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

PubMed

Fire, E; Zwart, D E; Roth, M G; Henis, Y I

1991-12-01

Replacement of cysteine at position 543 by tyrosine in the influenza virus hemagglutinin (HA) protein enables the endocytosis of the mutant protein (Tyr 543) through coated pits (Lazarovits, J., and M. G. Roth. 1988. Cell. 53:743-752). To investigate the interactions between Tyr 543 and the clathrin coats in the plasma membrane of live cells, we performed fluorescence photobleaching recovery measurements comparing the lateral mobilities of Tyr 543 (which enters coated pits) and wild-type HA (HA wt, which is excluded from coated pits), following their expression in CV-1 cells by SV-40 vectors. While both proteins exhibited the same high mobile fractions, the lateral diffusion rate of Tyr 543 was significantly slower than that of HA wt. Incubation of the cells in a sucrose-containing hypertonic medium, a treatment that disperses the membrane-associated coated pits, resulted in similar lateral mobilities for Tyr 543 and HA wt. These findings indicate that the lateral motion of Tyr 543 (but not of HA wt) is inhibited by transient interactions with coated pits (which are essentially immobile on the time scale of the lateral mobility measurements). Acidification of the cytoplasm by prepulsing the cells with NH4Cl (a treatment that arrests the pinching-off of coated vesicles from the plasma membrane and alters the clathrin lattice morphology) led to immobilization of a significant part of the Tyr 543 molecules, presumably due to their entrapment in coated pits for the entire duration of the lateral mobility measurement. Furthermore, in both untreated and cytosol-acidified cells, the restrictions on Tyr 543 mobility were less pronounced in the cold, suggesting that the mobility-restricting interactions are temperature dependent and become weaker at low temperatures. From these studies we conclude the following. (a) Lateral mobility measurements are capable of detecting interactions of transmembrane proteins with coated pits in intact cells. (b) The interactions of Tyr 543

Single Etch-Pit Shape on Off-Angled 4H-SiC(0001) Si-Face Formed by Chlorine Trifluoride

NASA Astrophysics Data System (ADS)

Hatayama, Tomoaki; Tamura, Tetsuya; Yano, Hiroshi; Fuyuki, Takashi

2012-07-01

The etch pit shape of an off-angled 4H-SiC Si-face formed by chlorine trifluoride (ClF3) in nitrogen (N2) ambient has been studied. One type of etch pit with a crooked hexagonal shape was formed at an etching temperature below 500 °C. The angle of the etch pit measured from a cross-sectional atomic force microscopy image was about 10° from the [11bar 20] view. The dislocation type of the etch pit was discussed in relation to the etch pit shape and an electron-beam-induced current image.

Pitting and stress corrosion cracking of stainless steel

NASA Astrophysics Data System (ADS)

Saithala, Janardhan R.

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

Acoustical measurements of sound fields between the stage and the orchestra pit inside an historical opera house

NASA Astrophysics Data System (ADS)

Sato, Shin-Ichi; Prodi, Nicola; Sakai, Hiroyuki

2004-05-01

To clarify the relationship of the sound fields between the stage and the orchestra pit, we conducted acoustical measurements in a typical historical opera house, the Teatro Comunale of Ferrara, Italy. Orthogonal factors based on the theory of subjective preference and other related factors were analyzed. First, the sound fields for a singer on the stage in relation to the musicians in the pit were analyzed. And then, the sound fields for performers in the pit in relation to the singers on the stage were considered. Because physical factors vary depending on the location of the sound source, performers can move on the stage or in the pit to find the preferred sound field.

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

PubMed

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

2016-07-01

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

Factors influencing habitat selection by arboreal pit vipers.

PubMed

Sawant, Nitin S; Jadhav, Trupti D

2013-01-01

We studied factors influencing habitat selection by two arboreal species of pit viper, namely Trimeresurus malabaricus (Malabar pit viper) and T. gramineus (Bamboo pit viper). The macrohabitat of these species was classified as forest, forest edge, or open habitat. To determine microhabitat selection, a variety of features at every other snake location were measured. Whether or not the animal was found in a tree, the tree species, its height of perch, position on the branch (distal/ apical/middle), diameter of the branch, the tree canopy (thick/sparse) and vegetation of the area (thick/sparse) were recorded. Assessment of habitat was done to determine how patterns of habitat use vary seasonally. Shaded ambient (air) temperatures and humidity were recorded. Data pertaining to 90 individuals of T. malabaricus and 100 individuals of T. gramineus were recorded. Trimeresurus malabaricus selected home ranges that included areas with thick vegetation and were encountered at regions of higher altitude. Neither of the species was found in open habitats. Both of the species preferred diverse habitats and were spread over the entire available space during the monsoon; they did not show any preference for the perch height during different seasons. Males had a positive correlation between body mass and preferred perch diameter. The present study suggests that several factors play an important role in habitat selection by these arboreal pit vipers, thus making them highly habitat-specific.

Ultimate open pit stochastic optimization

NASA Astrophysics Data System (ADS)

Marcotte, Denis; Caron, Josiane

2013-02-01

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

Martian Central Pit Craters

NASA Technical Reports Server (NTRS)

Hillman, E.; Barlow, N. G.

2005-01-01

Impact craters containing central pits are rare on the terrestrial planets but common on icy bodies. Mars is the exception among the terrestrial planets, where central pits are seen on crater floors ( floor pits ) as well as on top of central peaks ( summit pits ). Wood et al. [1] proposed that degassing of subsurface volatiles during crater formation produced central pits. Croft [2] argued instead that central pits might form during the impact of volatile-rich comets. Although central pits are seen in impact craters on icy moons such as Ganymede, they do show some significant differences from their martian counterparts: (a) only floor pits are seen on Ganymede, and (b) central pits begin to occur at crater diameters where the peak ring interior morphology begins to appear in terrestrial planet craters [3]. A study of craters containing central pits was conducted by Barlow and Bradley [4] using Viking imagery. They found that 28% of craters displaying an interior morphology on Mars contain central pits. Diameters of craters containing central pits ranged from 16 to 64 km. Barlow and Bradley noted that summit pit craters tended to be smaller than craters containing floor pits. They also noted a correlation of central pit craters with the proposed rings of large impact basins. They argued that basin ring formation fractured the martian crust and allowed subsurface volatiles to concentrate in these locations. They favored the model that degassing of the substrate during crater formation was responsible for central pit formation due to the preferential location of central pit craters along these basin rings.

