding average surface temperature rise at different sliding velocities, normal loads with different surface roughness experimentally. It also involves to prepare two different rough surfaces of alloy steels and to study their influences in the process of generating contact temperature rise under a given operating conditions.

  3. Severe Obesity and Comorbid Condition Impact on the Weight-Related Quality of Life of the Adolescent Patient

    PubMed Central

    Zeller, Meg H.; Inge, Thomas H.; Modi, Avani C.; Jenkins, Todd M.; Michalsky, Marc P.; Helmrath, Michael; Courcoulas, Anita; Harmon, Carroll M.; Rofey, Dana; Baughcum, Amy; Austin, Heather; Price, Karin; Xanthakos, Stavra A.; Brandt, Mary L.; Horlick, Mary; Buncher, Ralph

    2014-01-01

    Objectives To assess links between comorbid health status, severe excess weight, and weight-related quality of life (WRQOL) in adolescents with severe obesity and undergoing weight loss surgery (WLS) to inform clinical care. Study design Baseline (pre-operative) data from Teen-LABS, a prospective multicenter observational study of 242 adolescents with severe obesity (MdnBMI = 50.5 kg/m2; Mage=17.1; 75.6% female; 71.9% White) undergoing WLS, were utilized to examine the impact of demographics, body mass index (BMI), presence/absence of 16 comorbid conditions, and a cumulative comorbidity load (CLoad) index on WRQOL scores (Impact of Weight on Quality of Life-Kids; IWQOL-Kids). Results WRQOL was significantly lower than reference samples of healthy weight, overweight, and obese samples. Of 16 comorbid conditions, the most prevalent were dyslipidemia (74.4%), chronic pain (58.3%), and obstructive sleep apnea (56.6%). Males had a higher CLoad (p=.01) and BMI (p=.01), yet less impairment in total WRQOL (p<.01) than females. CLoad was a significant predictor of male WRQOL. For females, psychosocial (versus physical) comorbidities, BMI, and White race were significant predictors of WRQOL impairment. Less prevalent conditions (e.g., stress urinary incontinence) also emerged as contributors to lower WRQOL. Conclusions WRQOL impairment is substantial for adolescents with severe obesity undergoing WLS, with predictors varying by sex. These patient-data highlight targets for education, support, and adjunctive care referrals prior to WLS. Further, they provide a comprehensive empirical base for understanding heterogeneity in adolescent WRQOL outcomes following WLS, as weight and comorbidity profiles change over time. PMID:25556022

  4. Simulation of sliding of liquid droplets

    NASA Astrophysics Data System (ADS)

    Alen, Saif Khan; Farhat, Nazia; Rahman, Md. Ashiqur

    2016-07-01

    Numerical simulations of sliding behavior of liquid droplets on flat and periodic microgrooved surfaces with a range of groove geometry are conducted. A numerical model is developed which is capable of predicting the critical sliding angle of the drop by comparing the advancing and the receding angles obtained from numerical and experimental findings. The effect of microgroove topography, droplet size and inclination angle on the droplet sliding characteristics is analysed. Using an open-source platform (Surface Evolver), a 3D drop-shape model is developed to numerically determine the drop stability and contact angle hysteresis on tilted surfaces. In this numerical model, the three phase contact line of the drop is obtained by numerically calculating the vertex force and local contact angle at each vertex of the base contour. Several numerical models are developed based on various assumptions of base contour shape (circular or elliptical) and implementation of gravitational force to the droplet. Droplet shapes and critical sliding angles, obtained from these numerical models, are compared with those of experimental results and are found to be in very good agreement.

  5. Thresholds of elicitation depend on induction conditions. Could low level exposure induce sub-clinical allergic states that are only elicited under the severe conditions of clinical diagnosis?

    PubMed

    Hostynek, Jurij J; Maibach, Howard I

    2004-11-01

    While numerous studies have examined dose/response relationships occurring in the experimental induction of contact allergic dermatitis, fewer have examined the effects of varying the doses of both induction and challenge. Recently published studies have however done this and they all show the same remarkable observation: the threshold of elicitation decreases as the doses used to induce the allergy increase. This has important implications. One is that it may be more complicated to determine clear threshold doses below which allergic responses are not seen. It is also proposed that normal exposure to weak allergens such as some fragrance materials may induce "sub-clinical" allergic states which will not be elicited under these same exposure conditions but which may become apparent under the more severe conditions of clinical diagnosis. This may explain why the prevalence of Patch test reactions to some fragrance materials is apparently increasing in the absence of any clearly documented "epidemic" of consumer complaints.

  6. Constitutive modelling of lubricants in concentrated contacts at high slide to roll ratios

    NASA Technical Reports Server (NTRS)

    Tevaarwerk, J. L.

    1985-01-01

    A constitutive lubricant friction model for rolling/sliding concentrated contacts such as gears and cams was developed, based upon the Johnson and Tevaarwerk fluid rheology model developed earlier. The friction model reported herein differs from the earlier rheological models in that very large slide to roll ratios can now be accommodated by modifying the thermal response of the model. Also the elastic response of the fluid has been omitted from the model, thereby making it much simpler for use in the high slide to roll contacts. The effects of this simplification are very minimal on the outcome of the predicted friction losses (less than 1%). In essence then the lubricant friction model developed for the high slide to roll ratios treats the fluid in the concentrated contact as consisting of a nonlinear viscous element that is pressure, temperature, and strain rate dependent in its shear response. The fluid rheological constants required for the prediction of the friction losses at different contact conditions are obtained by traction measurements on several of the currently used gear lubricants. An example calculation, using this model and the fluid parameters obtained from the experiments, shows that it correctly predicts trends and magnitude of gear mesh losses measured elsewhere for the same fluids tested here.

  7. Robust sliding mode control applied to double Inverted pendulum system

    SciTech Connect

    Mahjoub, Sonia; Derbel, Nabil; Mnif, Faical

    2009-03-05

    A three hierarchical sliding mode control is presented for a class of an underactuated system which can overcome the mismatched perturbations. The considered underactuated system is a double inverted pendulum (DIP), can be modeled by three subsystems. Such structure allows the construction of several designs of hierarchies for the controller. For all hierarchical designs, the asymptotic stability of every layer sliding mode surface and the sliding mode surface of subsystems are proved theoretically by Barbalat's lemma. Simulation results show the validity of these methods.

  8. Robust sliding mode control applied to double Inverted pendulum system

    NASA Astrophysics Data System (ADS)

    Mahjoub, Sonia; Mnif, Faiçal; Derbel, Nabil

    2009-03-01

    A three hierarchical sliding mode control is presented for a class of an underactuated system which can overcome the mismatched perturbations. The considered underactuated system is a double inverted pendulum (DIP), can be modeled by three subsystems. Such structure allows the construction of several designs of hierarchies for the controller. For all hierarchical designs, the asymptotic stability of every layer sliding mode surface and the sliding mode surface of subsystems are proved theoretically by Barbalat's lemma. Simulation results show the validity of these methods.

  9. Early results from an experimental program to determine the behavior of containment piping penetration bellows subjected to severe accident conditions

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1994-09-01

    Containment piping penetration bellows are an integral part of the pressure boundary in steel containments in the United States (US). Their purpose is to minimize loading on the containment shell caused by differential movement between the piping and the containment. This differential movement is typically caused by thermal gradients generated during startup and shutdown of the reactor, but can be caused by earthquake, a loss-of-coolant accident (LOCA), or ``severe`` accidents. In the event of a severe accident, the bellows would be subjected to pressure, temperature, and deflection well beyond the design basis. Most bellows are installed such that they would be subjected to elevated internal pressure, elevated temperature, axial compression, and lateral deflection during a severe accident. A few bellows would be subjected to external pressure and axial elongation, as well as elevated temperature and lateral deflection. The purpose of this experimental program is to examine the potential for leakage of containment bellows during a severe accident. The test series subjects bellows to various levels and combinations of internal pressure, elevated temperature, axial compression or elongation, and lateral deformation. The experiments are being conducted in two parts. For Part 1, all bellows specimens are tested in ``like-new`` condition, without regard for the possible degrading effect of corrosion that has been observed in some containment piping bellows in the US Part I testing, which included 13 bellows tests, has been completed. The second part of the experimental program, in which bellows are subjected to simulated corrosive environments prior to testing, has just just begun. The Part I experiments have shown that bellows in ``like-new`` condition can withstand elevated temperatures and pressures along with large deformations before leaking. In most cases, the like-new bellows were fully compressed without developing any leakage.

  10. Using Scrap Slides for Art.

    ERIC Educational Resources Information Center

    Hanlon, Heather

    1979-01-01

    Using scrap slides for an art lesson can be an exciting, creative experience for people of all ages, and many techniques are applicable in both primary and secondary grades. Scrap slides are an inexpensive means to unique, original, and stimulating discoveries about film as an art form. (Author)

  11. Appearance normalization of histology slides.

    PubMed

    Vicory, Jared; Couture, Heather D; Thomas, Nancy E; Borland, David; Marron, J S; Woosley, John; Niethammer, Marc

    2015-07-01

    This paper presents a method for automatic color and intensity normalization of digitized histology slides stained with two different agents. In comparison to previous approaches, prior information on the stain vectors is used in the plane estimation process, resulting in improved stability of the estimates. Due to the prevalence of hematoxylin and eosin staining for histology slides, the proposed method has significant practical utility. In particular, it can be used as a first step to standardize appearance across slides and is effective at countering effects due to differing stain amounts and protocols and counteracting slide fading. The approach is validated against non-prior plane-fitting using synthetic experiments and 13 real datasets. Results of application of the method to adjustment of faded slides are given, and the effectiveness of the method in aiding statistical classification is shown.

  12. Sliding-Ring Catenanes.

    PubMed

    Fernando, Isurika R; Frasconi, Marco; Wu, Yilei; Liu, Wei-Guang; Wasielewski, Michael R; Goddard, William A; Stoddart, J Fraser

    2016-08-17

    Template-directed protocols provide a routine approach to the synthesis of mechanically interlocked molecules (MIMs), in which the mechanical bonds are stabilized by a wide variety of weak interactions. In this Article, we describe a strategy for the preparation of neutral [2]catenanes with sliding interlocked electron-rich rings, starting from two degenerate donor-acceptor [2]catenanes, consisting of a tetracationic cyclobis(paraquat-p-phenylene) cyclophane (CBPQT(4+)) and crown ethers containing either (i) hydroquinone (HQ) or (ii) 1,5-dioxynaphthalene (DNP) recognition units and carrying out four-electron reductions of the cyclophane components to their neutral forms. The donor-acceptor interactions between the CBPQT(4+) ring and both HQ and DNP units present in the crown ethers that stabilize the [2]catenanes are weakened upon reduction of the cyclophane components to their radical cationic states and are all but absent in their fully reduced states. Characterization in solution performed by UV-vis, EPR, and NMR spectroscopic probes reveals that changes in the redox properties of the [2]catenanes result in a substantial decrease of the energy barriers for the circumrotation and pirouetting motions of the interlocked rings, which glide freely through one another in the neutral states. The solid-state structures of the fully reduced catenanes reveal profound changes in the relative dispositions of the interlocked rings, with the glycol chains of the crown ethers residing in the cavities of the neutral CBPQT(0) rings. Quantum mechanical investigations of the energy levels associated with the four different oxidation states of the catenanes support this interpretation. Catenanes and rotaxanes with sliding rings are expected to display unique properties. PMID:27398609

  13. Grading of severity of the condition in burn patients by serum protein and albumin/globulin studies.

    PubMed

    Kumar, Pramod

    2010-07-01

    Capillary permeability increases after inflammation with consequent leak of fluid, electrolytes, and proteins. The albumin molecule size being smaller (69 kDa) than the globulin molecule (90-156 kDa) will leak relatively at an early stage of the disease (with moderate increase in capillary pore size) than globulin leading to albumin/globulin reversal. In cases with severe permeability changes with rapid progression to larger pore size with simultaneous leak of both albumin and globulin, albumin/globulin reversal will not occur. In this study estimation the serum protein and albumin/globulin (A/G) ratio at frequent intervals was done to grade the severity of the condition of burn patients by assessing the severity of capillary leak.A total of 61 admitted patients (from March 2002 to December 2004) based on the protein values were divided into 3 groups (group 1: 6-8 g/dL, group 2: 5.1-5.9 g/dL, group 3: < or =5.0 g/dL), and all the patients who showed change in their protein levels during the study were shifted to appropriate group and were classified as group shifters. The mean survival time and mortality of various groups were compared, and A/G ratio of all the expired cases was analyzed.Group 3 patients showed higher mortality (95%) as compared to that in other groups (group 1 and 2: 0% each and group shifters: 30.2%). Median survival time of group 3 was significantly low as compared to that of group 1 (P < 0.0026), group 2 (P < 0.0006), and group shifters (P < 0.0000). In group shifters the mean time (days) required for shifting from one group to other just before death or discharge in survivors was significantly higher than that in expired cases. Of 26 cases expired during the study, initial A/G ratio at the time of first assigning the group was not reversed in 22 cases (84.6%).The study concluded that the severity (indicated by lower serum protein values) and speed (judged by A/G ratio changes and median survival time analysis) of capillary permeability changes

  14. Elevated corticosterone levels and severe weather conditions decrease parental investment of incubating Adélie penguins.

    PubMed

    Thierry, Anne-Mathilde; Massemin, Sylvie; Handrich, Yves; Raclot, Thierry

    2013-03-01

    Corticosterone, the main stress hormone in birds, mediates resource allocation, allowing animals to adjust their physiology and behaviour to changes in the environment. Incubation is a time and energy-consuming phase of the avian reproductive cycle. It may be terminated prematurely, when the parents' energy stores are depleted or when environmental conditions are severe. In this study, the effects of experimentally elevated baseline corticosterone levels on the parental investment of incubating male Adélie penguins were investigated. Incubation duration and reproductive success of 60 penguins were recorded. The clutches of some birds were replaced by dummy eggs, which recorded egg temperatures and rotation rates, enabling a detailed investigation of incubation behaviour. Corticosterone levels of treated birds were 2.4-fold higher than those of controls 18 days post treatment. Exogenous corticosterone triggered nest desertion in 61% of the treated birds; consequently reducing reproductive success, indicating that corticosterone can reduce or disrupt parental investment. Regarding egg temperatures, hypothermic events became more frequent and more pronounced in treated birds, before these birds eventually abandoned their nest. The treatment also significantly decreased incubation temperatures by 1.3°C and lengthened the incubation period by 2.1 days. However, the number of chicks at hatching was similar among successful nests, regardless of treatment. Weather conditions appeared to be particularly important in determining the extent to which corticosterone levels affected the behaviour of penguins, as treated penguins were more sensitive to severe weather conditions. This underlines the importance of considering the interactions of organisms with their environment in studies of animal behaviour and ecophysiology.

  15. Mitigative techniques and analysis of generic site conditions for ground-water contamination associated with severe accidents

    SciTech Connect

    Shafer, J.M.; Oberlander, P.L.; Skaggs, R.L.

    1984-04-01

    The purpose of this study is to evaluate the feasibility of using ground-water contaminant mitigation techniques to control radionuclide migration following a severe commercial nuclear power reactor accident. The two types of severe commercial reactor accidents investigated are: (1) containment basemat penetration of core melt debris which slowly cools and leaches radionuclides to the subsurface environment, and (2) containment basemat penetration of sump water without full penetration of the core mass. Six generic hydrogeologic site classifications are developed from an evaluation of reported data pertaining to the hydrogeologic properties of all existing and proposed commercial reactor sites. One-dimensional radionuclide transport analyses are conducted on each of the individual reactor sites to determine the generic characteristics of a radionuclide discharge to an accessible environment. Ground-water contaminant mitigation techniques that may be suitable, depending on specific site and accident conditions, for severe power plant accidents are identified and evaluated. Feasible mitigative techniques and associated constraints on feasibility are determined for each of the six hydrogeologic site classifications. The first of three case studies is conducted on a site located on the Texas Gulf Coastal Plain. Mitigative strategies are evaluated for their impact on contaminant transport and results show that the techniques evaluated significantly increased ground-water travel times. 31 references, 118 figures, 62 tables.

  16. Friction microprobe investigation of particle layer effects on sliding friction

    SciTech Connect

    Blau, P.J.

    1993-01-01

    Interfacial particles (third-bodies), resulting from wear or external contamination, can alter and even dominate the frictional behavior of solid-solid sliding in the absence of effective particle removal processes (e.g., lubricant flow). A unique friction microprobe, developed at Oak Ridge National Laboratory, was used to conduct fine- scale friction studies using 1.0 mm diameter stainless steel spheres sliding on several sizes of loose layers of fine aluminum oxide powders on both aluminum and alumina surfaces. Conventional, pin-on-disk experiments were conducted to compare behavior with the friction microprobe results. The behavior of the relatively thick particle layers was found to be independent of the nature of underlying substrate, substantiating previous work by other investigators. The time-dependent behavior of friction, for a spherical macrocontact starting from rest, could generally be represented by a series of five rather distinct phases involving static compression, slider breakaway, transition to steady state, and dynamic layer instability. A friction model for the steady state condition, which incorporates lamellar powder layer behavior, is described.

  17. A novel adaptive sliding mode control with application to MEMS gyroscope.

    PubMed

    Fei, Juntao; Batur, Celal

    2009-01-01

    This paper presents a new adaptive sliding mode controller for MEMS gyroscope; an adaptive tracking controller with a proportional and integral sliding surface is proposed. The adaptive sliding mode control algorithm can estimate the angular velocity and the damping and stiffness coefficients in real time. A proportional and integral sliding surface, instead of a conventional sliding surface is adopted. An adaptive sliding mode controller that incorporates both matched and unmatched uncertainties and disturbances is derived and the stability of the closed-loop system is established. The numerical simulation is presented to verify the effectiveness of the proposed control scheme. It is shown that the proposed adaptive sliding mode control scheme offers several advantages such as the consistent estimation of gyroscope parameters including angular velocity and large robustness to parameter variations and external disturbances.

  18. Engineering theory of slide processes in the design of earth dams on a soft ground foundation

    SciTech Connect

    Krasil'nikov, N.A.

    1987-11-01

    This paper discusses the slope stability and landslide propensity of several hydroelectric plant earth dams throughout the Soviet Union from the standpoint of slide theory and compares the research of several Soviet institutions into this problem with existing standards and recommendations on dam stability and reliability. The comparisons are made for earth dams having a soft ground foundation under static loading conditions. Applicable properties are discussed for a wide range of soils and rocks including clays, loams, sands, alluvials, and soft and hard gravels. Seismic effects are not discussed.

  19. Plastic deformation at surface during unlubricated sliding

    NASA Technical Reports Server (NTRS)

    Yamamoto, T.; Buckley, D. H.

    1982-01-01

    The plastic deformation and wear of 304 stainless-steel surface slid against an aluminum oxide rider were observed by using a scanning electron microscope and an optical microscope. Experiments were conducted in a vacuum of 0.000001 Pa and in an environment of 0.0005 Pa chlorine gas at 25 C. The load was 500 grams and the sliding velocity was 0.5 centimeter per second. The deformed surface layer which accumulates and develops successively is left behind the rider, and step-shaped protuberances are developed even after single pass sliding under both environmental conditions. A fully developed surface layer is gradually torn off leaving a characteristic pattern. These observations result from both adhesion and an adhesive wear mechanism.

  20. Evaluation of resistance to change under different disrupter conditions in children with autism and severe intellectual disability.

    PubMed

    Lionello-DeNolf, Karen M; Dube, William V; McIlvane, William J

    2010-05-01

    Translational research inspired by behavioral momentum theory in the area of developmental disabilities has shown effects in individuals over a range of functioning levels. In the current study, behavioral momentum was assessed in 6 children diagnosed with autism and severe intellectual disability. In a repeated measures design, participants were exposed to relatively rich versus lean reinforcement contingencies in a multiple schedule with food reinforcers. This was followed by exposure to each of four disrupting conditions: prefeeding, presentation of a concurrent alternative stimulus, presentation of a movie, and the presence of a researcher dispensing response-independent reinforcers on a variable-time schedule. Consistently greater resistance to disruption in the component with the richer schedule occurred with the alternative stimulus disrupter but not with the other disrupters. These results suggest parameters that may be more (or less) effective if behavioral momentum inspired techniques are to be exploited in therapeutic environments.

  1. Evaluation of Resistance to Change under Different Disrupter Conditions in Children with Autism and Severe Intellectual Disability

    PubMed Central

    Lionello-DeNolf, Karen M; Dube, William V; McIlvane, William J

    2010-01-01

    Translational research inspired by behavioral momentum theory in the area of developmental disabilities has shown effects in individuals over a range of functioning levels. In the current study, behavioral momentum was assessed in 6 children diagnosed with autism and severe intellectual disability. In a repeated measures design, participants were exposed to relatively rich versus lean reinforcement contingencies in a multiple schedule with food reinforcers. This was followed by exposure to each of four disrupting conditions: prefeeding, presentation of a concurrent alternative stimulus, presentation of a movie, and the presence of a researcher dispensing response-independent reinforcers on a variable-time schedule. Consistently greater resistance to disruption in the component with the richer schedule occurred with the alternative stimulus disrupter but not with the other disrupters. These results suggest parameters that may be more (or less) effective if behavioral momentum inspired techniques are to be exploited in therapeutic environments. PMID:21119851

  2. Analysis of several hazardous conditions for large transfer and back-dilution sequences in Tank 241-SY-101

    SciTech Connect

    CW Stewart; LA Mahoney; WB Barton

    2000-01-28

    The first transfer of 89 kgal of waste and back-dilution of 61 kgal of water in Hanford Tank 241-SY-101 was accomplished December 18--20, 1999. Limits were placed on the transfer and back-dilution volumes because of concerns about potential gas release, crust sinking, and degradation of mixer pump performance. Additional transfers and back-dilutions are being planned that will bring the total to 500 kgal, which should dissolve a large fraction of the solids in the tank and dilute it well beyond the point where significant gas retention can occur. This report provides the technical bases for removing the limits on transfer and back-dilution volume by evaluating the potential consequences of several postulated hazardous conditions in view of the results of the first campaign and results of additional analyses of waste behavior.

  3. Measured performance of the heat exchanger in the NASA icing research tunnel under severe icing and dry-air conditions

    NASA Technical Reports Server (NTRS)

    Olsen, W.; Vanfossen, J.; Nussle, R.

    1987-01-01

    Measurements were made of the pressure drop and thermal perfomance of the unique refrigeration heat exchanger in the NASA Lewis Icing Research Tunnel (IRT) under severe icing and frosting conditions and also with dry air. This data will be useful to those planning to use or extend the capability of the IRT and other icing facilities (e.g., the Altitude Wind Tunnel-AWT). The IRT heat exchanger and refrigeration system is able to cool air passing through the test section down to at least a total temperature of -30 C (well below icing requirements), and usually up to -2 C. The system maintains a uniform temperature across the test section at all airspeeds, which is more difficult and time consuming at low airspeeds, at high temperatures, and on hot, humid days when the cooling towers are less efficient. The very small surfaces of the heat exchanger prevent any icing cloud droplets from passing through it and going through the tests section again. The IRT heat exchanger was originally designed not to be adversely affected by severe icing. During a worst-case icing test the heat exchanger iced up enough so that the temperature uniformaity was no worse than about +/- 1 deg C. The conclusion is that the heat exchanger design performs well.

  4. TRUMP-BD: A computer code for the analysis of nuclear fuel assemblies under severe accident conditions

    SciTech Connect

    Lombardo, N.J.; Marseille, T.J.; White, M.D.; Lowery, P.S.

    1990-06-01

    TRUMP-BD (Boil Down) is an extension of the TRUMP (Edwards 1972) computer program for the analysis of nuclear fuel assemblies under severe accident conditions. This extension allows prediction of the heat transfer rates, metal-water oxidation rates, fission product release rates, steam generation and consumption rates, and temperature distributions for nuclear fuel assemblies under core uncovery conditions. The heat transfer processes include conduction in solid structures, convection across fluid-solid boundaries, and radiation between interacting surfaces. Metal-water reaction kinetics are modeled with empirical relationships to predict the oxidation rates of steam-exposed Zircaloy and uranium metal. The metal-water oxidation models are parabolic in form with an Arrhenius temperature dependence. Uranium oxidation begins when fuel cladding failure occurs; Zircaloy oxidation occurs continuously at temperatures above 13000{degree}F when metal and steam are available. From the metal-water reactions, the hydrogen generation rate, total hydrogen release, and temporal and spatial distribution of oxide formations are computed. Consumption of steam from the oxidation reactions and the effect of hydrogen on the coolant properties is modeled for independent coolant flow channels. Fission product release from exposed uranium metal Zircaloy-clad fuel is modeled using empirical time and temperature relationships that consider the release to be subject to oxidation and volitization/diffusion ( bake-out'') release mechanisms. Release of the volatile species of iodine (I), tellurium (Te), cesium (Ce), ruthenium (Ru), strontium (Sr), zirconium (Zr), cerium (Cr), and barium (Ba) from uranium metal fuel may be modeled.

  5. Reduced Intensity Conditioning, Combined Transplantation of Haploidentical Hematopoietic Stem Cells and Mesenchymal Stem Cells in Patients with Severe Aplastic Anemia

    PubMed Central

    Li, Xiao-Hong; Gao, Chun-Ji; Da, Wan-Ming; Cao, Yong-Bin; Wang, Zhi-Hong; Xu, Li-Xin; Wu, Ya-Mei; Liu, Bei; Liu, Zhou-Yang; Yan, Bei; Li, Song-Wei; Yang, Xue-Liang; Wu, Xiao-Xiong; Han, Zhong-Chao

    2014-01-01

    We examined if transplantation of combined haploidentical hematopoietic stem cells (HSC) and mesenchymal stem cells (MSC) affected graft failure and graft-versus-host disease (GVHD) in patients with severe aplastic anemia (SAA). Patients with SAA-I (N = 17) received haploidentical HSCT plus MSC infusion. Stem cell grafts used a combination of granulocyte colony-stimulating factor (G-CSF)-primed bone marrow and G-CSF-mobilized peripheral blood stem cells of haploidentical donors and the culture-expanded third-party donor-derived umbilical cord MSCs (UC-MSCs), respectively. Reduced intensity conditioning consisted of fludarabine (30 mg/m2·d)+cyclosphamide (500 mg/m2·d)+anti-human thymocyte IgG. Transplant recipients also received cyclosporin A, mycophenolatemofetil, and CD25 monoclonal antibody. A total of 16 patients achieved hematopoietic reconstitution. The median mononuclear cell and CD34 count was 9.3×108/kg and 4.5×106/kg. Median time to ANC was >0.5×109/L and PLT count >20×109/L were 12 and 14 days, respectively. Grade III-IV acute GVHD was seen in 23.5% of the cases, while moderate and severe chronic GVHD were seen in 14.2% of the cases. The 3-month and 6-month survival rates for all patients were 88.2% and 76.5%, respectively; mean survival time was 56.5 months. Combined transplantation of haploidentical HSCs and MSCs on SAA without an HLA-identical sibling donor was safe, effectively reduced the incidence of severe GVHD, and improved patient survival. PMID:24594618

  6. Sliding Motility in Mycobacteria

    PubMed Central

    Martínez, Asunción; Torello, Sandra; Kolter, Roberto

    1999-01-01

    Mycobacteria are nonflagellated gram-positive microorganisms. Previously thought to be nonmotile, we show here that Mycobacterium smegmatis can spread on the surface of growth medium by a sliding mechanism. M. smegmatis spreads as a monolayer of cells which are arranged in pseudofilaments by close cell-to-cell contacts, predominantly along their longitudinal axis. The monolayer moves away from the inoculation point as a unit with only minor rearrangements. No extracellular structures such as pili or fimbriae appear to be involved in this process. The ability to translocate over the surface correlates with the presence of glycopeptidolipids, a mycobacterium-specific class of amphiphilic molecules located in the outermost layer of the cell envelope. We present evidence that surface motility is not restricted to M. smegmatis but is also a property of the slow-growing opportunistic pathogen M. avium. This form of motility could play an important role in surface colonization by mycobacteria in the environment as well as in the host. PMID:10572138

  7. An Airship Slide Rule

    NASA Technical Reports Server (NTRS)

    Weaver, E R; Pickering, S F

    1924-01-01

    This report prepared for the National Advisory Committee for Aeronautics, describes an airship slide rule developed by the Gas-Chemistry Section of the Bureau of Standards, at the request of the Bureau of Engineering of the Navy Department. It is intended primarily to give rapid solutions of a few problems of frequent occurrence in airship navigation, but it can be used to advantage in solving a great variety of problems, involving volumes, lifting powers, temperatures, pressures, altitudes and the purity of the balloon gas. The rule is graduated to read directly in the units actually used in making observations, constants and conversion factors being taken care of by the length and location of the scales. It is thought that with this rule practically any problem likely to arise in this class of work can be readily solved after the user has become familiar with the operation of the rule; and that the solution will, in most cases, be as accurate as the data warrant.

  8. Applications and challenges of digital pathology and whole slide imaging.

    PubMed

    Higgins, C

    2015-07-01

    Virtual microscopy is a method for digitizing images of tissue on glass slides and using a computer to view, navigate, change magnification, focus and mark areas of interest. Virtual microscope systems (also called digital pathology or whole slide imaging systems) offer several advantages for biological scientists who use slides as part of their general, pharmaceutical, biotechnology or clinical research. The systems usually are based on one of two methodologies: area scanning or line scanning. Virtual microscope systems enable automatic sample detection, virtual-Z acquisition and creation of focal maps. Virtual slides are layered with multiple resolutions at each location, including the highest resolution needed to allow more detailed review of specific regions of interest. Scans may be acquired at 2, 10, 20, 40, 60 and 100 × or a combination of magnifications to highlight important detail. Digital microscopy starts when a slide collection is put into an automated or manual scanning system. The original slides are archived, then a server allows users to review multilayer digital images of the captured slides either by a closed network or by the internet. One challenge for adopting the technology is the lack of a universally accepted file format for virtual slides. Additional challenges include maintaining focus in an uneven sample, detecting specimens accurately, maximizing color fidelity with optimal brightness and contrast, optimizing resolution and keeping the images artifact-free. There are several manufacturers in the field and each has not only its own approach to these issues, but also its own image analysis software, which provides many options for users to enhance the speed, quality and accuracy of their process through virtual microscopy. Virtual microscope systems are widely used and are trusted to provide high quality solutions for teleconsultation, education, quality control, archiving, veterinary medicine, research and other fields.

  9. Nanoscale incipient asperity sliding and interface micro-slip assessed by the measurment of tangential contact stiffness

    SciTech Connect

    Gao, Yanfei; Lucas, Barry N.; Hay, Jack C.; Oliver, Warren C.; Pharr, George Mathews

    2006-01-01

    Experiments with a multidimensional nano-contact system have shown that, prior to kinetic frictional sliding, there is a significant reduction of the tangential contact stiffness relative to the elastic prediction. The reduction occurs at contact sizes below about 50-200 nm for aluminum single crystals and several other materials. Using a cohesive interface model, we find that this reduction corresponds to a transition from a small-scale-slip to large-scale-slip condition of the interface.

  10. Effect of nontronite smectite clay on the chemical evolution of several organic molecules under simulated Mars surface UV radiation conditions

    NASA Astrophysics Data System (ADS)

    Poch, Olivier; Dequaire, Tristan; Stalport, Fabien; Jaber, Maguy; Lambert, Jean-François; Szopa, Cyril; Coll, Patrice

    2015-04-01

    The search for organic carbon-containing molecules at the surface of Mars, as clues of past habitability or remnants of life, is a major scientific goal for Mars exploration. Several lines of evidence, including the detection of phyllosilicates, suggest that early Mars offered favorable conditions for long-term sustaining of water. As a consequence, we can assume that in those days, endogenous chemical processes, or even primitive life, may have produced organic matter on Mars. Moreover, exogenous delivery from small bodies or dust particles is likely to have brought fresh organic molecules to the surface of Mars up today. Organic matter is therefore expected to be present at the surface/subsurface of the planet. But the current environmental conditions at the surface - UV radiation, oxidants and energetic particles - generate physico-chemical processes that may affect organic molecules. On the other hand, on Earth, phyllosilicates are known to accumulate and preserve organic matter. But are phyllosilicates efficient at preserving organic molecules under the current environmental conditions at the surface of Mars? We have monitored the qualitative and quantitative evolutions of glycine, urea and adenine interacting with the Fe3+-smectite clay nontronite, one of the most abundant phyllosilicates present at the surface of Mars, under simulated Martian surface ultraviolet light (190-400 nm), mean temperature (218 ± 2 K) and pressure (6 ± 1 mbar) in a laboratory simulation setup. We have tested organic-rich samples which may be representative of the evaporation of a warm little pond of liquid water having concentrated organics on Mars. For each molecule, we have observed how the nontronite influences the quantum efficiency of its photodecomposition and the nature of its solid evolution products. The results reveal a pronounced photoprotective effect of nontronite on the evolution of glycine and adenine: their efficiencies of photodecomposition are reduced by a factor

  11. Post-irradiation examination of AlFeNi cladded U 3Si 2 fuel plates irradiated under severe conditions

    NASA Astrophysics Data System (ADS)

    Leenaers, A.; Koonen, E.; Parthoens, Y.; Lemoine, P.; Van den Berghe, S.

    2008-04-01

    Three full size AlFeNi cladded U 3Si 2 fuel plates were irradiated in the BR2 reactor of the Belgian Nuclear Research Centre (SCK·CEN) under relatively severe, but well defined conditions. The irradiation was part of the qualification campaign for the fuel to be used in the future Jules Horowitz reactor in Cadarache, France. After the irradiation, the fuel plates were submitted to an extensive post-irradiation campaign in the hot cell laboratory of SCK·CEN. The PIE shows that the fuel plates withstood the irradiation successfully, as no detrimental defects have been found. At the cladding surface, a multilayered corrosion oxide film has formed. The U-Al-Si layer resulting from the interaction between the U 3Si 2 fuel and the Al matrix, has been quantified as U(Al,Si) 4.6. It is found that the composition of the fuel particles is not homogenous; zones of USi and U 3Si 2 are observed and measured. The fission gas-related bubbles generated in both phases show a different morphology. In the USi fuel, the bubbles are small and numerous while in U 3Si 2 the bubbles are larger but there are fewer.

  12. Soliton dynamics in a solid lubricant during sliding friction

    NASA Astrophysics Data System (ADS)

    Vigentini, Anna; Van Hattem, Barbara; Diato, Elena; Ponzellini, Paolo; Meledina, Tommaso; Vanossi, Andrea; Santoro, Giuseppe; Tosatti, Erio; Manini, Nicola

    2014-03-01

    Recent highly idealized model studies of lubricated nanofriction for two crystalline sliding surfaces with an interposed thin solid crystalline lubricant layer showed that the overall relative velocity of the lubricant vlub/vslider depends only on the ratio of the lattice spacings, and retains a strictly constant value even when system parameters are varied within a wide range. This peculiar "quantized" dynamical locking was understood as due to the sliding-induced motion of misfit dislocations, or soliton structures. So far the practical relevance of this concept to realistic sliding three-dimensional crystals has not been demonstrated. In this work, by means of classical molecular dynamics simulations and theoretical considerations, we realize a realistic three-dimensional crystal-lubricant-crystal geometry. Results show that the flux of lubricant particles associated with the advancing soliton lines gives rise here too to a quantized-velocity ratio. Moreover, depending on the interface lattice spacing mismatch, both forward and backward quantized motion of the lubricant is predicted. The persistence under realistic conditions of the dynamically pinned state and quantized sliding is further investigated by varying sliding speed, temperature, load, and lubricant film thickness. The possibilities of experimental observation of quantized sliding are also discussed.

  13. Relative sliding durability of candidate high temperature fiber seal materials

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher; Steinetz, Bruce M.

    1992-01-01

    The relative sliding durability behavior of six candidate ceramic fibers for high temperature sliding seal applications is reviewed and compared. Pin on disk tests were used to evaluate potential seal materials by sliding a tow or bundle of the candidate ceramic fiber against a superalloy test disk. Tests were conducted in air under a 2.65 N load, at a sliding velocity of 0.025 m/sec and at temperatures from 25 to 900 C. Friction was measured during the tests and fiber wear, indicated by the extent of fibers broken in the tow or bundle, was measured at the end of each test. For most of the fibers, friction and wear increase with test temperature. The relative fiber durability ranking correlates with tensile strength, indicating that tensile data, which is more readily available than sliding durability data, may be useful in predicting fiber wear behavior under various conditions. A dimensional analysis of the wear data shows that the fiber durability is related to a dimensionless durability ratio which represents the ratio of the fiber strength to the fiber stresses imposed by sliding. The analysis is applicable to fibers with similar diameters and elastic moduli. Based upon the results of the research program, three fiber candidates are recommended for further study as potential seal materials. They are a silicon based complex carbide-oxide fiber, an alumina-boria-silica and an aluminosilicate fiber.

  14. Simulating aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern China under severe haze conditions in winter

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Wang, Yuxuan; Hao, Jiming

    2015-04-01

    The aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern China under severe winter haze conditions during January 2013 are simulated using the fully coupled on-line Weather Research and Forecasting/Chemistry (WRF-Chem) model. Three simulation scenarios including different aerosol configurations are undertaken to distinguish the impact of aerosol radiative (direct and semi-direct) and indirect effects on meteorological variables and air quality. Simulated spatial and temporal variations of PM2.5 are generally consistent with surface observations, with a mean bias of -18.9 μg/m3 (-15.0%) averaged over 71 big cities in China. Comparisons between different scenarios reveal that aerosol radiative effects (direct effect and semi-direct effects) result in reductions of downward shortwave flux at the surface, 2 m temperature, 10 m wind speed and planetary boundary layer (PBL) height by up to 84.0 W/m2, 3.2 oC, 0.8 m/s, and 268 m, respectively. The simulated impact of the aerosol indirect effects is comparatively smaller. Through reducing the PBL height and wind speeds, the aerosol effects lead to increases in surface concentrations of primary pollutants (CO and SO2) and PM2.5. The aerosol feedbacks on secondary pollutants such as surface ozone and PM2.5 mass concentrations show some spatial variations. Surface O3 mixing ratio is reduced by up to 6.9 ppb due to reduced incoming solar radiation and lower temperature. Comparisons of model results with observations show that inclusion of aerosol feedbacks in the model significantly improves model performance in simulating meteorological variables and improves simulations of PM2.5 temporal distributions over the North China Plain, the Yangtze River Delta, the Pearl River Delta, and Central China. Although the aerosol-radiation-cloud feedbacks on aerosol mass concentrations are subject to uncertainties, this work demonstrates the significance of aerosol-radiation-cloud feedbacks for real-time air

  15. Simulating aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern China under severe haze conditions in winter

    NASA Astrophysics Data System (ADS)

    Zhang, B.; Wang, Y. X.; Hao, J. M.