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

USDA-ARS?s Scientific Manuscript database

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

Nucleation Of Ge 3D-islands On Pit-patterned Si Substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novikov, P. L.; Smagina, J. V.; Vlasov, D. Yu.

2011-12-23

Joint experimental and theoretical study of Ge nanoislands growth on pit-patterned Si substrate is carried out. Si substrates that have been templated by means of electron beam lithography and reactive ion etching have been used to grow Ge by molecular-beam epitaxy. Atomic-force-microscopy studies show that at Si(100) substrate temperature 550 deg. C, Ge nanoislands are formed at the pits' edges, rather than between the pits. The effect is interpreted in terms of energy barrier, that is formed near the edge of a pit and prevents Ge transport inside the pit. By molecular dynamics calculations the value of the energy barriermore » 0.9 eV was obtained.« less

On the influence of etch pits in the overall dissolution rate of apatite basal sections

NASA Astrophysics Data System (ADS)

Alencar, Igor; Guedes, Sandro; Palissari, Rosane; Hadler, Julio C.

2015-09-01

Determination of efficiencies for particle detection plays a central role for proper estimation of reaction rates. If chemical etching is employed in the revelation of latent particle tracks in solid-state detectors, dissolution rates and etchable lengths are important factors governing the revelation and observation. In this work, the mask method, where a reference part of the sample is protected during dissolution, was employed to measure step heights in basal sections of apatite etched with a nitric acid, HNO, solution at a concentration of 1.1 M and a temperature of 20 °C. We show a drastic increase in the etching velocity as the number of etch pits in the surface augments, in accordance with the dissolution stepwave model, where the outcrop of each etch pit generates a continuous sequence of stepwaves. The number of etch pits was varied by irradiation with neutrons and perpendicularly incident heavy ions. The size dependence of the etch-pit opening with etching duration for ion (200-300 MeV 152Sm and 238U) tracks was also investigated. There is no distinction for the etch pits between the different ions, and the dissolution seems to be governed by the opening velocity when a high number of etch pits are present in the surface. Measurements of the etchable lengths of these ion tracks show an increase in these lengths when samples are not pre-annealed before irradiation. We discuss the implications of these findings for fission-track modelling.

[Microsite characteristics of pit and mound and their effects on the vegetation regeneration in Pinus koraiensis-dominated broadleaved mixed forest].

PubMed

Du, Shan; Duan, Wen-Biao; Wang, Li-Xia; Chen, Li-Xin; Wei, Quan-Shuai; Li, Meng; Wang, Li-dong

2013-03-01

Abstract: An investigation was conducted in a 2.55 hm2 plot of Pinus koraiensis-dominated broad-leaved mixed forest to study the microsite characteristics of pit and mound formed by 42 treefalls and the status of vegetation regeneration on the microsites. The soil water content, soil temperature, relative air humidity, and photosynthetically active radiation (PAR) on five microsites (mound top, mound face, pit wall, pit bottom, and intact forest floor) were measured. Among the five mirosites, mound top had the highest PAR (527.9 micromol.m-2.s-1 ) while intact forest floor had the lowest one (58.7 micromol.m-2.s-), mound top had the highest soil temperature (16.0 degrees C) but pit bottom had the lowest one (13.3 degrees C), pit bottom had the highest soil water content (34.6%) but mound face had the lowest one (0.5%), and intact forest floor had the highest relative air humidity (75.9%) but mound top had the lowest one (68.0%). The frequency of forming pit/ mound complex by the tree species was decreased in the order of Pinus koraiensis (42. 9%) >Picea asperata (31.0%) > Betula platyphylla (16.7%) > Abies fabri (7. 1%) > Prunus padus (2.4%). Among the 42 treefalls, two-thirds of them were in northwest direction. The treefalls volume had significant positive correlations with pit depth, pit length, mound height, and mound width, but negative correlation with mound thickness. The treefall mean diameter at breast height had significant positive correlations with pit width (r=0.328, P=0.017) and pit length (r=0.527, P= 0). The tree species richness at the microsites decreased in the order of intact forest floor > pit > mound, and the tree species coverage was in the sequence of intact forest floor > pit > mound.

Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy

DOE PAGES

Yitamben, Esmeralda; Butera, Robert E.; Swartzentruber, Brian S.; ...

2017-10-16

Using scanning tunneling microscopy (STM), we investigate oxide-induced growth pits in Si thin films deposited by molecular beam epitaxy. In the transition temperature range from 2D adatom islanding to step-flow growth, systematic controlled air leaks into the growth chamber induce pits in the growth surface. We show that pits are also correlated with oxygen-contaminated flux from Si sublimation sources. From a thermodynamic standpoint, multilayer growth pits are unexpected in relaxed homoepitaxial growth, whereas oxidation is a known cause for step-pinning, roughening, and faceting on elemental surfaces, both with and without growth flux. Not surprisingly, pits are thermodynamically metastable and healmore » by annealing to recover a smooth periodic step arrangement. STM reveals new details about the pits' atomistic origins and growth dynamics. Here, we give a model for heterogeneous nucleation of pits by preferential adsorption of Å-sized oxide nuclei at intrinsic growth antiphase boundaries, and subsequent step pinning and bunching around the nuclei.« less

Stationary and transient thermal states of barometric pumping in the access pit of an underground quarry.