    2014-10-01

    The aerosol-radiation-cloud feedbacks on meteorology and air quality over eastern China under severe winter haze conditions during January~2013 are simulated using the fully coupled on-line Weather Research and Forecasting/Chemistry (WRF-Chem) model. Three simulation scenarios including different aerosol configurations are undertaken to distinguish the impact of aerosol radiative (direct and semi-direct) and indirect effects on meteorological variables and air quality. Simulated spatial and temporal variations of PM2.5 are generally consistent with surface observations, with a mean bias of -18.9 μg m-3 (-15.0%) averaged over 71 big cities in China. Comparisons between different scenarios reveal that aerosol radiative effects (direct effect and semi-direct effects) result in reductions of downward shortwave flux at the surface, 2 m temperature, 10 m wind speed and planetary boundary layer (PBL) height by up to 84.0 W m-2, 3.2 °C, 0.8 m s-1, and 268 m, respectively. The simulated impact of the aerosol indirect effects is comparatively smaller. Through reducing the PBL height and wind speeds, the aerosol effects lead to increases in surface concentrations of primary pollutants (CO and SO2) and PM2.5. The aerosol feedbacks on secondary pollutants such as surface ozone and PM2.5 mass concentrations show some spatial variations. Surface O3 mixing ratio is reduced by up to 6.9 ppb due to reduced incoming solar radiation and lower temperature. Comparisons of model results with observations show that inclusion of aerosol feedbacks in the model significantly improves model's performances in simulating meteorological variables and improves simulations of PM2.5 temporal distributions over the North China Plain, the Yangtze River Delta, the Pearl River Delta, and Central China. Although the aerosol-radiation-cloud feedbacks on aerosol mass concentrations are subject to uncertainties, this work demonstrates the significance of aerosol-radiation-cloud feedbacks for real

  16. Housing Conditions Modulate the Severity of Mycoplasma pulmonis Infection in Mice Deficient in Class A Scavenger Receptor

    PubMed Central

    Booth, Jennifer L; Umstead, Todd M; Hu, Sanmei; Dybvig, Kevin F; Cooper, Timothy K; Wilson, Ronald P; Chroneos, Zissis C

    2014-01-01

    Mycoplasmosis is a frequent causative microbial agent of community-acquired pneumonia and has been linked to exacerbation of chronic obstructive pulmonary disease. The macrophage class A scavenger receptor (SRA) facilitates the clearance of noxious particles, oxidants, and infectious organisms by alveolar macrophages. We examined wildtype and SRA−/− mice, housed in either individually ventilated or static filter-top cages that were cycled with fresh bedding every 14 d, as a model of gene–environment interaction on the outcome of pulmonary Mycoplasma pulmonis infection. Intracage NH3 gas measurements were recorded daily prior to infection. Mice were intranasally infected with 1 × 107 cfu M. pulmonis UAB CT and evaluated at 3, 7, and 14 d after inoculation. Wildtype mice cleared 99.5% of pulmonary M. pulmonis by 3 d after infection but remained chronically infected through the study. SRA−/− mice were chronically infected with 40-fold higher mycoplasma numbers than were wildtype mice. M. pulmonis caused a chronic mixed inflammatory response that was accompanied with high levels of IL1β, KC, MCP1, and TNFα in SRA−/− mice, whereas pulmonary inflammation in WT mice was represented by a monocytosis with elevation of IL1β. Housing had a prominent influence on the severity and persistence of mycoplasmosis in SRA−/− mice. SRA-/- mice housed in static cages had an improved recovery and significant changes in surfactant proteins SPA and SPD compared with baseline levels. These results indicate that SRA is required to prevent chronic mycoplasma infection of the lung. Furthermore, environmental conditions may exacerbate chronic inflammation in M. pulmonis-infected SRA−/− mice. PMID:25527023

  17. Grain boundary sliding behaviour of copper and alpha brass at intermediate temperatures

    NASA Technical Reports Server (NTRS)

    Raj, S. V.

    1991-01-01

    The role of grain boundary sliding in copper and Cu-30 pct Zn in the temperature range 0.50-0.72 Tm, where Tm is the absolute melting point of the material, is examined. First, sliding data obtained on these materials are presented. The results indicate that the stress exponent for sliding is similar to that for lattice deformation, while the activation energy for sliding varies between 0.5 and 1.6 of the activation energy for creep. Several models proposed for grain boundary sliding are discussed, and it is shown that they do not account for the observed results on copper and alpha brass. A phenomenological model is proposed, where it is assumed that grain boundary sliding results from the glide of dislocations on secondary slip planes.

  18. Influence of fluid pore pressure on chaotic sliding of tectonic faults

    NASA Astrophysics Data System (ADS)

    Turuntaev, Sergey; Riga, Vasily

    2016-04-01

    The problem of permeable rock pore pressure variation influence on tectonic fault sliding and generation of seismic events was studied in the scope of rate-and-state friction model with two-parametric friction law. The coupled problem of pore-elasticity and fault sliding governed by two-parametric rate-and-state equation was studied numerically. The main modes of the fault sliding were found, and transitions from one mode to another due to the fluid pore pressure change were observed. The conditions for transition from stable to chaotic sliding (considered as an analog of seismic event generations) were found. It was shown, that chaotic sliding has features of Poincare stability and can be characterized by finite values of correlation integral and embedding dimension, which depend on critical shear stresses. Change of the effective critical stresses by the pore pressure variation will result in change of the tectonic fault sliding mode and consequently change of the seismic regime.

  19. Robust fuzzy control for stochastic Markovian jumping systems via sliding mode method

    NASA Astrophysics Data System (ADS)

    Chen, Bei; Jia, Tinggang; Niu, Yugang

    2016-07-01

    This paper considers the problem of sliding mode control for stochastic Markovian jumping systems by means of fuzzy method. The Takagi-Sugeno (T-S) fuzzy stochastic model subject to state-dependent noise is presented. A key feature in this work is to remove the restricted condition that each local system model had to share the same input channel, which is usually assumed in some existing results. The integral sliding surface is constructed for every mode and the connections among various sliding surfaces are established via a set of coupled matrices. Moreover, the present sliding mode controller including the transition rates of modes can cope with the effect of Markovian switching. It is shown that both the reachability of sliding surfaces and the stability of sliding mode dynamics can be ensured. Finally, numerical simulation results are given.

  20. Projective synchronization of nonidentical fractional-order neural networks based on sliding mode controller.

    PubMed

    Ding, Zhixia; Shen, Yi

    2016-04-01

    This paper investigates global projective synchronization of nonidentical fractional-order neural networks (FNNs) based on sliding mode control technique. We firstly construct a fractional-order integral sliding surface. Then, according to the sliding mode control theory, we design a sliding mode controller to guarantee the occurrence of the sliding motion. Based on fractional Lyapunov direct methods, system trajectories are driven to the proposed sliding surface and remain on it evermore, and some novel criteria are obtained to realize global projective synchronization of nonidentical FNNs. As the special cases, some sufficient conditions are given to ensure projective synchronization of identical FNNs, complete synchronization of nonidentical FNNs and anti-synchronization of nonidentical FNNs. Finally, one numerical example is given to demonstrate the effectiveness of the obtained results.

  1. Physiological and behavioral basis for the successful adaptation of goats to severe water restriction under hot environmental conditions.

    PubMed

    Kaliber, M; Koluman, N; Silanikove, N

    2016-01-01

    Among domestic ruminants, goats are renowned for their ability to tolerate water deprivation, water restriction and energy restriction. However, some basic questions regarding their ability to endure water restriction under heat stress are still open. Three levels of water restriction (56%, 73% and 87% of the ad libitum) were imposed on 20 cross-bred 3-year-old female goats (75% German Fawn and 25% Hair Goat) distributed into four groups, with five animals per treatment. The experiment was conducted from the beginning of July to the end of August in a farm located in the Eastern Mediterranean region of Turkey (40 m in altitude; 36 59' N, 35 18'E), in which subtropical weather conditions prevail. The average daily temperature during the experiment was 34.2°C, whereas the highest and lowest temperatures were 42°C and 23.1°C, respectively. The average relative humidity was 68.2% and wind speed was 1.2 km/h. Weekly average thermal heat indexes during the experiment were 78.3 (week 1), 79.1 (week 2), 80.1 (weak 3), 79.8 (weak 4), 81.3 (weak 5) and on average 79.7. Feed intake, heart rate, thermoregulatory responses (rectal temperature, respiration rate), blood plasma concentrations of ions (Na, K), antidiuretic hormone (ADH), metabolites (glucose, cholesterol, creatinine and urea) and behavioral aspects (standing, walking, lying) were studied over 30 days. The responses to water restriction were proportional to the level of restriction. The reductions in feed intake (up to 13%), BW (up to 4.6%) and the increases in rectal temperature (0.5°C) and breath rate (10 respirations/min) were moderate and also were far from responses encountered under severe heat and water stresses. The increase in plasma Na (from 119 to 140 mM) and ADH concentrations (from 12.6 to 17.4 pg/ml) indicates that the physiological response to water restriction was in response to mild dehydration, which also explains the increase in blood plasma concentrations of glucose, cholesterol, creatinine

  2. A novel glass slide filing system for pathology slides.

    PubMed

    Tsai, Steve; Kartono, Francisca; Shitabata, Paul K

    2007-07-01

    The availability of a collection of microscope glass slides for review is essential in the study and practice of pathology. A common problem facing many pathologists is the lack of a well-organized filing system. We present a novel system that would be easily accessible, informative, protective, and portable.

  3. Manual stage acquisition and interactive display of digital slides in histopathology.

    PubMed

    Gherardi, Alessandro; Bevilacqua, Alessandro

    2014-07-01

    More powerful PC architectures, high-resolution cameras working at increasing frame rates, and more and more accurate motorized microscopes have boosted new applications in the field of biomedicine and medical imaging. In histopathology, the use of digital slides (DSs) imaging through dedicated hardware for digital pathology is increasing for several reasons: digital annotation of suspicious lesions, recorded clinical history, and telepathology as a collaborative environment. In this paper, we propose the first method known in the literature for real-time whole slide acquisition and displaying conceived for conventional nonautomated microscopes. Differently from DS scanner, our software enables biologists and histopathologists to build and view the DS in real time while inspecting the sample, as they are accustomed to. In addition, since our approach is compliant with existing common microscope positions, provided with camera and PC, this could contribute to disseminate the whole slide technology in the majority of small labs not endowed with DS hardware facilities. Experiments performed with different histologic specimens (referring to tumor tissues of different body parts as well as to tumor cells), acquired under different setup conditions and devices, prove the effectiveness of our approach both in terms of quality and speed performances. PMID:25014942

  4. Mechanism of shallow disrupted slide induced by extreme rainfall

    NASA Astrophysics Data System (ADS)

    Igwe, O.; Fukuoka, H.

    2010-12-01

    On July 16, 2010, extreme rainfall attacked western Japan and it caused very intense rainfall in Shobara city, Hiroshima prefecture, Japan. This rainfall induced hundreds of shallow disrupted slides and many of those became debris flows. One of this debris flows attacked a house standing in front of the exit of a channel, and claimed a resident’s life. Western Japan had repeatedly similar disasters in the past. Last event took place from July 19 to 26, 2009, when western Japan had a severe rainstorms and caused floods and landslides. Most of the landslides are debris slide - debris flows. Most devastated case took place in Hofu city, Japan. On July 21, extremely intense rainstorm caused numerous debris flows and mud flows in the hillslopes. Some of the debris flows destroyed residential houses and home for elderly people, and finally killed 14 residents. One of the unusual feature of both disaster was that landslides are distributed in very narrow area. In the 2010 Shobara city disaster, all of the landslides were distributed in 5 km x 3 km, and in the 2009 Hofu city disaster, most devastated zone of landslides were 10 km x 5 km. Rain radars of Meteorological Agency of Government of Japan detected the intense rainfall, however, the spatial resolution is usually larger than 5 km and the disaster area is too small to predict landslides nor issue warning. Furthermore, it was found that the growth rate of baby clouds was very quick. The geology of both areas are rhyolite (Shobara) and granite (Hofu), so the areal assessment of landslide hazard should be prepared before those intense rainfall will come. As for the Hofu city case, it was proved that debris flows took place in the high precipitation area and covered by covered by weathered granite sands and silts which is called “masa". This sands has been proved susceptible against landslides under extreme rainfall conditions. However, the transition from slide - debris flow process is not well revealed, except

  5. Design of anti-slide piles for slope stabilization in Wanzhou city, Three Gorges Area, China

    NASA Astrophysics Data System (ADS)

    Zhou, Chunmei; van Westen, Cees

    2013-04-01

    This study is related to the design of anti-slide piles for several landslides in Wanzhou city located in the Three Gorges area. Due to the construction of the Three Gorges Reservoir the hydro-geological conditions in this area have deteriorated significantly, leading to larger instability problems. China has invested a lot of money in slope stabilization measures for the treatment of landslides in the Three Gorges area. One of the methods for the stabilization of large landslides is the design of anti-sliding piles. This paper focuses on extensive slope stability analysis and modeling of the mechanical behavior of the landslide masses, and the parameters required for designing the number, size and dimensions of reinforced concrete stabilization piles. The study focuses on determining the rock parameters, anchor depth, and the pile and soil interaction coefficient. The study aims to provide guidelines for anti-slide pile stabilization works for landslides in the Wanzhou area. The research work contains a number of aspects. First a study is carried out on the distribution of pressures expected on the piles, using two different methods that take into account the expected pore water pressure and seismic acceleration. For the Ercengyan landslide , the Limit Equilibrium Method and Strength Reduction Method of FEM are compared through the results of the landslide pressure distributions on the piles and stress fields in the piles. The second component is the study of the required anchor depth of antislide piles, which is carried out using a statistical analysis with data from 20 landslides that have been controlled with anti-sliding piles. The rock characteristics of the anchor locations were obtained using laboratory tests, and a classification of rock mass quality is made for the anchors of antislide piles. The relationship between the critical anchor height and the angle of the landslide slip surface is determined. Two different methods are presented for the length

  6. Herbaceous Ornamental Plants. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven

    This document, which is one in a series of curriculum materials that has been developed for use in Ohio agricultural education programs, contains 338 black-and-white photographs of a set of color slides and an accompanying script that, together, are intended as an aid in the study and identification of 150 different commercially important…

  7. Automatic 35 mm slide duplicator

    NASA Technical Reports Server (NTRS)

    Seidel, H. F.; Texler, R. E.

    1980-01-01

    Automatic duplicator is readily assembled from conventional, inexpensive equipment and parts. Series of slides can be exposed without operator attention, eliminating considerable manual handling and processing ordinarily required. At end of programmed exposure sequence, unit shuts off and audible alarm signals completion of process.

  8. Optimal sliding guidance algorithm for Mars powered descent phase

    NASA Astrophysics Data System (ADS)

    Wibben, Daniel R.; Furfaro, Roberto

    2016-02-01

    Landing on large planetary bodies (e.g. Mars) with pinpoint accuracy presents a set of new challenges that must be addressed. One such challenge is the development of new guidance algorithms that exhibit a higher degree of robustness and flexibility. In this paper, the Zero-Effort-Miss/Zero-Effort-Velocity (ZEM/ZEV) optimal sliding guidance (OSG) scheme is applied to the Mars powered descent phase. This guidance algorithm has been specifically designed to combine techniques from both optimal and sliding control theories to generate an acceleration command based purely on the current estimated spacecraft state and desired final target state. Consequently, OSG yields closed-loop trajectories that do not need a reference trajectory. The guidance algorithm has its roots in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by defining a non-linear sliding surface as a function of the terms Zero-Effort-Miss and Zero-Effort-Velocity. With the addition of the sliding mode and using Lyapunov theory for non-autonomous systems, one can formally prove that the developed OSG law is globally finite-time stable to unknown but bounded perturbations. Here, the focus is on comparing the generalized ZEM/ZEV feedback guidance with the OSG law to explicitly demonstrate the benefits of the sliding mode augmentation. Results show that the sliding guidance provides a more robust solution in off-nominal scenarios while providing similar fuel consumption when compared to the non-sliding guidance command. Further, a Monte Carlo analysis is performed to examine the performance of the OSG law under perturbed conditions.

  9. Significance of grain sliding mechanisms for ductile deformation of rocks

    NASA Astrophysics Data System (ADS)

    Dimanov, A.; Bourcier, M.; Gaye, A.; Héripré, E.; Bornert, M.; Raphanel, J.; Ludwig, W.

    2013-12-01

    Ductile shear zones at depth present polyphase and heterogeneous rocks and multi-scale strain localization patterns. Most strain concentrates in ultramylonitic layers, which exhibit microstructural signatures of several concomitant deformation mechanisms. The latter are either active in volume (dislocation creep), or in the vicinity and along interfaces (grain sliding and solution mass transfer). Because their chronology of appearance and interactions are unclear, inference of the overall rheology seems illusory. We have therefore characterized over a decade the rheology of synthetic lower crustal materials with different compositions and fluid contents, and for various microstructures. Non-Newtonian flow clearly related to dominant dislocation creep. Conversely, Newtonian behavior involved grain sliding mechanisms, but crystal plasticity could be identified as well. In order to clarify the respective roles of these mechanisms we underwent a multi-scale investigation of the ductile deformation of rock analog synthetic halite with controlled microstructures. The mechanical tests were combined with in-situ optical microscopy, scanning electron microscopy and X ray computed tomography, allowing for digital image correlation (DIC) techniques and retrieval of full strain field. Crystal plasticity dominated, as evidenced by physical slip lines and DIC computed slip bands. Crystal orientation mapping allowed to identify strongly active easy glide {110} <110> systems. But, all other slip systems were observed as well, and especially near interfaces, where their activity is necessary to accommodate for the plastic strain incompatibilities between neighboring grains. We also evidenced grain boundary sliding (GBS), which clearly occurred as a secondary, but necessary, accommodation mechanism. The DIC technique allowed the quantification of the relative contribution of each mechanism. The amount of GBS clearly increased with decreasing grain size. Finite element (FE) modeling

  10. The Slide-Lecture: An Alternative to Chalkdust?

    ERIC Educational Resources Information Center

    Wilkins, S. A.

    Many instructors teaching large survey courses use the chalkboard to aid their lectures in spite of the waste of class time in writing and erasing, the clutter and confusion that may result, and the messiness of chalkdust. As an alternative, the slide-lecture method has been used for several years at Bossier Community College in teaching…

  11. Diseases of Landscape Ornamentals. Slide Script.

    ERIC Educational Resources Information Center

    Powell, Charles C.; Sydnor, T. Davis

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with recognizing and controlling diseases found on ornamental landscape plants. Included in the script are narrations for use with a total of 80 slides illustrating various foliar diseases (anthracnose, black spot, hawthorn leaf blight,…

  12. Linear Classification of Dairy Cattle. Slide Script.

    ERIC Educational Resources Information Center

    Sipiorski, James; Spike, Peter

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with principles of the linear classification of dairy cattle. Included in the guide are narrations for use with 63 slides, which illustrate the following areas that are considered in the linear classification system: stature, strength,…

  13. Approved Practices in Dairy Reproduction. Slide Script.

    ERIC Educational Resources Information Center

    Roediger, Roger D.; Barr, Harry L.

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with approved practices in dairy reproduction. Included in the guide are narrations for use with 200 slides dealing with the following topics: the importance of good reproduction, the male and female roles in reproduction, selection of…

  14. Global Trends in Environment and Development. Presentation Set [Slides].

    ERIC Educational Resources Information Center

    World Resources Inst., Washington, DC.

    This 50 slide set of presentation graphs and maps illustrates some of the major conditions and trends in population, agriculture, biodiversity, forests, water resources, energy, climate, and social and economic development that determine the state of the world's environment. Graphs and maps can be used by those in academic, professional, and…

  15. Studying the Activities of Microorganisms in Soil Using Slides.

    ERIC Educational Resources Information Center

    Cullimore, D. Roy; Pipe, Annette E.

    1980-01-01

    Two implanted slide techniques are described by which activity of proteolylic bacteria and the growth of algae in the soil can be readily studied by school students using simple apparatus and methods. Variations are suggested for studying the effects of agricultural practices and environmental conditions on the soil bacteria and algae. (Author/DS)

  16. Comparison of estimated core body temperature measured with the BioHarness and rectal temperature under several heat stress conditions.

    PubMed

    Seo, Yongsuk; DiLeo, Travis; Powell, Jeffrey B; Kim, Jung-Hyun; Roberge, Raymond J; Coca, Aitor

    2016-08-01

    Monitoring and measuring core body temperature is important to prevent or minimize physiological strain and cognitive dysfunction for workers such as first responders (e.g., firefighters) and military personnel. The purpose of this study is to compare estimated core body temperature (Tco-est), determined by heart rate (HR) data from a wearable chest strap physiology monitor, to standard rectal thermometry (Tre) under different conditions.  Tco-est and Tre measurements were obtained in thermoneutral and heat stress conditions (high temperature and relative humidity) during four different experiments including treadmill exercise, cycling exercise, passive heat stress, and treadmill exercise while wearing personal protective equipment (PPE).  Overall, the mean Tco-est did not differ significantly from Tre across the four conditions. During exercise at low-moderate work rates under heat stress conditions, Tco-est was consistently higher than Tre at all-time points. Tco-est underestimated temperature compared to Tre at rest in heat stress conditions and at a low work rate under heat stress while wearing PPE. The mean differences between the two measurements ranged from -0.1 ± 0.4 to 0.3 ± 0.4°C and Tco-est correlated well with HR (r = 0.795 - 0.849) and mean body temperature (r = 0.637 - 0.861).  These results indicate that, the comparison of Tco-est to Tre may result in over- or underestimation which could possibly lead to heat-related illness during monitoring in certain conditions. Modifications to the current algorithm should be considered to address such issues.

  17. Composite fuzzy sliding mode control of nonlinear singularly perturbed systems.

    PubMed

    Nagarale, Ravindrakumar M; Patre, B M

    2014-05-01

    This paper deals with the robust asymptotic stabilization for a class of nonlinear singularly perturbed systems using the fuzzy sliding mode control technique. In the proposed approach the original system is decomposed into two subsystems as slow and fast models by the singularly perturbed method. The composite fuzzy sliding mode controller is designed for stabilizing the full order system by combining separately designed slow and fast fuzzy sliding mode controllers. The two-time scale design approach minimizes the effect of boundary layer system on the full order system. A stability analysis allows us to provide sufficient conditions for the asymptotic stability of the full order closed-loop system. The simulation results show improved system performance of the proposed controller as compared to existing methods. The experimentation results validate the effectiveness of the proposed controller.

  18. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This article deals with a poster entitled, "Severe Weather," that has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in…

  19. Severe Weather

    ERIC Educational Resources Information Center

    Forde, Evan B.

    2004-01-01

    Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This month's insert, Severe Weather, has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in this poster are hurricanes,…

  20. Evaluation of Resistance to Change under Different Disrupter Conditions in Children with Autism and Severe Intellectual Disability

    ERIC Educational Resources Information Center

    Lionello-DeNolf, Karen M.; Dube, William V.; McIlvane, William J.

    2010-01-01

    Translational research inspired by behavioral momentum theory in the area of developmental disabilities has shown effects in individuals over a range of functioning levels. In the current study, behavioral momentum was assessed in 6 children diagnosed with autism and severe intellectual disability. In a repeated measures design, participants were…

  1. Enhancing the Aerobic Fitness of Individuals with Moderate and Severe Disabilities: A Peer-Mediated Aerobic Conditioning Program.

    ERIC Educational Resources Information Center

    Halle, James W.; And Others

    This manual describes a physical fitness program for students with moderate and severe disabilities, which has as additional goals integration with nondisabled peers and improved attitudes of nondisabled peers toward students with disabilities. The first section presents background information, describes the program's development, and presents the…

  2. Pressure vessel sliding support unit and system using the sliding support unit

    DOEpatents

    Breach, Michael R.; Keck, David J.; Deaver, Gerald A.

    2013-01-15

    Provided is a sliding support and a system using the sliding support unit. The sliding support unit may include a fulcrum capture configured to attach to a support flange, a fulcrum support configured to attach to the fulcrum capture, and a baseplate block configured to support the fulcrum support. The system using the sliding support unit may include a pressure vessel, a pedestal bracket, and a plurality of sliding support units.

  3. Controls on variations in MODIS fire radiative power in Alaskan boreal forests: implications for fire severity conditions

    USGS Publications Warehouse

    Barrett, Kirsten; Kasischke, Eric S.

    2013-01-01

    Fire activity in the Alaskan boreal forest, though episodic at annual and intra-annual time scales, has experienced an increase over the last several decades. Increases in burned area and fire severity are not only releasing more carbon to the atmosphere, but likely shifting vegetation composition in the region towards greater deciduous dominance and a reduction in coniferous stands. While some recent studies have addressed qualitative differences between large and small fire years in the Alaskan boreal forest, the ecological effects of a greater proportion of burning occurring during large fire years and during late season fires have not yet been examined. Some characteristics of wildfires that can be detected remotely are related to fire severity and can provide new information on spatial and temporal patterns of burning. This analysis focused on boreal wildfire intensity (fire radiative power, or FRP) contained in the Moderate Resolution Imaging Spectroradiometer (MODIS) daily active fire product from 2003 to 2010. We found that differences in FRP resulted from seasonality and intra-annual variability in fire activity levels, vegetation composition, latitudinal variation, and fire spread behavior. Our studies determined two general categories of active fire detections: new detections associated with the spread of the fire front and residual pixels in areas that had already experienced front burning. Residual pixels had a lower average FRP than front pixels, but represented a high percentage of all pixels during periods of high fire activity (large fire years, late season burning, and seasonal periods of high fire activity). As a result, the FRP from periods of high fire activity was less intense than those from periods of low fire activity. Differences related to latitude were greater than expected, with higher latitudes burning later in the season and at a higher intensity than lower latitudes. Differences in vegetation type indicate that coniferous vegetation

  4. Automated single-slide staining device

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Mills, S. M. (Inventor)

    1977-01-01

    A simple apparatus and method is disclosed for making individual single Gram stains on bacteria inoculated slides to assist in classifying bacteria in the laboratory as Gram-positive or Gram-negative. The apparatus involves positioning a single inoculated slide in a stationary position and thereafter automatically and sequentially flooding the slide with increments of a primary stain, a mordant, a decolorizer, a counterstain and a wash solution in a sequential manner without the individual lab technician touching the slide and with minimum danger of contamination thereof from other slides.

  5. VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions. Revision 1

    SciTech Connect

    Heams, T J; Williams, D A; Johns, N A; Mason, A; Bixler, N E; Grimley, A J; Wheatley, C J; Dickson, L W; Osborn-Lee, I; Domagala, P; Zawadzki, S; Rest, J; Alexander, C A; Lee, R Y

    1992-12-01

    The VICTORIA model of radionuclide behavior in the reactor coolant system (RCS) of a light water reactor during a severe accident is described. It has been developed by the USNRC to define the radionuclide phenomena and processes that must be considered in systems-level models used for integrated analyses of severe accident source terms. The VICTORIA code, based upon this model, predicts fission product release from the fuel, chemical reactions involving fission products, vapor and aerosol behavior, and fission product decay heating. Also included is a detailed description of how the model is implemented in VICTORIA, the numerical algorithms used, and the correlations and thermochemical data necessary for determining a solution. A description of the code structure, input and output, and a sample problem are provided.

  6. Total lymphoid irradiation and cyclophosphamide conditioning prior to bone marrow transplantation for patients with severe aplastic anemia

    SciTech Connect

    Ramsay, N.K.; Kim, T.H.; McGlave, P.; Goldman, A.; Nesbit, M.E. Jr.; Krivit, W.; Woods, W.G.; Kersey, J.H.

    1983-09-01

    A preparative regimen, consisting of total lymphoid irradiation and cyclophosphamide, was utilized in 40 patients with severe aplastic anemia undergoing allogeneic marrow transplantation. This regimen was successful in decreasing rejection in these previously transfused patients, as only one patient rejected the marrow graft. Twenty-nine of the 40 transplanted patients are surviving from 1.5 to 59 mo, with a median follow-up of 24 mo. The actuarial survival rate for these heavily transfused patients with aplastic anemia is 72% at 2 yr. This preparative regimen is extremely effective in decreasing rejection following transplantation for severe aplastic anemia. Future efforts in this area must be aimed at the elimination of graft-versus-host disease and control of fatal infections.

  7. Impact of Flight Enthalpy, Fuel Simulant, and Chemical Reactions on the Mixing Characteristics of Several Injectors at Hypervelocity Flow Conditions

    NASA Technical Reports Server (NTRS)

    Drozda, Tomasz G.; Baurle, Robert A.; Drummond, J. Philip

    2016-01-01

    The high total temperatures or total enthalpies required to duplicate the high-speed flight conditions in ground experiments often place stringent requirements on the material selection and cooling needs for the test articles and intrusive flow diagnostic equipment. Furthermore, for internal flows, these conditions often complicate the use of nonintrusive diagnostics that need optical access to the test section and interior portions of the flowpath. Because of the technical challenges and increased costs associated with experimentation at high values of total enthalpy, an attempt is often made to reduce it. This is the case for the Enhanced Injection and Mixing Project (EIMP) currently underway in the Arc-Heated Scramjet Test Facility at the NASA Langley Research Center. The EIMP aims to investigate supersonic combustion ramjet (scramjet) fuel injection and mixing physics, improve the understanding of underlying physical processes, and develop enhancement strategies and functional relationships between mixing performance and losses relevant to flight Mach numbers greater than 8. The experiments will consider a "direct-connect" approach and utilize a Mach 6 nozzle to simulate the combustor entrance flow of a scramjet engine. However, while the value of the Mach number is matched to that expected at the combustor entrance in flight, the maximum value of the total enthalpy for these experiments is limited by the thermal-structural limits of the uncooled experimental hardware. Furthermore, the fuel simulant is helium, not hydrogen. The use of "cold" flows and non-reacting mixtures of fuel simulants for mixing experiments is not new and has been extensively utilized as a screening technique for scramjet fuel injectors. In this study, Reynolds-averaged simulations are utilized (RAS) to systematically verify the implicit assumptions used by the EIMP. This is accomplished by first performing RAS of mixing for two injector configurations at planned nominal experimental

  8. Apparatus Would Stain Microscope Slides

    NASA Technical Reports Server (NTRS)

    Breeding, James D.

    1993-01-01

    Proposed apparatus meters specific amounts of fluid out of containers at specific times to stain microscope slides. Intended specifically for semiautomated staining of microbiological and hematological samples in microgravity, leakproof apparatus used in other environments in which technicians have little time to allocate to staining procedures and/or exposure to toxic staining agents or to micro-organisms to be stained hazardous. Apparatus adapted to perform almost any staining procedure and accommodates multiple staining reagents, useful for small or remote clinical laboratories.

  9. Color accuracy and reproducibility in whole slide imaging scanners

    PubMed Central

    Shrestha, Prarthana; Hulsken, Bas

    2014-01-01

    Abstract We propose a workflow for color reproduction in whole slide imaging (WSI) scanners, such that the colors in the scanned images match to the actual slide color and the inter-scanner variation is minimum. We describe a new method of preparation and verification of the color phantom slide, consisting of a standard IT8-target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several International Color Consortium (ICC) compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color space. Based on the quality of the color reproduction in histopathology slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed workflow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We quantify color difference using the CIE-DeltaE2000 metric, where DeltaE values below 1 are considered imperceptible. Our evaluation on 14 phantom slides, manufactured according to the proposed method, shows an average inter-slide color difference below 1 DeltaE. The proposed workflow is implemented and evaluated in 35 WSI scanners developed at Philips, called the Ultra Fast Scanners (UFS). The color accuracy, measured as DeltaE between the scanner reproduced colors and the reference colorimetric values of the phantom patches, is improved on average to 3.5 DeltaE in calibrated scanners from 10 DeltaE in uncalibrated scanners. The average inter-scanner color difference is found to be 1.2 DeltaE. The improvement in color performance upon using the proposed method is apparent with the visual color quality of the tissue scans. PMID:26158041

  10. Color accuracy and reproducibility in whole slide imaging scanners

    NASA Astrophysics Data System (ADS)

    Shrestha, Prarthana; Hulsken, Bas

    2014-03-01

    In this paper, we propose a work-flow for color reproduction in whole slide imaging (WSI) scanners such that the colors in the scanned images match to the actual slide color and the inter scanner variation is minimum. We describe a novel method of preparation and verification of the color phantom slide, consisting of a standard IT8- target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several ICC compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color-space. Based on the quality of color reproduction in histopathology tissue slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed work-ow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We measure objective color performance using CIE-DeltaE2000 metric, where DeltaE values below 1 is considered imperceptible. Our evaluation 14 phantom slides, manufactured according to the proposed method, show an average inter-slide color difference below 1 DeltaE. The proposed work-flow is implemented and evaluated in 35 Philips Ultra Fast Scanners (UFS). The results show that the average color difference between a scanner and the reference is 3.5 DeltaE, and among the scanners is 3.1 DeltaE. The improvement on color performance upon using the proposed method is apparent on the visual color quality of the tissues scans.

  11. Validity of the self-reported drug use section of the Addiction Severity Index and associated factors used under naturalistic conditions.

    PubMed

    Denis, Cécile; Fatséas, Mélina; Beltran, Virginie; Bonnet, Claire; Picard, Stéphane; Combourieu, Isabelle; Daulouède, Jean-Pierre; Auriacombe, Marc

    2012-03-01

    The study examined the validity of 1848 self-reported uses of drugs determined within an Addiction Severity Index interview in comparison with urinalysis results among drug-dependent subjects undergoing treatment in outpatient clinics (Aquitaine area, southwest France, 1994-2005). Agreement and kappa statistics were calculated for each substance. Factors associated with agreement were defined using a multivariate analysis. The conditional kappa coefficients were excellent for all substances assessed. The accuracy between self-reports and urinalysis results was influenced by factors that only slightly affected conditional kappa coefficients. Clients did not underreport their substance use in naturalistic clinical assessment conditions.

  12. Tribology of Si/SiO2 in humid air: transition from severe chemical wear to wearless behavior at nanoscale.

    PubMed

    Chen, Lei; He, Hongtu; Wang, Xiaodong; Kim, Seong H; Qian, Linmao

    2015-01-13

    Wear at sliding interfaces of silicon is a main cause for material loss in nanomanufacturing and device failure in microelectromechanical system (MEMS) applications. However, a comprehensive understanding of the nanoscale wear mechanisms of silicon in ambient conditions is still lacking. Here, we report the chemical wear of single crystalline silicon, a material used for micro/nanoscale devices, in humid air under the contact pressure lower than the material hardness. A transmission electron microscopy (TEM) analysis of the wear track confirmed that the wear of silicon in humid conditions originates from surface reactions without significant subsurface damages such as plastic deformation or fracture. When rubbed with a SiO2 ball, the single crystalline silicon surface exhibited transitions from severe wear in intermediate humidity to nearly wearless states at two opposite extremes: (a) low humidity and high sliding speed conditions and (b) high humidity and low speed conditions. These transitions suggested that at the sliding interfaces of Si/SiO2 at least two different tribochemical reactions play important roles. One would be the formation of a strong "hydrogen bonding bridge" between hydroxyl groups of two sliding interfaces and the other the removal of hydroxyl groups from the SiO2 surface. The experimental data indicated that the dominance of each reaction varies with the ambient humidity and sliding speed.

  13. Scale effects in sliding friction: An experimental study

    SciTech Connect

    Blau, P.J.

    1991-07-24

    Solid friction is considered by some to be a fundamental property of two contacting materials, while others consider it to be a property of the larger tribosystem in which the materials are contained. A set of sliding friction experiments were designed to investigate the hypothesis that the unlubricated sliding friction between two materials is indeed a tribosystems-related property and that the relative influence of the materials properties or those of the machine on friction varies from one situation to another. Three tribometers were used: a friction microprobe (FMP), a typical laboratory-scale reciprocating pin-on-flat device, and a heavy-duty commercial wear tester. The slider material was stainless steel (AISI 440C) and the flat specimen material was an ordered alloy of Ni{sub 3}Al (IC-50). Sphere-on-flat geometry was used at ambient conditions and at normal forces ranging from 0.01 N to 100 N and average sliding velocities of 0.01 to 100.0 mm/s. The nominal, steady-state sliding friction coefficient tended to decrease with increases in normal force for each of the three tribometers, and the steady state value of sliding friction tended to increase as the mass of the machine increased. The variation of the friction force during sliding was also a characteristic of the test system. These studies provide further support to the idea that the friction of both laboratory-scale and engineering tribosystems should be treated as a parameter which may take on a range of characteristic values and not conceived as having a single, unique value for each material pair.

  14. Sliding Wear and Friction Behavior of Fuel Rod Material in Water and Dry State

    NASA Astrophysics Data System (ADS)

    Park, Jin Moo; Kim, Jae Hoon; Jeon, Kyeong Lak; Park, Jun Kyu

    In water cooled reactors, the friction between spacer grid and fuel rod can lead to severe wear and it is an important topic to study. In the present study, sliding wear behavior of zirconium alloy was investigated in water and dry state using the pin-on-disc sliding wear tester. Sliding wear resistance of zirconium alloy against heat treated inconel alloy was examined at room temperature. The parameters in this study were sliding velocity, axial load and sliding distance. The wear characteristics of zirconium alloy was evaluated by friction coefficient, specific wear rate and wear volume. The micro-mechanisms responsible for wear in zirconium alloy were identified to be micro-cutting, micro-pitting, delamination and micro-cracking of deformed surface zone.

  15. Laboratory insights into the chemical and kinetic evolution of several organic molecules under simulated Mars surface UV radiation conditions

    NASA Astrophysics Data System (ADS)

    Poch, O.; Kaci, S.; Stalport, F.; Szopa, C.; Coll, P.

    2014-11-01

    The search for organic carbon at the surface of Mars, as clues of past habitability or remnants of life, is a major science goal of Mars' exploration. Understanding the chemical evolution of organic molecules under current martian environmental conditions is essential to support the analyses performed in situ. What molecule can be preserved? What is the timescale of organic evolution at the surface? This paper presents the results of laboratory investigations dedicated to monitor the evolution of organic molecules when submitted to simulated Mars surface ultraviolet radiation (190-400 nm), mean temperature (218 ± 2 K) and pressure (6 ± 1 mbar) conditions. Experiments are done with the MOMIE simulation setup (for Mars Organic Molecules Irradiation and Evolution) allowing both a qualitative and quantitative characterization of the evolution the tested molecules undergo (Poch, O. et al. [2013]. Planet. Space Sci. 85, 188-197). The chemical structures of the solid products and the kinetic parameters of the photoreaction (photolysis rate, half-life and quantum efficiency of photodecomposition) are determined for glycine, urea, adenine and chrysene. Mellitic trianhydride is also studied in order to complete a previous study done with mellitic acid (Stalport, F., Coll, P., Szopa, C., Raulin, F. [2009]. Astrobiology 9, 543-549), by studying the evolution of mellitic trianhydride. The results show that solid layers of the studied molecules have half-lives of 10-103 h at the surface of Mars, when exposed directly to martian UV radiation. However, organic layers having aromatic moieties and reactive chemical groups, as adenine and mellitic acid, lead to the formation of photoresistant solid residues, probably of macromolecular nature, which could exhibit a longer photostability. Such solid organic layers are found in micrometeorites or could have been formed endogenously on Mars. Finally, the quantum efficiencies of photodecomposition at wavelengths from 200 to 250 nm

  16. Sliding seal materials for adiabatic engines

    NASA Technical Reports Server (NTRS)

    Lankford, J.

    1985-01-01

    The sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, loading conditions that are representative of the adiabatic engine environment. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Microhardness tests were performed on the candidate materials at elevated temperatures, and in atmospheres relevant to the piston seal application, and optical and electron microscopy were used to elucidate the micromechanisms of wear following wear testing. X-ray spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Electrical effects in the friction and wear processes were explored in order to evaluate the potential usefulness of such effects in modifying the friction and wear rates in service. However, this factor was found to be of negligible significance in controlling friction and wear.

  17. Effect of nontronite smectite clay on the chemical evolution of several organic molecules under simulated martian surface ultraviolet radiation conditions.