PubMed

Perrier, Frédéric; Le Mouël, Jean-Louis

2016-04-15

The transition zone between free and underground atmospheres hosts spectacular phenomena, as demonstrated by temperature measurements performed in the 4.6m diameter and 20m deep vertical access pit of an abandoned underground quarry located in Vincennes, near Paris. In summer, a stable stratification of the atmosphere is maintained, with coherent temperature variations associated with atmospheric pressure changes, with a barometric tide S2 larger than 0.1°C peak to peak. When the winter regime of turbulent cold air avalanches is initiated, stratification with pressure induced signals can be restored transiently in the upper part of the pit, while the lower part remains fully mixed and insensitive to pressure variations. The amplitude of the pressure to temperature transfer function increases with frequency below 5×10(-4)Hz, with values at 3×10(-5)Hz varying from 0.1°C·hPa(-1) at the bottom up to 2°C·hPa(-1) towards the top of the pit. These temperature variations are accounted for by cave breathing, which is pressure induced motion of air amplified by the large volume of the quarry. This understanding is supported by a numerical model including advective heat transport, heat diffusion, and heat exchange with the pit walls. Mean lifetime in the pit is of the order of 9 to 13h, and barometric pumping results in an effective ventilation rate of the quarry of the order of 10(-7)s(-1). This study illustrates the important role of barometric pumping in heat and matter transport between atmosphere and lithosphere. The resulting stationary and transient states, revealed in this pit, are probably a general feature of functioning interface systems, and therefore are an important aspect to consider in problems of contaminant transport, or the preservation of precious heritage such as rare ecosystems or painted caves. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of physical mass transport through oil sands fluid fine tailings in an end pit lake: a multi-tracer study.

PubMed

Dompierre, Kathryn A; Barbour, S Lee

2016-06-01

Soft tailings pose substantial challenges for mine reclamation due to their high void ratios and low shear strengths, particularly for conventional terrestrial reclamation practices. Oil sands mine operators have proposed the development of end pit lakes to contain the soft tailings, called fluid fine tailings (FFT), generated when bitumen is removed from oil sands ore. End pit lakes would be constructed within mined-out pits with FFT placed below the lake water. However, the feasibility of isolating the underlying FFT has yet to be fully evaluated. Chemical constituents of interest may move from the FFT into the lake water via two key processes: (1) advective-diffusive mass transport with upward pore water flow caused by settling of the FFT; and (2) mixing created by wind events or unstable density profiles through the lake water and upper portion of the FFT. In 2013 and 2014, temperature and stable isotopes of water profiles were measured through the FFT and lake water in the first end pit lake developed by Syncrude Canada Ltd. Numerical modelling was undertaken to simulate these profiles to identify the key mechanisms controlling conservative mass transport in the FFT. Shallow mixing of the upper 1.1 m of FFT with lake water was required to explain the observed temperature and isotopic profiles. Following mixing, the re-establishment of both the temperature and isotope profiles required an upward advective flux of approximately 1.5 m/year, consistent with average FFT settling rates measured at the study site. These findings provide important insight on the ability to sequester soft tailings in an end pit lake, and offer a foundation for future research on the development of end pit lakes as an oil sands reclamation strategy. Copyright © 2016 Elsevier B.V. All rights reserved.

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

PubMed

Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

2017-02-01

Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass <20,000. For the pit valve hypothesis, we formed pit valves in the intervessel pits in the short stem segments and measured the maximum liquid pressure up to which gases in bordered pits were retained. The threshold pressure ranged from 0.025 to 0.10 MPa. These values matched the theoretical value calculated from the geometry of the pit chamber (0.0692-0.101 MPa). Our results suggest that gas in the pits is retained by surface tension, even under substantial positive pressure to resolve gases in the refilling vessel, whereas the molecule size required for the pit membrane osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Investigating pitting in X65 carbon steel using potentiostatic polarisation

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

The Pits

NASA Technical Reports Server (NTRS)

2006-01-01

8 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a pit chain on the lower, northern flank of the giant martian volcano, Arsia Mons. Pits such as these commonly form as a result of collapse of surface materials into a subsurface void, possibly along a fault or into an old lava tube. The layered material, exposed near the top of several of the pits, is shedding house-sized boulders which can be seen resting on the sloping sidewalls and floors of many of the pits.

Location near: 6.7oS, 120.1oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

Comet 67P's Pitted Surface

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-11-01

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

Infrared snake eyes: TRPA1 and the thermal sensitivity of the snake pit organ.

PubMed

Panzano, Vincent C; Kang, Kyeongjin; Garrity, Paul A

2010-06-22

The pit organs of pit vipers, pythons, and boas are remarkable sensory devices that allow these snakes to detect infrared radiation emitted by warm-blooded prey. It has been theorized that this capacity reflects the pit organ's exceptional sensitivity to subtle fluctuations in temperature, but the molecules responsible for this extreme thermal resolution have been unknown. New evidence shows that pit organs respond to temperature using the warmth-activated cation channel TRPA1 (transient receptor potential ankyrin 1), a finding that provides a first glimpse of the underlying molecular hardware. The properties of these snake TRPA1s raise intriguing questions about the mechanisms responsible for the exceptional sensitivity of many biological thermoreceptors and about the evolutionary origins of these warmth-activated TRP channels.

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining—a thermal manikin and questionnaire study

PubMed Central

JUSSILA, Kirsi; RISSANEN, Sirkka; AMINOFF, Anna; WAHLSTRÖM, Jens; VAKTSKJOLD, Arild; TALYKOVA, Ljudmila; REMES, Jouko; MÄNTTÄRI, Satu; RINTAMÄKI, Hannu

2017-01-01

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers’ cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (Icl) of the reported clothing was estimated (ISO 9920). The Icl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the Icl of the selected clothing was on average 1.2 and 1.5 clo in mild (−5 to +5°C) and dry cold (−20 to −10°C) conditions, respectively. The Icl of the clothing measured by thermal manikin was 1.9–2.3 clo. The results show that the Arctic open-pit miners’ selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below −10°C. PMID:29021416

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study.