    PubMed

    Poch, Olivier; Jaber, Maguy; Stalport, Fabien; Nowak, Sophie; Georgelin, Thomas; Lambert, Jean-François; Szopa, Cyril; Coll, Patrice

    2015-03-01

    Most of the phyllosilicates detected at the surface of Mars today are probably remnants of ancient environments that sustained long-term bodies of liquid water at the surface or subsurface and were possibly favorable for the emergence of life. Consequently, phyllosilicates have become the main mineral target in the search for organics on Mars. But are phyllosilicates efficient at preserving organic molecules under current environmental conditions at the surface of Mars? We monitored the qualitative and quantitative evolutions of glycine, urea, and adenine in interaction with the Fe(3+)-smectite clay nontronite, one of the most abundant phyllosilicates present at the surface of Mars, under simulated martian surface ultraviolet light (190-400 nm), mean temperature (218 ± 2 K), and pressure (6 ± 1 mbar) in a laboratory simulation setup. We tested organic-rich samples that were representative of the evaporation of a small, warm pond of liquid water containing a high concentration of organics. For each molecule, we observed how the nontronite influences its quantum efficiency of photodecomposition and the nature of its solid evolution products. The results reveal a pronounced photoprotective effect of nontronite on the evolution of glycine and adenine; their efficiencies of photodecomposition were reduced by a factor of 5 when mixed at a concentration of 2.6 × 10(-2) mol of molecules per gram of nontronite. Moreover, when the amount of nontronite in the sample of glycine was increased by a factor of 2, the gain of photoprotection was multiplied by a factor of 5. This indicates that the photoprotection provided by the nontronite is not a purely mechanical shielding effect but is also due to stabilizing interactions. No new evolution product was firmly identified, but the results obtained with urea suggest a particular reactivity in the presence of nontronite, leading to an increase of its dissociation rate.

  18. Effect of nontronite smectite clay on the chemical evolution of several organic molecules under simulated martian surface ultraviolet radiation conditions.

    PubMed

    Poch, Olivier; Jaber, Maguy; Stalport, Fabien; Nowak, Sophie; Georgelin, Thomas; Lambert, Jean-François; Szopa, Cyril; Coll, Patrice

    2015-03-01

    Most of the phyllosilicates detected at the surface of Mars today are probably remnants of ancient environments that sustained long-term bodies of liquid water at the surface or subsurface and were possibly favorable for the emergence of life. Consequently, phyllosilicates have become the main mineral target in the search for organics on Mars. But are phyllosilicates efficient at preserving organic molecules under current environmental conditions at the surface of Mars? We monitored the qualitative and quantitative evolutions of glycine, urea, and adenine in interaction with the Fe(3+)-smectite clay nontronite, one of the most abundant phyllosilicates present at the surface of Mars, under simulated martian surface ultraviolet light (190-400 nm), mean temperature (218 ± 2 K), and pressure (6 ± 1 mbar) in a laboratory simulation setup. We tested organic-rich samples that were representative of the evaporation of a small, warm pond of liquid water containing a high concentration of organics. For each molecule, we observed how the nontronite influences its quantum efficiency of photodecomposition and the nature of its solid evolution products. The results reveal a pronounced photoprotective effect of nontronite on the evolution of glycine and adenine; their efficiencies of photodecomposition were reduced by a factor of 5 when mixed at a concentration of 2.6 × 10(-2) mol of molecules per gram of nontronite. Moreover, when the amount of nontronite in the sample of glycine was increased by a factor of 2, the gain of photoprotection was multiplied by a factor of 5. This indicates that the photoprotection provided by the nontronite is not a purely mechanical shielding effect but is also due to stabilizing interactions. No new evolution product was firmly identified, but the results obtained with urea suggest a particular reactivity in the presence of nontronite, leading to an increase of its dissociation rate. PMID:25734356

  19. "Discoveries in Planetary Sciences": Slide Sets Highlighting New Advances for Astronomy Educators

    NASA Astrophysics Data System (ADS)

    Brain, David; Schneider, N.; Molaverdikhani, K.; Afsharahmadi, F.

    2012-10-01

    We present two new features of an ongoing effort to bring recent newsworthy advances in planetary science to undergraduate lecture halls. The effort, called 'Discoveries in Planetary Sciences', summarizes selected recently announced discoveries that are 'too new for textbooks' in the form of 3-slide PowerPoint presentations. The first slide describes the discovery, the second slide discusses the underlying planetary science concepts at a level appropriate for students of 'Astronomy 101', and the third presents the big picture implications of the discovery. A fourth slide includes links to associated press releases, images, and primary sources. This effort is generously sponsored by the Division for Planetary Sciences of the American Astronomical Society, and the slide sets are available at http://dps.aas.org/education/dpsdisc/ for download by undergraduate instructors or any interested party. Several new slide sets have just been released, and we summarize the topics covered. The slide sets are also being translated into languages other than English (including Spanish and Farsi), and we will provide an overview of the translation strategy and process. Finally, we will present web statistics on how many people are using the slide sets, as well as individual feedback from educators.

  20. Development of a teledermatopathology consultation system using virtual slides

    PubMed Central

    2012-01-01

    Background An online consultation system using virtual slides (whole slide images; WSI) has been developed for pathological diagnosis, and could help compensate for the shortage of pathologists, especially in the field of dermatopathology and in other fields dealing with difficult cases. This study focused on the performance and future potential of the system. Method In our system, histological specimens on slide glasses are digitalized by a virtual slide instrument, converted into web data, and up-loaded to an open server. Using our own purpose-built online system, we then input patient details such as age, gender, affected region, clinical data, past history and other related items. We next select up to ten consultants. Finally we send an e-mail to all consultants simultaneously through a single command. The consultant receives an e-mail containing an ID and password which is used to access the open server and inspect the images and other data associated with the case. The consultant makes a diagnosis, which is sent to us along with comments. Because this was a pilot study, we also conducted several questionnaires with consultants concerning the quality of images, operability, usability, and other issues. Results We solicited consultations for 36 cases, including cases of tumor, and involving one to eight consultants in the field of dermatopathology. No problems were noted concerning the images or the functioning of the system on the sender or receiver sides. The quickest diagnosis was received only 18 minutes after sending our data. This is much faster than in conventional consultation using glass slides. There were no major problems relating to the diagnosis, although there were some minor differences of opinion between consultants. The results of questionnaires answered by many consultants confirmed the usability of this system for pathological consultation. (16 out of 23 consultants.) Conclusion We have developed a novel teledermatopathological consultation

  1. Tape-recorded Lectures With Slide Synchronization

    ERIC Educational Resources Information Center

    Goodhue, D.

    1969-01-01

    Describes "Taped Explanation Slide Synchronization" programs used for individual study or group showing in college zoology. Discusses preparation of programs, class organization, equipment, and costs. (EB)

  2. Instant slides of radiographs for lectures.

    PubMed

    Rothstein, S G; Stewart, P L

    1989-10-01

    High quality slides of radiographs may be made with a simple, fast, and inexpensive technique using Kodak Rapid Process Copy film. Lecture presentations may include a slide of a pertinent plain radiograph, computed tomography (CT) scan, or magnetic resonance imaging (MRI). Although these slides may be made with a 35 mm SLR camera and flash or with a 35 mm SLR camera and a lighted viewbox, an alternative method is available that is easy to perform, inexpensive, and can produce quality slides in as little as 30 minutes. PMID:2477785

  3. "Slide less pathology": Fairy tale or reality?

    PubMed

    Indu, M; Rathy, R; Binu, M P

    2016-01-01

    Pathology practice is significantly advanced in various frontiers. Therefore, "slide less digital" pathology will not be a mere imagination in near future. Digitalization of histopathological slides (whole slide imaging [WSI]) is possible with the help of whole slide scanner. The WSI has a positive impact not only in routine practice but also in research field, medical education and bioindustry. Even if digital pathology has definitive advantages, its widespread use is not yet possible. As it is an upcoming technology in our field, this article is aimed to discussessential aspects of WSI. PMID:27601824

  4. Insights from new high-resolution data from the Traenadjupet Slide on the Norwegian margin

    NASA Astrophysics Data System (ADS)

    Mozzato, Alessandro; Tappin, David; Talling, Peter; Cartigny, Matthieu; Long, David; Hunt, James; Watts, Camilla; Pope, Ed; Allin, Joshua; Stanford, Jennifer; Dowdeswell, Julian

    2015-04-01

    Submarine landslides are among the largest mass flows on Earth and can be far larger than landslides on land. They can generate tsunami and therefore represent a significant geohazard. A series of large submarine landslides have been studied previously in unusual detail along the Norwegian continental margin, including the Storegga and Traenadjupet Slides. The most closely studied is the Storegga slide(1,2) which occurred 8.2k BP and moved >3,000 km3 of sediment(2). A tsunami with run up heights sometimes reaching 20m high has been identified from deposits mapped along the Norwegian, Shetland and mainland Scottish coasts (1). The Traenadjupet Slide is the second largest slide on the Norwegian margin with a volume of about 900km3. It has been dated to ~4k BP(3,4). The volume is comparable to that of the Storegga Slide. However, no major tsunami deposit at 4ka has yet been mapped that links to the Traenadjupet Slide (Stein Bondevik, pers. comm.). The purpose of this study is to obtain new insights into how the Traenadjupet Slide was emplaced. In particular, why did movement of 900km3 of sediment during the Traenadjupet Slide fail to produce a major tsunami at 4ka? We present a new field dataset for the Traendajupet Slide including MBES bathymetry, sub-bottom profiles, and piston cores acquired during the 64PE391 research expedition in July 2014, together with data acquired previously during the JCR51 cruise. These datasets cover a large part of Traenadjupet slide and give new insights into the mechanism of the slide failure. The Traenadjupet Slide morphology is very different to that of the Storegga Slide. The Storegga Slide disintegrated generating debris flows and turbidity currents that propagated for hundreds of kilometres. The Traenadjupet Slide, on the other hand, appears not to have disintegrated in a similar manner, but rather left thick mounded deposits at the foot of the slope(5). Several distinct lobes covered with 500m-scale sediment blocks are visible

  5. Slide Tape. A Guide to the Production of Slide-Tape Programmes.

    ERIC Educational Resources Information Center

    Rowatt, Robert W.

    Step by step instructions are provided for planning and executing a slide tape program, as well as diagrams of equipment for presenting such programs. Guidelines are given for ways to: (1) define a program's purpose and objectives, (2) complete a storyboard, (3) produce slides from transparencies and photographed artwork, (4) write on slides, (5)…

  6. Influence of the sliding velocity and the applied potential on the corrosion and wear behavior of HC CoCrMo biomedical alloy in simulated body fluids.

    PubMed

    Gil, Roberto Alonso; Muñoz, Anna Igual

    2011-11-01

    The corrosion and tribocorrosion behavior of an as-cast high carbon CoCrMo alloy immersed in phosphate buffered solution (PBS) and phosphate buffered solution with bovine serum albumin (PBS+BSA) have been analyzed by electrochemical techniques and surface microscopy. After the electrochemical characterization of the alloy in both solutions, the sample was studied tribo-electrochemically (by open circuit potential, OCP measurements, potentiodynamic curves and potentiostatic tests) in a ball-on-disk tribometer rotating in different sliding velocities. The influence of solution chemistry, sliding velocity and applied potential on the corrosion and tribocorrosion behavior of the CoCrMo alloy has been studied. Anodic current density increases with sliding velocity but wear rate does not change at an applied anodic potential; on the other hand, BSA modifies the wear debris behavior (by agglomerating the debris formed by mechanical removal of particles) thus increasing the mechanical wear volume. Under cathodic conditions, cathodic current density also increases during mechanical contact while the wear rate decreases with sliding velocity and BSA lubricates the contact thus reducing the total wear volume with respect to the non-containing BSA solution. The work shows how the electrode potential critically affects the corrosion and tribocorrosion rates by increasing the wear coefficients at applied anodic potentials due to severe wear accelerated corrosion.

  7. [Heritage Education Lesson Plans and Slide Presentations].

    ERIC Educational Resources Information Center

    Van Buren, Maurie

    Field tested in 27 schools and in grades four through twelve, this teaching unit stresses heritage education through the study of southern U.S. architectural styles for homes from the pioneer log structures to the 1950s ranch home. Each of the four lessons in this unit focuses around a slide presentation of 20 slides designed to fit into one…

  8. Getting Clever with the Sliding Ladder

    ERIC Educational Resources Information Center

    De, Subhranil

    2014-01-01

    The familiar system involving a uniform ladder sliding against a vertical wall and a horizontal floor is considered again. The floor is taken to be smooth and the wall to be possibly rough--a situation where no matter how large the static friction coefficient between the ladder and the wall, the ladder cannot lean at rest and must slide down.…

  9. The Cancer Digital Slide Archive - TCGA

    Cancer.gov

    Dr. David Gutman and Dr. Lee Cooper developed The Cancer Digital Slide Archive (CDSA), a web platform for accessing pathology slide images of TCGA samples. Find out how they did it and how to use the CDSA website in this Case Study.

  10. Swarm slide - debris flow disaster induced by extreme rainfall in Hiroshima, August 2014 and lessons learnt in urban designing

    NASA Astrophysics Data System (ADS)

    Fukuoka, H.; Wang, C.

    2015-12-01

    Hiroshima city was hit by swarm debris flows along a narrow, and linear-shaped rain band of 2 km x 10 km which appeared in the early morning of August 20, 2014. Most of the flows were induced by shallow slide in the upstream. This disaster claimed 74 death, although this city experienced very similar disaster in 1999, claiming more than 30 residents lives. In the most severely affected debris flow torrent, more than 50 residents were killed. Most of the casualties arose in the wooden, vulnerable houses constructed in front of the exit of torrents. Points and lessons learnt from the disaster are as follows:1. Authors collected two types of sands from the source scar of the initial debris slides which induced debris flows. Tested by the ring shear apparatus under pore-pressure control condition, clear "Sliding surface liquefaction" was confirmed for both samples even under small normal stress, representing the small thickness of the slides. These results shows even instant excess pore pressure could initiate the slides and trigger slide-induced debris flow byundrained loading onto the torrent deposits.2. Apparently long-term land-use change since 1945 affected and raised the vulnerability of the community. Residential area had expanded into hill-slope (mountainous / semi-mountainous area) especially along the torrents. Those communities were developed on the past debris flow fan.3. As the devastated area is very close to downtown of Hiroshima city, it gave large societal impact to the Japanese citizens. After 1999 Hiroshima debris flow disaster, the Landslide disaster reduction law which intends to promote designation of landslide potential risk zones, was adopted in 2000. Immediately after 2014 disaster, national diet approved revision of the bill to promote rapid completion of the designation over the national territory. MLIT (Ministry of Land, Infrastructure, Tranportation and Tourism) decided to install X-band rain radars at more sites to cover whole city zones

  11. Thermal and thermomechanical effects in dry sliding

    NASA Technical Reports Server (NTRS)

    Kennedy, F. E., Jr.

    1984-01-01

    Developments in the study of interrelated thermal and mechanical phenomena in sliding systems are reviewed. The topics reviewed include mechanisms of frictional heating and the distribution of heat during sliding friction, the experimental measurement and analysis of surface and near-surface temperatures resulting from frictional heating, thermal deformation around sliding contacts and the changes in contact geometry caused by thermal deformation and thermoelastic instability, and the thermomechanical stress distribution around the frictionally heated and thermally deformed contact spots. The influence of the thermal and thermomechanical contact phenomena on friction and wear, surface melting, softening, chemical deterioration, and thermocracking are discussed. The phenomena have important implications in the design and application of sliding or sliding-rolling mechanical components such as dynamic seals, brakes, clutches, plastic bearings, solid or boundary-lubricated bearings, and gears.

  12. Sliding mode control with PID sliding surface and experimental application to an electromechanical plant.

    PubMed

    Eker, Ilyas

    2006-01-01

    In this study, a sliding mode control system with a proportional+integral+derivative (PID) sliding surface is adopted to control the speed of an electromechanical plant. A robust sliding mode controller is derived so that the actual trajectory tracks the desired trajectory despite uncertainty, nonlinear dynamics, and external disturbances. The proposed sliding mode controller is chosen to ensure the stability of overall dynamics during the reaching phase and sliding phase. The stability of the system is guaranteed in the sense of the Lyapunov stability theorem. The chattering problem is overcome using a hyperbolic function for the sliding surface. Experimental results that are compared with the results of conventional PID verify that the proposed sliding mode controller can achieve favorable tracking performance, and it is robust with regard to uncertainties and disturbances.

  13. Sliding Over a Phase Transition

    NASA Astrophysics Data System (ADS)

    Tosatti, Erio; Benassi, Andrea; Vanossi, Andrea; Santoro, Giuseppe E.

    2011-03-01

    The frictional response experienced by a stick-slip slider when a phase transition occurs in the underlying solid substrate is a potentially exciting, poorly explored problem. We show, based on 2-dimensional simulations modeling the sliding of a nanotip, that indeed friction may be heavily affected by a continuous structural transition. First, friction turns nonmonotonic as temperature crosses the transition, peaking at the critical temperature Tc where fluctuations are strongest. Second, below Tc friction depends upon order parameter directions, and is much larger for those where the frictional slip can cause a local flip. This may open a route towards control of atomic scale friction by switching the order parameter direction by an external field or strain, with possible application to e.g., displacive ferroelectrics such as BaTi O3 , as well as ferro- and antiferro-distortive materials. Supported by project ESF FANAS/AFRI sponsored by the Italian Research Council (CNR).

  14. Evaluation of materials for sliding at 600F-1800F in air.

    NASA Technical Reports Server (NTRS)

    Finkin, E. F.; Calabrese, S. J.; Peterson, M. B.

    1972-01-01

    Oscillating sliding tests were conducted in air under the following operating conditions: 500 psi, 600 F; 500 psi, 1200 F; 500 psi, 1800 F; 1500 psi, 1800 F; 3000 psi, 1800 F. Sixteen materials combinations were tested including ceramics, alloys and eutectics, cermets, and combinations of these. Friction, wear and surface damage (including surface roughening) were studied. The most outstanding materials combination was found to be nickel-molybdenum-bonded titanium carbide cermet sliding against dense magnesia stabilized ZrO2.

  15. Automated robust registration of grossly misregistered whole-slide images with varying stains

    NASA Astrophysics Data System (ADS)

    Litjens, G.; Safferling, K.; Grabe, N.

    2016-03-01

    Cancer diagnosis and pharmaceutical research increasingly depend on the accurate quantification of cancer biomarkers. Identification of biomarkers is usually performed through immunohistochemical staining of cancer sections on glass slides. However, combination of multiple biomarkers from a wide variety of immunohistochemically stained slides is a tedious process in traditional histopathology due to the switching of glass slides and re-identification of regions of interest by pathologists. Digital pathology now allows us to apply image registration algorithms to digitized whole-slides to align the differing immunohistochemical stains automatically. However, registration algorithms need to be robust to changes in color due to differing stains and severe changes in tissue content between slides. In this work we developed a robust registration methodology to allow for fast coarse alignment of multiple immunohistochemical stains to the base hematyoxylin and eosin stained image. We applied HSD color model conversion to obtain a less stain color dependent representation of the whole-slide images. Subsequently, optical density thresholding and connected component analysis were used to identify the relevant regions for registration. Template matching using normalized mutual information was applied to provide initial translation and rotation parameters, after which a cost function-driven affine registration was performed. The algorithm was validated using 40 slides from 10 prostate cancer patients, with landmark registration error as a metric. Median landmark registration error was around 180 microns, which indicates performance is adequate for practical application. None of the registrations failed, indicating the robustness of the algorithm.

  16. Were the Trænadjupet and Nyk Slides multi-staged?

    NASA Astrophysics Data System (ADS)

    Allin, Joshua; Mozzato, Alessandro; Tappin, David; Talling, Peter; Hunt, James

    2016-04-01

    Submarine landslides originating from active and extinct trough mouth fans are some of the largest single mass movements evident on Earth. These landslides are capable of damaging offshore infrastructure and can also trigger far-reaching tsunamis. For these reasons understanding the timing, dynamics, and triggering mechanisms of large submarine landslides is important for regional geohazard assessment. The Trænadjupet Slide occurred 4,000 ca. years ago and originated from the Trænadjupet paleo-ice stream on the Central Norwegian margin. The Trænadjupet Slide partially buried the deposits of a previous slide originating from the same section of the Norwegian margin; the Nyk Slide, which occurred at 16,000 ca years ago. Although the Trænadjupet Slide had an estimated volume of 900 km3 and originated from a shallow water depth, it does not appear to have triggered a tsunami. This is in contrast to the comparably-sized Storegga Slide, which produced a tsunami that devastated coastal areas as far away as Scotland. The apparent absence of a tsunami suggests that the failure dynamics for the Trænadjupet slide were different to that of other large slides along the Norwegian Margin. The deposits of both the Trænadjupet and Nyk Slides consist of several blocky lobes extending out into the Lofoten Basin. The lobate morphology of the deposits may imply that both slides occurred in a number of different and possibly temporally-disparate stages. Importantly, multi-staged failures have a much lower tsunamigenic potential due to the lower initial volume displacement. These staggered failures consisting of smaller sediment volumes might explain why no contemporaneous onshore tsunami deposits are found on nearby coastlines, particularly in the case of the post-glacial Trænadjupet Slide. Here we present a new sediment core dataset collected from the previously un-sampled lobes of the Trænadjupet and Nyk Slides. These cores will help us better characterise the deposit types

  17. Growth, biomass allocation and photosynthetic responses are related to intensity of root severance and soil moisture conditions in the plantation tree Cunninghamia lanceolata.

    PubMed

    Dong, Tingfa; Duan, Baoli; Zhang, Sheng; Korpelainen, Helena; Niinemets, Ülo; Li, Chunyang

    2016-07-01

    We employed the warm temperate conifer Cunninghamia lanceolata (Lamb.) Hook. as a model of plantation forest species to investigate ecophysiological responses to root treatments (control (0%), and ∼25, 50 or 75% of the initial root mass) under well-watered and water-limited conditions. Our results indicated that total root dry mass accumulation was negatively associated with the severity of root pruning, but there was evidence of multiple compensatory responses. The plants exhibited higher instantaneous and long-term (assessed by carbon isotope composition, δ(13)C) water-use efficiency in pruning treatments, especially under low water availability. Root pruning also increased the fine root/total root mass ratio, specific root length and fine root vitality in both water availability treatments. As a result of the compensatory responses, under well-watered conditions, height, stem dry mass accumulation, leaf/fine root biomass ratio (L/FR), transpiration rate, photosynthetic capacity and photosynthetic nitrogen-use efficiency (EN) were the highest under 25% pruning. Yet, all these traits except L/FR and foliage nitrogen content were severely reduced under 75% pruning. Drought negatively affected growth and leaf gas exchange rates, and there was a greater negative effect on growth, water potential, gas exchange and EN when >25% of total root biomass was removed. The stem/aboveground mass ratio was the highest under 25% pruning in both watering conditions. These results indicate that the responses to root severance are related to the excision intensity and soil moisture content. A moderate root pruning proved to be an effective means to improve stem dry mass accumulation. PMID:27122365

  18. Cooling Characteristics of the V-1650-7 Engine. II - Effect of Coolant Conditions on Cylinder Temperatures and Heat Rejection at Several Engine Powers

    NASA Technical Reports Server (NTRS)

    Povolny, John H.; Bogdan, Louis J.; Chelko, Louis J.

    1947-01-01

    An investigation has been conducted on a V-1650-7 engine to determine the cylinder temperatures and the coolant and oil heat rejections over a range of coolant flows (50 to 200 gal/min) and oil inlet temperatures (160 to 2150 F) for two values of coolant outlet temperature (250 deg and 275 F) at each of four power conditions ranging from approximately 1100 to 2000 brake horsepower. Data were obtained for several values of block-outlet pressure at each of the two coolant outlet temperatures. A mixture of 30 percent by volume of ethylene glycol and 70-percent water was used as the coolant. The effect of varying coolant flow, coolant outlet temperature, and coolant outlet pressure over the ranges investigated on cylinder-head temperatures was small (0 deg to 25 F) whereas the effect of increasing the engine power condition from ll00 to 2000 brake horsepower was large (maximum head-temperature increase, 110 F).

  19. MECHANICAL AND CHEMICAL PROPERTIES OF CEMENTITIOUS MATERIALS USING γ-2CaO.SiO2 UNDER THE SEVERAL CONDITIONS IN ACCELERATED CARBONATION CURING

    NASA Astrophysics Data System (ADS)

    Watanabe, Kenzo; Yokozeki, Kosuke; Torichigai, Takeshi; Sakai, Etsuo

    The experiments have been conducted in order to investigate the mechanical and chemical properties of mortar with three different binders under the several conditions in accelerated carbonation curing. As the results, the depth of carbonation varied among each mix proportion. It is proven that by increasing CO2 density in the mortar having γ-2CaO.SiO2, the CaCO3 production will increase, which leads to the increase of filling ability in the pore of mortar. Furthermore, as a result from the calculation of Tritium permeation, it shows that the permeation decreases with an increase of CO2 density.

  20. Perceived stigma of patients with severe mental illness in Hong Kong: relationships with patients' psychosocial conditions and attitudes of family caregivers and health professionals.

    PubMed

    Chien, Wai-Tong; Yeung, Frederick K K; Chan, Alan H L

    2014-03-01

    This descriptive survey investigated the level of perceived stigma among Chinese patients with severe mental illness (SMI) and its relationships with patients' psychosocial conditions and family caregivers' and mental health professionals' attitudes toward SMI in Hong Kong. A clustered, random sample of 311 patients and their family caregivers and 73 Chinese professionals participated. The patients reported a high level of withdrawal/secrecy and the professionals perceived a low to moderate level of stereotype/restriction to their patients. Families' expressed emotion and caregiving burden could increase patients' perceived stigma. Strategies in de-stigmatization of mental illness have been discussed, particularly from family-based approach.

  1. Whole slide imaging for educational purposes

    PubMed Central

    Pantanowitz, Liron; Szymas, Janusz; Yagi, Yukako; Wilbur, David

    2012-01-01

    Digitized slides produced by whole slide image scanners can be easily shared over a network or by transferring image files to optical or other data storage devices. Navigation of digitized slides is interactive and intended to simulate viewing glass slides with a microscope (virtual microscopy). Image viewing software permits users to edit, annotate, analyze, and easily share whole slide images (WSI). As a result, WSI have begun to replace the traditional light microscope, offering a myriad of opportunities for education. This article focuses on current applications of WSI in education and proficiency testing. WSI has been successfully explored for graduate education (medical, dental, and veterinary schools), training of pathology residents, as an educational tool in allied pathology schools (e.g., cytotechnology), for virtual tracking and tutoring, tele-education (tele-conferencing), e-learning, virtual workshops, at tumor boards, with interactive publications, and on examinations. WSI supports flexible and cost-effective distant learning and augments problem-oriented teaching, competency evaluation, and proficiency testing. WSI viewed on touchscreen displays and with tablet technology are especially beneficial for education. Further investigation is necessary to develop superior WSI applications that better support education and to design viewing stations with ergonomic tools that improve the WSI-human interface and navigation of virtual slides. Studies to determine the impact of training pathologists without exposure to actual glass slides are also needed. PMID:23372987

  2. SSP: Sketching Slide Presentations, a Syntactic Approach

    NASA Astrophysics Data System (ADS)

    Mas, Joan; Sanchez, Gemma; Lladós, Josep

    The design of a slide presentation is a creative process. In this process first, humans visualize in their minds what they want to explain. Then, they have to be able to represent this knowledge in an understandable way. There exists a lot of commercial software that allows to create our own slide presentations but the creativity of the user is rather limited. In this article we present an application that allows the user to create and visualize a slide presentation from a sketch. A slide may be seen as a graphical document or a diagram where its elements are placed in a particular spatial arrangement. To describe and recognize slides a syntactic approach is proposed. This approach is based on an Adjacency Grammar and a parsing methodology to cope with this kind of grammars. The experimental evaluation shows the performance of our methodology from a qualitative and a quantitative point of view. Six different slides containing different number of symbols, from 4 to 7, have been given to the users and they have drawn them without restrictions in the order of the elements. The quantitative results give an idea on how suitable is our methodology to describe and recognize the different elements in a slide.

  3. Reutilization of previously hybridized slides for fluorescence in situ hybridization

    SciTech Connect

    Epstein, L.; DeVries, S.; Waldman, F.M.

    1995-12-01

    Application of fluorescence in situ hybridization (FISH) to clinical material is sometimes limited by sample size. In addition, heterogeneity among slides prepared from a single sample may lead to variation in FISH analyses. Reutilization of material for repeated FISH analyses would help to alleviate these problems. We have developed a simple procedure for repeated FISH analyses with directly conjugated probes. Previously hybridized probes are removed by incubation in denaturing solution, and slides can then be rehybridized without residual signals remaining. Several cycles of this procedure allow a full complement of chromosomal loci to be analyzed on the same population of cells. Advantages of this protocol include gaining more cytogenetic information from small samples and eliminating the problem of intratumorvariability. 5 refs., 4 figs.

  4. Real-time misfire detection via sliding mode observer

    NASA Astrophysics Data System (ADS)

    Wang, Yunsong; Chu, Fulei

    2005-07-01

    A new method to detect misfire in internal combustion engines is presented. It is based on the estimation of the cylinder deviation torque by using sliding mode observer. The input estimation problem is transformed into the control tracking problem. The sliding controller is utilised to continuously track the measured varying crank speed by changing the estimated deviation torque. During the process of tracking, the speed estimation errors decrease and the gradual stability of the dynamics is assured. The mean deviation torque during the power stroke derived from the estimated deviation torque can be employed to detect easily engine misfires. Experimental results for a four-cylinder engine indicate that the method is a suitable tool for real-time misfire detection on board vehicle under various working conditions.

  5. The Earth surface slide movement at Soledad

    NASA Astrophysics Data System (ADS)

    Moreno, A.

    1986-11-01

    The Earth surface slide movement at Soledad is a mountain-slide type of movement. Estimations of the thickness of the layer which is moving range between 10 and 100 m. There is no proof that the movement is water induced, but it could be influenced by the water household. The slope of the slide area is H: D = 1: 2. The height difference in the moving area studied, according to this paper, is 1 km. The actual rate of movement is about 12 cm/yr.

  6. Rheological behavior of Slide Ring Gels.

    NASA Astrophysics Data System (ADS)

    Sharma, Vivek; Park, Jong Seung; Park, Jung O.; Srinivasarao, Mohan

    2006-03-01

    Slide ring gels were synthesized by chemically crosslinking, sparsely populated α-cyclodextrin (α-CD) present on the polyrotaxanes consisting of α-CD and polyethylene glycol (PEG). [1] Unlike physically or chemically crosslinked gels, slide ring gels are topological gels where crosslinks can slide along the chain. [2] We investigate the rheological behavior of these gels swollen in water and compare their viscoelastic properties to those of physical and chemical gels. We also study the equilibrium swelling behavior of these gels. [1] Okumura and Ito, Adv. Mater. 2001, 13, 485 [2] C. Zhao et al, J. Phys. Cond. Mat. 2005, 17, S2841

  7. Increase in friction force with sliding speed

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2005-09-01

    A block sliding down an inclined plane normally accelerates. However, if the friction force increases with speed, then the block can slide at a constant terminal speed in a manner similar to the fall of an object through a fluid. Measurements of the increase in the coefficient of friction for tennis ball cloth sliding on a smooth surface are described over speeds varying by a factor of 9000. For the low speed measurements, the ball cloth was attached to the bottom of a weighted box and pulled along a horizontal surface by a constant horizontal force. Results at higher speeds were obtained by bouncing a tennis ball off the surface.

  8. Severe early life stress hampers spatial learning and neurogenesis, but improves hippocampal synaptic plasticity and emotional learning under high-stress conditions in adulthood.

    PubMed

    Oomen, Charlotte A; Soeters, Heleen; Audureau, Nathalie; Vermunt, Lisa; van Hasselt, Felisa N; Manders, Erik M M; Joëls, Marian; Lucassen, Paul J; Krugers, Harm

    2010-05-12

    Early life stress increases the risk for developing stress-related pathologies later in life. Recent studies in rats suggest that mild early life stress, rather than being overall unfavorable, may program the hippocampus such that it is optimally adapted to a stressful context later in life. Here, we tested whether this principle of "adaptive programming" also holds under severely adverse early life conditions, i.e., 24 h of maternal deprivation (MD), a model for maternal neglect. In young adult male rats subjected to MD on postnatal day 3, we observed reduced levels of adult hippocampal neurogenesis as measured by cell proliferation, cell survival, and neuronal differentiation. Also, mature dentate granule cells showed a change in their dendritic morphology that was most noticeable in the proximal part of the dendritic tree. Lasting structural changes due to MD were paralleled by impaired water maze acquisition but did not affect long-term potentiation in the dentate gyrus. Importantly, in the presence of high levels of the stress hormone corticosterone, even long-term potentiation in the dentate gyrus of MD animals was facilitated. In addition to this, contextual learning in a high-stress environment was enhanced in MD rats. These morphological, electrophysiological, and behavioral observations show that even a severely adverse early life environment does not evolve into overall impaired hippocampal functionality later in life. Rather, adversity early in life can prepare the organism to perform optimally under conditions associated with high corticosteroid levels in adulthood.

  9. Understanding the desensitizing mechanism of olefin in explosives: shear slide of mixed HMX-olefin systems.

    PubMed

    Zhang, Chaoyang; Cao, Xia; Xiang, Bin

    2012-04-01

    We simulated the shear slide behavior of typical mixed HMX-olefin systems and the effect of thickness of olefin layers (4-22 Å) on the behavior at a molecular level by considering two cases: bulk shear and interfacial shear. The results show that: (1) the addition of olefin into HMX can reduce greatly the shear sliding barriers relative to the pure HMX in the two cases, suggesting that the desensitizing mechanism of olefin is controlled dominantly by its good lubricating property; (2) the change of interaction energy in both systoles of shear slide is strongly dominated by van der Waals interaction; and (3) the thickness of olefin layers in the mixed explosives can influence its desensitizing efficiency. That is, the excessive thinness of olefin layers in the mixed explosive systems, for example, several angstroms, can lead to very high sliding barriers.

  10. Influence of Subsurface Structure on the Linear Reciprocating Sliding Wear Behavior of Steels with Different Microstructures

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sangal, S.; Mondal, K.

    2014-12-01

    The present work investigates the influence of subsurface microstructure on the linear reciprocating sliding wear behavior of a number of steels with ferrite-pearlitic, pearlitic, bainitic, and martensitic microstructures under dry unlubricated condition. The change in the underlying microstructure with depth from worn-out surface of steel sample intimately relates to the associated hardness variation and wear volume. The present paper is not about comparison of wear resistance of steels with different structures; rather it is on mutual influence of wear and substructure for individual microstructure. Inherent toughness of the matrix and ability of microstructural components to get deformed under the reciprocating action of the ball decide the wear resistance of the steels. Bainite has good amount of stability to plastic deformation. Ferrite shows severe banding due to wear action. Work hardening renders pearlite to be wear resistant. Temperature rise and associated tempering of martensite are observed during wear.

  11. Influence of Subsurface Structure on the Linear Reciprocating Sliding Wear Behavior of Steels with Different Microstructures

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sangal, S.; Mondal, K.

    2014-09-01

    The present work investigates the influence of subsurface microstructure on the linear reciprocating sliding wear behavior of a number of steels with ferrite-pearlitic, pearlitic, bainitic, and martensitic microstructures under dry unlubricated condition. The change in the underlying microstructure with depth from worn-out surface of steel sample intimately relates to the associated hardness variation and wear volume. The present paper is not about comparison of wear resistance of steels with different structures; rather it is on mutual influence of wear and substructure for individual microstructure. Inherent toughness of the matrix and ability of microstructural components to get deformed under the reciprocating action of the ball decide the wear resistance of the steels. Bainite has good amount of stability to plastic deformation. Ferrite shows severe banding due to wear action. Work hardening renders pearlite to be wear resistant. Temperature rise and associated tempering of martensite are observed during wear.

  12. Plastic deformation and wear process at a surface during unlubricated sliding

    NASA Technical Reports Server (NTRS)

    Yamamoto, T.; Buckley, D. H.

    1982-01-01

    The plastic deformation and wear of a 304 stainless steel surface sliding against an aluminum oxide rider with a spherical surface (the radius of curvature: 1.3 cm) were observed by using scanning electron and optical microscopes. Experiments were conducted in a vacuum of one million Pa and in an environment of fifty thousandth Pa of chlorine gas at 25 C. The load was 500 grams and the sliding velocity was 0.5 centimeter per second. The deformed surface layer which accumulates and develops successively is left behind the rider, and step shaped proturbances are developed even after single pass sliding under both environmental conditions. A fully developed surface layer is gradually torn off leaving a characteristic pattern. The mechanism for tearing away of the surface layer from the contact area and sliding track contour is explained assuming the simplified process of material removal based on the adhesion theory for the wear of materials.

  13. Micro and Nano-structure Development and Multiscale Physics at Sliding Metal Interfaces

    SciTech Connect

    Rigney; David; A.

    2006-06-01

    This final report describes research on the response of ductile materials to extreme loading conditions and high strain rates during impact combined with sliding friction. The work has involved a collaboration among two groups at Los Alamos National Laboratory and a tribology research grouup at The Ohio State University. The project involved experimental work and computer simulations at both laboratories and continuum mechanics analysis at OSU, supplemented by testing at AWE, Harwell, UK. Results demonstrated the importance of vorticity and mechanical mixing near the sliding interface in the development of nanocrystalline tribomaterial that is far from equilibrium. The work also revealed that strain rate sensitivity is an important materials property for determining the development of the velocity profile during sliding. As such, it is a property that is key to understanding the evolution of sliding behavior.

  14. Discrete sliding mode control for robust tracking of higher order delay time systems with experimental application.

    PubMed

    Khandekar, A A; Malwatkar, G M; Patre, B M

    2013-01-01

    In this paper, a discrete time sliding mode controller (DSMC) is proposed for higher order plus delay time (HOPDT) processes. A sliding mode surface is selected as a function of system states and error and the tuning parameters of sliding mode controller are determined using dominant pole placement strategy. The condition for the existence of stable sliding mode is obtained by using Lyapunov function. The proposed method is applicable to HOPDT processes with oscillatory and integrating behavior, open loop instability or non-minimum phase characteristics and works satisfactory under the effect of parametric uncertainty. The method does not require reduced order model and provides simple way to design the controllers. The simulation and experimentation results show that the proposed method ensures desired tracking dynamics.

  15. Risk Analysis for Unintentional Slide Deployment During Airline Operations.

    PubMed

    Ayra, Eduardo S; Insua, David Ríos; Castellanos, María Eugenia; Larbi, Lydia

    2015-09-01

    We present a risk analysis undertaken to mitigate problems in relation to the unintended deployment of slides under normal operations within a commercial airline. This type of incident entails relevant costs for the airline industry. After assessing the likelihood and severity of its consequences, we conclude that such risks need to be managed. We then evaluate the effectiveness of various countermeasures, describing and justifying the chosen ones. We also discuss several issues faced when implementing and communicating the proposed measures, thus fully illustrating the risk analysis process.

  16. Conditioning with rabbit versus horse ATG dramatically alters clinical outcomes in identical twins with severe aplastic anemia transplanted with the same allogeneic donor.

    PubMed

    Vo, P T; Pantin, J; Ramos, C; Cook, L; Cho, E; Kurlander, R; Khuu, H; Barrett, J; Leitman, S; Childs, R W

    2015-01-01

    Severe aplastic anemia (SAA) is a rare disorder leading to bone marrow failure, which if left untreated, is invariably fatal. Conventional therapies with immunosuppressive therapy or allogeneic hematopoietic stem cell transplantation (HSCT) are highly effective. HSCT can offer a greater outcome in younger patients who have an available HLA match-related donor. Recent studies showing the addition of antithymocyte globulin (ATG) to the conditioning regimen improves engraftment and reduces the risk of graft-versus-host disease (GVHD).There are currently two ATG preparations in the USA, equine (or horse) and rabbit ATG. These agents are pharmacologically distinct, having significant differences in their pharmacokinetics and in vivo immunosuppressive effects [N Engl J Med 365(5):430-438, 2011]. Here, we report a case of two monozygotic twins with constitutional SAA that evolved to myelodysplastic syndrome (MDS) who both underwent allogeneic peripheral blood stem cell transplantation (PBSC) from the same single HLA antigen mismatched sibling donor with the only difference in the transplant regimen being the type of ATG used in the preparative regimen; one twin received horse ATG and the other received rabbit ATG during conditioning. This report emphasizes that dramatic differences in donor T cell chimerism and clinical outcomes including GVHD can occur as a consequence of the type of ATG that is utilized in the transplant conditioning regimen. These differences highlight that these agents should not be considered interchangeable drugs when used in this setting. PMID:26113077

  17. Foam-filled cushions for sliding trays

    NASA Technical Reports Server (NTRS)

    Nahin, S. B.; Robb, P. H.