PubMed

Jussila, Kirsi; Rissanen, Sirkka; Aminoff, Anna; Wahlström, Jens; Vaktskjold, Arild; Talykova, Ljudmila; Remes, Jouko; Mänttäri, Satu; Rintamäki, Hannu

2017-12-07

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (I cl ) of the reported clothing was estimated (ISO 9920). The I cl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the I cl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The I cl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

41. 44INCH SOAKING PITS. A MORGAN CRANE LOWERS THE STEEL ...

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

41. 44-INCH SOAKING PITS. A MORGAN CRANE LOWERS THE STEEL INGOT INTO A 'SOAKING PIT,' WHERE IT IS HEATED TO A UNIFORM TEMPERATURE PRIOR TO ROLLING. THE INGOT RECEIVES ITS FIRST ROLLING ON THE 44-INCH BLOOMING MILL. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

Measurement of optical scattered power from laser-induced shallow pits on silica

DOE PAGES

Feigenbaum, Eyal; Nielsen, Norman; Matthews, Manyalibo J.

2015-10-01

We describe a model for far-field scattered power and irradiance by a silica glass slab with a shallow-pitted exit surface and is experimentally validated. The comparison to the model is performed using a precisely micromachined ensemble of ~11 μm wide laser ablated shallow pits producing 1% of the incident beam scatter in a 10 mrad angle. This series of samples with damage initiations and laser-induced shallow pits resulting from 351 nm, 5 ns pulsed laser cleaning of metal microparticles at different fluences between 2 J/cm 2 and 11 J/cm 2 are characterized as well and found in good agreement withmore » model predictions.« less

Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy

NASA Astrophysics Data System (ADS)

Yitamben, E. N.; Butera, R. E.; Swartzentruber, B. S.; Simonson, R. J.; Misra, S.; Carroll, M. S.; Bussmann, E.

2017-11-01

Using scanning tunneling microscopy (STM), we investigate oxide-induced growth pits in Si thin films deposited by molecular beam epitaxy. In the transition temperature range from 2D adatom islanding to step-flow growth, systematic controlled air leaks into the growth chamber induce pits in the growth surface. We show that pits are also correlated with oxygen-contaminated flux from Si sublimation sources. From a thermodynamic standpoint, multilayer growth pits are unexpected in relaxed homoepitaxial growth, whereas oxidation is a known cause for step pinning, roughening, and faceting on elemental surfaces, both with and without growth flux. Not surprisingly, pits are thermodynamically metastable and heal by annealing to recover a smooth periodic step arrangement. STM reveals new details about the pits’ atomistic origins and growth dynamics. We give a model for heterogeneous nucleation of pits by preferential adsorption of Å-sized oxide nuclei at intrinsic growth antiphase boundaries, and subsequent step pinning and bunching around the nuclei.

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

The efficiencies of cast blasting in wide pits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, R.L.; King, M.G.

Blasting activities in all four pits at Thunder Basin Coal`s Black Thunder Mine are focused on cast blasting. With widths varying from 190 feet to 265 feet and bench heights varying from 90 feet to 175 feet, casting efficiencies vary with different geometry`s. For example, the percent cast to final in the 200 foot pit is on the average higher than the 270 foot pit. The powder factors are somewhat higher in the narrower pits, thus increasing the cost of blasting. This leads to a very detailed look at the actual benefit of cast blasting and the associated cost ofmore » these benefits. The simple solution would be to reduce the width of the pits, thereby increasing the percent cast to final. However, the lower rehandle and low coal loss associated with wide pits would be fortified. Upon further review it becomes obvious that the wider pits could not be compared to the narrow pits with the cast to final percent indices. The focus should be shifted to cubic yards cast to final per lineal foot of pit. This will allow for more accurate measures of the casting efficiency of the shot. When comparing the pits with these indices their performances were much closer than the percent cast to final indices. The powder factors being higher in the narrow pits drove up the cost per cubic yard cast to final. Therefore, even though the percent cast to final was higher, the cost per cubic yard was also higher.« less

[Microclimate dynamics of pit and mound complex within different sizes of forest gaps in Pinus koraiensis-dominated broadleaved mixed forest].

PubMed

Wei, Quan-Shuai; Wang, Jing-Hua; Duan, Wen-Biao; Chen, Li-Xin; Wang, Ting; Han, Dong-Hui; Gu, Wei

2014-03-01

An investigation was conducted in a 2.25 hm2 plot of Pinus koraiensis-dominated broad-leaved mixed forest to study basic characteristics of 7 small gaps, 5 middle gaps, 3 large gaps and 7 closed stands within 38 pit and mound complexes caused by treefall in May 2012. From June to September 2012, the soil temperature, soil water content and relative humidity at five microsites (pit bottom, pit wall, mound top, mound face and undisturbed closed stands) were measured in six sunny days each month. The results showed that among the five microsites in every month, the mound top had the highest soil temperature and the lowest water content and relative humidity, and vice versa for the pit bottom. Mostly, the differences in the above indicators among the five microsites were significant. From June to September, the mean soil temperatures for all microsites at pit and mound complex in the various gaps and closed stands were in the order of large gap>middle gap >small gap>closed stand; but the soil water content ranked differently every month. In June, August and September, the mean relative humidities for all microsites in the various gaps and closed stands were in the order of closed stand>small gap>middle gap>large gap. Mostly, the differences in the above indicators between all microsites in the various gaps and closed stand were significant. The mean monthly soil temperature and relative humidity were highest in July, but lowest in September. The maximal mean monthly soil water content occurred in July and the minimal one in September for each microsite except the undisturbed closed stands, where the maximal mean monthly soil water content occurred in July. The variation of the microclimate at the pit and mound complex was mainly influenced by gap size, microsite, and time.

Pluto Pits

NASA Image and Video Library

2015-11-10

NASA New Horizons cameras have spied swarms of mysterious pits across the informally named Sputnik Planum. Scientists believe the pits may form through a combination of sublimation and ice fracturing. http://photojournal.jpl.nasa.gov/catalog/PIA20151

Utilization of open pit burned household waste ash--a feasibility study in Dhaka.