    1980-01-01

    Polytetrafluoroethylene tube filled with polyurethane foam forms low friction sliding surface that cushions vibrations and absorbs manufacturing tolerances and misalignment. Possible uses include packaging of components for shipping and seals for doors in lockers, cars, and refrigerators.

  18. Automated single-slide staining system

    NASA Technical Reports Server (NTRS)

    Mills, S. M.; Wilkins, J. R.

    1974-01-01

    Apparatus developed to Gram-stain single slides automatically is flexible enough to accommodate other types of staining procedures. Method frees operator and eliminates necessity for subjective evaluations as to length of staining or decolorizing time.

  19. Variations of the Sliding Ladder Problem

    ERIC Educational Resources Information Center

    Kapranidis, Stelios; Koo, Reginald

    2008-01-01

    This article takes another look at the sliding ladder problem that students meet in the study of related rates in calculus. Physically realistic situations with both constrained and understrained ladders are explored.

  20. The Foley Acoustic Wave Front Slides

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2004-04-01

    In 1912 Arthur L. Foley of Indiana University published an article in Physical Review about his technique for photographing acoustic wave fronts. Subsequently, the Central Scientific Company published a series of glass lantern slides of his illustrations. These have been unavailable for about 60 years. Here I discuss how Foley made his slides and give examples of use to the present-day physics teacher.

  1. WTP Pretreatment Facility Potential Design Deficiencies--Sliding Bed and Sliding Bed Erosion Assessment

    SciTech Connect

    Hansen, E. K.

    2015-05-06

    This assessment is based on readily available literature and discusses both Newtonian and non-Newtonian slurries with respect to sliding beds and erosion due to sliding beds. This report does not quantify the size of the sliding beds or erosion rates due to sliding beds, but only assesses if they could be present. This assessment addresses process pipelines in the Pretreatment (PT) facility and the high level waste (HLW) transfer lines leaving the PT facility to the HLW vitrification facility concentrate receipt vessel.

  2. The Louisiana Slide Library; A Humanities Program. Bulletin 1755.

    ERIC Educational Resources Information Center

    Louisiana Council for Music and Performing Arts, New Orleans.

    The Louisiana Slide Library is an extensive collection of slides, lectures, and tapes designed for use in the arts, the humanities, social and ethnic studies, languages, home economics, careers, crafts, and special education. This bibliography lists these slide sets and indicates the grade level intended for each set and the number of slides in…

  3. Ornamental Annual Plants and Their Uses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven

    This slide script, part of a series of slide scripts designed for use in vocational agriculture classes, deals with ornamental annual plants and their uses. Included in the script are narrations for use with a total of 254 slides illustrating 97 different plants. At least two slides are provided for each plant: one shows the growth habits of the…

  4. Compact, Automated Centrifugal Slide-Staining System

    NASA Technical Reports Server (NTRS)

    Feeback, Daniel L.; Clarke, Mark S. F.

    2004-01-01

    The Directional Acceleration Vector-Driven Displacement of Fluids (DAVD-DOF) system, under development at the time of reporting the information for this article, would be a relatively compact, automated, centrifugally actuated system for staining blood smears and other microbiological samples on glass microscope slides in either a microgravitational or a normal Earth gravitational environment. The DAVD-DOF concept is a successor to the centrifuge-operated slide stainer (COSS) concept, which was reported in Slide-Staining System for Microgravity or Gravity (MSC-22949), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 64. The COSS includes reservoirs and a staining chamber that contains a microscope slide to which a biological sample is affixed. The staining chamber is sequentially filled with and drained of staining and related liquids from the reservoirs by use of a weighted plunger to force liquid from one reservoir to another at a constant level of hypergravity maintained in a standard swing-bucket centrifuge. In the DAVD-DOF system, a staining chamber containing a sample would also be sequentially filled and emptied, but with important differences. Instead of a simple microscope slide, one would use a special microscope slide on which would be fabricated a network of very small reservoirs and narrow channels connected to a staining chamber (see figure). Unlike in the COSS, displacement of liquid would be effected by use of the weight of the liquid itself, rather than the weight of a plunger.

  5. Sliding contact fatigue damage in layered ceramic structures.

    PubMed

    Kim, J-W; Kim, J-H; Thompson, V P; Zhang, Y

    2007-11-01

    Porcelain-veneered restorations often chip and fracture from repeated occlusal loading, making fatigue studies relevant. Most fatigue studies are limited to uni-axial loading without sliding motion. We hypothesized that bi-axial loading (contact-load-slide-liftoff, simulating a masticatory cycle), as compared with uni-axial loading, accelerates the fatigue of layered ceramics. Monolithic glass plates were epoxy-joined to polycarbonate substrates as a transparent model for an all-ceramic crown on dentin. Uni-and bi-axial cyclic contact was applied through a hard sphere in water, by means of a mouth-motion simulator apparatus. The uni-axial (contact-load-hold-liftoff) and traditional R-ratio fatigue (indenter never leaves the specimen surface) produced similar lifespans, while bi-axial fatigue was more severe. The accelerated crack growth rate in bi-axial fatigue is attributed to enhanced tensile stresses at the trailing edges of a moving indenter. Fracture mechanics descriptions for damage evolution in brittle materials loaded repeatedly with a sliding sphere are provided. Clinical relevance is addressed.

  6. A sliding cell technique for diffusion measurements in liquid metals

    SciTech Connect

    Geng, Yongliang; Zhu, Chunao; Zhang, Bo

    2014-03-15

    The long capillary and shear cell techniques are the usual methods for diffusion measurements in liquid metals. Here we present a new “sliding cell technique” to measure interdiffusion in liquid alloys, which combines the merits of these two methods. Instead of a number of shear cells, as used in the shear cell method, only one sliding cell is designed to separate and join the liquid diffusion samples. Using the sliding cell technique, the influence of the heating process (which affects liquid diffusion measurements in the conventional long capillary method) can be eliminated. Time-dependent diffusion measurements at the same isothermal temperature were carried out in Al-Cu liquids. Compared with the previous results measured by in-situ X-ray radiography, the obtained liquid diffusion coefficient in this work is believed to be influenced by convective flow. The present work further supports the idea that to obtain accurate diffusion constants in liquid metals, the measurement conditions must be well controlled, and there should be no temperature gradients or other disturbances.

  7. How to measure diagnosis-associated information in virtual slides.

    PubMed

    Kayser, Klaus; Görtler, Jürgen; Borkenfeld, Stephan; Kayser, Gian

    2011-01-01

    The distribution of diagnosis-associated information in histological slides is often spatial dependent. A reliable selection of the slide areas containing the most significant information to deriving the associated diagnosis is a major task in virtual microscopy. Three different algorithms can be used to select the appropriate fields of view: 1) Object dependent segmentation combined with graph theory; 2) time series associated texture analysis; and 3) geometrical statistics based upon geometrical primitives. These methods can be applied by sliding technique (i.e., field of view selection with fixed frames), and by cluster analysis. The implementation of these methods requires a standardization of images in terms of vignette correction and gray value distribution as well as determination of appropriate magnification (method 1 only). A principle component analysis of the color space can significantly reduce the necessary computation time. Method 3 is based upon gray value dependent segmentation followed by graph theory application using the construction of (associated) minimum spanning tree and Voronoi's neighbourhood condition. The three methods have been applied on large sets of histological images comprising different organs (colon, lung, pleura, stomach, thyroid) and different magnifications, The trials resulted in a reproducible and correct selection of fields of view in all three methods. The different algorithms can be combined to a basic technique of field of view selection, and a general theory of "image information" can be derived. The advantages and constraints of the applied methods will be discussed. PMID:21489204

  8. Estimation of thermal loads on the VVER vessel under conditions of inversion of the stratified molten pool in a severe accident

    NASA Astrophysics Data System (ADS)

    Loktionov, V. D.; Mukhtarov, E. S.

    2016-09-01

    Analysis of the thermal state of molten pools that can be formed on the vessel bottom of the VVER-600 medium-power reactor during a severe anticipated accident with melting of the core is represented. Two types of the molten pool of core materials, with the two-layer and inverse three-layer stratification, are considered. Thermal loads acting on the reactor vessel from the melt are estimated depending on its formation time. Features of the thermal state of the melt in the case of its inverse stratification are analyzed. It is shown that thermal loads on the reactor vessel exceed the critical heat flux (CHF) when forming the two-layer stratified molten pool 10 and 24 h after its shutdown, and the thermal load is close to the corresponding CHF or somewhat exceeds it in 72 h. In the case of the formation of the inverse structure of the melt, one can observe a decrease by more than 2.5 times (in comparison with the two-layer stratified structure) in the thermal load on the reactor vessel in the region of its contact with the upper layer of the steel melt. Analysis of results showed that maximum densities of heat flux to the reactor vessel from the bottom metallic layer with the melt inversion did not exceed corresponding CHFs 24 and 72 h after the reactor shutdown. Because the thermal load on the reactor vessel can be localized in the region of its bottom, where the CHF is relatively small, during the inverse stratification of the melt, there is a need to carry out further in-depth experimental and analytical investigations of conditions for formation of the stratified molten pool and to obtain corrected experimental CHFs for conditions and outlines of cooling the external surface of the VVER-600 vessel in a severe accident.

  9. HIF-1α is a protective factor in conditional PHD2-deficient mice suffering from severe HIF-2α–induced excessive erythropoiesis

    PubMed Central

    Franke, Kristin; Kalucka, Joanna; Mamlouk, Soulafa; Singh, Rashim Pal; Muschter, Antje; Weidemann, Alexander; Iyengar, Vasuprada; Jahn, Steffen; Wieczorek, Kathrin; Geiger, Kathrin; Muders, Michael; Sykes, Alex M.; Poitz, David M.; Ripich, Tatsiana; Otto, Teresa; Bergmann, Sybille; Breier, Georg; Baretton, Gustavo; Fong, Guo-Hua; Greaves, David R.; Bornstein, Stefan; Chavakis, Triantafyllos; Fandrey, Joachim; Gassmann, Max

    2013-01-01

    Erythropoiesis must be tightly balanced to guarantee adequate oxygen delivery to all tissues in the body. This process relies predominantly on the hormone erythropoietin (EPO) and its transcription factor hypoxia inducible factor (HIF). Accumulating evidence suggests that oxygen-sensitive prolyl hydroxylases (PHDs) are important regulators of this entire system. Here, we describe a novel mouse line with conditional PHD2 inactivation (cKO P2) in renal EPO producing cells, neurons, and astrocytes that displayed excessive erythrocytosis because of severe overproduction of EPO, exclusively driven by HIF-2α. In contrast, HIF-1α served as a protective factor, ensuring survival of cKO P2 mice with HCT values up to 86%. Using different genetic approaches, we show that simultaneous inactivation of PHD2 and HIF-1α resulted in a drastic PHD3 reduction with consequent overexpression of HIF-2α-related genes, neurodegeneration, and lethality. Taken together, our results demonstrate for the first time that conditional loss of PHD2 in mice leads to HIF-2α–dependent erythrocytosis, whereas HIF-1α protects these mice, providing a platform for developing new treatments of EPO-related disorders, such as anemia. PMID:23264599

  10. Different MK-801 administration schedules induce mild to severe learning impairments in an operant conditioning task: role of buspirone and risperidone in ameliorating these cognitive deficits.

    PubMed

    Rapanelli, Maximiliano; Frick, Luciana Romina; Bernardez-Vidal, Micaela; Zanutto, Bonifacio Silvano

    2013-11-15

    Blockade of N-methyl-d-aspartate receptor (NMDA) by the noncompetitive NMDA receptor (NMDAR) antagonist MK-801 produces behavioral abnormalities and alterations in prefrontal cortex (PFC) functioning. Due to the critical role of the PFC in operant conditioning task learning, we evaluated the effects of acute, repeated postnatal injections of MK-801 (0.1mg/kg) on learning performance. We injected Long-Evans rats i.p. with MK-801 (0.1mg/kg) using three different administration schedules: injection 40 min before beginning the task (during) (n=12); injection twice daily for six consecutive days prior to beginning the experimental procedures (prior) (n=12); or twice daily subcutaneous injections from postnatal day 7 to 11 (postnatal) (n=12). Next, we orally administered risperidone (serotonin receptor 2A and dopamine receptor 2 antagonist, 1mg/kg) or buspirone (serotonin receptor 1A partial agonist, 10mg/kg) to animals treated with the MK-801 schedule described above. The postnatal and prior administration schedules produced severe learning deficits, whereas injection of MK-801 just before training sessions had only mild effects on acquisition of an operant conditioning. Risperidone was able to reverse the detrimental effect of MK-801 in the animals that were treated with MK-801 during and prior training sessions. In contrast, buspirone was only effective at mitigating the cognitive deficits induced by MK-801 when administered during the training procedures. The data demonstrates that NMDA antagonism disrupts basic mechanisms of learning in a simple PFC-mediated operant conditioning task, and that buspirone and risperidone failed to attenuate the learning deficits when NMDA neurotransmission was blocked in the early stages of the postnatal period.

  11. Modelling Conditions and Health Care Processes in Electronic Health Records: An Application to Severe Mental Illness with the Clinical Practice Research Datalink

    PubMed Central

    Olier, Ivan; Springate, David A.; Ashcroft, Darren M.; Doran, Tim; Reeves, David; Planner, Claire; Reilly, Siobhan; Kontopantelis, Evangelos

    2016-01-01

    Background The use of Electronic Health Records databases for medical research has become mainstream. In the UK, increasing use of Primary Care Databases is largely driven by almost complete computerisation and uniform standards within the National Health Service. Electronic Health Records research often begins with the development of a list of clinical codes with which to identify cases with a specific condition. We present a methodology and accompanying Stata and R commands (pcdsearch/Rpcdsearch) to help researchers in this task. We present severe mental illness as an example. Methods We used the Clinical Practice Research Datalink, a UK Primary Care Database in which clinical information is largely organised using Read codes, a hierarchical clinical coding system. Pcdsearch is used to identify potentially relevant clinical codes and/or product codes from word-stubs and code-stubs suggested by clinicians. The returned code-lists are reviewed and codes relevant to the condition of interest are selected. The final code-list is then used to identify patients. Results We identified 270 Read codes linked to SMI and used them to identify cases in the database. We observed that our approach identified cases that would have been missed with a simpler approach using SMI registers defined within the UK Quality and Outcomes Framework. Conclusion We described a framework for researchers of Electronic Health Records databases, for identifying patients with a particular condition or matching certain clinical criteria. The method is invariant to coding system or database and can be used with SNOMED CT, ICD or other medical classification code-lists. PMID:26918439

  12. Musical slide show MAF with protection and governance using MPEG-21 IPMP Components and REL

    NASA Astrophysics Data System (ADS)

    Sabirin, Muhammad Syah Houari; Tan, Hendry; Lim, Jeongyeon; Kim, Munchurl

    2007-02-01

    The Musical Slide Show Multimedia Application Format (MAF) which is currently being standardized by the Moving Picture Expert Group (MPEG) conveys the concept of combining several established standard technologies in a single file format. It defines the format of packing up MP3 audio data, along with JPEG images, MPEG-7 Simple Profile metadata, timed text, and MPEG-4 LASeR script. The presentation of Musical Slide Show MAF contents is made in a synchronized manner with JPEG images, timed text to MP3 audio track. Also, the rendering effect on JPEG images can be supported by the MPEG-4 LASeR script. This Musical Slide Show MAF will enrich the consumption of MP3 contents assisted with synchronized and rendered JPEG images, text as well as MPEG-7 metadata about the MP3 audio contents. However, there is no protection and governance mechanism for Musical Slide Show MAF which is the essential elements to deploy the sorts of contents. In this paper, to manage the Musical Slide Show MAF contents in a controlled manner, we present a protection and governance mechanism by using MPEG-21 Intellectual Property Management and Protection (IPMP) Components and MPEG-21 Rights Expression Language (REL) technologies We implement an authoring tool and a player tool for Musical Slide Show MAF contents and show the experimental results as well.

  13. Sliding Wear Response of Beryl Reinforced Aluminum Composite - A Factorial Design Approach

    NASA Astrophysics Data System (ADS)

    Bharat, V.; Durga Prasad, B.; Prabhakar, M. Bhovi; Venkateswarlu, K.

    2016-02-01

    Al-Beryl MMCs were successfully fabricated using powder metallurgy route. Processing conditions such as beryl content and particle size were varied and its influence on dry sliding wear response was studied. Effect of test parameters like applied load and sliding distance on wear performance of Al-Beryl MMCs were discussed detail. Sliding wear tests were conducted using a pin on disc machine based on the 24 (4 factors at 2 levels) factorial design. Analysis of variance (ANOVA) was performed to obtain the contribution of control parameters on wear rate. The present study shows that wear resistance of Al-beryl MMCs not only depends on the beryl content but also influenced by normal load, sliding distance and particle size. The results show that most significant variables affecting wear rate of Al - beryl MMCs are size of the beryl particles (22%), beryl content (19.60%), sliding distance (18.47%), and normal load (10.30%). The interaction effects of these parameters are less significant in influencing wear rate compared to the individual parameters. The correlation between sliding wear and its parameters was obtained by multiple regression analysis. Regression model developed in the present study can be successfully implemented to predict the wear response of Al-Beryl MMCs.

  14. Pseudomonas aeruginosa Exhibits Sliding Motility in the Absence of Type IV Pili and Flagella▿ †

    PubMed Central

    Murray, Thomas S.; Kazmierczak, Barbara I.

    2008-01-01

    Pseudomonas aeruginosa exhibits swarming motility on 0.5 to 1% agar plates in the presence of specific carbon and nitrogen sources. We have found that PAO1 double mutants expressing neither flagella nor type IV pili (fliC pilA) display sliding motility under the same conditions. Sliding motility was inhibited when type IV pilus expression was restored; like swarming motility, it also decreased in the absence of rhamnolipid surfactant production. Transposon insertions in gacA and gacS increased sliding motility and restored tendril formation to spreading colonies, while transposon insertions in retS abolished motility. These changes in motility were not accompanied by detectable changes in rhamnolipid surfactant production or by the appearance of bacterial surface structures that might power sliding motility. We propose that P. aeruginosa requires flagella during swarming to overcome adhesive interactions mediated by type IV pili. The apparent dependence of sliding motility on environmental cues and regulatory pathways that also affect swarming motility suggests that both forms of motility are influenced by similar cohesive factors that restrict translocation, as well as by dispersive factors that facilitate spreading. Studies of sliding motility may be particularly well-suited for identifying factors other than pili and flagella that affect community behaviors of P. aeruginosa. PMID:18065549

  15. An adaptive supervisory sliding fuzzy cerebellar model articulation controller for sensorless vector-controlled induction motor drive systems.

    PubMed

    Wang, Shun-Yuan; Tseng, Chwan-Lu; Lin, Shou-Chuang; Chiu, Chun-Jung; Chou, Jen-Hsiang

    2015-01-01

    This paper presents the implementation of an adaptive supervisory sliding fuzzy cerebellar model articulation controller (FCMAC) in the speed sensorless vector control of an induction motor (IM) drive system. The proposed adaptive supervisory sliding FCMAC comprised a supervisory controller, integral sliding surface, and an adaptive FCMAC. The integral sliding surface was employed to eliminate steady-state errors and enhance the responsiveness of the system. The adaptive FCMAC incorporated an FCMAC with a compensating controller to perform a desired control action. The proposed controller was derived using the Lyapunov approach, which guarantees learning-error convergence. The implementation of three intelligent control schemes--the adaptive supervisory sliding FCMAC, adaptive sliding FCMAC, and adaptive sliding CMAC--were experimentally investigated under various conditions in a realistic sensorless vector-controlled IM drive system. The root mean square error (RMSE) was used as a performance index to evaluate the experimental results of each control scheme. The analysis results indicated that the proposed adaptive supervisory sliding FCMAC substantially improved the system performance compared with the other control schemes. PMID:25815450

  16. An Adaptive Supervisory Sliding Fuzzy Cerebellar Model Articulation Controller for Sensorless Vector-Controlled Induction Motor Drive Systems

    PubMed Central

    Wang, Shun-Yuan; Tseng, Chwan-Lu; Lin, Shou-Chuang; Chiu, Chun-Jung; Chou, Jen-Hsiang

    2015-01-01

    This paper presents the implementation of an adaptive supervisory sliding fuzzy cerebellar model articulation controller (FCMAC) in the speed sensorless vector control of an induction motor (IM) drive system. The proposed adaptive supervisory sliding FCMAC comprised a supervisory controller, integral sliding surface, and an adaptive FCMAC. The integral sliding surface was employed to eliminate steady-state errors and enhance the responsiveness of the system. The adaptive FCMAC incorporated an FCMAC with a compensating controller to perform a desired control action. The proposed controller was derived using the Lyapunov approach, which guarantees learning-error convergence. The implementation of three intelligent control schemes—the adaptive supervisory sliding FCMAC, adaptive sliding FCMAC, and adaptive sliding CMAC—were experimentally investigated under various conditions in a realistic sensorless vector-controlled IM drive system. The root mean square error (RMSE) was used as a performance index to evaluate the experimental results of each control scheme. The analysis results indicated that the proposed adaptive supervisory sliding FCMAC substantially improved the system performance compared with the other control schemes. PMID:25815450

  17. Geometrical and hydrogeological impact on the behaviour of deep-seated rock slides during reservoir impoundment

    NASA Astrophysics Data System (ADS)

    Lechner, Heidrun; Zangerl, Christian

    2015-04-01

    Given that there are still uncertainties regarding the deformation and failure mechanisms of deep-seated rock slides this study concentrates on key factors that influence the behaviour of rock slides in the surrounding of reservoirs. The focus is placed on the slope geometry, hydrogeology and kinematics. Based on numerous generic rock slide models the impacts of the (i) rock slide geometry, (ii) reservoir impoundment and level fluctuations, (iii) seepage and buoyancy forces and (iv) hydraulic conductivity of the rock slide mass and the basal shear zone are examined using limit equilibrium approaches. The geometry of many deep-seated rock slides in metamorphic rocks is often influenced by geological structures, e.g. fault zones, joints, foliation, bedding planes and others. With downslope displacement the rock slide undergoes a change in shape. Several observed rock slides in an advanced stage show a convex, bulge-like topography at the foot of the slope and a concave topography in the middle to upper part. Especially, the situation of the slope toe plays an important role for stability. A potentially critical situation can result from a partially submerged flat slope toe because the uplift due to water pressure destabilizes the rock slide. Furthermore, it is essential if the basal shear zone daylights at the foot of the slope or encounters alluvial or glacial deposits at the bottom of the valley, the latter having a buttressing effect. In this study generic rock slide models with a shear zone outcropping at the slope toe are established and systematically analysed using limit equilibrium calculations. Two different kinematic types are modelled: (i) a translational or planar and (ii) a rotational movement behaviour. Questions concerning the impact of buoyancy and pore pressure forces that develop during first time impoundment are of key interest. Given that an adverse effect on the rock slide stability is expected due to reservoir impoundment the extent of

  18. Can sliding-window correlations reveal dynamic functional connectivity in resting-state fMRI?

    PubMed Central

    Hindriks, R.; Adhikari, M.H.; Murayama, Y.; Ganzetti, M.; Mantini, D.; Logothetis, N.K.; Deco, G.

    2016-01-01

    During the last several years, the focus of research on resting-state functional magnetic resonance imaging (fMRI) has shifted from the analysis of functional connectivity averaged over the duration of scanning sessions to the analysis of changes of functional connectivity within sessions. Although several studies have reported the presence of dynamic functional connectivity (dFC), statistical assessment of the results is not always carried out in a sound way and, in some studies, is even omitted. In this study, we explain why appropriate statistical tests are needed to detect dFC, we describe how they can be carried out and how to assess the performance of dFC measures, and we illustrate the methodology using spontaneous blood-oxygen level-dependent (BOLD) fMRI recordings of macaque monkeys under general anesthesia and in human subjects under resting-state conditions. We mainly focus on sliding-window correlations since these are most widely used in assessing dFC, but also consider a recently proposed non-linear measure. The simulations and methodology, however, are general and can be applied to any measure. The results are twofold. First, through simulations, we show that in typical resting-state sessions of 10 min, it is almost impossible to detect dFC using sliding-window correlations. This prediction is validated by both the macaque and the human data: in none of the individual recording sessions was evidence for dFC found. Second, detection power can be considerably increased by session- or subject-averaging of the measures. In doing so, we found that most of the functional connections are in fact dynamic. With this study, we hope to raise awareness of the statistical pitfalls in the assessment of dFC and how they can be avoided by using appropriate statistical methods. PMID:26631813

  19. On a model of frictional sliding

    NASA Astrophysics Data System (ADS)

    Estrin, Y.; Bréchet, Y.

    1996-10-01

    A model of frictional sliding with an N-shaped curve for the sliding velocity dependence of the coefficient of friction is considered. This type of friction law is shown to be related to dynamic i.e., velocity dependent ‘ageing’ of asperity junctions. Mechanisms of ‘ageing’ for ductile (Bowden-Tabor) and brittle (Byerlee) materials, though different in nature, lead to qualitatively similar N-shaped velocity dependencies of the coefficient of friction. Estimates for the velocities limiting the range of negative velocity sensitivity of the coefficient of friction are obtained for the ductile case and—albeit with a lesser degree of reliability—for the brittle one. It is shown by linear stability analysis that discontinuous sliding (stick-slip) is associated with the descending portion of the N-shaped curve. An instability criterion is obtained. An expression for the period of the attendant relaxation oscillations of the sliding velocity is given in terms of the calculated velocity dependence of the coefficient of friction. It is suggested that the micromechanically motivated friction law proposed should be used in models of earthquakes due to discontinuous frictional sliding on a crustal fault.

  20. Resistance to Sliding on Atomic Scales

    NASA Technical Reports Server (NTRS)

    Dominik, C.; Tielens, A.; Cuzzi, Jeffrey (Technical Monitor)

    1995-01-01

    The structure and stability of agglomerates of micron-sized particles is determined by the mechanical properties of the individual contacts between the constituent particles. In this paper we study the possibility of aggregate rearrangements by sliding. Since the contacts between (sub)micron particles are only a few hundred atoms in diameter, processes on atomic levels will play the dominating roll. We study a theoretical model of sliding friction for surfaces that are either flat or contain steps in their grids. The results show that sliding over flat surfaces may produce a large range of friction coefficients, including zero if the adhesive forces are small compared to the binding forces inside a body. However, both grid alignment and steps in the surface will lead to high values for friction. These processes combined virtually eliminate the possibility of sliding in a collision of two (sub)micron sized particles at velocities low enough for sticking to occur. On the other hand we show that in collisions between aggregates sliding may be an important factor for energy dissipation and compaction.

  1. Theory of sliding-mode triboelectric nanogenerators.

    PubMed

    Niu, Simiao; Liu, Ying; Wang, Sihong; Lin, Long; Zhou, Yu Sheng; Hu, Youfan; Wang, Zhong Lin

    2013-11-20

    The triboelectric nanogenerator (TENG) is a powerful approach toward new energy technology, especially for portable electronics. A theoretical model for the sliding-mode TENG is presented in this work. The finite element method was utilized to characterize the distributions of electric potential, electric field, and charges on the metal electrodes of the TENG. Based on the FEM calculation, the semi-analytical results from the interpolation method and the analytical V-Q-x relationship are built to study the sliding-mode TENG. The analytical V-Q-x equation is validated through comparison with the semi-analytical results. Furthermore, based on the analytical V-Q-x equation, dynamic output performance of sliding-mode TENG is calculated with arbitrary load resistance, and good agreement with experimental data is achieved. The theory presented here is a milestone work for in-depth understanding of the working mechanism of the sliding-mode TENG, and provides a theoretical basis for further enhancement of the sliding-mode TENG for both energy scavenging and self-powered sensor applications.

  2. Attenuation of Diabetic Conditions by Sida rhombifolia in Moderately Diabetic Rats and Inability to Produce Similar Effects in Severely Diabetic in Rats

    PubMed Central

    Chaturvedi, Padmaja; Kwape, Tebogo Elvis

    2015-01-01

    Objectives: This study was done out to evaluate the effects of Sida rhombifolia methanol extract (SRM) on diabetes in moderately diabetic (MD) and severely diabetic (SD) Sprague-Dawley rats. Methods: SRM was prepared by soaking the powdered plant material in 70% methanol and rota evaporating the methanol from the extract. Effective hypoglycemic doses were established by performing oral glucose tolerance tests (OGTTs) in normal rats. Hourly effects of SRM on glucose were observed in the MD and the SD rats. Rats were grouped, five rats to a group, into normal control 1 (NC1), MD control 1 (MDC1), MD experimental 1 (MDE1), SD control 1 (SDC1), and SD experimental 1 (SDE1) groups. All rats in the control groups were administered 1 mL of distilled water (DW). The rats in the MDE1 and the SDE1 groups were administered SRM orally at 200 and 300 mg/kg body weight (BW), respectively, dissolved in 1 mL of DW. Blood was collected initially and at intervals of 1 hour for 6 hours to measure blood glucose. A similar experimental design was followed for the 30-day long-term trial. Finally, rats were sacrificed, and blood was collected to measure blood glucose, lipid profiles, thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH). Results: OGTTs indicated that two doses (200 and 300 mg/kg BW) were effective hypoglycemic doses in normal rats. Both doses reduced glucose levels after 1 hour in the MDE1 and the SDE1 groups. A long-term trial of SRM in the MD group showed a reduced glucose level, a normal lipid profile, and normal GSH and TBARS levels. In SD rats, SRM had no statistically significant effects on these parameters. Normal weight was achieved in the MD rats, but the SD rats showed reduced BW. Conclusion: The study demonstrates that SRM has potential to alleviate the conditions of moderate diabetic, but not severe diabetes. PMID:26998385

  3. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    PubMed

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens.

  4. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    PubMed

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens. PMID:26469870

  5. A comparative study of wave-current interactions over the eastern Canadian shelf under severe weather conditions using a coupled wave-circulation model

    NASA Astrophysics Data System (ADS)

    Wang, Pengcheng; Sheng, Jinyu

    2016-07-01

    A coupled wave-circulation model is used to examine interactions between surface gravity waves and ocean currents over the eastern Canadian shelf and adjacent deep waters during three severe weather events. The simulated significant wave heights (SWHs) and peak wave periods reveal the importance of wave-current interactions (WCI) during and after the storm. In two fast-moving hurricane cases, the maximum SWHs are reduced by more than 11% on the right-hand side of the storm track and increased by about 5% on the left-hand side due to different WCI mechanisms on waves on two sides of the track. The dominate mechanisms of the WCI on waves include the current-induced modification of wind energy input to the wave generation, and current-induced wave advection and refraction. In the slow-moving winter storm case, the effect of WCI decreases the maximum SWHs on both sides of the storm track due to different results of the current-induced wave advection, which is affected greatly by the storm translation speed. The simulated sea surface temperature (SST) cooling induced by hurricanes and SST warming induced by the winter storm are also enhanced (up to 1.2°C) by the WCI mechanisms on circulation and hydrography. The 3D wave forces can affect water columns up to 200 m in all three storm cases. By comparison, the effect of breaking wave-induced mixing in the ocean upper layer is more important under strong stratification conditions in two hurricane cases than under weak stratification conditions in the winter storm case.

  6. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions

    PubMed Central

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400–450 ppm CO2, 18–22°C; 2) 800–850 ppm CO2, 18–22°C; 3) 400–450 ppm CO2, 22–26°C, 4) 800–850 ppm CO2, 22–26°C, 5) 400–450 ppm CO2, 26–30°C; 6) 800–850 ppm CO2, 26–30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens. PMID:26469870

  7. Dynamic instabilities of frictional sliding at a bimaterial interface

    NASA Astrophysics Data System (ADS)

    Brener, Efim A.; Weikamp, Marc; Spatschek, Robert; Bar-Sinai, Yohai; Bouchbinder, Eran

    2016-04-01

    Understanding the dynamic stability of bodies in frictional contact steadily sliding one over the other is of basic interest in various disciplines such as physics, solid mechanics, materials science and geophysics. Here we report on a two-dimensional linear stability analysis of a deformable solid of a finite height H, steadily sliding on top of a rigid solid within a generic rate-and-state friction type constitutive framework, fully accounting for elastodynamic effects. We derive the linear stability spectrum, quantifying the interplay between stabilization related to the frictional constitutive law and destabilization related both to the elastodynamic bi-material coupling between normal stress variations and interfacial slip, and to finite size effects. The stabilizing effects related to the frictional constitutive law include velocity-strengthening friction (i.e. an increase in frictional resistance with increasing slip velocity, both instantaneous and under steady-state conditions) and a regularized response to normal stress variations. We first consider the small wave-number k limit and demonstrate that homogeneous sliding in this case is universally unstable, independent of the details of the friction law. This universal instability is mediated by propagating waveguide-like modes, whose fastest growing mode is characterized by a wave-number satisfying kH ∼ O(1) and by a growth rate that scales with H-1. We then consider the limit kH → ∞ and derive the stability phase diagram in this case. We show that the dominant instability mode travels at nearly the dilatational wave-speed in the opposite direction to the sliding direction. In a certain parameter range this instability is manifested through unstable modes at all wave-numbers, yet the frictional response is shown to be mathematically well-posed. Instability modes which travel at nearly the shear wave-speed in the sliding direction also exist in some range of physical parameters. Previous results

  8. A series of abnormal climatic conditions caused the most severe outbreak of first-generation adults of the meadow moth ( Loxostege sticticalis L.) in China

    NASA Astrophysics Data System (ADS)

    Chen, Xiao; Zeng, Juan; Zhai, Baoping

    2016-06-01

    The meadow moth, Loxostege sticticalis L., is a destructive migratory pest in the northern temperate zone. The outbreak mechanism of first-generation adults in China remains unclear. In 2008, the density of first-generation larvae was very low or even negligible in most sites in China. However, a great number of first-generation adults appeared unexpectedly in late July, and their offspring caused the most severe infestation on record. The present study aims to determine where the large influx of immigrant adults originated from and how this unprecedented population was established. Source areas were explored by trajectory analysis, and climatic patterns related to the population increase were investigated. Results showed that the outbreak population mainly immigrated from Northeast Mongolia and the Chita State of Russia, and the buildup of such a large population could be attributed to an exceptional northward migration of overwintered adults from North China to East Mongolia in the spring of 2007 and unusually favourable climatic conditions in the next two growth seasons. These results indicated that the population dynamics of meadow moth in Northeast Asia would be difficult to predict when only considering local climatic factors and population size within one country. International joint monitoring and information sharing related to this pest between China, Mongolia and Russia should be implemented.

  9. Better slides needed at AGU Meetings

    NASA Astrophysics Data System (ADS)

    Jacobson, Randall S.

    Recent AGU meetings show a dangerous trend in the quality of presentations. A fair percentage of slides used during oral presentations consisted of a black background and colored lines and/or words for data. Such slides are illegible and serve to undercut the speaker's points by not demonstrating the data clearly.A typical example consisted of dark red, dark blue, and green data on a black background. Even the author had difficulty in pointing out the data using his light arrow. Line drawings, in particular, should not use colors, but instead use high-contrast white-on-black for the following reasons: dark colors on black backgrounds provide little contrast, making it difficult to discern patterns; people who are colorblind are at a disadvantage; and the same information can be obtained using a variety of line weights (dotdash, solid, dotted, etc.) with single color slides.

  10. NEMD simulations for ductile metal sliding

    SciTech Connect

    Hammerberg, James E; Germann, Timothy C; Ravelo, Ramon J; Holian, Brad L

    2011-01-31

    We have studied the sliding behavior for a 19 M Al(110)/Al(110) defective crystal at 15 GPa as a function of relative sliding velocity. The general features are qualitatively similar to smaller scale (1.4 M) atom simulations for Al(111)/Al(110) nondefective single crystal sliding. The critical velocity, v{sub c}, is approximately the same for the defective crystal as the size scaled v{sub c}. The lower velocity tangential force is depressed relative to the perfect crystal. The critical temperature, T*, is depressed relative to the perfect crystal. These conclusions are consistent with a lower value for f{sub c} for the defective crystal. The detailed features of structural transformation and the high velocity regime remain to be mapped.

  11. Optimal second order sliding mode control for nonlinear uncertain systems.

    PubMed

    Das, Madhulika; Mahanta, Chitralekha

    2014-07-01

    In this paper, a chattering free optimal second order sliding mode control (OSOSMC) method is proposed to stabilize nonlinear systems affected by uncertainties. The nonlinear optimal control strategy is based on the control Lyapunov function (CLF). For ensuring robustness of the optimal controller in the presence of parametric uncertainty and external disturbances, a sliding mode control scheme is realized by combining an integral and a terminal sliding surface. The resulting second order sliding mode can effectively reduce chattering in the control input. Simulation results confirm the supremacy of the proposed optimal second order sliding mode control over some existing sliding mode controllers in controlling nonlinear systems affected by uncertainty.

  12. Develop and Manufacture an airlock sliding tray

    SciTech Connect

    Lawton, Cindy M.

    2014-02-26

    Objective: The goal of this project is to continue to develop an airlock sliding tray and then partner with an industrial manufacturing company for production. The sliding tray will be easily installed into and removed from most glovebox airlocks in a few minutes. Technical Approach: A prototype of a sliding tray has been developed and tested in the LANL cold lab and 35 trays are presently being built for the plutonium facility (PF-4). The current, recently approved design works for a 14-inch diameter round airlock and has a tray length of approximately 20 inches. The grant will take the already tested and approved round technology and design for the square airlock. These two designs will be suitable for the majority of the existing airlocks in the multitude of DOE facilities. Partnering with an external manufacturer will allow for production of the airlock trays at a much lower cost and increase the availability of the product for all DOE sites. Project duration is estimated to be 12-13 months. Benefits: The purpose of the airlock sliding trays is fourfold: 1) Mitigate risk of rotator cuff injuries, 2) Improve ALARA, 3) Reduce risk of glovebox glove breaches and glove punctures, and 4) Improve worker comfort. I have had the opportunity to visit many other DOE facilities including Savannah, Y-12, ORNL, Sandia, and Livermore for assistance with ergonomic problems and/or injuries. All of these sites would benefit from the airlock sliding tray and I can assume all other DOE facilities with gloveboxes built prior to 1985 could also use the sliding trays.

  13. Sliding-mode control design for nonlinear systems using probability density function shaping.

    PubMed

    Liu, Yu; Wang, Hong; Hou, Chaohuan

    2014-02-01

    In this paper, we propose a sliding-mode-based stochastic distribution control algorithm for nonlinear systems, where the sliding-mode controller is designed to stabilize the stochastic system and stochastic distribution control tries to shape the sliding surface as close as possible to the desired probability density function. Kullback-Leibler divergence is introduced to the stochastic distribution control, and the parameter of the stochastic distribution controller is updated at each sample interval rather than using a batch mode. It is shown that the estimated weight vector will converge to its ideal value and the system will be asymptotically stable under the rank-condition, which is much weaker than the persistent excitation condition. The effectiveness of the proposed algorithm is illustrated by simulation.