PubMed

Haque, Md Obaidul; Sharif, Ahmed

2014-05-01

Informal incineration or open pit burning of waste materials is a common practice in the peripheral area of Dhaka, one of the fastest growing mega-cities in the world. This study deals with the effect of open pit burned (i.e. open burned) household waste bottom ash on fired clay bricks. Between 0 to 50% (by weight) of open pit burned household waste bottom ash was mixed with clay to make bricks. The molded specimens were air-dried at room temperature for 24 h and then oven dried at 100 °C for another 24 h to remove the water. The raw bricks were fired in a muffle furnace to a designated temperature (800, 900 and 1000 °C, respectively). The firing behaviour (mechanical strength, water absorption and shrinkage) was determined. The microstructures, phase compositions and leachates were evaluated for bricks manufactured at different firing temperatures. These results demonstrate that open pit burned ash can be recycled in clay bricks. This study also presents physical observations of the incinerated ash particles and determination of the chemical compositions of the raw materials by wet analysis. Open pit burned ash can be introduced easily into bricks up to 20% wt. The concentrations of hazardous components in the leachates were below the standard threshold for inert waste category landfill and their environmental risk during their use-life step can be considered negligible.

Pitted keratolysis: a clinical review.

PubMed

Bristow, Ivan R; Lee, Yong Leng H

2014-03-01

Pitted keratolysis is a bacterial infection that affects the plantar epidermis. Despite the condition being reported in many countries affecting both shod and unshod populations, there is little guidance for clinicians providing evidence or best practice guidelines on the management of this often stubborn infection. Using a structured search of a range of databases, papers were identified that reported treatments tested on patients with the condition. Most of the literature uncovered was generally of a low level, such as case-based reporting or small case series. Studies were focused mainly on the use of topical antibiotic agents, such as clindamycin, erythromycin, fusidic acid, and mupirocin, often in combination with other measures, such as hygiene advice and the use of antiperspirants. From the limited evidence available, the use of topical antibiotic agents shows some efficacy in the treatment of pitted keratolysis. However, there is currently no suggestion that oral antibiotic drug therapy alone is effective in managing the condition. Currently, there is no consensus on the most effective approach to managing pitted keratolysis, but a combination of antimicrobial agents and adjunctive measures, such as antiperspirants, seems to demonstrate the most effective approach from the current literature available.

New Generation Energy Efficient Refractory Application in Soaking Pits of Bhilai Steel Plant, Sail

NASA Astrophysics Data System (ADS)

Roy, Indranil; Chintaiah, Perumetla; Bhattacharya, Ajoy Kr.; Garai, Swapan Kr.; Ray Choudhury, Pankaj Kr.; Tiwari, Laksman

In Bhilai Steel Plant (BSP), soaking pits are used for heating ingots for successive rolling into blooms. Pits are operated at a temperature of around 1350°C. Mixed gas (Mixture of Blast Furnace gas & Coke Oven gas) of calorific value around 2040 kcal/Nm3 is used as fuel. The walls of soaking pits were lined with traditional 38% Al2O3 firebricks and top 500mm was cast with 70% Al2O3 low cement castable (LCC). This type of lining results in frequent damages due to hitting by ingots while being lifted from pit by overhead cranes thus affecting the availability of pit. Life of pits was 2 to 2.5 years in BSP with 3-4 cold repairs and 3-4 hot repairs. Energy loss through the wall is also quite high in this type of lining. To triumph over the limitations of the conventional lining, a lining design was developed for the walls which consist of special 70% Al2O3 LCC having high hot strength (HMOR) in combination with specially design flexible SS-304 anchors. Ceramic fiber blanket and insulation bricks were provided between castable and the metallic shell of the pit to minimize the heat loss. A heating schedule was developed and introduced based on available infrastructure at BSP for proper curing of modified LCC based lining. After introduction of modified lining, pit no. 14/2 is running for more than 2.5 years without any repair. To capitalize the success, two more pits i.e. 12/1 and 9/2 were converted to modified lining. These pits are also running satisfactorily for more than 1.5 years. The modification has resulted in higher availability with substantial increase in production. Shell temperature of the modified pits reduced to 90° - 140°C from 120° - 200°C of conventional pits. This shows reduction in heat loss through walls, resulting less fuel consumption and energy saving of about 18%.

Limitation of the Cavitron technique by conifer pit aspiration.

PubMed

Beikircher, B; Ameglio, T; Cochard, H; Mayr, S

2010-07-01

The Cavitron technique facilitates time and material saving for vulnerability analysis. The use of rotors with small diameters leads to high water pressure gradients (DeltaP) across samples, which may cause pit aspiration in conifers. In this study, the effect of pit aspiration on Cavitron measurements was analysed and a modified 'conifer method' was tested which avoids critical (i.e. pit aspiration inducing) DeltaP. Four conifer species were used (Juniperus communis, Picea abies, Pinus sylvestris, and Larix decidua) for vulnerability analysis based on the standard Cavitron technique and the conifer method. In addition, DeltaP thresholds for pit aspiration were determined and water extraction curves were constructed. Vulnerability curves obtained with the standard method showed generally a less negative P for the induction of embolism than curves of the conifer method. Differences were species-specific with the smallest effects in Juniperus. Larix showed the most pronounced shifts in P(50) (pressure at 50% loss of conductivity) between the standard (-1.5 MPa) and the conifer (-3.5 MPa) methods. Pit aspiration occurred at the lowest DeltaP in Larix and at the highest in Juniperus. Accordingly, at a spinning velocity inducing P(50), DeltaP caused only a 4% loss of conductivity induced by pit aspiration in Juniperus, but about 60% in Larix. Water extraction curves were similar to vulnerability curves indicating that spinning itself did not affect pits. Conifer pit aspiration can have major influences on Cavitron measurements and lead to an overestimation of vulnerability thresholds when a small rotor is used. Thus, the conifer method presented here enables correct vulnerability analysis by avoiding artificial conductivity losses.

Measurement of Direct Current Voltage Causing Electrical Pitting

NASA Astrophysics Data System (ADS)

Noguchi, Shoji; Kakinuma, Shin-Nosuke; Kanada, Tohru

It is widely known that electrical pitting occurs when an electrical current is passed through a ball or roller bearing. The authors have investigated critical electrical current density causing electrical pitting and have shown that it occurs in a ball bearing even at an extremely low current. In this paper we present the results of an experiment in which a small ball bearing was supplied with a direct current (DC) voltage to determine the voltage required to induce a current. A film of grease acts as the insulator on an antifriction bearing used, and the thickness of this film is an important consideration and the current must pass through this film. Four types of grease were used on the bearing, which was rotated at various speed during 500 hours. A potential of 1.3V to 1.5V was necessary to induce the flow of current. The results indicate that the voltage supplied by typical dry cell batteries is sufficient to drive a currents through a small bearing, and that the experimental conditions had little effect on the magnitude of the flowing current.

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

NASA Astrophysics Data System (ADS)

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

2018-06-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Joan K.; Weimar, Mark R.; Balducci, Patrick J.

2003-06-30

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

Collapse Pits

NASA Technical Reports Server (NTRS)

2005-01-01

24 April 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a large and several small pits formed by collapse along the trend of a fault system in the Uranius Fossae region of Mars. Running diagonal from middle-right toward lower left is a trough that intersects the pit. The trough is a typical graben formed by faulting as the upper crust of Mars split and pulled apart at this location. The opening of the graben also led to formation of the collapse pits.

Location near: 26.2oN, 88.7oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

Experimental research on micro-pit defects of SUS 430 stainless steel strip in cold rolling process

NASA Astrophysics Data System (ADS)

Li, Changsheng; Li, Miao; Zhu, Tao; Huo, Gang

2013-05-01

In order to improve surface glossiness of stainless steel strip in tandem cold rolling, experimental research on micro-pit defects of SUS 430 ferrite stainless steel was investigated in laboratory. The surface morphology of micro-pit defects was observed by SEM. The effects of micro-pit defects on rolling reduction, roll surface roughness and emulsion parameters were analyzed. With the pass number increasing, the quantity and surface of micro-pit defects were reduced, uneven peak was decreased and gently along rolling direction, micro-pit defects had equally distributed tendency along tranverse direction. The micro-pit defects were increased with the roll surface roughness increase. The defects ratio was declined with larger gradient at pass number 1 to 3, but gentle slope at pass number 4 to 5. The effects of temperature 55° and 63°, concentration 3% and 6% of emulsion on micro-pit effects had not obvious difference. Maintain of micro-pit was effected by rolling oil or air in the micro-pit, the quality of oil was much more than the air in the micro-pit in lubrication rolling.

Pitting Corrosion of alloy 690 in thiosulfate-containing chloride solutions

NASA Astrophysics Data System (ADS)

Tsai, Wen-Ta; Wu, Tsung-Feng

2000-01-01

The effects of thiosulfate ion and solution pH on pitting corrosion of Alloy 690 in chloride solution were explored. Potentiodynamic polarization measurements were conducted to evaluate pitting corrosion susceptibility of Alloy 690 in these environments. The results showed that pitting corrosion occurred in the mill-annealed (1050°C/5min) Alloy 690 in 1 wt% NaCl solution but not in 0.1 M Na 2S 2O 3 solution. The value of pitting nucleation potential ( Enp) determined in 1 wt% NaCl solution (without Na 2S 2O 3 ) increased with increasing solution pH value in the range of 2-10. The addition of Na 2S 2O 3 to 1 wt% NaCl solution greatly affected the pitting corrosion behavior, which was dependent on concentration. The preformed nickel sulfide surface film due to the presence of Na 2S 2O 3 caused Alloy 690 to become more susceptible to pitting corrosion in 1 wt% NaCl solution.

Surface monitoring for pitting evolution into uniform corrosion on Cu-Ni-Zn ternary alloy in alkaline chloride solution: ex-situ LCM and in-situ SECM

NASA Astrophysics Data System (ADS)

Kong, Decheng; Dong, Chaofang; Zheng, Zhaoran; Mao, Feixiong; Xu, Aoni; Ni, Xiaoqing; Man, Cheng; Yao, Jizheng; Xiao, Kui; Li, Xiaogang

2018-05-01

The evolution of the corrosion process on Cu-Ni-Zn alloy in alkaline chloride solution was investigated by in-situ scanning electrochemical microscopy, X-ray photoelectron spectroscopy, and ex-situ laser confocal microscopy, and the effects of ambient temperature and polarization time were also discussed. The results demonstrated a higher pitting nucleation rate and lower pit growth rate at low temperature. The ratio of pit depth to mouth diameter decreased with increasing pit volume and temperature, indicating that pits preferentially propagate in the horizontal direction rather than the vertical direction owing to the presence of corrosion products and deposited copper. The surface current was uniform and stabilized at approximately 2.2 nA during the passive stage, whereas the current increased after the pits were formed with the maximum approaching 3 nA. Increasing the temperature led to an increase in porous corrosion products (CuO, Zn(OH)2, and Ni(OH)2) and significantly increased the rate of transition from pitting to uniform corrosion. Dezincification corrosion was detected by energy dispersive spectrometry, and a mechanism for pitting transition into uniform corrosion induced by dezincification at the grain boundaries is proposed.

Adsorbate-driven morphological changes on Cu(111) nano-pits

DOE PAGES

Mudiyanselage, K.; Xu, F.; Hoffmann, F. M.; ...