  14. Formation of metalsbnd F bonds during frictional sliding: Influence of water and applied load

    NASA Astrophysics Data System (ADS)

    Shen, J. T.; Pei, Y. T.; De Hosson, J. Th. M.

    2016-04-01

    Effects of water lubrication and applied load on the formation of PTFE transfer films and metalsbnd F bonds during sliding when PTFE filled composites sliding against steel and Al2O3 are investigated. In water-lubricated conditions, XPS analysis reveals that a thin layer of water molecules at the sliding interface inhibits the formation of PTFE transfer films and Alsbnd F bonds on the Al2O3 ball, leading to a detrimental effect on the tribo-performance. Under various normal loads in dry sliding condition, it is found that the smearing of PTFE onto the wear surface of the composite and the transfer of PTFE onto the surface of the steel counterpart are stimulated by a high load. During sliding, the contact pressure is found to be the driving force of the reaction between steel and PTFE. It is concluded that under various loads, the total amount of PTFE transfer films has a larger impact on the friction behavior than the formation of Fesbnd F bonds.

  15. Sliding mode control of wind-induced vibrations using fuzzy sliding surface and gain adaptation

    NASA Astrophysics Data System (ADS)

    Thenozhi, Suresh; Yu, Wen

    2016-04-01

    Although fuzzy/adaptive sliding mode control can reduce the chattering problem in structural vibration control applications, they require the equivalent control and the upper bounds of the system uncertainties. In this paper, we used fuzzy logic to approximate the standard sliding surface and designed a dead-zone adaptive law for tuning the switching gain of the sliding mode control. The stability of the proposed controller is established using Lyapunov stability theory. A six-storey building prototype equipped with an active mass damper has been used to demonstrate the effectiveness of the proposed controller towards the wind-induced vibrations.

  16. Visual Insight into How Low pH Alone Can Induce Actin-severing Ability in Gelsolin under Calcium-free Conditions

    PubMed Central

    Garg, Renu; Peddada, Nagesh; Sagar, Amin; Nihalani, Deepak; Ashish

    2011-01-01

    Gelsolin is a key actin cytoskeleton-modulating protein primarily regulated by calcium and phosphoinositides. In addition, low pH has also been suggested to activate gelsolin in the absence of Ca2+ ions, although no structural insight on this pathway is available except for a reported decrement in its diffusion coefficient at low pH. We also observed ∼1.6-fold decrease in the molecular mobility of recombinant gelsolin when buffer pH was lowered from 9 to 5. Analysis of the small angle x-ray scattering data collected over the same pH range indicated that the radius of gyration and maximum linear dimension of gelsolin molecules increased from 30.3 to 34.1 Å and from 100 to 125 Å, respectively. Models generated for each dataset indicated that similar to the Ca2+-induced process, low pH also promotes unwinding of this six-domain protein but only partially. It appeared that pH is able to induce extension of the G1 domain from the rest of the five domains, whereas the Ca2+-sensitive latch between G2 and G6 domains remains closed. Interestingly, increasing the free Ca2+ level to merely ∼40 nm, the partially open pH 5 shape “sprung open” to a shape seen earlier for this protein at pH 8 and 1 mm free Ca2+. Also, pH alone could induce a shape where the g3-g4 linker of gelsolin was open when we truncated the C-tail latch from this protein. Our results provide insight into how under physiological conditions, a drop in pH can fully activate the F-actin-severing shape of gelsolin with micromolar levels of Ca2+ available. PMID:21498516

  17. Extended Survival of Several Microorganisms and Relevant Amino Acid Biomarkers under Simulated Martian Surface Conditions as a Function of Burial Depth

    SciTech Connect

    Johnson, Adam; Pratt, L.M.; Vishnivetskaya, Tatiana A; Pfiffner, S. M.; Bryan, R. A.; Dadachova, E.; Whyte, L G; Radtke, K.; Chan, E.; Tronick, S.; Borgonie, G.; Mancinelli, R.; Rothschild, L.; Rogoff, D.; Horikawa, D. D.; Onstott, T. C.

    2011-01-01

    Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40 days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical

  18. Physiological and productive responses of multiparous lactating Holstein cows exposed to short-term cooling during severe summer conditions in an arid region of Mexico

    NASA Astrophysics Data System (ADS)

    Avendaño-Reyes, L.; Hernández-Rivera, J. A.; Álvarez-Valenzuela, F. D.; Macías-Cruz, U.; Díaz-Molina, R.; Correa-Calderón, A.; Robinson, P. H.; Fadel, J. G.

    2012-11-01

    Heat stress generates a significant economic impact for the dairy industry in arid and semi-arid regions of the world, so that heat abatement is an important issue for dairy producers. The objective of this study was to evaluate effects of two short-term cooling periods on physiological and productive status of lactating Holstein cows during hot ambient temperatures. Thirty-nine multiparous cows were blocked by milk yield and assigned to one of three treatments including: control group (C), cows cooled before milking time (0500 and 1700 h daily, 1 h cooling); AM group, cows cooled at 1000 h and before milking (2 h cooling); and AM + PM group, cows cooled at 1100, 1500 and 2200 h, as well as before milking (4 h cooling). The cooling system was placed in the holding pen which the cows were moved through for cooling. Respiratory rate, and temperatures of thurl and right flank, were lower ( P < 0.05) in cows from the AM + PM group than AM and C cows during the morning and afternoon. However, udder temperature was higher in the AM + PM group compared to AM and C groups during the afternoon, although lower than the AM group during the morning. Rectal temperature was similar in all groups. Thyroxin concentrations tended ( P < 0.10) to be lower in AM + PM relative to the AM and C groups. The AM + PM group had higher ( P < 0.05) milk production than C (18.70 vs. 17.43 kg, respectively), and AM + PM cows had a trend ( P < 0.10) to increased milk energy output vs. the C and AM groups (13.75 vs. 13.18 and 13.15 Mcal, respectively). Protein and fat in milk, body condition score, glucose, cholesterol, triglycerides and triiodothyronine were similar among the groups. Four hours of cooling with spray and fans during severe summer temperatures only modestly improved milk yield of lactating Holstein cows.

  19. Influence of carbon nanotube addition on sliding wear behaviour of pulse electrodeposited cobalt (Co)-phosphorus (P) coatings

    NASA Astrophysics Data System (ADS)

    Edward Anand, E.; Natarajan, S.

    2015-09-01

    This work examines the sliding wear behaviour of nanostructured cobalt-phosphorus (Co-P) alloy electrodeposits reinforced with multiwalled carbon nanotubes (MWCNTs). Nanocrystalline cobalt-phosphorus alloy coatings reinforced with carbon nanotubes were produced by pulse electrodeposition from an aqueous bath. Tribological properties of the coatings with and without MWCNT addition were characterized. Anisotropic tribological behaviour was observed for the coatings reinforced with MWCNTs when slided against hard steel counterparts. The nanocrystalline Co-P-CNT coatings display better wear resistance and friction reduction compared with the nanocrystalline Co-P coating. The friction coefficients and wear rates of the nanocrystalline Co-P-CNT coating are influenced by the test conditions including the applied load, sliding speed and more importantly the alignment of MWCNTs in the deposits. The wear mechanisms of the nanocrystalline Co-P and Co-P-CNT alloy coatings involved in different sliding conditions are explained related to their friction and wear properties.

  20. Seismically reactivated Hattian slide in Kashmir, Northern Pakistan

    NASA Astrophysics Data System (ADS)

    Schneider, Jean F.

    2009-07-01

    The Pakistan 2005 earthquake, of magnitude 7.6, caused severe damage on landscape and infrastructure, in addition to numerous casualties. The event reactivated Hattian Slide, creating a rock avalanche in a location where earlier mass movements had happened already, as indicated by satellite imagery and ground investigation. The slide originated on Dana Hill, in the upper catchment area of Hattian on Karli Stream, a tributary of Jhelum River, Pakistan, and buried the hamlet Dandbeh and several farms nearby. A natural dam accumulated, impounding two lakes, the larger one threatening parts of downstream Hattian Village with flooding. An access road and artificial spillways needed to be constructed in very short time to minimize the flooding risk. As shown by this example, when pointing out the risk of large-scale damage to population and infrastructure by way of hazard indication maps of seismically active regions, and preparing for alleviation of that risk, it is advisable to consider the complete Holocene history of the slopes involved.

  1. How to Prepare Clay-Lift and Sandwich Slides.

    ERIC Educational Resources Information Center

    Barman, Charles R.

    1984-01-01

    Describes two techniques for making 35 millimeter slides without using photographic film. One method uses clear adhesive contact paper and the other uses transparency film. Both techniques are inexpensive and require only a few minutes of preparation per slide. (JM)

  2. Enhancing Creative Thinking through Designing Electronic Slides

    ERIC Educational Resources Information Center

    Mokaram, Al-Ali Khaled; Al-Shabatat, Ahmad Mohammad; Fong, Fook Soon; Abdallah, Andaleeb Ahmad

    2011-01-01

    During the shifting of teaching and learning methods using computer technologies, much emphasis was paid on the knowledge content more than the thinking skills. Thus, this study investigated the effects of a computer application, namely, designing electronic slides on the development of creative thinking skills of a sample of undergraduate…

  3. Particle Sliding on a Rough Incline

    ERIC Educational Resources Information Center

    Zurcher, Ulrich

    2007-01-01

    We study a particle sliding on a rough inclined plane as an example of a mechanical problem with nonholonomic constraint. The particle is launched in an arbitrary direction so that its motion has both a horizontal and a "vertical" (i.e., up- and downhill) direction. The friction force acts along the instantaneous velocity, so that the horizontal…

  4. Color Microfiche as a Replacement for Slides.

    ERIC Educational Resources Information Center

    Schwarz, Philip

    This is the summary of a larger paper describing the evolution of a mediated elementary accounting course at the University of Wisconsin-Stout. The course was initially developed as a 25 slide-tape lesson course which included 950 visuals and approximately 25 hours of instruction. One hundred students per semester took the course in the following…

  5. A study of grain boundary sliding in copper with and without an addition of phosphorus

    NASA Astrophysics Data System (ADS)

    Pettersson, Kjell

    2010-10-01

    Copper will be used as a corrosion barrier in the storage of high level nuclear waste. In order to improve the creep fracture properties of the material it will contain 30-50 ppm of phosphorus, OFP copper as opposed to OF copper without P. It has been suggested that the phosphorus impedes grain boundary sliding in copper and recently a quantitative theory based on this idea has shown that there is no risk for creep-brittle fracture of OFP copper under waste storage conditions. In order to verify the basis of this theory grain boundary sliding has been investigated in copper with and without a P addition. The method has been to examine intentionally scratched surfaces of tensile specimens tension tested to plastic strains of 1%, 2% and 4% at 150 and 200 °C. After testing specimen surfaces have been examined in SEM and sliding distances have been measured as in-surface displacement of scratches. The results have been plotted as distribution functions where the fraction of slides smaller than a given value is plotted versus sliding distance. The result is that in most cases the distribution functions for OF and OFP copper overlap. In a small number of cases there is a tendency that less sliding has occurred in OFP copper. The overall conclusion is however that although there may be a slight difference between the materials with regard to grain boundary sliding it is not large enough to explain the observed difference in creep brittleness. Tension tests to fracture in the temperature range 100-200 °C show that the tensile properties of the two copper qualities are more or less identical until intergranular cracking starts in the OF copper. Then the flow stress decreases in comparison with OFP. It is suggested that at least part of the observed differences in creep strength between the two coppers may be due to the effect of intergranular cracking.

  6. Mechanism of sand slide - cold lahar induced by extreme rainfall

    NASA Astrophysics Data System (ADS)

    Fukuoka, Hiroshi; Yamada, Masumi; Dok, Atitkagna

    2014-05-01

    reveal the mechanism of rapid motion. In the undrained or partially drained tests under pore water pressure test, monotonic loading of shear stress, and constant shear speed conditions, we found that immediately after failure takes place, a big excess pore pressure was generated and accelerating motions had stated in all cases. The reduced shear resistance thereafter was maintained because of the lasting high pore pressure. Even in the partially-drained test, we found once the pore pressure reached almost same with the normal stress and then gradually decreased due to dissipation. Those tests apparently shows that the high mobility and high acceleration of the motion are expected and this could be the key mechanism of the fluidization of initial shallow slides into sand flows, i.e., cold lahars. In the past ring shear test series on volcanic materials from fluidized landslides at El Picaccho of El Salvador, Mt Aso of Kumamto Prefecture, and Nagari Tandikat near Padang, Indonesia, show very similar trends. In all those cases, we expected serious grain crushing during shear, contributed to the generation of excess pore pressure, because those material are deposited recently (in geological time) and suffered no big overburden pressure which means no consolidation and no serious grain crushing ever before. So those volcanic materials are generally susceptible to crushing and expect high mobility when slides are initiated under fully saturated condition.

  7. Experimental studies of compaction and dilatancy during frictional sliding on faults containing gouge

    USGS Publications Warehouse

    Morrow, C.A.; Byerlee, J.D.

    1989-01-01

    Transient strength changes are observed in fault gouge materials when the velocity of shearing is varied. A transient stress peak is produced when the strain rate in the gouge is suddenly increased, whereas a transient stress drop results from a sudden change to a slower strain rate. We have studied the mechanism responsible for these observations by performing frictional sliding experiments on sawcut granite samples filled with a layer of several different fault gouge types. Changes in pore volume and strength were monitored as the sliding velocity alternated between fast and slow rates. Pore volume increased at the faster strain rate, indicating a dilation of the gouge layer, whereas volume decreased at the slower rate indicating compaction. These results verify that gouge dilation is a function of strain rate. Pore volume changed until an equilibrium void ratio of the granular material was reached for a particular rate of strain. Using arguments from soil mechanics, we find that the dense gouge was initially overconsolidated relative to the equilibrium level, whereas the loose gouge was initially underconsolidated relative to this level. Therefore, the transient stress behavior must be due to the overconsolidated state of the gouge at the new rate when the velocity is increased and to the underconsolidated state when the velocity is lowered. Time-dependent compaction was also shown to cause a transient stress response similar to the velocity-dependent behavior. This may be important in natural fault gouges as they become consolidated and stronger with time. In addition, the strain hardening of the gouge during shearing was found to be a function of velocity, rendering it difficult to quantify the change in equilibrium shear stress when velocity is varied under certain conditions. ?? 1989.

  8. Distinguishing sediment waves from slope failure deposits: Field examples, including the 'humboldt slide', and modelling results

    USGS Publications Warehouse

    Lee, H.J.; Syvitski, J.P.M.; Parker, G.; Orange, Daniel L.; Locat, J.; Hutton, E.W.H.; Imran, J.

    2002-01-01

    Migrating sediment waves have been reported in a variety of marine settings, including submarine levee-fan systems, floors of fjords, and other basin or continental slope environments. Examination of such wave fields reveals nine diagnostic characteristics. When these characteristics are applied to several features previously attributed to submarine landslide deformation, they suggest that the features should most likely be reinterpreted as migrating sediment-wave fields. Sites that have been reinterpreted include the 'Humboldt slide' on the Eel River margin in northern California, the continental slope in the Gulf of Cadiz, the continental shelf off the Malaspina Glacier in the Gulf of Alaska, and the Adriatic shelf. A reassessment of all four features strongly suggests that numerous turbidity currents, separated by intervals of ambient hemipelagic sedimentation, deposited the wave fields over thousands of years. A numerical model of hyperpycnal discharge from the Eel River, for example, shows that under certain alongshore-current conditions, such events can produce turbidity currents that flow across the 'Humboldt slide', serving as the mechanism for the development of migrating sediment waves. Numerical experiments also demonstrate that where a series of turbidity currents flows across a rough seafloor (i.e. numerical steps), sediment waves can form and migrate upslope. Hemipelagic sedimentation between turbidity current events further facilitates the upslope migration of the sediment waves. Physical modelling of turbidity currents also confirms the formation and migration of seafloor bedforms. The morphologies of sediment waves generated both numerically and physically in the laboratory bear a strong resemblance to those observed in the field, including those that were previously described as submarine landslides.

  9. Studying the Effects of Nuclear Weapons Using a Slide-Rule Computer

    ERIC Educational Resources Information Center

    Shastri, Ananda

    2007-01-01

    This paper describes the construction of a slide-rule computer that allows one to quickly determine magnitudes of several effects that result from the detonation of a nuclear device. Suggestions for exercises are also included that allow high school and college-level physics students to explore scenarios involving these effects. It is hoped that…

  10. Reliability of whole slide images as a diagnostic modality for renal allograft biopsies.

    PubMed

    Jen, Kuang-Yu; Olson, Jean L; Brodsky, Sergey; Zhou, Xin J; Nadasdy, Tibor; Laszik, Zoltan G

    2013-05-01

    The use of digital whole slide images (WSI) in the field of pathology has become feasible for routine diagnostic purposes and has become more prevalent in recent years. This type of technology offers many advantages but must show the same degree of diagnostic reliability as conventional glass slides. Several studies have examined this issue in various settings and indicate that WSI are a reliable method for diagnostic pathology. Since transplant pathology is a highly specialized field that requires not only accurate but rapid diagnostic evaluation of biopsy materials, this field may greatly benefit from the use of WSI. In this study, we assessed the reliability of using WSI compared to conventional glass slides in renal allograft biopsies. We examined morphologic features and diagnostic categories defined by the Banff 07 Classification of Renal Allograft Pathology as well as additional morphologic features not included in this classification scheme. We found that intraobserver scores, when comparing the use of glass slides versus WSI, showed substantial agreement for both morphologic features (κ = 0.68) and acute rejection diagnostic categories (κ = 0.74). Furthermore, interobserver reliability was comparable for morphologic features (κ = 0.44 [glass] vs 0.42 [WSI]) and acute rejection diagnostic categories (κ = 0.49 [glass] vs 0.51 [WSI]). These data indicate that WSI are as reliable as glass slides for the evaluation of renal allograft biopsies.

  11. The Influence of Interfacial Roughness on Fiber Sliding in Oxide Composites with La-Monazite Interphases

    NASA Technical Reports Server (NTRS)

    Davis, J. B.; Hay, R. S.; Marshall, D. B.; Morgan, P. E. D.; Sayir, A.; Gray, Hugh R. (Technical Monitor); Farmer, Serene C. (Technical Monitor)

    2002-01-01

    Room temperature debonding and sliding of La-Monazite coated fibers is assessed using a composite with a polycrystalline alumina matrix and fibers of several different single crystal (mullite, sapphire) and directionally solidified eutectic (Al2O3/Y3Al5O12 and Al2O3/Y-ZrO2) compositions. These fibers provide a range of residual stresses and interfacial roughnesses. Sliding occurred over a debond crack at the fiber-coating interface when the sliding displacement and surface roughness were relatively small. At large sliding displacements with relatively rough interfaces, the monazite coatings were deformed extensively by fracture, dislocations and occasional twinning, whereas the fibers were undamaged. Dense, fine-grained (10 nm) microstructures suggestive of dynamic recrystallization were also observed in the coatings. Frictional heating during sliding is assessed. The possibility of low temperature recrystallization is discussed in the light of the known resistance of monazite to radiation damage. The ability of La-Monazite to undergo plastic deformation relatively easily at low temperatures may be enabling for its use as a composite interface.

  12. Investigations of the air flow velocity field structure above the wavy surface under severe wind conditions by particle image velosimetry technique.

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Kandaurov, Alexander; Sergeev, Daniil; Ermakova, Olga

    2013-04-01

    both method were in a good agreement. The application of PIV method enabled us measuring wind velocity profiles much closer to water surface than in the case of contact method. As a result there exists the logarithmic parts in velocity profiles, which yield turbulent momentum flux from the slope and also the equivalent 10-m wind speed and the surface drag coefficient. It was shown that similarly to [2] the surface drag coefficient tends to saturate at wind velocities exceeding 25 m/s. The decrease of the water surface drag coefficient with wind velocity increase was not observed. This work was supported by RFBR (project 11-05-12047-ofi-m, 13-05-00865-a, 12-05-33070 mol-a-ved, 12-05-31435 mol-a, 12-05-01064-a). References 1. Canny, J. A. Computational approach to edge detection/ J.A. Canny// IEEE Trans. Pattern Analysis and Machine Intelligence. - 1986. - V. 8(6). - P. 679-698.. 2. Troitskaya, Y. I., D. A. Sergeev, A. A. Kandaurov, G. A. Baidakov, M. A. Vdovin, and V. I. Kazakov Laboratory and theoretical modeling of air-sea momentum transfer under severe wind conditions J.Geophys. Res., 117, C00J21, doi:10.1029/2011JC007778.

  13. Slide Presentations as Speech Suppressors: When and Why Learners Miss Oral Information

    ERIC Educational Resources Information Center

    Wecker, Christof

    2012-01-01

    The objective of this study was to test whether information presented on slides during presentations is retained at the expense of information presented only orally, and to investigate part of the conditions under which this effect occurs, and how it can be avoided. Such an effect could be expected and explained either as a kind of redundancy…

  14. Micro and Nano-structure Development and Multiscale Physics at Sliding Metal Interfaces

    SciTech Connect

    Rigney, David A.

    2005-03-07

    This report describes research on the response of ductile materials to extreme loading conditions and high strain rates during impact combined with sliding friction. The work is a collaboration among two groups at Los Alamos National Laboratory and a tribology research group at The Ohio State University. The work involves experimental work and computer simulations at both laboratories and continuum mechanics analysis at OSU. Results to date demonstrate the importance of vorticity and mechanical mixing near the sliding interface in the development of tribomaterial.

  15. A Balanced-pressure Sliding Seal for Transfer of Pressurized Air Between Stationary and Rotating Parts

    NASA Technical Reports Server (NTRS)

    Curren, Arthur N; Cochran, Reeves P

    1957-01-01

    A combination sliding-ring and pressure-balancing seal capable of transferring pressurize air from stationary to rotating parts was developed and experimentally investigated at sliding velocities and cooling-air pressures up to 10,000 feet per minute and 38.3 pounds per square inch absolute, respectively. Leakage of cooling air was completely eliminated with an expenditure of balance air less than one-fourth the leakage loss of air from labyrinth seals under the same conditions. Additional cooling of the carbon-base seal rings was required, and the maximum wear rate on the rings was about 0.0005 inch per hour.

  16. Fluid pressure responses for a Devil's Slide-like system: problem formulation and simulation

    USGS Publications Warehouse

    Thomas, Matthew A.; Loague, Keith; Voss, Clifford I.

    2015-01-01

    This study employs a hydrogeologic simulation approach to investigate subsurface fluid pressures for a landslide-prone section of the central California, USA, coast known as Devil's Slide. Understanding the relative changes in subsurface fluid pressures is important for systems, such as Devil's Slide, where slope creep can be interrupted by episodic slip events. Surface mapping, exploratory core, tunnel excavation records, and dip meter data were leveraged to conceptualize the parameter space for three-dimensional (3D) Devil's Slide-like simulations. Field observations (i.e. seepage meter, water retention, and infiltration experiments; well records; and piezometric data) and groundwater flow simulation (i.e. one-dimensional vertical, transient, and variably saturated) were used to design the boundary conditions for 3D Devil's Slide-like problems. Twenty-four simulations of steady-state saturated subsurface flow were conducted in a concept-development mode. Recharge, heterogeneity, and anisotropy are shown to increase fluid pressures for failure-prone locations by up to 18.1, 4.5, and 1.8% respectively. Previous estimates of slope stability, driven by simple water balances, are significantly improved upon with the fluid pressures reported here. The results, for a Devil's Slide-like system, provide a foundation for future investigations

  17. Dry sliding wear behavior of epoxy composite reinforced with short palmyra fibers

    NASA Astrophysics Data System (ADS)

    Biswal, Somen; Satapathy, Alok

    2016-02-01

    The present work explores the possibility of using palmyra fiber as a replacement for synthetic fiber in conventional polymer composites for application against wear. An attempt has been made in this work to improve the sliding wear resistance of neat epoxy by reinforcing it with short palmyra fibers (SPF). Epoxy composites with different proportions (0, 4, 8 and 12 wt. %) of SPF are fabricated by conventional hand lay-up technique. Dry sliding wear tests are performed on the composite samples using a pin-on-disc test rig as per ASTM G 99-05 standards under various operating parameters. Design of experiment approach based on Taguchi's L16 Orthogonal Arrays is used for the analysis of the wear. This parametric analysis reveals that the SPF content is the most significant factor affecting the wear process followed by the sliding velocity. The sliding wear behavior of these composites under an extensive range of test conditions is predicted by a model based on the artificial neural network (ANN). A well trained ANN has been used to predict the sliding wear response of epoxy based composites over a wide range.

  18. A multitask sliding mode control for mismatched uncertain large-scale systems

    NASA Astrophysics Data System (ADS)

    Tsai, Yao-Wen; Van Huynh, Van

    2015-09-01

    A new sliding mode control (SMC) approach, output variables only, single phase only and chattering phenomenon free, is presented for a class of mismatched uncertain large-scale systems. For a new multitask SMC, it is not required that the system states are available. Moreover, the sliding function in this study just depends on output variables. Using an exponential type sliding surface, the system states are always in the sliding mode at the beginning time t = 0. Using a newly appropriate linear matrix inequality stability conditions by the Lyapunov method are derived such that each subsystem in the new sliding mode is completely invariant to matched uncertainties. As a result, robustness of the mismatched uncertain large-scale systems can be assured throughout an entire response of the system starting from the initial time t = 0. In every subsystem, a scheme of decentralised control using only output states is proposed. In addition, a continuous controller is finally designed for chattering removal. Finally, a numerical example is used to demonstrate the efficacy of the proposed method.

  19. Sliding mode control for multi-agent systems under a time-varying topology

    NASA Astrophysics Data System (ADS)

    Dong, Lijing; Chai, Senchun; Zhang, Baihai; Kiong Nguang, Sing

    2016-07-01

    This paper addresses the tracking problem of a class of multi-agent systems under uncertain communication environments which has been modelled by a finite number of constant Laplacian matrices together with their corresponding scheduling functions. Sliding mode control method is applied to solve this nonlinear tracking problem under a time-varying topology. The controller of each tracking agent has been designed by using only its own and neighbours' information. Sufficient conditions for the existence of a sliding mode control tracking strategy have been provided by the solvability of linear matrix inequalities. At the end of this work, numerical simulations are employed to demonstrate the effectiveness of the proposed sliding mode control tracking strategy.

  20. Further Evidence that Severe Scores in the Aggression/Anxiety-Depression/Attention Subscales of Child Behavior Checklist (Severe Dysregulation Profile) Can Screen for Bipolar Disorder Symptomatology: A Conditional Probability Analysis

    PubMed Central

    Uchida, Mai; Faraone, Stephen V; Martelon, MaryKate; Kenworthy, Tara; Woodworth, K Yvonne; Spencer, Thomas; Wozniak, Janet; Biederman, Joseph

    2014-01-01

    Background Previous work shows that children with high scores (2 SD, combined score ≥ 210) on the Attention Problems, Aggressive Behavior, and Anxious-Depressed (A-A-A) subscales of the Child Behavior Checklist (CBCL) are more likely than other children to meet criteria for bipolar (BP)-I disorder. However, the utility of this profile as a screening tool has remained unclear. Methods We compared 140 patients with pediatric BP-I disorder, 83 with attention deficit hyperactivity disorder (ADHD), and 114 control subjects. We defined the CBCL-Severe Dysregulation profile as an aggregate cutoff score of ≥ 210 on the A-A-A scales. Patients were assessed with structured diagnostic interviews and functional measures. Results Patients with BP-I disorder were significantly more likely than both control subjects (Odds Ratio [OR]: 173.2; 95% Confidence Interval [CI], 21.2 to 1413.8; P < 0.001) and those with ADHD (OR: 14.6; 95% CI, 6.2 to 34.3; P < 0.001) to have a positive CBCL-Severe Dysregulation profile. Receiver Operating Characteristics analyses showed that the area under the curve for this profile comparing children with BP-I disorder against control subjects and those with ADHD was 99% and 85%, respectively. The corresponding positive predictive values for this profile were 99% and 92% with false positive rates of < 0.2% and 8% for the comparisons with control subjects and patients with ADHD, respectively. Limitations Non-clinician raters administered structured diagnostic interviews, and the sample was referred and largely Caucasian. Conclusions The CBCL-Severe Dysregulation profile can be useful as a screen for BP-I disorder in children in clinical practice. PMID:24882182

  1. Shallow translational slides hazard evaluation in Santa Marta de Penaguião (Douro valley - Portugal)

    NASA Astrophysics Data System (ADS)

    Pereira, Susana; Luís Zêzere, José; Bateira, Carlos

    2010-05-01

    The present study is developed for the municipality of Santa Marta de Penaguião (70 square kilometers), located in the Douro Valley region (Northern Portugal). In the past, several destructive landslides occurred in this area, and were responsible for deaths and destruction of houses and roads. Despite these losses, mitigation and landslide zonation programs are missing, and the land use planning at the municipal level did not solve yet the problem. The study area is mainly composed by metamorphic rocks (e.g., schist and quartzite). These rocks are strongly fractured, and weathered materials are abundant in clayed schist, mainly in those areas where agricultural terraces were constructed centuries ago for the vineyard monoculture. From the geomorphologic point of view, the study area is characterized by deep incised valleys, tectonic depressions and slopes controlled by the geological structure. Elevation ranges from 49 m to 1416 m. The main landslide triggering factor is rainfall and the mean annual precipitation ranges from 700 mm (in the bottom of fluvial valleys) to 2500 mm (in the mountains top). A landslide inventory was performed in 2005-2009 using aerial photo-interpretation (1/5.000 scale) and field work. The inventory includes 848 landslides, most of shallow translational slide type (85% of total slope movements). The landslide density is 10.5 events/square kilometers, and the average landslide area is 535 square meters. The susceptibility to shallow translational slide occurrence was assessed at the 1: 10 000 scale in a GIS environment. Two different bivariate statistical methods were used to evaluate landslide susceptibility: the Information Value and the Fuzzy Logic Gamma operator. Eight conditioning factors were weighted and integrated to model susceptibility: slope angle, slope aspect, slope curvature, lithology, geomorphologic units, fault density, land use and terrace structures build in slopes. The susceptibility results were validated using a

  2. Analysis of containment performance and radiological consequences under severe accident conditions for the Advanced Neutron Source Reactor at the Oak Ridge National Laboratory

    SciTech Connect

    Kim, S.H.; Taleyarkhan, R.P.

    1994-01-01

    A severe accident study was conducted to evaluate conservatively scoped source terms and radiological consequences to support the Advanced Neutron Source (ANS) Conceptual Safety Analysis Report (CSAR). Three different types of severe accident scenarios were postulated with a view of evaluating conservatively scoped source terms. The first scenario evaluates maximum possible steaming loads and associated radionuclide transport, whereas the next scenario is geared towards evaluating conservative containment loads from releases of radionuclide vapors and aerosols with associated generation of combustible gases. The third scenario follows the prescriptions given by the 10 CFR 100 guidelines. It was included in the CSAR for demonstrating site-suitability characteristics of the ANS. Various containment configurations are considered for the study of thermal-hydraulic and radiological behaviors of the ANS containment. Severe accident mitigative design features such as the use of rupture disks were accounted for. This report describes the postulated severe accident scenarios, methodology for analysis, modeling assumptions, modeling of several severe accident phenomena, and evaluation of the resulting source term and radiological consequences.

  3. Sliding seal materials for low heat rejection engines

    NASA Technical Reports Server (NTRS)

    Beaty, Kevin; Lankford, James; Vinyard, Shannon

    1989-01-01

    Sliding friction coefficients and wear rates of promising piston seal materials were measured under temperature, environmental, velocity, and loading conditions that are representative of the low heat rejection (LHR) diesel engine environment. These materials included carbides, oxides, and nitrides. In addition, silicon nitride and partially stablized zirconia disks (cylinder liners) were ion-implanted with TiNi, Ni, Co, and Cr, and subsequently run against carbide pins (piston rings), with the objective of producing reduced friction via solid lubrication at elevated temperature. Friction and wear measurements were obtained using pin-on-disk laboratory experiments and a unique engine friction test rig. Unmodified ceramic sliding couples were characterized at all temperatures by friction coefficients of 0.24 and above during the pin-on-disk tests. The coefficient at 800 C in an oxidizing environment was reduced to below 0.1, for certain material combination, by the ion-implantation of TiNi or Co. This beneficial effect was found to derive from the lubricious Ti, Ni, and Co oxides. Similar results were demonstrated on the engine friction test rig at lower temperatures. The structural integrity and feasibility of engine application with the most promising material combination were demonstrated during a 30-hour single-cylinder, direct-injection diesel engine test.

  4. Sliding Seal Materials for Adiabatic Engines, Phase 2

    NASA Technical Reports Server (NTRS)

    Lankford, J.; Wei, W.

    1986-01-01

    An essential task in the development of the heavy-duty adiabatic diesel engine is identification and improvements of reliable, low-friction piston seal materials. In the present study, the sliding friction coefficients and wear rates of promising carbide, oxide, and nitride materials were measured under temperature, environmental, velocity, and loading conditions that are representative of the adiabatic engine environment. In addition, silicon nitride and partially stabilized zirconia disks were ion implanted with TiNi, Ni, Co, and Cr, and subsequently run against carbide pins, with the objective of producing reduced friction via solid lubrication at elevated temperature. In order to provide guidance needed to improve materials for this application, the program stressed fundamental understanding of the mechanisms involved in friction and wear. Electron microscopy was used to elucidate the micromechanisms of wear following wear testing, and Auger electron spectroscopy was used to evaluate interface/environment interactions which seemed to be important in the friction and wear process. Unmodified ceramic sliding couples were characterized at all temperatures by friction coefficients of 0.24 and above. The coefficient at 800 C in an oxidizing environment was reduced to below 0.1, for certain material combinations, by the ion implanation of TiNi or Co. This beneficial effect was found to derive from lubricious Ti, Ni, and Co oxides.

  5. Buckling of a Flexible Strip Sliding on a Frictional Base

    NASA Astrophysics Data System (ADS)

    Huynen, Alexandre; Marck, Julien; Denoel, Vincent; Detournay, Emmanuel

    2013-03-01

    The main motivation for this contribution is the buckling of a drillstring sliding on the bottom of the horizontal section of borehole. The open questions that remain today are related to the determination of the onset of instability, and to the conditions under which different modes of constrained buckling occur. In this presentation, we are concerned by a two-dimensional version of this problem; namely, the sliding of a flexible strip being fed inside a conduit. The ribbon, which has a flexural rigidity EI and a weight per unit length w, is treated as an inextensible elastica of negligible thickness. The contact between the ribbon and the wall of the conduit is characterized by a friction coefficient μ. First, we report the result of a stability analysis that aims at determining the critical inserted length of the ribbon l* (μ) (scaled by the characteristic length λ =(EI / w) 1 / 3) at which there is separation between the strip and the conduit bottom, as well as the buckling mode. Next, the relationship between the feeding force F and the inserted length l after bifurcation is computed. Finally, the results of a ``kitchen table'' experiment involving a strip of silicon rubber being pushed on a plank are reported and compared with predictions.

  6. Texturing in metals as a result of sliding

    NASA Technical Reports Server (NTRS)

    Wheeler, D. R.; Buckley, D. H.

    1973-01-01

    Sliding friction experiments were conducted with copper, nickel, iron, and cobalt sliding on themselves in air and argon. The resulting wear surfaces were examined with X-ray analysis to determine if surface texturing had occurred as a result of sliding. Results of the investigation indicate that, for the face-centered-cubic metals copper and nickel, a (111) texture develops with the (111) planes tilted 10 deg in the direction of sliding. The body-centered-cubic metal iron exhibited a (110) texture with the (100) direction oriented in the direction of sliding. It also exhibited a 10 deg tilt in the direction of sliding. The environment influenced the results in that the degree of texture observed in argon was less than that seen in air for iron. No texturing was observed for the close-packed-hexagonal metal cobalt. Recrystallization was observed with copper as a result of sliding.

  7. Sliding friction on wet and dry sand.

    PubMed

    Fall, A; Weber, B; Pakpour, M; Lenoir, N; Shahidzadeh, N; Fiscina, J; Wagner, C; Bonn, D

    2014-05-01

    We show experimentally that the sliding friction on sand is greatly reduced by the addition of some-but not too much-water. The formation of capillary water bridges increases the shear modulus of the sand, which facilitates the sliding. Too much water, on the other hand, makes the capillary bridges coalesce, resulting in a decrease of the modulus; in this case, we observe that the friction coefficient increases again. Our results, therefore, show that the friction coefficient is directly related to the shear modulus; this has important repercussions for the transport of granular materials. In addition, the polydispersity of the sand is shown to also have a large effect on the friction coefficient. PMID:24836256

  8. Operational seismic network estimates rock slide properties

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2012-02-01

    During the spring of 1991, two subsequent landslides near Randa, Switzerland, dropped 30,000,000 cubic meters of debris on the town below. The rocks dammed the Vispa River, a temporary reservoir that would have failed catastrophically had the army not carved a channel through it. Many rock slides occur in remote alpine locations, so it can sometimes take days or weeks before they are detected, a delay that could have cost the town of Randa. Rock slides can range from deadly, to disruptive, to simple scientific curiosities.Dammeier et al. have developed a method to remotely estimate their volume, location, and runout distances that could potentially be used in real time.

  9. Vesicocutaneous fistula after sliding hernia repair

    PubMed Central

    Mittal, Varun; Kapoor, Rakesh; Sureka, Sanjoy

    2016-01-01

    Sliding inguinal hernias are usually direct inguinal hernias containing various abdominal viscera. The incidence of bladder forming a part of an inguinal hernia, called as “scrotal cystocele,” is 1–4%. The risk of bladder injury is as high as 12% when repairing this type of hernia. This case report emphasizes this aspect in a 65-year-old man who presented with urinary leak through the scrotal wound following right inguinal hernia repair. PMID:26941501

  10. Slide-specific models for segmentation of differently stained digital histopathology whole slide images

    NASA Astrophysics Data System (ADS)

    Brieu, Nicolas; Pauly, Olivier; Zimmermann, Johannes; Binnig, Gerd; Schmidt, Günter

    2016-03-01

    The automatic analysis of whole slide images (WSIs) of stained histopathology tissue sections plays a crucial role in the discovery of predictive biomarkers in the field on immuno-oncology by enabling the quantification of the phenotypic information contained in the tissue sections. The automatic detection of cells and nuclei, while being one of the major steps of such analysis, remains a difficult problem because of the low visual differentiation of high pleomorphic and densely cluttered objects and of the diversity of tissue appearance between slides. The key idea of this work is to take advantage of well-differentiated objects in each slide to learn about the appearance of the tissue and in particular about the appearance of low-differentiated objects. We detect well-differentiated objects on a automatically selected set of representative regions, learn slide-specific visual context models, and finally use the resulting posterior maps to perform the final detection steps on the whole slide. The accuracy of the method is demonstrated against manual annotations on a set of differently stained images.

  11. Improving protein array performance: focus on washing and storage conditions.

    PubMed

    Nath, Nidhi; Hurst, Robin; Hook, Brad; Meisenheimer, Poncho; Zhao, Kate Q; Nassif, Nadine; Bulleit, Robert F; Storts, Douglas R

    2008-10-01

    For protein microarrays, maintaining protein stability during the slide processing steps of washing, drying, and storage is of major concern. Although several studies have focused on the stability of immobilized antibodies in antibody microarrays, studies on protein-protein interaction arrays and enzyme arrays are lacking. In this paper we used five bait-prey protein interaction pairs and three enzymes to optimize the washing, drying, and storage conditions for protein arrays. The protein arrays for the study were fabricated by combining HaloTag technology and cell-free protein expression. The HaloTag technology, in combination with cell-free expression, allowed rapid expression and immobilization of fusion proteins on hydrogel-coated glass slides directly from cell extracts without any prior purification. Experimental results indicate enzyme captured on glass slides undergoes significant loss of activity when washed and spin-dried using only phosphate buffer, as is typically done with antibody arrays. The impact of washing and spin-drying in phosphate buffer on protein-protein interaction arrays was minimal. However, addition of 5% glycerol to the wash buffer helps retain enzyme activity during washing and drying. We observed significant loss of enzyme activity when slides were stored dry at 4 degrees C, however immobilized enzymes remained active for 30 days when stored at -20 degrees C in 50% glycerol. We also found that cell-free extract containing HaloTag-fused enzymes could undergo multiple freeze/thaw cycles without any adverse impact on enzyme activity. The findings indicate that for large ongoing studies, proteins of interest expressed in cell-free extract can be stored at -70 degrees C and repeatedly used to print small batches of protein array slides to be used over a few weeks.