2014-12-09

Adsorbate-driven morphological changes of pitted-Cu(111) surfaces have been investigated following the adsorption and desorption of CO and H. The morphology of the pitted-Cu(111) surfaces, prepared by Ar + sputtering, exposed a few atomic layers deep nested hexagonal pits of diameters from 8 to 38 nm with steep step bundles. The roughness of pitted-Cu(111) surfaces can be healed by heating to 450-500 K in vacuum. Adsorption of CO on the pitted-Cu(111) surface leads to two infrared peaks at 2089-2090 and 2101-2105 cm -1 for CO adsorbed on under-coordinated sites in addition to the peak at 2071 cm -1 for CO adsorbedmore » on atop sites of the close-packed Cu(111) surface. CO adsorbed on under-coordinated sites is thermally more stable than that of atop Cu(111) sites. Annealing of the CO-covered surface from 100 to 300 K leads to minor changes of the surface morphology. In contrast, annealing of a H covered surface to 300 K creates a smooth Cu(111) surface as deduced from infrared data of adsorbed CO and scanning tunnelling microscopy (STM) imaging. The observation of significant adsorbate-driven morphological changes with H is attributed to its stronger modification of the Cu(111) surface by the formation of a sub-surface hydride with a hexagonal structure, which relaxes into the healed Cu(111) surface upon hydrogen desorption. These morphological changes occur ~150 K below the temperature required for healing of the pitted-Cu(111) surface by annealing in vacuum. In contrast, the adsorption of CO, which only interacts with the top-most Cu layer and desorbs by 160 K, does not significantly change the morphology of the pitted-Cu(111) surface.« less

Chronoamperometric study of mild steel pitting in sodium sulfide aqueous solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Otero, T.F.; Achucarro, C.

1994-08-01

Mild steel samples were studied by chronoamperometry in sodium sulfide (Na[sub 2]S) aqueous solution. Pit nucleation and growth also were monitored by optical microscopy. The influence of variables such as temperature, polarization potential, surface roughness, the presence of electrochemically generated oxide layers, and the simultaneous presence of potassium hydroxide (KOH) was studied. The influence of each parameter on pit shape and growth was reviewed. Different reactions and competitive processes were proposed based on the experimental results.

Note on the thermally induced changes of intervessel pits in black cherry (Prunus serotina EHRH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elder, T.J.; Murphey, W.K.; Blankenhorn, P.R.

1979-01-01

Dimensions of intervessel pits decrease as charring temperatures increase to 600 C; above 600 C pit apertures remain relatively constant. Reported increases in density of chars above 600 C are attributed to coalescing of the cell wall or changes in intercellular interstices shrinkage. 1 figure, 1 table.

Central Pit Crater

NASA Image and Video Library

2015-11-13

Crater floors can have a range of features, from flat to a central peak or a central pit. This image from NASA 2001 Mars Odyssey spacecraft shows an unnamed crater in Terra Sabaea has a central pit. This unnamed crater in Terra Sabaea has a central pit. The different floor features develop do due several factors, including the size of the impactor, the geology of the surface material and the geology of the materials at depth. Orbit Number: 60737 Latitude: 22.3358 Longitude: 61.2019 Instrument: VIS Captured: 2015-08-23 20:13 http://photojournal.jpl.nasa.gov/catalog/PIA20092

PitScan: Computer-Assisted Feature Detection

NASA Astrophysics Data System (ADS)

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

2018-04-01

We developed PitScan to assist in searching the very large LROC image dataset for pits — unusual <200m wide vertical-walled holes in the Moon's surface. PitScan reduces analysts' workload by pre-filtering images to identify possible pits.

Microstructure, Pitting Corrosion Resistance and Impact Toughness of Duplex Stainless Steel Underwater Dry Hyperbaric Flux-Cored Arc Welds.

PubMed

Hu, Yu; Shi, Yong-Hua; Shen, Xiao-Qin; Wang, Zhong-Min

2017-12-18

Duplex stainless steel multi-pass welds were made at 0.15 MPa, 0.45 MPa, and 0.75 MPa pressure, simulating underwater dry hyperbaric welding by the flux-cored arc welding (FCAW) method, with welds of normal pressure as a benchmark. The purpose of this work was to estimate the effect of ambient pressure on the microstructure, pitting corrosion resistance and impact toughness of the weld metal. The microstructure measurement revealed that the ferrite content in the weld metal made at 0.45 MPa is the lowest, followed by that of 0.75 MPa and 0.15 MPa. The analysis of potentiodynamic polarization tests at 30 °C and 50 °C demonstrated that the pitting corrosion resistance depends on the phases of the lower pitting resistance equivalent numbers (PREN), secondary austenite and ferrite. The weld metal made at 0.45 MPa had the best resistance to pitting corrosion at 30 °C and 50 °C with the highest PRENs of secondary austenite and ferrite. The weld metal made at 0.15 MPa displayed the lowest pitting corrosion resistance at 30 °C with the lowest PREN of secondary austenite, while the weld metal made at 0.75 MPa was the most seriously eroded after being tested at 50 °C for the lowest PREN of ferrite, with large cluster pits seen in ferrite at 50 °C. The impact tests displayed a typical ductile-brittle transition because of the body-centered cubic (BCC) structure of the ferrite when the test temperature was lowered. All the weld metals met the required value of 34 J at -40 °C according to the ASTM A923. The highest ferrite content corresponded to the worst impact toughness, but the highest toughness value did not correspond to the greatest austenite content. With the decreasing of the test temperature, the drop value of absorbed energy was correlated to the ferrite content. Additionally, in this work, the weld metal made at 0.45 MPa had the best combined properties of pitting resistance and impact toughness.

Detecting Cavitation Pitting Without Disassembly

NASA Technical Reports Server (NTRS)

Barkhoudarian, S.

1986-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowan, Catherine M.; Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095; Zhang, Xinli

2012-06-08

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

An InGaN/GaN Superlattice to Enhance the Performance of Green LEDs: Exploring the Role of V-Pits.