  12. Assessing Visual Attention in Young Children and Adolescents with Severe Mental Retardation Utilizing Conditional-Discrimination Tasks and Multiple Testing Procedures

    ERIC Educational Resources Information Center

    Huguenin, Nancy H.

    2004-01-01

    To effectively reduce overselective attention, a fine-grained analysis of the control exhibited by compound training cues is first needed. Computer software was developed in this study to administer two different stimulus control-testing procedures to assess how three young children of normal development and three adolescents with severe mental…

  13. Melatonin versus Placebo in Children with Autism Spectrum Conditions and Severe Sleep Problems Not Amenable to Behaviour Management Strategies: A Randomised Controlled Crossover Trial

    ERIC Educational Resources Information Center

    Wright, Barry; Sims, David; Smart, Siobhan; Alwazeer, Ahmed; Alderson-Day, Ben; Allgar, Victoria; Whitton, Clare; Tomlinson, Heather; Bennett, Sophie; Jardine, Jenni; McCaffrey, Nicola; Leyland, Charlotte; Jakeman, Christine; Miles, Jeremy

    2011-01-01

    Twenty-two children with autism spectrum disorders who had not responded to supported behaviour management strategies for severe dysomnias entered a double blind, randomised, controlled crossover trial involving 3 months of placebo versus 3 months of melatonin to a maximum dose of 10 mg. 17 children completed the study. There were no significant…

  14. Predictors of Age of Diagnosis for Children with Autism Spectrum Disorder: The Role of a Consistent Source of Medical Care, Race, and Condition Severity

    ERIC Educational Resources Information Center

    Emerson, Natacha D.; Morrell, Holly E. R.; Neece, Cameron

    2016-01-01

    Having a consistent source of medical care may facilitate diagnosis of autism spectrum disorders (ASD). This study examined predictors of age of ASD diagnosis using data from the 2011-2012 National Survey of Children's Health. Using multiple linear regression analysis, age of diagnosis was predicted by race, ASD severity, having a consistent…

  15. Application of Sliding Mode Methods to the Design of Reconfigurable Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Wells, Scott R.

    2002-01-01

    Observer-based sliding mode control is investigated for application to aircraft reconfigurable flight control. A comprehensive overview of reconfigurable flight control is given, including, a review of the current state-of-the-art within the subdisciplines of fault detection, parameter identification, adaptive control schemes, and dynamic control allocation. Of the adaptive control methods reviewed, sliding mode control (SMC) appears very promising due its property of invariance to matched uncertainty. An overview of sliding mode control is given and its remarkable properties are demonstrated by example. Sliding mode methods, however, are difficult to implement because unmodeled parasitic dynamics cause immediate and severe instability. This presents a challenge for all practical applications with limited bandwidth actuators. One method to deal with parasitic dynamics is the use of an asymptotic observer in the feedback path. Observer-based SMC is investigated, and a method for selecting observer gains is offered. An additional method for shaping the feedback loop using a filter is also developed. It is shown that this SMC prefilter is equivalent to a form of model reference hedging. A complete design procedure is given which takes advantage of the sliding mode boundary layer to recast the SMC as a linear control law. Frequency domain loop shaping is then used to design the sliding manifold. Finally, three aircraft applications are demonstrated. An F-18/HARV is used to demonstrate a SISO pitch rate tracking controller. It is also used to demonstrate a MIMO lateral-directional roll rate tracking controller. The last application is a full linear six degree-of-freedom advanced tailless fighter model. The observer-based SMC is seen to provide excellent tracking with superior robustness to parameter changes and actuator failures.

  16. Submarine slumps, slides, and flows dominate sculpting of Beringian Margin, Alaska

    SciTech Connect

    Carlson, P.R.; Karl, H.A.; Edwards, B.D.; Gardner, J.V.; Hall, R. )

    1990-06-01

    The 1,400 km long Beringian margin is characterized by several very large submarine canyons and by a large oceanic plateau at the southern end. GLORIA sidescan-sonar imagery provides a perspective of this margin that is unattainable with conventional acoustic profiles. The broad coverage of GLORIA images emphasizes that, of all the sedimentary processes affecting this vast margin, mass movement is clearly the dominant shaping process. Styles of failure include mud and debris flows, slumps, and massive block slides, some covering areas greater than 1,500 km{sup 2}. GLORIA imagery and seismic-reflection profiles show evidence for a wide variety of slides and slumps in the canyons of the northern margin, Navarin and Pervenets. The 100 km long shelf edge between these two canyons is characterized by a series of scalloped slide scars and incipient scars associated with blocks of sedimentary material, 1 to 2 km across. One of the largest single slide masses is a huge block tens of kilometers wide that occurs on the rise in the central part of the margin beyond the mouth of Zhemchug Canyon. Sliding of this block may have initiated the incision of the world's largest submarine canyon. The removal of this block accelerated headward erosion by retrograde failure until Zhemchug Canyon was cut back to a fault parallel to the shelf edge. Mass movement along the southern margin is widespread at the edges of Umnak Plateau. One mass failure, well-defined by GLORIA, is about 30 km wide and 55 km long. This and other slides along the plateau are associated with diapiric-like structures, suggesting relatively recent tectonism.

  17. [Clinical trial of a topical preparation containing urea, sunflower oil, evening primrose oil, wheat germ oil and sodium pyruvate, in several hyperkeratotic skin conditions].

    PubMed

    Ferrando, J

    1986-01-01

    A topical clinical trial with preparations containing urea and sodium pyruvate has been made. It was used for diverse hyperkeratotic skin conditions (psoriasis, xerosis, pityriasis rubra pilaris, stuccokeratosis, seborrheic dermatitis, stasis dermatitis, pityriasis lichenoides chronica). A month later a clinical improvement was evident in all cases except in pityriasis lichenoides.

  18. FASTGRASS: A mechanistic model for the prediction of Xe, I, Cs, Te, Ba, and Sr release from nuclear fuel under normal and severe-accident conditions

    SciTech Connect

    Rest, J.; Zawadzki, S.A. )

    1992-09-01

    The primary physical/chemical models that form the basis of the FASTGRASS mechanistic computer model for calculating fission-product release from nuclear fuel are described. Calculated results are compared with test data and the major mechanisms affecting the transport of fission products during steady-state and accident conditions are identified.

  19. A hybrid biomechanical model-based image registration method for sliding objects

    NASA Astrophysics Data System (ADS)

    Han, Lianghao; Hawkes, David; Barratt, Dean

    2014-03-01

    The sliding motion between two anatomic structures, such as lung against chest wall, liver against surrounding tissues, produces a discontinuous displacement field between their boundaries. Capturing the sliding motion is quite challenging for intensity-based image registration methods in which a smoothness condition has commonly been applied to ensure the deformation consistency of neighborhood voxels. Such a smoothness constraint contradicts motion physiology at the boundaries of these anatomic structures. Although various regularisation schemes have been developed to handle sliding motion under the framework of non-rigid intensity-based image registration, the recovered displacement field may still not be physically plausible. In this study, a new framework that incorporates a patient-specific biomechanical model with a non-rigid image registration scheme for motion estimation of sliding objects has been developed. The patient-specific model provides the motion estimation with an explicit simulation of sliding motion, while the subsequent non-rigid image registration compensates for smaller residuals of the deformation due to the inaccuracy of the physical model. The algorithm was tested against the results of the published literature using 4D CT data from 10 lung cancer patients. The target registration error (TRE) of 3000 landmarks with the proposed method (1.37+/-0.89 mm) was significantly lower than that with the popular B-spline based free form deformation (FFD) registration (4.5+/-3.9 mm), and was smaller than that using the B-spline based FFD registration with the sliding constraint (1.66+/-1.14 mm) or using the B-spline based FFD registration on segmented lungs (1.47+/-1.1 mm). A paired t-test showed that the improvement of registration performance with the proposed method was significant (p<0.01). The propose method also achieved the best registration performance on the landmarks near lung surfaces. Since biomechanical models captured most of the lung

  20. Two dimensional nanoscale reciprocating sliding contacts of textured surfaces

    NASA Astrophysics Data System (ADS)

    Tong, Ruiting; Liu, Geng; Liu, Tianxiang

    2016-05-01

    Detailed behaviors of nanoscale textured surfaces during the reciprocating sliding contacts are still unknown although they are widely used in mechanical components to improve tribological characteristics. The current research of sliding contacts of textured surfaces mainly focuses on the experimental studies, while the cost is too high. Molecular dynamics(MD) simulation is widely used in the studies of nanoscale single-pass sliding contacts, but the CPU cost of MD simulation is also too high to simulate the reciprocating sliding contacts. In this paper, employing multiscale method which couples molecular dynamics simulation and finite element method, two dimensional nanoscale reciprocating sliding contacts of textured surfaces are investigated. Four textured surfaces with different texture shapes are designed, and a rigid cylindrical tip is used to slide on these textured surfaces. For different textured surfaces, average potential energies and average friction forces of the corresponding sliding processes are analyzed. The analyzing results show that "running-in" stages are different for each texture, and steady friction processes are discovered for textured surfaces II, III and IV. Texture shape and sliding direction play important roles in reciprocating sliding contacts, which influence average friction forces greatly. This research can help to design textured surfaces to improve tribological behaviors in nanoscale reciprocating sliding contacts.

  1. Beam size reduction of a several hundred-keV compact ion microbeam system by improving the extraction condition in an ion source

    NASA Astrophysics Data System (ADS)

    Ishii, Yasuyuki; Ohkubo, Takeru; Kamiya, Tomihiro; Saitoh, Yuichi

    2015-04-01

    A several hundred-keV compact ion microbeam system with a three-stage acceleration lens has been developed to form an ion beam of several micrometers in diameter. In a previous study of the Ohkubo et al. (2013) and Ishii et al. (2014), a hydrogen beam of 143 keV having 17 μm diameter was experimentally formed using such a microbeam system. It was demonstrated that a three-stage acceleration lens functioned as a focusing lens and indicated that the beam diameter (hereinafter referred to as the "beam size") depended on the extraction voltage to generate the ion beam and the vacuum pressure in the extraction space in a plasma-type ion source. In this study, the hydrogen beam sizes were experimentally measured at 130 keV as functions of the extraction voltage and vacuum pressure to form the beam size with several micrometers in diameter. These two relationships showed that beam sizes were reduced in the extraction voltage range of 400-500 V and when the vacuum pressure was lowered to a minimum value of 5.33 × 10-5 Pa. In addition, the result showed that the beam size was dominantly influenced by the vacuum pressure. Consequently, a hydrogen beam 5.8 μm in diameter was formed experimentally-the smallest beam yet obtained.

  2. Sliding contacts on printed circuit boards and wear behavior

    NASA Astrophysics Data System (ADS)

    Le Solleu, J.-P.

    2010-04-01

    Automotive suppliers use since decades printed circuit boards (PCB) gold plating pads, as direct contact interface for low current sliding contacts. Several gold plating processes are available on the market, providing various wear behaviour. Some specific galvanic hard gold (AuCo or AuNi). plating was developed on PCB's. This specific plating generates extra costs due to the material quantity and also the process complexity. In a cost driven industry, the challenge is to use a standard low cost PCB for systems requesting high reliability performances. After a brief overview of standard PCB manufacturing processes and especially gold plating processes, the global experimental results of wear behaviour of three different gold plating technologies will be exposed and an explanation of the correlation between surface key parameters and wear out will be provided.

  3. Sliding Contact Bearings for Service to 700 C

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.

    1996-01-01

    Cylindrical, sliding contact bearings made entirely of a self-lubricating powder metallurgy composite (PM212) or of super alloy shells lined with clad PM212 were tested in an oscillating mode at temperatures from 25 to 700 C. Tests of 100 hr duration or longer were conducted at a bearing unit load of 3.45 Mpa (500 psi). Shorter duration tests at various unit loads up to 24.1 Mpa (3500 psi) were also conducted. In comparison tests, bearings lubricated with PM212 had superior anti-wear characteristics compared to the baseline, unlubricated, super alloy bearings: no galling of PM212-lubricated bearings occurred, while severe surface damage including galling occurred, especially at high loads, during the baseline tests. A heat treatment procedure, which dimensionally stabilizes PM212 and thereby minimizes clearance changes during high temperature bearing operation, is described.

  4. Towards slide enhancement with the titanium-molybdenum wire?

    PubMed

    Thiry, Pol; Barthélémi, Stéphane

    2010-12-01

    This study aims to improve the tribological properties of titanium-molybdenum wire. Following an analysis of the wire/bracket/ligation friction parameters and an overview of the technological research into means of reducing such friction,we set up several types of surface treatment in the laboratory by physical deposition in the vapor phase and using cold plasma technology. The specimens obtained underwent two types of tribological tests and were then subjected to traction and bending tests in order to determine the variations in their mechanical properties induced by the different types of treatment. For purposes of comparison, all the tests were conducted on untreated wire, TMA® Low-friction® wire and stainless steel wire and with two types of elastomeric ties. We were able to demonstrate some remarkable slide performances obtained using cold plasma nitriding while preserving the mechanical properties. A significant difference was observed relative to the other surface treatments.

  5. Is perceived nervousness and anxiety a predictor of premature mortality and severe morbidity? A longitudinal follow up of the Swedish survey of living conditions

    PubMed Central

    Ringback, W; Rosen, M.

    2005-01-01

    Study objective: To find out if people perceiving nervousness, uneasiness, and anxiety have excess risks of premature death and severe morbidity. Design, setting, participants: Random samples of the Swedish population aged 16–74 years in 1980–81, 1988–89, and 1995–96 were followed up for 5 and 10 years with regard to deaths and hospital admissions for different causes. Relative risks were estimated by Poisson regression, comparing those who reported perceived nervousness, uneasiness, and anxiety with those who did not and adjustments were made for baseline characteristics as age, education, smoking, and longstanding illness. Main results: Perceived nervousness, uneasiness, and anxiety was strongly related to subsequent risks of suicide attempt and psychiatric disease. Those perceiving severe complaints of anxiety had a relative risk (fully adjusted) for suicide attempt of 9.2 (95% CI 3.0 to 28.8) for men and 3.1 (1.4 to 7.1) for women. Even for less severe complaints, there was a significant, but less pronounced excess risk. These negative feelings were also associated with later risks for all cause mortality, hospital care, and ischaemic heart disease, although to a lesser extent and more strongly among men. Unchanged relative risks over time shows no trend in response attitude and perceived anxiety seems to be a better predictor of a negative health outcome than self reported longstanding illness. Conclusions: Positive responses to self report survey questions about anxiety/nervousness are associated with adverse health outcomes, particularly hospital admission for deliberate self harm. This is an alarming signal bearing in mind the rapid increase in prevalence of perceived anxiety in the Swedish society. PMID:16100319

  6. Pulmonary Interstitial Glycogenosis: A Reversible Underlying Condition Associated With D-Transposition of the Great Arteries and Severe Persistent Pulmonary Hypertension.

    PubMed

    Sanchez-de-Toledo, Joan; González-Peris, Sebastià; Gran, Ferran; Gregoraci, Angela; Ferreres, Joan Carles; Ruiz, Cèsar W; Balcells, Joan; Abella, Raul F

    2015-07-01

    Transposition of the great arteries with intact ventricular septum and persistent pulmonary hypertension (TGA-IVS PPHN) is a rare association with a poor prognosis. We report the case of a term newborn with TGA-IVS PPHN successfully managed with perioperative extracorporeal membrane oxygenation (ECMO) and aggressive pulmonary vasodilation therapy that underwent successful arterial switch procedure. A lung biopsy obtained during the surgical procedure showed pulmonary interstitial glycogenosis, a reversible condition. Concerns over left ventricle deconditioning after ECMO could be minimized with appropriate management and monitoring of the ductus arteriosus and appropriate timing of surgery.

  7. Optimal second order sliding mode control for linear uncertain systems.

    PubMed

    Das, Madhulika; Mahanta, Chitralekha

    2014-11-01

    In this paper an optimal second order sliding mode controller (OSOSMC) is proposed to track a linear uncertain system. The optimal controller based on the linear quadratic regulator method is designed for the nominal system. An integral sliding mode controller is combined with the optimal controller to ensure robustness of the linear system which is affected by parametric uncertainties and external disturbances. To achieve finite time convergence of the sliding mode, a nonsingular terminal sliding surface is added with the integral sliding surface giving rise to a second order sliding mode controller. The main advantage of the proposed OSOSMC is that the control input is substantially reduced and it becomes chattering free. Simulation results confirm superiority of the proposed OSOSMC over some existing.

  8. Planning Robotic Manipulation Strategies for Sliding Objects

    NASA Astrophysics Data System (ADS)

    Peshkin, Michael A.

    Automated planning of grasping or manipulation requires an understanding of both the physics and the geometry of manipulation, and a representation of that knowledge which facilitates the search for successful strategies. We consider manipulation on a level conveyor belt or tabletop, on which a part may slide when touched by a robot. Manipulation plans for a given part must succeed in the face of two types of uncertainty: that of the details of surfaces in contact, and that of the initial configuration of the part. In general the points of contact between the part and the surface it slides on will be unknown, so the motion of the part in response to a push cannot be predicted exactly. Using a simple variational principle (which is derived), we find the set of possible motions of a part for a given push, for all collections of points of contact. The answer emerges as a locus of centers of rotation (CORs). Manipulation plans made using this locus will succeed despite unknown details of contact. Results of experimental tests of the COR loci are presented. Uncertainty in the initial configuration of a part is usually also present. To plan in the presence of uncertainty, configuration maps are defined, which map all configurations of a part before an elementary operation to all possible outcomes, thus encapsulating the physics and geometry of the operation. The configuration map for an operation sequence is a product of configuration maps of elementary operations. Using COR loci we compute configuration maps for elementary sliding operations. Appropriate search techniques are applied to find operation sequences which succeed in the presence of uncertainty in the initial configuration and unknown details of contact. Such operation sequences may be used as parts feeder designs or as manipulation or grasping strategies for robots. As an example we demonstrate the automated design of a class of passive parts feeders consisting of multiple sequential fences across a conveyor

  9. Bi-directional planar slide mechanism

    SciTech Connect

    Bieg, Lothar F.

    2003-11-04

    A bi-directional slide mechanism. A pair of master and slave disks engages opposite sides of the platform. Rotational drivers are connected to master disks so the disks rotate eccentrically about their respective axes of rotation. Opposing slave disks are connected to master disks on opposite sides of the platform by a circuitous mechanical linkage, or are electronically synchronized together using stepper motors, to effect coordinated motion. The synchronized eccentric motion of the pairs of master/slave disks compels smooth linear motion of the platform forwards and backwards without backlash. The apparatus can be incorporated in a MEMS device.

  10. Energy Partitioning during Frictional Sliding at Coseismic Slip Rates

    NASA Astrophysics Data System (ADS)

    Hirose, T.; Mizoguchi, K.

    2008-12-01

    Determination of the energy partitioning during an earthquake is key to understanding the physics of earthquakes (e.g., Kanamori and Rivera, 2006). Observations made on natural faults that have experienced earthquakes suggest that part of the energy dissipates into a volume of rock surrounding the fault though grain crushing processes, forming fault gouge (e.g., Wilson et al., 2005). Thus we performed high-velocity wear experiments using a rotary-shear apparatus, in order to estimate the partitioning of the frictional work into heat and surface energy during frictional sliding at nearly coseismic slip rates. In particular, we attempted to test whether the ratio of the energy partitioning varies as a function of slip rate. The ratio of dissipated energy as heat to the total frictional work was estimated from the difference between measured temperature around the sliding surfaces and calculated temperature by 2D-FEM on the assumption that all frictional work converts into heat. The surface energy was estimated based on the particle size distribution of the wear materials, which was determined by FE-SEM image analysis. The particles size ranged between 0.03 and 10 μm in average diameter. In the experiments, hollow cylindrical specimens of gabbro were slid at slip rates of 0.004 to 0.3 m/s and normal stresses of 0.2 to 5.6 MPa under unconfined and dry conditions. Rock powder (gouge) was continuously produced by abrasive wear of initially bare fault surfaces during sliding. Because the sliding surfaces were not confined in the experiments, the gouge was extruded from the fault surfaces, resulting in shortening of axial length of specimen. In this study, we defined the dimensionless wear rate, given by that an axial shortening rate of the specimen was divided by slip rate. Then, we examined how the wear rate and temperature changed as a function of the rate of frictional work per a unit fault area, Ef, determined by shear stress multiplied by slip rate. Hereafter, Q and

  11. Impact of the amount of straw provided to pigs kept in intensive production conditions on the occurrence and severity of gastric ulceration at slaughter.

    PubMed

    Herskin, Mette S; Jensen, Henrik E; Jespersen, Anna; Forkman, Björn; Jensen, Margit B; Canibe, Nuria; Pedersen, Lene J

    2016-02-01

    This study examined effects of the amount of straw offered on occurrence and severity of gastric lesions in pigs kept in pens (18 pigs, 0.7 m(2)/pig) with partly slatted flooring and 10, 500 or 1000 g straw/pig/day from 30 kg live weight. The pigs had ad libitum access to dry feed. Forty-five pigs were used, three from each of 15 pens. After euthanization, the dimension of the non-glandular region of the stomach was measured. Lesions were characterized and scored. Irrespective of straw provided, 67% of the pigs showed signs of gastric pathology. Pigs provided with 500 or 1000 g straw were pooled as 'permanent access'. The proportion of pigs with ulcerations was reduced by permanent access to straw (7 vs. 33%; P<0.05), suggesting that permanent access to straw may improve animal health, and be considered as one possible strategy to limit gastric ulceration in pigs. PMID:26850561

  12. 21 CFR 864.3800 - Automated slide stainer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3800..., cytology, and hematology slides for diagnosis. (b) Classification. Class I (general controls). This...

  13. 21 CFR 864.3800 - Automated slide stainer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3800..., cytology, and hematology slides for diagnosis. (b) Classification. Class I (general controls). This...

  14. 21 CFR 864.3800 - Automated slide stainer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3800..., cytology, and hematology slides for diagnosis. (b) Classification. Class I (general controls). This...

  15. 21 CFR 864.3800 - Automated slide stainer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3800..., cytology, and hematology slides for diagnosis. (b) Classification. Class I (general controls). This...

  16. 21 CFR 864.3800 - Automated slide stainer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Pathology Instrumentation and Accessories § 864.3800..., cytology, and hematology slides for diagnosis. (b) Classification. Class I (general controls). This...

  17. Second order sliding mode control for a quadrotor UAV.

    PubMed

    Zheng, En-Hui; Xiong, Jing-Jing; Luo, Ji-Liang

    2014-07-01

    A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method.

  18. Slide less pathology”: Fairy tale or reality?

    PubMed Central

    Indu, M; Rathy, R; Binu, MP

    2016-01-01

    Pathology practice is significantly advanced in various frontiers. Therefore, “slide less digital” pathology will not be a mere imagination in near future. Digitalization of histopathological slides (whole slide imaging [WSI]) is possible with the help of whole slide scanner. The WSI has a positive impact not only in routine practice but also in research field, medical education and bioindustry. Even if digital pathology has definitive advantages, its widespread use is not yet possible. As it is an upcoming technology in our field, this article is aimed to discussessential aspects of WSI.

  19. Slide less pathology”: Fairy tale or reality?

    PubMed Central

    Indu, M; Rathy, R; Binu, MP

    2016-01-01

    Pathology practice is significantly advanced in various frontiers. Therefore, “slide less digital” pathology will not be a mere imagination in near future. Digitalization of histopathological slides (whole slide imaging [WSI]) is possible with the help of whole slide scanner. The WSI has a positive impact not only in routine practice but also in research field, medical education and bioindustry. Even if digital pathology has definitive advantages, its widespread use is not yet possible. As it is an upcoming technology in our field, this article is aimed to discussessential aspects of WSI. PMID:27601824

  20. Application of partial sliding mode in guidance problem.

    PubMed

    Shafiei, M H; Binazadeh, T

    2013-03-01

    In this paper, the problem of 3-dimensional guidance law design is considered and a new guidance law based on partial sliding mode technique is presented. The approach is based on the classification of the state variables within the guidance system dynamics with respect to their required stabilization properties. In the proposed law by using a partial sliding mode technique, only trajectories of a part of states variables are forced to reach the partial sliding surfaces and slide on them. The resulting guidance law enables the missile to intercept highly maneuvering targets within a finite interception time. Effectiveness of the proposed guidance law is demonstrated through analysis and simulations.

  1. Sliding-Mode Control Applied for Robust Control of a Highly Unstable Aircraft

    NASA Technical Reports Server (NTRS)

    Vetter, Travis Kenneth

    2002-01-01

    An investigation into the application of an observer based sliding mode controller for robust control of a highly unstable aircraft and methods of compensating for actuator dynamics is performed. After a brief overview of some reconfigurable controllers, sliding mode control (SMC) is selected because of its invariance properties and lack of need for parameter identification. SMC is reviewed and issues with parasitic dynamics, which cause system instability, are addressed. Utilizing sliding manifold boundary layers, the nonlinear control is converted to a linear control and sliding manifold design is performed in the frequency domain. An additional feedback form of model reference hedging is employed which is similar to a prefilter and has large benefits to system performance. The effects of inclusion of actuator dynamics into the designed plant is heavily investigated. Multiple Simulink models of the full longitudinal dynamics and wing deflection modes of the forward swept aero elastic vehicle (FSAV) are constructed. Additionally a linear state space models to analyze effects from various system parameters. The FSAV has a pole at +7 rad/sec and is non-minimum phase. The use of 'model actuators' in the feedback path, and varying there design, is heavily investigated for the resulting effects on plant robustness and tolerance to actuator failure. The use of redundant actuators is also explored and improved robustness is shown. All models are simulated with severe failure and excellent tracking, and task dependent handling qualities, and low pilot induced oscillation tendency is shown.

  2. Reciprocating sliding wear of in-situ reinforced silicon nitride

    SciTech Connect

    Yust, C.S.

    1995-10-01

    The reciprocating sliding wear response of two in-situ reinforced-silicon nitride compositions provided by AlliedSignal have been evaluated. The materials were prepared by AlliedSignal-Ceramic Components Division and were tested at conditions of interest to the Bendix Engine Controls Division (South Bend, IN) and AlliedSignal Research and Technology (Des Plaines, IL). The materials are being considered for a variety of new applications, and the current tests provide critical friction and wear values under anticipated operating conditions. Both pin and disk specimens of GS-44 and GN-10 in-situ reinforced silicon nitride of specified dimensions for wear testing were provided by the AlliedSignal participants. An initial series of tests examined the unlubricated behavior of these materials at elevated temperature (up to 900 C) in an inert atmosphere. The results revealed excessive levels of both friction and wear in the unlubricated condition. The test conditions were modified to include the use of jet fuel as a lubricant because of an intended application in that medium. The introduction of the lubricant resulted in very limited wear of both the pin and disk specimens.

  3. Segmentation of vessel structures in serial whole slide sections using region-based context features

    NASA Astrophysics Data System (ADS)

    Schwier, Michael; Hahn, Horst K.; Dahmen, Uta; Dirsch, Olaf

    2016-03-01

    We present a method for the automatic segmentation of vascular structures in stacks of serial sections. It was initially motivated within the Virtual Liver Network research project that aims at creating a multi-scale virtual model of the liver. For this the vascular systems of several murine livers under different conditions need to be analyzed. To get highly detailed datasets, stacks of serial sections of the whole organs are prepared. Due to the huge amount of image data an automatic approach for segmenting the vessels is required. After registering the slides with an established method we use a set of Random Forest classifiers to distinguish vessels from tissue. Instead of a pixel-wise approach we perform the classification on small regions. This allows us to use more meaningful features. Besides basic intensity and texture features we introduce the concept of context features, which allow the classifiers to also consider the neighborhood of a region. Classification is performed in two stages. In the second stage the previous classification result of a region and its neighbors is used to refine the decision for a particular region. The context features and two stage classification process make our method very successful. It can handle different stainings and also detect vessels in which residue like blood cells remained. The specificity reaches 95%-99% for pure tissue, depending on staining and zoom level. Only in the direct vicinity of vessels the specificity declines to 88%-96%. The sensitivity rates reach between 89% and 98%.

  4. Effects of Different Ligature Materials on Friction in Sliding Mechanics

    PubMed Central

    Khamatkar, Aparna; Sonawane, Sushma; Narkhade, Sameer; Gadhiya, Nitin; Bagade, Abhijit; Soni, Vivek; Betigiri, Asha

    2015-01-01

    Background: During orthodontic tooth movement friction occurs at the bracket wire interface. Out of the total force applied to the tooth movement, some of it is dissipated as friction, and the remainder is transferred to the supporting structures of the tooth to mediate tooth movement. However many factors affect friction, and method of arch wire ligation being an important contributing factor. Hence, this study was carried out to evaluate the effects of different ligature materials on friction in sliding mechanics and to compare the effect of environment (dry and wet) on friction produced in sliding mechanics. Materials and Methods: The evaluation of friction between the bracket and the archwire consisted of a simulated half arch fixed appliance with archwire ligated in a vertical position. Four 0.022” maxillary stainless steel premolar brackets having a - 0° torque and 0° angulation were aligned with a 0.019” × 0.025” stainless steel arch wire onto a rigid Plexiglass sheet. The movable test bracket was fitted with a 10 mm long, 0.045” thick stainless steel power arm on the bonding surface. Testing was performed on a Hounsfield material testing machine. A total of 100 g weight was suspended from the power arm and the load needed to move the bracket over the distance of not <4 mm across the central span was recorded separately. Fifteen representative readings were taken with one reading per test sample. Results: The results showed that the mean frictional force of different groups in dry and wet state was statistically significantly different. The mean frictional force in a dry state was statistically significantly higher than wet state in elastomeric group. Conclusion: The type of ligation material and environment significantly affected the degree of friction generated during sliding mechanics. Teflon coated stainless steel ligatures produced the least friction among the materials tested in both dry and wet conditions and there was no significant effect

  5. A Model to Study Articular Cartilage Mechanical and Biological Responses to Sliding Loads.

    PubMed

    Schätti, Oliver R; Gallo, Luigi M; Torzilli, Peter A

    2016-08-01

    In physiological conditions, joint function involves continuously moving contact areas over the tissue surface. Such moving contacts play an important role for the durability of the tissue. It is known that in pathological joints these motion paths and contact mechanics change. Nevertheless, limited information exists on the impact of such physiological and pathophysiological dynamic loads on cartilage mechanics and its subsequent biological response. We designed and validated a mechanical device capable of applying simultaneous compression and sliding forces onto cartilage explants to simulate moving joint contact. Tests with varying axial loads (1-4 kg) and sliding speeds (1-20 mm/s) were performed on mature viable bovine femoral condyles to investigate cartilage mechanobiological responses. High loads and slow sliding speeds resulted in highest cartilage deformations. Contact stress and effective cartilage moduli increased with increasing load and increasing speed. In a pilot study, changes in gene expression of extracellular matrix proteins were correlated with strain, contact stress and dynamic effective modulus. This study describes a mechanical test system to study the cartilage response to reciprocating sliding motion and will be helpful in identifying mechanical and biological mechanisms leading to the initiation and development of cartilage degeneration.

  6. Sliding Mode Control of the X-33 with an Engine Failure

    NASA Technical Reports Server (NTRS)

    Shtessel, Yuri B.; Hall, Charles E.

    2000-01-01

    Ascent flight control of the X-3 is performed using two XRS-2200 linear aerospike engines. in addition to aerosurfaces. The baseline control algorithms are PID with gain scheduling. Flight control using an innovative method. Sliding Mode Control. is presented for nominal and engine failed modes of flight. An easy to implement, robust controller. requiring no reconfiguration or gain scheduling is demonstrated through high fidelity flight simulations. The proposed sliding mode controller utilizes a two-loop structure and provides robust. de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of engine failure, bounded external disturbances (wind gusts) and uncertain matrix of inertia. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues. Conditions that restrict engine failures to robustness domain of the sliding mode controller are derived. Overall stability of a two-loop flight control system is assessed. Simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in the presence of external disturbances and vehicle inertia uncertainties, as well as the single engine failed case. The designed robust controller will significantly reduce the time and cost associated with flying new trajectory profiles or orbits, with new payloads, and with modified vehicles

  7. Sliding mechanics of coated composite wires and the development of an engineering model for binding.

    PubMed

    Zufall, S W; Kusy, R P

    2000-02-01

    A tribological (friction and wear) study, which was designed to simulate clinical sliding mechanics, was conducted as part of an effort to determine the suitability of poly(chloro-p-xylylene) coatings for composite orthodontic archwires. Prototype composite wires, having stiffnesses similar to those of current initial and intermediate alignment wires, were tested against stainless steel and ceramic brackets in the passive and active configurations (with and without angulation). Kinetic coefficient of friction values, which were determined to quantify sliding resistances as functions of the normal forces of ligation, had a mean that was 72% greater than uncoated wire couples at 0.43. To improve analysis of the active configuration, a mathematical model was developed that related bracket angulation, bracket width, interbracket distance, wire geometry, and wire elastic modulus to sliding resistance. From this model, kinetic coefficients of binding were determined to quantify sliding resistances as functions of the normal forces of binding. The mean binding coefficient was the same as that of uncoated wire couples at 0.42. Although penetrations through the coating were observed on many specimens, the glass-fiber reinforcement within the composite wires was undamaged for all conditions tested. This finding implies that the risk of glass fiber release during clinical use would be eliminated by the coating. In addition, the frictional and binding coefficients were still within the limits outlined by conventional orthodontic wire-bracket couples. Consequently, the coatings were regarded as an improvement to the clinical acceptability of composite orthodontic archwires.

  8. Relative sliding durability of two candidate high temperature oxide fiber seal materials

    NASA Technical Reports Server (NTRS)

    Dellacorte, Christopher; Steinetz, Bruce M.

    1991-01-01

    A test program to determine the relative sliding durability of two candidate ceramic fibers for high temperature sliding seal applications is described. Pin on disk tests were used to evaluate potential seal materials. Friction during the tests and fiber wear, indicated by the extent of fibers broken in a test bundle or yarn, was measured at the end of a test. In general, friction and wear increase with test temperature. This may be due to a reduction in fiber strength, a change in the surface chemistry at the fiber/counterface interface due to oxidation, adsorption and/or desorption of surface species and, to a lesser extent, an increase in counterface surface roughness due to oxidation at elevated temperatures. The relative fiber durability correlates with tensile strength indicating that tensile data, which is more readily available than sliding durability data, may be useful in predicting fiber wear behavior under various conditions. A simple model developed using dimensional analysis shows that the fiber durability is related to a dimensionless parameter which represents the ratio of the fiber strength to the fiber stresses imposed by sliding.

  9. Plastic deformation and wear process at a surface during unlubricated sliding

    NASA Technical Reports Server (NTRS)

    Yamamoto, T.; Buckley, D. H.

    1983-01-01

    The plastic deformation and wear of a 304 stainless steel surface sliding against an aluminum oxide rider with a spherical surface (the radius of curvature: 1.3 cm) were observed by using scanning electron and optical microscopes. Experiments were conducted in a vacuum of one million Pa and in an environment of fifty thousandth Pa of chlorine gas at 25 C. The load was 500 grams and the sliding velocity was 0.5 centimeter per second. The deformed surface layer which accumulates and develops successively is left behind the rider, and step shaped proturbances are developed even after single pass sliding under both environmental conditions. A fully developed surface layer is gradually torn off leaving a characteristic pattern. The mechanism for tearing away of the surface layer from the contact area and sliding track contour is explained assuming the simplified process of material removal based on the adhesion theory for the wear of materials. Previously announced in STAR as N82-32735

  10. The impact of treatment condition and the lagged effects of PTSD symptom severity and alcohol use on changes in alcohol craving.

    PubMed

    Kaczkurkin, Antonia N; Asnaani, Anu; Alpert, Elizabeth; Foa, Edna B

    2016-04-01

    Given the high rates of comorbidity between posttraumatic stress disorder (PTSD) and substance use disorder (SUD), we investigated an integrated treatment for these disorders. Individuals with comorbid PTSD and alcohol dependence were randomized to receive naltrexone or placebo, with or without prolonged exposure (PE). All participants also received BRENDA (supportive counseling). The naltrexone plus PE group showed a greater decline in alcohol craving symptoms than those in the placebo with no PE group. The PE plus placebo and the naltrexone without PE groups did not differ significantly from the placebo with no PE group in terms of alcohol craving. No treatment group differences were found for percentage of drinking days. Alcohol craving was moderated by PTSD severity, with those with higher PTSD symptoms showing faster decreases in alcohol craving. Both PTSD and alcohol use had a lagged effect on alcohol craving, with changes in PTSD symptoms and percentage of days drinking being associated with subsequent changes in craving. These results support the relationship between greater PTSD symptoms leading to greater alcohol craving and suggest that reducing PTSD symptoms may be beneficial to reducing craving in those with co-occurring PTSD/SUD.

  11. Sliding viscoelastic drops on slippery surfaces

    NASA Astrophysics Data System (ADS)

    Xu, H.; Clarke, A.; Rothstein, J. P.; Poole, R. J.

    2016-06-01

    We study the sliding of drops of constant-viscosity dilute elastic liquids (Boger fluids) on various surfaces caused by sudden surface inclination. For smooth or roughened hydrophilic surfaces, such as glass or acrylic, there is essentially no difference between these elastic liquids and a Newtonian comparator fluid (with identical shear viscosity, surface tension, and static contact angle). In contrast for embossed polytetrafluoroethylene superhydrophobic surfaces, profound differences are observed: the elastic drops slide at a significantly reduced rate and complex branch-like patterns are left on the surface by the drop's wake including, on various scales, beads-on-a-string like phenomena. Microscopy images indicate that the strong viscoelastic effect is caused by stretching filaments of fluid from isolated islands, residing at pinning sites on the surface pillars, of the order ˜30 μm in size. On this scale, the local strain rates are sufficient to extend the polymer chains, locally increasing the extensional viscosity of the solution, retarding the drop and leaving behind striking branch-like structures on much larger scales.

  12. [Effect of anionic detergents sodium dodecyl sulfate and alkylbenzyl sulfonate on adsorption and transport behavior of several enterotropic viruses in the soil under model conditions].

    PubMed

    Dizer, H

    1990-09-01

    The adsorption of poliovirus 3, coxsackievirus B1, and coliphage f2 on soil from an irrigation field loaded for years with waste water and sandy soil from an aquifer was investigated under the influence of two anionic detergents, sodium dodecylsulphate (SDS) and alkylbenzolsulphonate (ABS). The investigation was carried out through batch and column experiments under simulated conditions. The concentrations of both detergents found generally in surface water (0.2-10 mg/l) had no effect on the adsorption of tested viruses. The concentration of 100 mg/l was the lowest intensity that led to an impaired adsorption of viruses on the sediments. The desorbing effect of SDS was relatively higher than ABS. Both detergents gave rise to a desorption and migration of viruses. Especially in soil from an irrigation field the effect was stronger at pH 7.2 than at pH 5.1. Despite low concentrations of detergents in surface water, such procedures as bank filtration, waste water irrigation for the enrichment of groundwater, and the use of sewage sludge on agricultural fields or forest grounds can cause an accumulation of detergents or their metabolites which impairs the binding of viruses to sediments. Therefore, the danger occurrence of a groundwater contamination with enteroviruses should be considered in those sectors.

  13. Contribution to the description of the absorber rod behavior in severe accident conditions: An experimental investigation of the Ag-Zr phase diagram

    NASA Astrophysics Data System (ADS)

    Decreton, A.; Benigni, P.; Rogez, J.; Mikaelian, G.; Barrachin, M.; Lomello-Tafin, M.; Antion, C.; Janghorban, A.; Fischer, E.

    2015-10-01

    Most pressurized water reactor (PWR) absorber rods are composed of an Ag-In-Cd (SIC) alloy inside a stainless steel (SS) cladding, themselves inserted into a Zircaloy tube. During a severe accident, the SIC alloy which melts at 800 °C does not practically interact with SS. However, the cladding failure results from its internal pressurization and its eutectic interaction with Zircaloy and occurs at temperatures greater than 1200 °C. The subsequent interaction between the SIC melt and the Zircaloy has a strong impact on the quantities of aerosols released into the primary circuit and finally on the iodine chemistry. Accurate knowledge of the Ag-Zr system is a prerequisite to address this issue. Within this concern, our experimental work is focused both on the investigation of the Ag-Zr phase diagram and on the determination of the thermodynamic properties of the intermetallic compounds in the system. Two intermetallic compounds (AgZr and AgZr2) were identified. Ag-Zr cast alloys with a Ag/Zr ratio of 1:1 elaborated using an arc-melting furnace, once annealed, contained only a single phase AgZr. From metallographic observations, it appears that AgZr2 likely forms by the peritectic reaction from liquid and the bcc (βZr) phase. The partial enthalpies of solution of silver and zirconium in aluminum were experimentally determined at 723 °C in order to determine the enthalpies of formation of the intermetallic compounds. For silver solution calorimetry in aluminum bath, our measurements were successful and in agreement with the previous data. Yet, this study shows that liquid aluminum should not be used as a solvent for zirconium below 1000 °C.

  14. Downregulation of TNIP1 Expression Leads to Increased Proliferation of Human Keratinocytes and Severer Psoriasis-Like Conditions in an Imiquimod-Induced Mouse Model of Dermatitis.

    PubMed

    Chen, Yan; Yan, Heng; Song, Zhiqiang; Chen, Fangru; Wang, Huan; Niu, Jun; Shi, Xiaowei; Zhang, Dongmei; Zhang, Na; Zhai, Zhifang; Zhong, Baiyu; Cheng, Liangjin; Qian, Tian; Hao, Fei

    2015-01-01

    Psoriasis is a chronic, inflammatory skin disease involving both environmental and genetic factors. According to genome-wide association studies (GWAS), the TNIP1 gene, which encodes the TNF-α-induced protein 3-interacting protein 1 (TNIP1), is strongly linked to the susceptibility of psoriasis. TNIP1 is a widely expressed ubiquitin sensor that binds to the ubiquitin-editing protein A20 and restricts TNF- and TLR-induced signals. In our study, TNIP1 expression decreased in specimens of epidermis affected by psoriasis. Based on previous studies suggesting a role for TNIP1 in modulating cancer cell growth, we investigated its role in keratinocyte proliferation, which is clearly abnormal in psoriasis. To mimic the downregulation or upregulation of TNIP1 in HaCaT cells and primary human keratinocytes (PHKs), we used a TNIP1 specific small interfering hairpin RNA (TNIP1 shRNA) lentiviral vector or a recombinant TNIP1 (rTNIP1) lentiviral vector, respectively. Blocking TNIP1 expression increased keratinocyte proliferation, while overexpression of TNIP1 decreased keratinocyte proliferation. Furthermore, we showed that TNIP1 signaling might involve extracellular signal-regulated kinase1/2 (Erk1/2) and CCAAT/enhancer-binding protein β (C/EBPβ) activity. Intradermal injection of TNIP1 shRNA in BALB/c mice led to exaggerated psoriatic conditions in imiquimod (IMQ)-induced psoriasis-like dermatitis. These findings indicate that TNIP1 has a protective role in psoriasis and therefore could be a promising therapeutic target. PMID:26046540

  15. Dry sliding wear system response of ferritic and tempered martensitic ductile iron

    NASA Astrophysics Data System (ADS)

    Jha, V. K.; Mozumder, Y. H.; Shama, S.; Behera, R. K.; Pattaniak, A.; P, Sindhoora L.; Mishra, S. C.; Sen, S.

    2015-02-01

    Spheroidal graphite cast iron (SG iron) is the most preferable member of cast iron family due to its strength and toughness along with good tribological properties. SG iron specimens with annealed and martensitic matrix were subjected to dry sliding wear condition and the system response was correlated to matrix microstructure. Respective microstructure was obtained by annealing and quench and tempering heat treatment process for an austenitizing temperature of 1000°C. Specimens were subjected to Ball on plate wear tester under 40N, 50N, 60N load for a sliding distance of 7.54m. Except for quench and tempered specimen at 50N, weight loss was observed in every condition. The wear surface under optical microscope reveals adhesive mechanism for as-cast and annealed specimen whereas delaminated wear track feature was observed for quench and tempered specimen.

  16. Severe Sarcoidosis.

    PubMed

    Kouranos, Vasileios; Jacob, Joe; Wells, Athol U

    2015-12-01

    In sarcoidosis, reduction in mortality and the prevention of disability due to major organ involvement are treatment goals. Thus, it is important to recognize severe disease and identify patients at higher risk of progression to severe disease. In this article, fibrotic lung disease and cardiac sarcoidosis are reviewed as the major contributors to sarcoidosis mortality and morbidity. In the absence of a standardized definition of severe pulmonary disease, a multidisciplinary approach to clinical staging is suggested, based on symptoms, pulmonary function tests, and imaging findings at presentation, integrated with the duration of disease and longitudinal disease behavior during early follow-up.

  17. Sever's Disease

    MedlinePlus

    ... Are Reading Upsetting News Reports? What to Say Vaccines: Which Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's Story" 5 Things to Know About Zika & Pregnancy Sever's Disease KidsHealth > ...

  18. Lecture Handouts of Projected Slides in a Medical Course.

    ERIC Educational Resources Information Center

    Amato, Dominick; Quirt, Ian

    1991-01-01

    In a third-year medical school hematology course, handouts reproducing all or most of the 35mm slides used during the lecture are given at the beginning of class. The slides are reproduced on the left, with room for note-taking on the right. Despite some disadvantages, the method is seen as helpful. (Author/MSE)

  19. 45 CFR 98.42 - Sliding fee scales.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Welfare Department of Health and Human Services GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Program Operations (Child Care Services)-Lead Agency and Provider Requirements § 98.42 Sliding fee scales... provides for cost sharing by families that receive CCDF child care services. (b) A sliding fee...

  20. 45 CFR 98.42 - Sliding fee scales.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Program Operations (Child Care Services)-Lead Agency and Provider Requirements § 98.42 Sliding fee scales... provides for cost sharing by families that receive CCDF child care services. (b) A sliding fee...

  1. 45 CFR 98.42 - Sliding fee scales.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Program Operations (Child Care Services)-Lead Agency and Provider Requirements § 98.42 Sliding fee scales... provides for cost sharing by families that receive CCDF child care services. (b) A sliding fee...

  2. 45 CFR 98.42 - Sliding fee scales.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Program Operations (Child Care Services)-Lead Agency and Provider Requirements § 98.42 Sliding fee scales... provides for cost sharing by families that receive CCDF child care services. (b) A sliding fee...

  3. 45 CFR 98.42 - Sliding fee scales.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Program Operations (Child Care Services)-Lead Agency and Provider Requirements § 98.42 Sliding fee scales... provides for cost sharing by families that receive CCDF child care services. (b) A sliding fee...

  4. Determining the Ecosystem Services Important for Urban Landscapes-Slides

    EPA Science Inventory

    This presentation consists of introductory slides on ecosystem services in urban landscapes and then a discussion of two case studies concerning the provision of water quality in urban landscapes. The introductory slides will explore the range of ecosystem services provided by u...

  5. Optimizing Student Learning: Examining the Use of Presentation Slides

    ERIC Educational Resources Information Center

    Strauss, Judy; Corrigan, Hope; Hofacker, Charles F.

    2011-01-01

    Sensory overload and split attention result in reduced learning when instructors read slides with bullet points and complex graphs during a lecture. Conversely, slides containing relevant visual elements, when accompanied by instructor narration, use both the visual and verbal channels of a student's working memory, thus improving the chances of…

  6. The Easy Way to Create Computer Slide Shows.

    ERIC Educational Resources Information Center

    Anderson, Mary Alice

    1995-01-01

    Discusses techniques for creating computer slide shows. Topics include memory; format; color use; HyperCard and CD-ROM; font styles and sizes; graphs and graphics; the slide show option; special effects; and tips for effective presentation. (Author/AEF)

  7. A Simple Measurement of the Sliding Friction Coefficient

    ERIC Educational Resources Information Center

    Gratton, Luigi M.; Defrancesco, Silvia

    2006-01-01

    We present a simple computer-aided experiment for investigating Coulomb's law of sliding friction in a classroom. It provides a way of testing the possible dependence of the friction coefficient on various parameters, such as types of materials, normal force, apparent area of contact and sliding velocity.

  8. 49 CFR 229.115 - Slip/slide alarms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... sliding wheels on powered axles under power. When two or more locomotives are coupled in multiple or remote control, the wheel slip/slide alarm of each locomotive shall be shown in the cab of the... road service, or continue in road service following a daily inspection, unless the wheel...

  9. 49 CFR 229.115 - Slip/slide alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... sliding wheels on powered axles under power. When two or more locomotives are coupled in multiple or remote control, the wheel slip/slide alarm of each locomotive shall be shown in the cab of the... road service, or continue in road service following a daily inspection, unless the wheel...

  10. 49 CFR 229.115 - Slip/slide alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... sliding wheels on powered axles under power. When two or more locomotives are coupled in multiple or remote control, the wheel slip/slide alarm of each locomotive shall be shown in the cab of the... road service, or continue in road service following a daily inspection, unless the wheel...

  11. Qualification test unit slide stainer (Beckman P/N 673753)

    NASA Technical Reports Server (NTRS)

    Bernier, P. S.

    1972-01-01

    Specifications for a slide stainer unit for the Skylab program are presented. The qualification test slide stainer was designed to be a self-contained system capable of performing an eight-step Gram stain of microorganisms and a Wright's stain of blood smears.

  12. A Transformational Approach to Slip-Slide Factoring

    ERIC Educational Resources Information Center

    Steckroth, Jeffrey

    2015-01-01

    In this "Delving Deeper" article, the author introduces the slip-slide method for solving Algebra 1 mathematics problems. This article compares the traditional method approach of trial and error to the slip-slide method of factoring. Tools that used to be taken for granted now make it possible to investigate relationships visually,…

  13. 8. Photocopy of original USRS glass plate slide (from original ...

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

    8. Photocopy of original USRS glass plate slide (from original slide on file at National Archives, Rocky Mountain Region, Denver, Colorado) Photographer unknown, ca. 1908 The diversion weir of the Okanogan National Irrigation Project - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  14. AFRD WAREHOUSE, WEST SIDE DETAIL OF ALTERED SLIDING DOORS, FACING ...

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

    AFRD WAREHOUSE, WEST SIDE DETAIL OF ALTERED SLIDING DOORS, FACING EAST. WEATHER COVER OVER RAIL IS ORIGINAL. SHEET METAL SIDING HAS BEEN INSERTED BETWEEN TWO HALVES OF SLIDING DOORS. - Minidoka Relocation Center Warehouse, 111 South Fir Street, Shoshone, Lincoln County, ID

  15. Detection of felt tip markers on microscope slides

    NASA Astrophysics Data System (ADS)

    Friedrich, David; Meyer-Ebrecht, Dietrich; Böcking, Alfred; Merhof, Dorit

    2014-03-01

    Sensitivity and specificity of conventional cytological methods for cancer diagnosis can be raised significantly by applying further adjuvant cytological methods. To this end, the pathologist marks regions of interest (ROI) with a felt tip pen on the microscope slide for further analysis. This paper presents algorithms for the automated detection of these ROIs, which enables further automated processing of these regions by digital pathology solutions and image analysis. For this purpose, an overview scan is obtained at low magnification. Slides from different manufacturers need to be treated, as they might contain certain regions which need to be excluded from the analysis. Therefore the slide type is identified first. Subsequently, the felt tip marks are detected automatically, and gaps appearing in the case of ROIs which have been drawn incompletely are closed. Based on the marker detection, the ROIs are obtained. The algorithms have been optimized on a training set of 82 manually annotated images. On the test set, the slide types of all but one out of 81 slides were identified correctly. A sensitivity of 98.31% and a positive predictive value of 97.48% were reached for the detection of ROIs. In combination with a slide loader or a whole slide imaging scanner as well as automated image analysis, this enables fully automated batch processing of slides.

  16. A Computer System for Making Quick and Economical Color Slides.

    ERIC Educational Resources Information Center

    Pryor, Harold George

    1986-01-01

    A computer-based method for producing 35mm color slides has been used in Ohio State University's College of Dentistry. The method can produce both text and slides in less than two hours, providing substantial flexibility in planning and revising visual presentations. (Author/MLW)

  17. Validation of whole slide imaging for frozen section diagnosis in surgical pathology

    PubMed Central

    Bauer, Thomas W.; Slaw, Renee J.; McKenney, Jesse K.; Patil, Deepa T.

    2015-01-01

    Background: Whole slide imaging (WSI) using high-resolution scanners is gaining acceptance as a platform for consultation as well as for frozen section (FS) evaluation in surgical pathology. We report results of an intra-observer concordance study comparing evaluation of WSI of scanned FS microscope slides with the original interpretation of the same microscope slides after an average lag time of approximately 1-year. Methods: A total of 70 FS cases (148 microscope slides) originally interpreted by 2 pathologists were scanned at ×20 using Aperio CS2 scanner (Leica Biosystems, San Diego, CA, USA). Reports were redacted such that the study pathologists reviewed images using eSlide Manager Healthcare Network application (Leica Biosystems) accompanied by the same clinical information available at the time of original FS evaluation. Discrepancies between the original FS diagnosis and WSI diagnosis were categorized as major (impacted patient care) or minor (no impact on patient care). Results: Lymph nodes, margins for head and neck cancer resections, and arthroplasty specimens to exclude infection, were the most common FS specimens. The average wash-out interval was 380 days (range: 303–466 days). There was one major discrepancy (1.4% of 70 cases) where the original FS was interpreted as severe squamous dysplasia, and the WSI FS diagnosis was mild dysplasia. There were two minor discrepancies; one where the original FS was called focal moderate squamous dysplasia and WSI FS diagnosis was negative for dysplasia. The second case was an endometrial adenocarcinoma that was originally interpreted as Federation of Gynecology and Obstetrics (FIGO) Grade I, while the WSI FS diagnosis was FIGO Grade II. Conclusions: These findings validate and support the use of WSI to provide interpretation of FS in our network of affiliated hospitals and ambulatory surgery centers. PMID:26430537

  18. Terrain analysis of the racetrack basin and the sliding rocks of Death Valley

    USGS Publications Warehouse

    Messina, P.; Stoffer, P.

    2000-01-01

    The Racetrack Playa's unusual surface features known as sliding rocks have been the subject of an ongoing debate and several mapping projects for half a century, although the causative mechanism remains unresolved. Clasts ranging in volume from large pebbles to medium boulders have, unwitnessed, maneuvered around the nearly flat dry lake over considerable distances. The controversy has persisted partly because eyewitness accounts of the phenomenon continue to be lacking, and the earlier mapping missions were limited in method and geographic range. In July 1996, we generated the first complete map of all observed sliding rock trails by submeter differential Global Positioning System (DGPS) mapping technology. The resulting map shows 162 sliding rocks and associated trails to an accuracy of approximately 30 cm. Although anemometer data are not available in the Racetrack wilderness, wind is clearly a catalyst for sliding rock activity; an inferred wind rose was constructed from DGPS trail segment data. When the entire trail network is examined in plan, some patterns emerge, although other (perhaps expected relations) remain elusive: terrain analysis of the surrounding topography demonstrates that the length and morphology of trails are more closely related to where rocks rested at the onset of motion than to any physical attribute of the rocks themselves. Follow-up surveys in May 1998, May 1999, August 1999, and November 1999 revealed little modification of the July, 1996 sliding rock configuration. Only four rocks were repositioned during the El Nino winter of 1997-1998, suggesting that activity may not be restricted to winter storms. (C) 2000 Elsevier Science B.V. All rights reserved.

  19. Thermal Stress Cracking of Slide-Gate Plates in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Lee, Hyoung-Jun; Thomas, Brian G.; Kim, Seon-Hyo

    2016-04-01

    The slide-gate plates in a cassette assembly control the steel flow through the tundish nozzle, and may experience through-thickness cracks, caused by thermal expansion and/or mechanical constraint, leading to air aspiration and safety concerns. Different mechanisms for common and rare crack formation are investigated with the aid of a three-dimensional finite-element model of thermal mechanical behavior of the slide-gate plate assembly during bolt pretensioning, preheating, tundish filling, casting, and cooling stages. The model was validated with previous plant temperature measurements of a ladle plate during preheating and casting, and then applied to a typical tundish-nozzle slide-gate assembly. The formation mechanisms of different types of cracks in the slide-gate plates are investigated using the model and evaluated with actual slide-gate plates at POSCO. Common through-thickness radial cracks, found in every plate, are caused during casting by high tensile stress on the outside surfaces of the plates, due to internal thermal expansion. In the upper plate, these cracks may also arise during preheating or tundish filling. Excessive bolt tightening, combined with thermal expansion during casting may cause rare radial cracks in the upper and lower plates. Rare radial and transverse cracks in middle plate appear to be caused during tundish filling by impingement of molten steel on the middle of the middle plate that generates tensile stress in the surrounding refractory. The mechanical properties of the refractory, the bolt tightening conditions, and the cassette/plate design are all important to service life.

  20. [Whole slide imaging technology: from digitization to online applications].

    PubMed

    Ameisen, David; Le Naour, Gilles; Daniel, Christel

    2012-11-01

    As e-health becomes essential to modern care, whole slide images (virtual slides) are now an important clinical, teaching and research tool in pathology. Virtual microscopy consists of digitizing a glass slide by acquiring hundreds of tiles of regions of interest at different zoom levels and assembling them into a structured file. This gigapixel image can then be remotely viewed over a terminal, exactly the way pathologists use a microscope. In this article, we will first describe the key elements of this technology, from the acquisition, using a scanner or a motorized microscope, to the broadcasting of virtual slides through a local or distant viewer over an intranet or Internet connection. As virtual slides are now commonly used in virtual classrooms, clinical data and research databases, we will highlight the main issues regarding its uses in modern pathology. Emphasis will be made on quality assurance policies, standardization and scaling.

  1. Roles of hardness in the sliding behavior of materials

    NASA Astrophysics Data System (ADS)

    Rigney, D. A.

    1994-06-01

    It is generally recognized that hardness is one of the key factors which influence the sliding behavior of different materials combinations. However, in many discussions the only hardness value considered is that of the softer of the two materials in a tribological pair. This is usually the case when a simple linear wear equation (Holm, Archard, Khruschov) is cited. Observations on many materials combinations demonstrate that the effects of hardness are much more complex. Hardness varies with position and time. It can depend on temperature, sliding speed and the chemical environment. The sign of hardness gradients adjacent to the sliding surface affects sliding behavior. Transfer and subsequent mechanical mixing strongly influence local hardness. Changes in hardness can affect transitions in friction and wear. Relative hardness values can help to explain differences in debris and in smooth and rough sliding. They can also help us to understand geometric effects such as those noted when materials are interchanged in a test system. Examples are described.

  2. Teaching Veterinary Histopathology: A Comparison of Microscopy and Digital Slides.

    PubMed

    Brown, Peter J; Fews, Debra; Bell, Nick J

    2016-01-01

    Virtual microscopy using digitized slides has become more widespread in teaching in recent years. There have been no direct comparisons of the use of virtual microscopy and the use of microscopes and glass slides. Third-year veterinary students from two different schools completed a simple objective test, covering aspects of histology and histopathology, before and after a practical class covering relevant material presented as either glass slides viewed with a microscope or as digital slides. There was an overall improvement in performance by students at both veterinary schools using both practical formats. Neither format was consistently better than the other, and neither school consistently outperformed the other. In a comparison of student appraisal of use of digital slides and microscopes, the digital technology was identified as having many advantages.

  3. Sliding Mode Control of Steerable Needles

    PubMed Central

    Rucker, D. Caleb; Das, Jadav; Gilbert, Hunter B.; Swaney, Philip J.; Miga, Michael I.; Sarkar, Nilanjan; Webster, Robert J.

    2014-01-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation. PMID:25400527

  4. Sliding Mode Control of Steerable Needles.

    PubMed

    Rucker, D Caleb; Das, Jadav; Gilbert, Hunter B; Swaney, Philip J; Miga, Michael I; Sarkar, Nilanjan; Webster, Robert J

    2013-10-01

    Steerable needles can potentially increase the accuracy of needle-based diagnosis and therapy delivery, provided they can be adequately controlled based on medical image information. We propose a novel sliding mode control law that can be used to deliver the tip of a flexible asymmetric-tipped needle to a desired point, or to track a desired trajectory within tissue. The proposed control strategy requires no a priori knowledge of model parameters, has bounded input speeds, and requires little computational resources. We show that if the standard nonholonomic model for tip-steered needles holds, then the control law will converge to desired targets in a reachable workspace, within a tolerance that can be defined by the control parameters. Experimental results validate the control law for target points and trajectory following in phantom tissue and ex vivo liver. Experiments with targets that move during insertion illustrate robustness to disturbances caused by tissue deformation.

  5. Cancer Digital Slide Archive: an informatics resource to support integrated in silico analysis of TCGA pathology data

    PubMed Central

    Gutman, David A; Cobb, Jake; Somanna, Dhananjaya; Park, Yuna; Wang, Fusheng; Kurc, Tahsin; Saltz, Joel H; Brat, Daniel J; Cooper, Lee A D

    2013-01-01

    Background The integration and visualization of multimodal datasets is a common challenge in biomedical informatics. Several recent studies of The Cancer Genome Atlas (TCGA) data have illustrated important relationships between morphology observed in whole-slide images, outcome, and genetic events. The pairing of genomics and rich clinical descriptions with whole-slide imaging provided by TCGA presents a unique opportunity to perform these correlative studies. However, better tools are needed to integrate the vast and disparate data types. Objective To build an integrated web-based platform supporting whole-slide pathology image visualization and data integration. Materials and methods All images and genomic data were directly obtained from the TCGA and National Cancer Institute (NCI) websites. Results The Cancer Digital Slide Archive (CDSA) produced is accessible to the public (http://cancer.digitalslidearchive.net) and currently hosts more than 20 000 whole-slide images from 22 cancer types. Discussion The capabilities of CDSA are demonstrated using TCGA datasets to integrate pathology imaging with associated clinical, genomic and MRI measurements in glioblastomas and can be extended to other tumor types. CDSA also allows URL-based sharing of whole-slide images, and has preliminary support for directly sharing regions of interest and other annotations. Images can also be selected on the basis of other metadata, such as mutational profile, patient age, and other relevant characteristics. Conclusions With the increasing availability of whole-slide scanners, analysis of digitized pathology images will become increasingly important in linking morphologic observations with genomic and clinical endpoints. PMID:23893318

  6. DPS Discovery Slide Sets for the Introductory Astronomy Instructor

    NASA Astrophysics Data System (ADS)

    Meinke, Bonnie K.; Jackson, Brian; Buxner, Sanlyn; Horst, Sarah; Brain, David; Schneider, Nicholas M.

    2016-10-01

    The DPS actively supports the E/PO needs of the society's membership, including those at the front of the college classroom. The DPS Discovery Slide Sets are an opportunity for instructors to put the latest planetary science into their lectures and for scientists to get their exciting results to college students.In an effort to keep the astronomy classroom apprised of the fast moving field of planetary science, the Division for Planetary Sciences (DPS) has developed "DPS Discoveries", which are 3-slide presentations that can be incorporated into college lectures. The slide sets are targeted at the Introductory Astronomy undergraduate level. Each slide set consists of three slides which cover a description of the discovery, a discussion of the underlying science, and a presentation of the big picture implications of the discovery, with a fourth slide that includes links to associated press releases, images, and primary sources. Topics span all subdisciplines of planetary science, and 26 sets are available in Farsi and Spanish. We intend for these slide sets to help Astronomy 101 instructors include new developments (not yet in their textbooks) into the broader context of the course. If you need supplemental material for your classroom, please checkout the archived collection: http://dps.aas.org/education/dpsdiscMore slide sets are now in development and will be available soon! In the meantime, we seek input, feedback, and help from the DPS membership to add fresh slide sets to the series and to connect the college classroom to YOUR science. It's easy to get involved – we'll provide a content template, tips and tricks for a great slide set, and pedagogy reviews. Talk to a coauthor to find out how you can disseminate your science or get involved in E/PO with your contributions.

  7. Recurrent Pleistocene sub-marine slide events on the south Vøring Plateau, mid-Norwegian continental margin

    NASA Astrophysics Data System (ADS)

    Hjelstuen, B.; Skaug, M.; Haflidason, H.

    2009-12-01

    Throughout the Pleistocene the sediment input and depositional environments on the continental slope off Norway have been strongly controlled by variability in the ocean circulation, glaciations and sea-level changes. Repeated occurrence of shelf edge glaciations along the whole NW European margin, from Ireland to Svalbard, started at Marine Isotope Stage 12 (c. 0.5 Ma). During these periods, fast moving ice streams crossed the continental shelf on a number of locations, and large submarine fans and prograding wedges accumulated on the continental slope. During glacial maximums and in the early phases of the deglaciations high sedimentation rates, >2000 cm/ka, characterised the Norwegian continental margin. Within these depositional environments more than 30 large-scale mass failures have been identified. Here, we report on three slide events on the south Vøring Plateau, on the mid-Norwegian margin. These slides have affected an area between 2900 and 12000 km2 and involved 580-2400 km3 of sediments, noting that the slide debrites left by the failure events reach a maximum thickness of c. 150 m. For comparison the Holocene Storegga Slide, considered the largest exposed sub-marine slide in the world today, mobilized c. 2500-3500 km3 of masses and affected an area of c. 95 000 km2. The Vøring Plateau sub-marine slides are most likely younger than 0.5 Ma, thus occurring in a time period of repeated ice sheet growth to the shelf edge and high accumulation rates. The failures have occurred within an area dominated by gradients less than 1 degree, and observation of long run-out distances indicate that hydroplaning was important during slide development. Our multichannel seismic profiles further show that gas hydrate bearing sediments are observed on the mid-Norwegian continental margin. Thus, dissociation of gas hydrates and high sedimentation rates may have promoted conditions for failures to occur.

  8. Resultant knee joint moments for lateral movement tasks on sliding and non-sliding sport surfaces.

    PubMed

    Nigg, Benno M; Stefanyshyn, Darren J; Rozitis, Antra I; Mundermann, Annegret

    2009-03-01

    The aim of this study was to compare ankle and knee joint moments observed when playing on sport surfaces that slide slightly relative to the ground with the moments observed when playing on conventional sport surfaces. Three-dimensional resultant internal joint moments and kinematic characteristics of the lower extremity were quantified for 21 university basketball players when performing v-cut and side-shuffle tasks on three types of sliding surface (interlocking tiles) and on two types of conventional surface (maple wood and rolled vinyl). Translational and rotational friction between the five test surfaces and a test shoe were also quantified. The five sport surfaces moved horizontally between 0.2 and 1.6 mm during the landing phase of the two tasks. The medio-lateral ground reaction forces were lowest for the surfaces with the highest horizontal movement. Resultant ankle joint moments were lower and resultant knee moments were higher on the sliding surfaces than the conventional surfaces. Sport surfaces that allow a few millimetres of horizontal movement during ground contact may reduce joint loading at the ankle joint, but increase joint loading at the knee joint, when compared with conventional sport surfaces, and thus may influence the prevalence of knee injuries.

  9. The Evolution of Interfacial Sliding Stresses During Cyclic Push-in Testing of C- and BN-Coated Hi-Nicalon Fiber-Reinforced CMCs

    NASA Technical Reports Server (NTRS)

    Eldridge, J. I.; Bansal, N. P.; Bhatt, R. T.

    1998-01-01

    Interfacial debond cracks and fiber/matrix sliding stresses in ceramic matrix composites (CMCs) can evolve under cyclic fatigue conditions as well as with changes in the environment, strongly affecting the crack growth behavior, and therefore, the useful service lifetime of the composite. In this study, room temperature cyclic fiber push-in testing was applied to monitor the evolution of frictional sliding stresses and fiber sliding distances with continued cycling in both C- and BN-coated Hi-Nicalon SiC fiber-reinforced CMCs. A SiC matrix composite reinforced with C-coated Hi-Nical on fibers as well as barium strontium aluminosilicate (BSAS) matrix composites reinforced with BN-coated (four different deposition processes compared) Hi-Nicalon fibers were examined. For failure at a C interface, test results indicated progressive increases in fiber sliding distances during cycling in room air but not in nitrogen. These results suggest the presence of moisture will promote crack growth when interfacial failure occurs at a C interface. While short-term testing environmental effects were not apparent for failure at the BN interfaces, long-term exposure of partially debonded BN-coated fibers to humid air resulted in large increases in fiber sliding distances and decreases in interfacial sliding stresses for all the BN coatings, presumably due to moisture attack. A wide variation was observed in debond and frictional sliding stresses among the different BN coatings.

  10. Fecal Microbiota Transplantation Using Upper Gastrointestinal Tract for the Treatment of Refractory or Severe Complicated Clostridium difficile Infection in Elderly Patients in Poor Medical Condition: The First Study in an Asian Country

    PubMed Central

    Gweon, Tae-Geun; Kim, Jinsu; Lim, Chul-Hyun; Park, Jae Myung; Lee, Dong-Gun; Lee, In Seok; Cho, Young-Seok; Kim, Sang Woo; Choi, Myung-Gyu

    2016-01-01

    Background and Aims. Fecal microbiota transplantation (FMT) is a highly effective treatment option for refractory Clostridium difficile infection (CDI). FMT may be challenging in patients with a low performance status, because of their poor medical condition. The aims of this study were to describe our experience treating patients in poor medical condition with refractory or severe complicated CDI using FMT via the upper GI tract route. Methods. This study was a retrospective review of seven elderly patients with refractory or severe complicated CDI and a poor medical condition who were treated with FMT through the upper GI tract route from May 2012 through August 2013. The outcomes studied included the cure rate of CDI and adverse events. Results. Of these seven patients who received FMT via the upper GI tract route, all patients were cured. During the 11-month follow-up period, CDI recurrence was observed in two patients; rescue FMT was performed in these patients, which led to a full cure. Vomiting was observed in two patients. Conclusions. FMT via the upper gastrointestinal tract route may be effective for the treatment of refractory or severe complicated CDI in patients with a low performance status. Physicians should be aware of adverse events, especially vomiting. PMID:27127501

  11. Student Teachers' Evaluations of Slides of Children with Down Syndrome: Impact of Facial Plastic Surgery, Labelling and Factual Knowledge.

    ERIC Educational Resources Information Center

    Elkabetz, R.; And Others

    1990-01-01

    This study examined the impact of facial plastic surgery, labeling (mentally retarded, normal, Down's syndrome), and level of knowledge of Down's syndrome on 127 student teachers' evaluations of slides of persons with such characteristics. Although there was no overall significant main effect for the pre-post operation condition, there was a…

  12. Preliminary evaluation of feeder and lint slide moisture addition on ginning, fiber quality, and textile processing of western cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the effects of moisture addition at the gin stand feeder conditioning hopper and/or the battery condenser slide on gin performance and Western cotton fiber quality and textile processing. The test treatments included no moisture addition, feeder hopper hum...

  13. Particle Dynamics Simulations of Rate and State Dependent Frictional Sliding of Granular Fault Gouge

    NASA Astrophysics Data System (ADS)

    Morgan, J. K.

    2002-12-01

    Particle dynamics methods (PDM) have proven very valuable in the study of fault processes, fault mechanics, and associated deformation. Such discrete numerical techniques capture the heterogeneity and discontinuous nature of earth materials, and can reproduce many behaviors and geometries observed in natural and experimentally-generated shear zones. These include strain localization and delocalization, stick-slip sliding, and characteristic fracture arrays. However, several fundamental experimental results thought to be important in the earthquake generation process, have not been well represented by PDM models: 2D simulations conducted on idealized assemblages of particles using simple elastic-frictional contact laws, generally yield friction values much lower than natural materials, and lack second-order time- and velocity-dependent changes in strength that influence dynamic fault slip. In efforts to reconcile these differences between experimental and numerical friction, new simulations using the discrete element method (DEM) have been carried out using more realistic particle motions conditions and interparticle contact laws: (a) particle rotations are restricted as a proxy for grain roughness, interlocking, and out-of-plane contacts that resist rolling, and (b) time-dependent contact healing is introduced to capture temporal strengthening of granular assemblages. The resulting mechanical behavior qualitatively reproduces the scale and phenomenology of empirically based rate and state constitutive laws for friction. Frictional strength is increased, and in the absence of interparticle rolling, can attain values comparable to those observed in the lab. Even though interparticle contact strength depends only on time of static contact in these models, the bulk assemblage shows velocity- and slip-dependent behavior associated with changes in deformation mechanism, particle configuration and packing, and contact orientation. These results demonstrate the complexity

  14. Automated detection of diagnostically relevant regions in H&E stained digital pathology slides

    NASA Astrophysics Data System (ADS)

    Bahlmann, Claus; Patel, Amar; Johnson, Jeffrey; Ni, Jie; Chekkoury, Andrei; Khurd, Parmeshwar; Kamen, Ali; Grady, Leo; Krupinski, Elizabeth; Graham, Anna; Weinstein, Ronald

    2012-03-01

    We present a computationally efficient method for analyzing H&E stained digital pathology slides with the objective of discriminating diagnostically relevant vs. irrelevant regions. Such technology is useful for several applications: (1) It can speed up computer aided diagnosis (CAD) for histopathology based cancer detection and grading by an order of magnitude through a triage-like preprocessing and pruning. (2) It can improve the response time for an interactive digital pathology workstation (which is usually dealing with several GByte digital pathology slides), e.g., through controlling adaptive compression or prioritization algorithms. (3) It can support the detection and grading workflow for expert pathologists in a semi-automated diagnosis, hereby increasing throughput and accuracy. At the core of the presented method is the statistical characterization of tissue components that are indicative for the pathologist's decision about malignancy vs. benignity, such as, nuclei, tubules, cytoplasm, etc. In order to allow for effective yet computationally efficient processing, we propose visual descriptors that capture the distribution of color intensities observed for nuclei and cytoplasm. Discrimination between statistics of relevant vs. irrelevant regions is learned from annotated data, and inference is performed via linear classification. We validate the proposed method both qualitatively and quantitatively. Experiments show a cross validation error rate of 1.4%. We further show that the proposed method can prune ~90% of the area of pathological slides while maintaining 100% of all relevant information, which allows for a speedup of a factor of 10 for CAD systems.

  15. Single molecule study of a processivity clamp sliding on DNA

    SciTech Connect

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  16. Humboldt slide - A large shear-dominated retrogressive slope failure

    USGS Publications Warehouse

    Gardner, J.V.; Prior, D.B.; Field, M.E.

    1999-01-01

    Humboldt Slide is a large, complex slide zone located on the northern California continental margin. Its three-dimensional architecture has been imaged by a combination of multibeam bathymetry, Huntec Deep-Tow seismic profiling, and sidescan sonar. The slide is interpreted to be Late Pleistocene to early Holocene in age and was caused by a combination of factors. The area of the slide is a local depocenter with high accumulation rates of organic-rich sediment; there has been local steepening of slopes by tectonic uplifts; and the entire area is one of high seismicity. Overall, the failure occurred by retrogressive, shear-dominated, minimum movement apparently as a sequence of events. Failure initially occurred by subsidence extension at the middle of the feature, followed by upslope retrogressive failure and downslope compression, and finally by translational sliding at the top of the slide. Degassing, as evidenced by abundant pockmarks, may have inhibited downslope translation. The slide may still be active, as suggested by offsets in Holocene hemipelagic sediment draped over some of the shear surfaces. Crown cracks occur above the present head of the failure and may represent the next generation of failure.

  17. Estimation of lung lobar sliding using image registration

    NASA Astrophysics Data System (ADS)

    Amelon, Ryan; Cao, Kunlin; Reinhardt, Joseph M.; Christensen, Gary E.; Raghavan, Madhavan

    2012-03-01

    MOTIVATION: The lobes of the lungs slide relative to each other during breathing. Quantifying lobar sliding can aid in better understanding lung function, better modeling of lung dynamics, and a better understanding of the limits of image registration performance near fissures. We have developed a method to estimate lobar sliding in the lung from image registration of CT scans. METHODS: Six human lungs were analyzed using CT scans spanning functional residual capacity (FRC) to total lung capacity (TLC). The lung lobes were segmented and registered on a lobe-by-lobe basis. The displacement fields from the independent lobe registrations were then combined into a single image. This technique allows for displacement discontinuity at lobar boundaries. The displacement field was then analyzed as a continuum by forming finite elements from the voxel grid of the FRC image. Elements at a discontinuity will appear to have undergone significantly elevated 'shear stretch' compared to those within the parenchyma. Shear stretch is shown to be a good measure of sliding magnitude in this context. RESULTS: The sliding map clearly delineated the fissures of the lung. The fissure between the right upper and right lower lobes showed the greatest sliding in all subjects while the fissure between the right upper and right middle lobe showed the least sliding.

  18. Second-order sliding mode control with experimental application.

    PubMed

    Eker, Ilyas

    2010-07-01

    In this article, a second-order sliding mode control (2-SMC) is proposed for second-order uncertain plants using equivalent control approach to improve the performance of control systems. A Proportional + Integral + Derivative (PID) sliding surface is used for the sliding mode. The sliding mode control law is derived using direct Lyapunov stability approach and asymptotic stability is proved theoretically. The performance of the closed-loop system is analysed through an experimental application to an electromechanical plant to show the feasibility and effectiveness of the proposed second-order sliding mode control and factors involved in the design. The second-order plant parameters are experimentally determined using input-output measured data. The results of the experimental application are presented to make a quantitative comparison with the traditional (first-order) sliding mode control (SMC) and PID control. It is demonstrated that the proposed 2-SMC system improves the performance of the closed-loop system with better tracking specifications in the case of external disturbances, better behavior of the output and faster convergence of the sliding surface while maintaining the stability.

  19. Specificity and sensitivity of the anterior slide test in throwing athletes with superior glenoid labral tears.

    PubMed

    Kibler, W B

    1995-06-01

    This study documents the sensitivity and specificity of a clinical test to aid in the diagnosis of superior glenoid labral lesions. The anterior slide test, a method of applying an anteriorly and superiorly directed force to the glenohumeral joint, was performed on several groups of athletes. These included symptomatic athletes with isolated superior labral tears, rotator cuff tears, and instabilities, and asymptomatic athletes with rotational deficits. In addition, non-throwing athletes were tested. The sensitivity of the test was 78.4%, and the specificity was 91.5%. This study shows that the anterior slide test can be used in the clinical examination, in that it has high specificity for superior labral lesions, but not enough sensitivity to be the sole diagnostic criterion for these lesions.

  20. Slide Conveying of Granular Materials-Thinking Out of the Glovebox

    NASA Technical Reports Server (NTRS)

    Goddard, J. D.; Didwania, A. K.; Nott, P. R.

    2000-01-01

    The vibratory conveyor, routinely employed for normal-gravity transport of granular materials, usually consists of a continuous open trough vibrated sinusoidally to induce axial movement of a granular material. Motivated in part by a hypothetical application in zero gravity, we propose a novel modification of the vibratory conveyor based on a closed 2d trough operating in a "slide-conveying" mode, with the granular mass remaining permanently in contact with the trough walls. We present a detailed analysis of the mechanics of transport, based on a rigid-slab model for the granular mass with frictional (Coulomb) slip at the upper and lower walls. The form of the vibration cycle plays a crucial role, and the optimal conveying cycle is not the commonly assumed rectilinear sinusoidal motion. The conveying efficiency for the novel slide conveyor will be presented for several simple vibration cycles, including one believed to represent the theoretical optimum.

  1. Comparing whole slide digital images versus traditional glass slides in the detection of common microscopic features seen in dermatitis

    PubMed Central

    Vyas, Nikki S.; Markow, Michael; Prieto-Granada, Carlos; Gaudi, Sudeep; Turner, Leslie; Rodriguez-Waitkus, Paul; Messina, Jane L.; Jukic, Drazen M.

    2016-01-01

    Background: The quality and limitations of digital slides are not fully known. We aimed to estimate intrapathologist discrepancy in detecting specific microscopic features on glass slides and digital slides created by scanning at ×20. Methods: Hematoxylin and eosin and periodic acid–Schiff glass slides were digitized using the Mirax Scan (Carl Zeiss Inc., Germany). Six pathologists assessed 50–71 digital slides. We recorded objective magnification, total time, and detection of the following: Mast cells; eosinophils; plasma cells; pigmented macrophages; melanin in the epidermis; fungal bodies; neutrophils; civatte bodies; parakeratosis; and sebocytes. This process was repeated using the corresponding glass slides after 3 weeks. The diagnosis was not required. Results: The mean time to assess digital slides was 176.77 s and 137.61 s for glass slides (P < 0.001, 99% confidence interval [CI]). The mean objective magnification used to detect features using digital slides was 18.28 and 14.07 for glass slides (P < 0.001, 99.99% CI). Parakeratosis, civatte bodies, pigmented macrophages, melanin in the epidermis, mast cells, eosinophils, plasma cells, and neutrophils, were identified at lower objectives on glass slides (P = 0.023–0.001, 95% CI). Average intraobserver concordance ranged from κ = 0.30 to κ = 0.78. Features with poor to fair average concordance were: Melanin in the epidermis (κ = 0.15–0.58); plasma cells (κ = 0.15–0.49); and neutrophils (κ = 0.12–0.48). Features with moderate average intrapathologist concordance were: parakeratosis (κ = 0.21–0.61); civatte bodies (κ = 0.21–0.71); pigment-laden macrophages (κ = 0.34–0.66); mast cells (κ = 0.29–0.78); and eosinophils (κ = 0.31–0.79). The average intrapathologist concordance was good for sebocytes (κ = 0.51–1.00) and fungal bodies (κ = 0.47–0.76). Conclusions: Telepathology using digital slides scanned at ×20 is sufficient for detection of histopathologic features routinely

  2. SurfaceSlide: A Multitouch Digital Pathology Platform

    PubMed Central

    Wang, Yinhai; Williamson, Kate E.; Kelly, Paul J.; James, Jacqueline A.; Hamilton, Peter W.

    2012-01-01

    Background Digital pathology provides a digital environment for the management and interpretation of pathological images and associated data. It is becoming increasing popular to use modern computer based tools and applications in pathological education, tissue based research and clinical diagnosis. Uptake of this new technology is stymied by its single user orientation and its prerequisite and cumbersome combination of mouse and keyboard for navigation and annotation. Methodology In this study we developed SurfaceSlide, a dedicated viewing platform which enables the navigation and annotation of gigapixel digitised pathological images using fingertip touch. SurfaceSlide was developed using the Microsoft Surface, a 30 inch multitouch tabletop computing platform. SurfaceSlide users can perform direct panning and zooming operations on digitised slide images. These images are downloaded onto the Microsoft Surface platform from a remote server on-demand. Users can also draw annotations and key in texts using an on-screen virtual keyboard. We also developed a smart caching protocol which caches the surrounding regions of a field of view in multi-resolutions thus providing a smooth and vivid user experience and reducing the delay for image downloading from the internet. We compared the usability of SurfaceSlide against Aperio ImageScope and PathXL online viewer. Conclusion SurfaceSlide is intuitive, fast and easy to use. SurfaceSlide represents the most direct, effective and intimate human–digital slide interaction experience. It is expected that SurfaceSlide will significantly enhance digital pathology tools and applications in education and clinical practice. PMID:22292040

  3. Geomorphology, stability and mobility of the Currituck slide

    USGS Publications Warehouse

    Locat, J.; Lee, H.; ten Brink, U.S.; Twichell, D.; Geist, E.; Sansoucy, M.

    2009-01-01

    Over the last 100,000??years, the U.S. Atlantic continental margin has experienced various types of mass movements some of which are believed to have taken place at times of low sea level. At one of these times of low sea level a significant trigger caused a major submarine mass movement off the coast of Virginia: the Currituck slide which is believed to have taken place between 24 and 50??ka ago. This slide removed a total volume of about 165??km3 from this section of the continental slope. The departure zone still shows a very clean surface that dips at 4?? and is only covered by a thin veneer of postglacial sediment. Multibeam bathymetric and seismic survey data suggest that this slide took place along three failures surfaces. The morphology of the source area suggests that the sediments were already at least normally consolidated at the time of failure. The slide debris covers an area as much as 55??km wide that extends 180??km from the estimated toe of the original slope. The back analysis of slide initiation indicates that very high pore pressure, a strong earthquake, or both had to be generated to trigger slides on such a low failure plane angle. The shape of the failure plane, the fact that the surface is almost clear of any debris, and the mobility analysis, all support the argument that the slides took place nearly simultaneously. Potential causes for the generation of high pore pressures could be seepage forces from coastal aquifers, delta construction and related pore pressure generation due to the local sediment loading, gas hydrates, and earthquakes. This slide, and its origin, is a spectacular example of the potential threat that submarine mass movements can pose to the US Atlantic coast and underline the need to further assess the potential for the generation of such large slides, like the Grand Banks 1927 landslide of similar volume. ?? 2008 Elsevier B.V.

  4. Introducing Slide Sets for the Introductory Astronomy Instructor

    NASA Astrophysics Data System (ADS)

    Meinke, Bonnie K.; Schneider, Nicholas; Brain, David; Schultz, Gregory; Buxner, Sanlyn; Smith, Denise

    2014-11-01

    The NASA Science Mission Directorate (SMD) Science Education and Public Outreach (E/PO) community and Forums work together to bring the cutting-edge discoveries of NASA Astrophysics and Planetary Science missions to the introductory astronomy college classroom. These mission- and grant-based E/PO programs are uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. We present two new opportunities for college instructors to bring the latest NASA discoveries in Space Science into their classrooms.In an effort to keep the astronomy classroom apprised of the fast moving field of planetary science, the Division of Planetary Sciences (DPS) has developed “DPS Discoveries”, which are short, topical presentations that can be incorporated into college lectures. The slide sets are targeted at the Introductory Astronomy undergraduate level. Each slide set consists of three slides that cover a description of the discovery, a discussion of the underlying science, and a presentation of the big picture implications of the discovery, with a fourth slide that includes links to associated press releases, images, and primary sources. Topics span all subdisciplines of planetary science, and sets are available in Farsi and Spanish. The NASA SMD Planetary Science Forum has recently partnered with the DPS to continue producing the Discovery slides and connect them to NASA mission science. http://dps.aas.org/education/dpsdisc Similarly, the NASA SMD Astrophysics Forum is coordinating the development of a series of slide sets to help Astronomy 101 instructors incorporate new discoveries in their classrooms. The “Astro 101 slide sets” are presentations 5-7 slides in length on a new development or discovery from a NASA Astrophysics mission relevant to topics in introductory astronomy courses. We intend for these slide sets to help Astronomy 101 instructors include new developments (not yet in their textbooks) into the

  5. Static and kinetic friction force and surface roughness of different archwire-bracket sliding contacts.

    PubMed

    Carrion-Vilches, Francisco J; Bermudez, María-Dolores; Fructuoso, Paula

    2015-01-01

    The aim of this study was to determine the static and kinetic friction forces of the contact bracket-archwire with different dental material compositions in order to select those materials with lower resistance to sliding. We carried out sliding friction tests by means of a universal testing machine following an experimental procedure as described in ASTM D1894 standard. We determined the static and kinetic friction forces under dry and lubricating conditions using an artificial saliva solution at 36.5ºC. The bracket-archwire pairs studied were: stainless steel-stainless steel; stainless steel-glass fiber composite; stainless steel-Nitinol 60; sapphire-stainless steel; sapphire-glass fiber composite; and sapphire-Nitinol 60. The best performance is obtained for Nitinol 60 archwire sliding against a stainless steel bracket, both under dry and lubricated conditions. These results are in agreement with the low surface roughness of Nitinol 60 with respect to the glass fiber composite archwire. The results described here contribute to establishing selection criteria for materials for dental archwire-brackets.

  6. Basal sliding in ice streams as seen through the lens of rock mechanics: an experimental study of ice-on-rock friction

    NASA Astrophysics Data System (ADS)

    McCarthy, C.; Savage, H. M.; Nettles, M.

    2015-12-01

    An understanding of the controls on ice stream flow is critical for improved predictions of sea level rise and glacier response to climate change. Basal sliding is one aspect of ice stream motion that has received relatively little attention. Although it is difficult and costly to measure direct motion at the base of a glacier, laboratory experiments can be used to recreate the physics of ice sliding over bedrock. Using a new, custom-built, servo-controlled biaxial loading apparatus, we are measuring the friction of polycrystalline ice samples sliding on rock in a double direct shear configuration. Temperature is maintained with an insulated cryostat that uses liquid cooling blocks and a programmable circulating bath. We will share results from a series of velocity stepping and slide-hold-slide experiments designed to measure key properties of rate- and state-dependent frictional behavior. The experimental conditions for the study are as follows: temperatures ranging from -20ºC to the pressure melting point; normal stresses of 20 - 200 kPa, velocities from 10-6 to 10-3 m s-1; and ambient pressure. Ice sample microstructure (grain size, porosity, purity) and surface roughness are carefully controlled and characterized before and after experiments to identify microstructural sources for macroscopic behavior. Careful monitoring of temperature at the sliding interface will elucidate the role of frictional heating/melting on both sliding behavior and microstructure evolution. By measuring rate-state friction parameters, we will explore the transition between stable sliding and stick-slip motion of glaciers and ice streams. These results can be directly compared to the differing sliding styles observed for ice streams feeding into the Ross Ice Shelf to infer characteristics of the bed interface and the bulk glacier. The values obtained from this study will provide better constraints for next generation modeling of glacier and ice-stream response to external forcing.

  7. Implementation of fuzzy-sliding mode based control of a grid connected photovoltaic system.

    PubMed

    Menadi, Abdelkrim; Abdeddaim, Sabrina; Ghamri, Ahmed; Betka, Achour

    2015-09-01

    The present work describes an optimal operation of a small scale photovoltaic system connected to a micro-grid, based on both sliding mode and fuzzy logic control. Real time implementation is done through a dSPACE 1104 single board, controlling a boost chopper on the PV array side and a voltage source inverter (VSI) on the grid side. The sliding mode controller tracks permanently the maximum power of the PV array regardless of atmospheric condition variations, while The fuzzy logic controller (FLC) regulates the DC-link voltage, and ensures via current control of the VSI a quasi-total transit of the extracted PV power to the grid under a unity power factor operation. Simulation results, carried out via Matlab-Simulink package were approved through experiment, showing the effectiveness of the proposed control techniques. PMID:26243440

  8. Transitions between smooth and complex stick-slip sliding of surfaces

    NASA Astrophysics Data System (ADS)

    Gourdon, Delphine; Israelachvili, Jacob N.

    2003-08-01

    Shear measurements were performed on mica surfaces with molecularly thin films of squalane (C30H62) confined between them. Squalane is a branched hydrocarbon liquid that can be in the liquid, glassy, or liquid-crystalline state under confinement. The friction forces, especially the transitions between smooth and intermittent (e.g., stick-slip) sliding, were measured over a wider range of applied loads (pressures), sliding velocities (shear rates), and temperatures than in previous studies. The results reveal that, depending on the conditions, qualitatively different behavior can arise in the same system. These include both abrupt and continuous transitions, both upper and lower critical transition temperatures, short and very long transient effects, and chaotic, sawtooth, or sinusoidal stick-slip that can slowly decay with time or distance sheared. The differences between these branched and simpler, e.g., spherical, unbranched molecules are compared, as well as with unlubricated (dry) surfaces and macroscopic (geological) systems.

  9. Wear of selected materials and composites sliding against MoS2 films

    NASA Astrophysics Data System (ADS)

    Ruff, A. W.; Peterson, M. B.

    1993-04-01

    Improved vacuum deposition methods are now available to produce dense, suitably oriented, durable films of molybdenum disulfide on substrates appropriate for tribological applications. It is of interest to examine materials in sliding contact with such films in order to identify optimum combinations, and to improve further tribological performance of the system. Results of wear and friction measurements are presented on a number of materials including self-lubricating composites sliding against four different types of vacuum-deposited MoS2 films. The testing program utilized a controlled environment, pin-on-ring tribometer, with load and speed conditions appropriate to a possible application. Differences in wear over four orders of magnitude, and friction up to a factor of seven times, were measured among the materials. One application area of interest for these material combinations would be as ball retainers in rolling element bearings for space satellite systems.

  10. Sliding Motility, Biofilm Formation, and Glycopeptidolipid Production in Mycobacterium colombiense Strains

    PubMed Central

    Maya-Hoyos, Milena; Leguizamón, John; Mariño-Ramírez, Leonardo; Soto, Carlos Y.

    2015-01-01

    Mycobacterium colombiense is a novel member of the Mycobacterium avium complex, which produces respiratory and disseminated infections in immunosuppressed patients. Currently, the morphological and genetic bases underlying the phenotypic features of M. colombiense strains remain unknown. In the present study, we demonstrated that M. colombiense strains displaying smooth morphology show increased biofilm formation on hydrophobic surfaces and sliding on motility plates. Thin-layer chromatography experiments showed that M. colombiense strains displaying smooth colonies produce large amounts of glycolipids with a chromatographic behaviour similar to that of the glycopeptidolipids (GPLs) of M. avium. Conversely, we observed a natural rough variant of M. colombiense (57B strain) lacking pigmentation and exhibiting impaired sliding, biofilm formation, and GPL production. Bioinformatics analyses revealed a gene cluster that is likely involved in GPL biosynthesis in M. colombiense CECT 3035. RT-qPCR experiments showed that motile culture conditions activate the transcription of genes possibly involved in key enzymatic activities of GPL biosynthesis. PMID:26180799

  11. A Numerical Dynamic Contact Angle Model Applied to Droplets Sliding Down An Incline

    NASA Astrophysics Data System (ADS)

    Afkhami, Shahriar; Bussmann, Markus

    2007-11-01

    A numerical dynamic contact angle model based on a well-known hydrodynamic theory is developed for the imposition of a boundary condition at the contact line. The efficacy of this new model is demonstrated via 3D examples of a viscous droplet sliding down a partially wetting incline. As experimentally observed (Phys. Rev. Lett. 87 (2001), 036102), when the inclination angle increases, the rear of the drop becomes elongated until it develops a ``corner'' which eventually breaks up into smaller droplets, while the leading edge of the drop remains rounded. Using the open source code ``Gerris'' (http://gfs.sf.net), we present the results of droplets sliding on an inclined plane. A similar behaviour (asymmetry between advancing and receding contact lines) is demonstrated. Results are in qualitative agreement with experimental observations. The role of surface inclination on the distribution of the dynamic contact angle along the droplet perimeter is also presented.

  12. Yeast actin filaments display ATP-dependent sliding movement over surfaces coated with rabbit muscle myosin.

    PubMed Central

    Kron, S J; Drubin, D G; Botstein, D; Spudich, J A

    1992-01-01

    The yeast Saccharomyces cerevisiae has been used to study the function of components of the actin cytoskeleton in vivo, mainly because it is easy to derive and characterize mutations affecting these proteins. In contrast, biochemical studies have generally used proteins derived from higher eukaryotes. We have devised a simple procedure to prepare, in high yield, homogeneous native actin from wild-type and act1 mutant yeast. Using intensified video fluorescence microscopy, we found that actin filaments polymerized from these preparations exhibit ATP-dependent sliding movement over surfaces coated with rabbit skeletal muscle myosin. The rates of sliding movement of the wild-type and mutant yeast actins were each about half that of rabbit skeletal muscle actin under similar conditions. We conclude that over the large evolutionary distance between yeast and mammals there has been significant conservation of actin function, specifically the ability to be moved by interaction with myosin. Images PMID:1533933

  13. Implementation of fuzzy-sliding mode based control of a grid connected photovoltaic system.

    PubMed

    Menadi, Abdelkrim; Abdeddaim, Sabrina; Ghamri, Ahmed; Betka, Achour

    2015-09-01

    The present work describes an optimal operation of a small scale photovoltaic system connected to a micro-grid, based on both sliding mode and fuzzy logic control. Real time implementation is done through a dSPACE 1104 single board, controlling a boost chopper on the PV array side and a voltage source inverter (VSI) on the grid side. The sliding mode controller tracks permanently the maximum power of the PV array regardless of atmospheric condition variations, while The fuzzy logic controller (FLC) regulates the DC-link voltage, and ensures via current control of the VSI a quasi-total transit of the extracted PV power to the grid under a unity power factor operation. Simulation results, carried out via Matlab-Simulink package were approved through experiment, showing the effectiveness of the proposed control techniques.

  14. Resistance to Sliding in Clear and Metallic Damon 3 and Conventional Edgewise Brackets: an In vitro Study

    PubMed Central

    Karim Soltani, Mohammad; Golfeshan, Farzaneh; Alizadeh, Yoones; Mehrzad, Jabraiel

    2015-01-01

    Statement of the Problem Frictional forces are considered as important counterforce to orthodontic tooth movement. It is claimed that self-ligating brackets reduce the frictional forces. Purpose The aim of this study was to compare the resistance to sliding in metallic and clear Damon brackets with the conventional brackets in a wet condition. Materials and Method The samples included 4 types of brackets; metallic and clear Damon brackets and metallic and clear conventional brackets (10 brackets in each group). In this study, stainless steel wires sized 0.019×0.025 were employed and the operator’s saliva was used to simulate the conditions of oral cavity. The tidy-modified design was used for simulation of sliding movement. The resistance to sliding and static frictional forces was measured by employing Testometric machine and load cell. Results The mean (±SD) of resistance to sliding was 194.88 (±26.65) and 226.62 (±39.9) g in the esthetic and metallic Damon brackets, while these values were 187.81(±27.84) and 191.17(±66.68) g for the clear and metallic conventional brackets, respectively. Static frictional forces were 206.4(±42.45) and 210.38(±15.89) g in the esthetic and metallic Damon brackets and 220.63(±49.29) and 215.13(±62.38) g in the clear and metallic conventional brackets. According to two-way ANOVA, no significant difference was observed between the two bracket materials (clear and metal) and the two types of bracket (self-ligating versus conventional) regarding resistance to sliding (p= 0.17 and p= 0.23, respectively) and static frictional forces (p= 0.55 and p= 0.96, respectively). Conclusion Neither the type of bracket materials nor their type of ligation made difference in resistance to sliding and static friction. PMID:26106630

  15. [Severe asthma].

    PubMed

    González, Claudio D

    2016-01-01

    The objectives of this work were to investigate the frequency of severe asthma (SA) according to WHO definition and to compare SA patients' characteristics with those of non-severe asthma (NSA); secondly, to investigate the level of control reached throughout a period of regular treatment. Between 1-1-2005 and 12-31-2014, 471 medical records from patients with bronchial asthma assisted in Buenos Aires City were analyzed. SA frequency was 40.1% (189/471), being significantly higher among patients from the public health system (47.7%, 108/226 vs. 33%, 81/245, p = 0.001). SA patients were older than NSA ones (51.3 ± 17.4 vs. 42.6 ± 17.1 years, p = 0.000), presented longer time since onset of the disease (median 30 vs. 20 years, p = 0.000), lower educational levels (secondary level or higher 41.7% vs. 58.1%, p = 0.000), lower frequency of rhinitis (47% vs. 60.6%, p = 0.004), more severe levels of airway obstruction (FEV% 50.2 ± 13.7 vs. 77.7 ± 12.4, p = 0.000), more frequent antecedents of Near Fatal Asthma (11.1% vs. 2.8%, p = 0.000), higher levels of serum IgE (median of 410 vs. 279 UI/l, p = 0.01) and higher demand of systemic steroids requirements and hospitalizations (68.7% vs. 50.7%, p = 0.000 and 37.5% vs. 15.9%, p = 0.000, respectively). A 30.6% of SA patients (58/189) reached a follow-up period of 12 months, 13 (22.5%) of whom reached the controlled asthma level. The frequency of SA found seems to be considerable. Multicenter studies to investigate the levels of control reached by SA patients with access to proper treatment are recommended.

  16. Evaluation of two transport aircraft and several ground test vehicle friction measurements obtained for various runway surface types and conditions. A summary of test results from joint FAA/NASA Runway Friction Program

    NASA Technical Reports Server (NTRS)

    Yager, Thomas J.; Vogler, William A.; Baldasare, Paul

    1990-01-01

    Tests with specially instrumented NASA Boeing 737 and 727 aircraft together with several different ground friction measuring devices were conducted for a variety of runway surface types and conditions. These tests are part of joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program aimed at obtaining a better understanding of aircraft ground handling performance under adverse weather conditions and defining relationships between aircraft and ground vehicle tire friction measurements. Aircraft braking performance on dry, wet, snow and ice-covered runway conditions is discussed as well as ground vehicle friction data obtained under similar runway conditions. For a given contaminated runway surface condition, the correlation between ground vehicles and aircraft friction data is identified. The influence of major test parameters on friction measurements such as speed, test tire characteristics, type and amount of surface contaminant, and ambient temperature are discussed. The effect of surface type on wet friction levels is also evaluated from comparative data collected on grooved and ungrooved concrete and asphalt surfaces.

  17. Towards a numerical run-out model for quick-clay slides

    NASA Astrophysics Data System (ADS)

    Issler, Dieter; L'Heureux, Jean-Sébastien; Cepeda, José M.; Luna, Byron Quan; Gebreslassie, Tesfahunegn A.

    2015-04-01

    Highly sensitive glacio-marine clays occur in many relatively low-lying areas near the coasts of eastern Canada, Scandinavia and northern Russia. If the load exceeds the yield stress of these clays, they quickly liquefy, with a reduction of the yield strength and the viscosity by several orders of magnitude. Leaching, fluvial erosion, earthquakes and man-made overloads, by themselves or combined, are the most frequent triggers of quick-clay slides, which are hard to predict and can attain catastrophic dimensions. The present contribution reports on two preparatory studies that were conducted with a view to creating a run-out model tailored to the characteristics of quick-clay slides. One study analyzed the connections between the morphological and geotechnical properties of more than 30 well-documented Norwegian quick-clay slides and their run-out behavior. The laboratory experiments by Locat and Demers (1988) suggest that the behavior of quick clays can be reasonably described by universal relations involving the liquidity index, plastic index, remolding energy, salinity and sensitivity. However, these tests should be repeated with Norwegian clays and analyzed in terms of a (shear-thinning) Herschel-Bulkley fluid rather than a Bingham fluid because the shear stress appears to grow in a sub-linear fashion with the shear rate. Further study is required to understand the discrepancy between the material parameters obtained in laboratory tests of material from observed slides and in back-calculations of the same slides with the simple model by Edgers & Karlsrud (1982). The second study assessed the capability of existing numerical flow models to capture the most important aspects of quick-clay slides by back-calculating three different, well documented events in Norway: Rissa (1978), Finneidfjord (1996) and Byneset (2012). The numerical codes were (i) BING, a quasi-two-dimensional visco-plastic model, (ii) DAN3D (2009 version), and (iii) MassMov2D. The latter two are

  18. Depth Estimation Using a Sliding Camera.

    PubMed

    Ge, Kailin; Hu, Han; Feng, Jianjiang; Zhou, Jie

    2016-02-01

    Image-based 3D reconstruction technology is widely used in different fields. The conventional algorithms are mainly based on stereo matching between two or more fixed cameras, and high accuracy can only be achieved using a large camera array, which is very expensive and inconvenient in many applications. Another popular choice is utilizing structure-from-motion methods for arbitrarily placed camera(s). However, due to too many degrees of freedom, its computational cost is heavy and its accuracy is rather limited. In this paper, we propose a novel depth estimation algorithm using a sliding camera system. By analyzing the geometric properties of the camera system, we design a camera pose initialization algorithm that can work satisfyingly with only a small number of feature points and is robust to noise. For pixels corresponding to different depths, an adaptive iterative algorithm is proposed to choose optimal frames for stereo matching, which can take advantage of continuously pose-changing imaging and save the time consumption amazingly too. The proposed algorithm can also be easily extended to handle less constrained situations (such as using a camera mounted on a moving robot or vehicle). Experimental results on both synthetic and real-world data have illustrated the effectiveness of the proposed algorithm. PMID:26685238

  19. Depth Estimation Using a Sliding Camera.

    PubMed

    Ge, Kailin; Hu, Han; Feng, Jianjiang; Zhou, Jie

    2016-02-01

    Image-based 3D reconstruction technology is widely used in different fields. The conventional algorithms are mainly based on stereo matching between two or more fixed cameras, and high accuracy can only be achieved using a large camera array, which is very expensive and inconvenient in many applications. Another popular choice is utilizing structure-from-motion methods for arbitrarily placed camera(s). However, due to too many degrees of freedom, its computational cost is heavy and its accuracy is rather limited. In this paper, we propose a novel depth estimation algorithm using a sliding camera system. By analyzing the geometric properties of the camera system, we design a camera pose initialization algorithm that can work satisfyingly with only a small number of feature points and is robust to noise. For pixels corresponding to different depths, an adaptive iterative algorithm is proposed to choose optimal frames for stereo matching, which can take advantage of continuously pose-changing imaging and save the time consumption amazingly too. The proposed algorithm can also be easily extended to handle less constrained situations (such as using a camera mounted on a moving robot or vehicle). Experimental results on both synthetic and real-world data have illustrated the effectiveness of the proposed algorithm.

  20. Soft hydrated sliding interfaces as complex fluids.

    PubMed

    Kim, Jiho; Dunn, Alison C

    2016-08-21

    Hydrogel surfaces are biomimics for sensing and mobility systems in the body such as the eyes and large joints due to their important characteristics of flexibility, permeability, and integrated aqueous component. Recent studies have shown polymer concentration gradients resulting in a less dense region in the top micrometers of the surface. Under shear, this gradient is hypothesized to drive lubrication behavior due to its rheological similarity to a semi-dilute polymer solution. In this work we map 3 distinct lubricating regimes between a polyacrylamide surface and an aluminum annulus using stepped-velocity tribo-rheometry over 5 decades of sliding speed in increasing and decreasing steps. These regimes, characterized by weakly or strongly time-dependent response and thixotropy-like hysteresis, provide the skeleton of a lubrication curve for hydrogel-against-hard material interfaces and support hypotheses of polymer mechanics-driven lubrication. Tribo-rheometry is particularly suited to uncover the lubrication mechanisms of complex interfaces such as are formed with hydrated hydrogel surfaces and biological surfaces. PMID:27425448

  1. Effects of surface grinding conditions on the reciprocating friction and wear behavior of silicon nitride

    SciTech Connect

    Blau, P.J.; Martin, R.L.; Zanoria, E.S.

    1997-12-31

    The relationship between two significantly different surface grinding conditions and the reciprocating ball-on-flat friction and wear behavior of a high-quality, structural silicon nitride material (GS-44) was investigated. The slider materials were silicon nitride NBD 200 and 440C stainless steel. Two machining conditions were selected based on extensive machining and flexural strength test data obtained under the auspices of an international, interlaboratory grinding study. The condition categorized as {open_quotes}low strength{close_quote} grinding used a coarse 80 grit wheel and produced low flexure strength due to machining-induced flaws in the surface. The other condition, regarded as {open_quotes}high strength grinding,{close_quotes} utilized a 320 grit wheel and produced a flexural strength nearly 70% greater. Grinding wheel surface speeds were 35 and 47 m/s. Reciprocating sliding tests were conducted following the procedure described in a newly-published ASTM standard (G- 133) for linearly-reciprocating wear. Tests were performed in directions both parallel and perpendicular to the grinding marks (lay) using a 25 N load, 5 Hz reciprocating frequency, 10 mm stroke length, and 100 m of sliding at room temperature. The effects of sliding direction relative to the lay were more pronounced for stainless steel than for silicon nitride sliders. The wear of stainless steel was less than the wear of the silicon nitride slider materials because of the formation of transfer particles which covered the sharp edges of the silicon nitride grinding grooves and reduced abrasive contact. The wear of the GS-44 material was much greater for the silicon nitride sliders than for the stainless steel sliders. The causes for the effects of surface-grinding severity and sliding direction on friction and wear of GS-44 and its counterface materials are explained.

  2. Micromorphological evidence of liquefaction, injection and sediment deposition during basal sliding

    NASA Astrophysics Data System (ADS)

    Phillips, Emrys; Lipka, Ewelina; van der Meer, Jaap J. M.

    2013-04-01

    The sliding of an ice mass over its bed represents one of the main mechanisms for the forward motion of glacier and ice sheets. The basal sliding process is thought to be facilitated by either regelation of the overriding ice and/or the introduction of meltwater along the ice-bed interface. The periodic nature of these conditions results in a stick-slip style of motion with phases of basal sliding leading to the repeated decoupling of the ice from its bed. However, in the geological record, physical evidence of this process having occurred beneath former glacier and ice sheets is limited. We present the results of a detailed micromorphological study of thinly stratified subglacial tills exposed at two sites: (i) Galmis in Switzerland and (ii) Plumpe Farm, near Gretna Green in SW Scotland. The stratification within these tills comprises alternating layers of massive to weakly foliated diamicton and variably deformed (folded, faulted) laminated silt and clay. Micromorphological and microstructural evidence is interpreted in terms of repeated phases of basal sliding as the ice overrode a soft-sediment bed. Elevated meltwater contents/pressures encountered immediately prior to, and during basal sliding promoted localised liquefaction within the underlying bed. Decoupling of the ice from the bed enabled the injection of the liquefied diamicton along the ice-bed interface and/or into the laminated sediments immediately adjacent to this boundary. The laminated silts and clays record the settling out of fines (clay, slit) from meltwater trapped along the ice-bed interface after an individual phase of basal sliding has ceased. Injection of till into the locally water saturated silts and clays resulted in partial liquefaction and incomplete mixing of these fine-grained sediments with the diamicton. Density contrasts between the two liquefied sediments led to the development of a complex 'vinaigrette' like texture (in analogy with igneous petrological terminology) comprising

  3. Spalling Behavior of Cu Plate Under Sliding Detonation Loading

    NASA Astrophysics Data System (ADS)

    Fan, Cheng; Liu, Mingtao; Guo, Zhaoliang; Tang, Tiegang

    2015-06-01

    We study the fracture behavior of a Cu plate under sliding detonation loading using wire explosion technique. Both Doppler Pins Systems (DPS) and Scanning Electron Microscope (SEM) are employed in the experiments to study the velocity of the free surface and the microstructure of the recovered samples. A novel spalling phenomenon is substantially observed. Unlike the flyer impact method, the typical spalling signals are not currently obtained in the velocity curves. But the microstructure images of recovered samples show obvious spalling characters. Several microholes are created and arranged along the direction perpendicular to the loading axis. Moreover, these holes all aline within a wide band with about 1 mm width. This is quite different from the case in the flyer impact experiment, in which the microholes all aline in a very narrow region. This is caused by the complex tensile stress state in the sample initiated by the explosive loading. More interestingly, all the microholes are initiated at the grain boundary and the grain size is much smaller in the band, especially at the edge of the big holes. These results may reveal the mechanism of the nucleation and growth process for the microholes.

  4. Finite element based simulation of dry sliding wear

    NASA Astrophysics Data System (ADS)

    Hegadekatte, V.; Huber, N.; Kraft, O.

    2005-01-01

    In order to predict wear and eventually the life-span of complex mechanical systems, several hundred thousand operating cycles have to be simulated. Therefore, a finite element (FE) post-processor is the optimum choice, considering the computational expense. A wear simulation approach based on Archard's wear law is implemented in an FE post-processor that works in association with a commercial FE package, ABAQUS, for solving the general deformable-deformable contact problem. Local wear is computed and then integrated over the sliding distance using the Euler integration scheme. The wear simulation tool works in a loop and performs a series of static FE-simulations with updated surface geometries to get a realistic contact pressure distribution on the contacting surfaces. It will be demonstrated that this efficient approach can simulate wear on both two-dimensional and three-dimensional surface topologies. The wear on both the interacting surfaces is computed using the contact pressure distribution from a two-dimensional or three-dimensional simulation, depending on the case. After every wear step the geometry is re-meshed to correct the deformed mesh due to wear, thus ensuring a fairly uniform mesh for further processing. The importance and suitability of such a wear simulation tool will be enunciated in this paper.

  5. Finding Frequent Closed Itemsets in Sliding Window in Linear Time

    NASA Astrophysics Data System (ADS)

    Chen, Junbo; Zhou, Bo; Chen, Lu; Wang, Xinyu; Ding, Yiqun

    One of the most well-studied problems in data mining is computing the collection of frequent itemsets in large transactional databases. Since the introduction of the famous Apriori algorithm [14], many others have been proposed to find the frequent itemsets. Among such algorithms, the approach of mining closed itemsets has raised much interest in data mining community. The algorithms taking this approach include TITANIC [8], CLOSET+[6], DCI-Closed [4], FCI-Stream [3], GC-Tree [15], TGC-Tree [16] etc. Among these algorithms, FCI-Stream, GC-Tree and TGC-Tree are online algorithms work under sliding window environments. By the performance evaluation in [16], GC-Tree [15] is the fastest one. In this paper, an improved algorithm based on GC-Tree is proposed, the computational complexity of which is proved to be a linear combination of the average transaction size and the average closed itemset size. The algorithm is based on the essential theorem presented in Sect. 4.2. Empirically, the new algorithm is several orders of magnitude faster than the state of art algorithm, GC-Tree.

  6. QUALITY ASSESSMENT OF CONFOCAL MICROSCOPY SLIDE-BASED SYSTEMS: INSTABLITY

    EPA Science Inventory

    Background: All slide-based fluorescence cytometry detections systems basically include an excitation light source, intermediate optics, and a detection device (CCD or PMT). Occasionally, this equipment becomes unstable, generating unreliable and inferior data. Methods: A num...

  7. DETAIL OF WEST END SLIDING DOOR AND EAVE VENTS ON ...

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

    DETAIL OF WEST END SLIDING DOOR AND EAVE VENTS ON THE SOUTH SIDE - Hickam Field, Practice Bomb Loading Shed, Bomb Storage Road near the intersection of Moffet and Kamakahi Streets, Honolulu, Honolulu County, HI

  8. BASEMENT, A view looking southwest toward the three panel, sliding ...

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

    BASEMENT, A view looking southwest toward the three panel, sliding glass door of walk-in hood and dial guage - Department of Energy, Mound Facility, Hydrolysis House Building (HH Building), One Mound Road, Miamisburg, Montgomery County, OH

  9. 2. WEST ELEVATION, SHOWING TAILRACE AND SLIDING DOOR UNDER SHED ...

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

    2. WEST ELEVATION, SHOWING TAILRACE AND SLIDING DOOR UNDER SHED ROOF. ADMINISTRATIVE OFFICE IS IN BACKGROUND AT RIGHT. VIEW TO EAST-NORTHEAST. - Santa Ana River Hydroelectric System, SAR-3 Powerhouse, San Bernardino National Forest, Redlands, San Bernardino County, CA

  10. 19. INTERIOR OF NORTHEAST REAR BEDROOM SHOWING ALUMINUMFRAME SLIDING GLASS ...

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

    19. INTERIOR OF NORTHEAST REAR BEDROOM SHOWING ALUMINUM-FRAME SLIDING GLASS WINDOWS. VIEW TO NORTHEAST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  11. 21. INTERIOR OF SOUTHEAST REAR BEDROOM SHOWING ALUMINUMFRAME SLIDING GLASS ...

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

    21. INTERIOR OF SOUTHEAST REAR BEDROOM SHOWING ALUMINUM-FRAME SLIDING GLASS WINDOWS. VIEW TO SOUTHEAST. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  12. 30 CFR 816.99 - Slides and other damage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 816.99 Slides and other damage. (a) An undisturbed natural barrier shall be provided beginning at the... determined by the regulatory authority as is needed to assure stability. The barrier shall be retained...

  13. 32. DETAIL OF CONCRETE TOWER AND SLIDE GATE LIFTING GEARS ...

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

    32. DETAIL OF CONCRETE TOWER AND SLIDE GATE LIFTING GEARS ON HEADWORKS OF DEER FLAT LOW LINE CANAL ON LOWER EMBANKMENT. VIEW TO SOUTHEAST. - Boise Project, Deer Flat Embankments, Lake Lowell, Nampa, Canyon County, ID

  14. 13. DETAIL OF CONCRETE TOWER AND SLIDE GATE LIFTING GEARS ...

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

    13. DETAIL OF CONCRETE TOWER AND SLIDE GATE LIFTING GEARS ON HEADWORKS OF DEER FLAT NAMPA CANAL ON UPPER EMBANKMENT. VIEW TO SOUTHWEST. - Boise Project, Deer Flat Embankments, Lake Lowell, Nampa, Canyon County, ID

  15. 17. Sliding access doors typical of those covering opening to ...

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

    17. Sliding access doors typical of those covering opening to filtration bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  16. Detail of the exterior "selfclosing" sliding door with vent above. ...

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

    Detail of the exterior "self-closing" sliding door with vent above. View facing northeast - U.S. Naval Base, Pearl Harbor, Paint & Oil Storehouse, Avenue D near Seventh Street intersection, Pearl City, Honolulu County, HI

  17. Interior of screened lanai with selfclosing sliding door and steel ...

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

    Interior of screened lanai with self-closing sliding door and steel roof support, view facing west - U.S. Naval Base, Pearl Harbor, Paint & Oil Storehouse, Avenue D near Seventh Street intersection, Pearl City, Honolulu County, HI

  18. AUTOMOTIVE REPAIR SHOP, SLIDING DOOR LEADING TO BOILER ROOM ON ...

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

    AUTOMOTIVE REPAIR SHOP, SLIDING DOOR LEADING TO BOILER ROOM ON SOUTH SIDE OF SOUTH WING, WITH SCALE. - Cedar City Automotive Repair Shop, Automotive Repair Shop, 820 North Main Street, Cedar City, Iron County, UT

  19. AUTOMOTIVE REPAIR SHOP, SLIDING DOOR LEADING TO BOILER ROOM ON ...

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

    AUTOMOTIVE REPAIR SHOP, SLIDING DOOR LEADING TO BOILER ROOM ON SOUTH SIDE OF SOUTH WING. - Cedar City Automotive Repair Shop, Automotive Repair Shop, 820 North Main Street, Cedar City, Iron County, UT

  20. Physical Geography Slide Sets of America's National Parks.

    ERIC Educational Resources Information Center

    Miller, E. Willard

    1984-01-01

    The national parks of the United States are widely known for their unique physical environments. Described are 10 sets of slides that will acquaint students with the parks' landforms and geologic processes. (RM)