PubMed

Liu, Mengling; Zhao, Jie; Zhou, Shengjun; Gao, Yilin; Hu, Jinfeng; Liu, Xingtong; Ding, Xinghuo

2018-06-21

Despite the fact that an InGaN/GaN superlattice (SL) is useful for enhancing the performance of a GaN-based light-emitting diode (LED), its role in improving the efficiency of green LEDs remains an open question. Here, we investigate the influence of a V-pits-embedded InGaN/GaN SL on optical and electrical properties of GaN-based green LEDs. We recorded a sequence of light emission properties of InGaN/GaN multiple quantum wells (MQWs) grown on a 0- and 24-pair InGaN/GaN SL by using scanning electron microscopy (SEM) in combination with a room temperature cathodoluminescence (CL) measurement, which demonstrated the presence of a potential barrier formed by the V-pits around threading dislocations (TDs). We find that an increase in V-pit diameter would lead to the increase of V-pit potential barrier height. Our experimental data suggest that a V-pits-embedded, 24-pair InGaN/GaN SL can effectively suppress the lateral diffusion of carriers into non-recombination centers. As a result, the external quantum efficiency (EQE) of green LEDs is improved by 29.6% at an injection current of 20 mA after implementing the V-pits-embedded InGaN/GaN SL layer. In addition, a lower reverse leakage current was achieved with larger V-pits.

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

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

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

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

PubMed Central

Huang, Yongfang; Gang, Tieqiang; Chen, Lijie

2017-01-01

For pre-corroded aluminum alloy 7075-T6, the interacting effects of two neighboring pits on the stress concentration are comprehensively analyzed by considering various relative position parameters (inclination angle θ and dimensionless spacing parameter λ) and pit depth (d) with the finite element method. According to the severity of the stress concentration, the critical corrosion regions, bearing high susceptibility to fatigue damage, are determined for intersecting and adjacent pits, respectively. A straightforward approach is accordingly proposed to conservatively estimate the combined stress concentration factor induced by two neighboring pits, and a concrete application example is presented. It is found that for intersecting pits, the normalized stress concentration factor Ktnor increases with the increase of θ and λ and always reaches its maximum at θ = 90°, yet for adjacent pits, Ktnor decreases with the increase of λ and the maximum value appears at a slight asymmetric location. The simulations reveal that Ktnor follows a linear and an exponential relationship with the dimensionless depth parameter Rd for intersecting and adjacent cases, respectively. PMID:28772758

Pyramidal pits created by single highly charged ions in BaF{sub 2} single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

El-Said, A. S.; Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura; Heller, R.

2010-07-15

In various insulators, the impact of individual slow highly charged ions (eV-keV) creates surface nanostructures, whose size depends on the deposited potential energy. Here we report on the damage created on a cleaved BaF{sub 2} (111) surface by irradiation with 4.5xq keV highly charged xenon ions from a room-temperature electron-beam ion trap. Up to charge states q=36, no surface topographic changes on the BaF{sub 2} surface are observed by scanning force microscopy. The hidden stored damage, however, can be made visible using the technique of selective chemical etching. Each individual ion impact develops into a pyramidal etch pits, as canmore » be concluded from a comparison of the areal density of observed etch pits with the applied ion fluence (typically 10{sup 8} ions/cm{sup 2}). The dimensional analysis of the measured pits reveals the significance of the deposited potential energy in the creation of lattice distortions/defects in BaF{sub 2}.« less

Measuring subcutaneous temperature and differential rates of rewarming from hibernation and daily torpor in two species of bats.

PubMed

Currie, Shannon E; Körtner, Gerhard; Geiser, Fritz

2015-12-01

Prolonged and remote measurement of body temperature (Tb) in undisturbed small hibernators was not possible in the past because of technological limitations. Although passive integrated transponders (PITs) have been used previously to measure subcutaneous temperature (Tsub) during daily torpor in a small marsupial, no study has attempted to use these devices at Tbs below 10°C. Therefore, we investigated whether subcutaneous interscapular PITs can be used as a viable tool for measuring Tb in a small hibernating bat (Nyctophilus gouldi; Ng) and compared it with measurements of Tb during daily torpor in a heterothermic bat (Syconycteris australis; Sa). The precision of transponders was investigated as a function of ambient temperature (Ta) and remote Tsub readings enabled us to quantify Tsub-Tb differentials during steady-state torpor and arousal. Transponders functioned well outside the manufacturer's recommended range, down to ~5°C. At rest, Tsub and rectal Tb (Trec) were strongly correlated for both bat species (Ng r(2)=0.88; Sa r(2)=0.95) and this was also true for N. gouldi in steady-state torpor (r(2)=0.93). During induced rewarming Tsub increased faster than Trec in both species. Our results demonstrate that transponders can be used to provide accurate remote measurement of Tb in two species of bats during different physiological states, both during steady-state conditions and throughout dynamic phases such as rewarming from torpor. We show that, at least during rewarming, regional heterothermy common to larger hibernators and other hibernating bats is also present in bats capable of daily torpor. Copyright © 2015 Elsevier Inc. All rights reserved.

Inconsistent identification of pit bull-type dogs by shelter staff.

PubMed

Olson, K R; Levy, J K; Norby, B; Crandall, M M; Broadhurst, J E; Jacks, S; Barton, R C; Zimmerman, M S

2015-11-01

Shelter staff and veterinarians routinely make subjective dog breed identification based on appearance, but their accuracy regarding pit bull-type breeds is unknown. The purpose of this study was to measure agreement among shelter staff in assigning pit bull-type breed designations to shelter dogs and to compare breed assignments with DNA breed signatures. In this prospective cross-sectional study, four staff members at each of four different shelters recorded their suspected breed(s) for 30 dogs; there was a total of 16 breed assessors and 120 dogs. The terms American pit bull terrier, American Staffordshire terrier, Staffordshire bull terrier, pit bull, and their mixes were included in the study definition of 'pit bull-type breeds.' Using visual identification only, the median inter-observer agreements and kappa values in pair-wise comparisons of each of the staff breed assignments for pit bull-type breed vs. not pit bull-type breed ranged from 76% to 83% and from 0.44 to 0.52 (moderate agreement), respectively. Whole blood was submitted to a commercial DNA testing laboratory for breed identification. Whereas DNA breed signatures identified only 25 dogs (21%) as pit bull-type, shelter staff collectively identified 62 (52%) dogs as pit bull-type. Agreement between visual and DNA-based breed assignments varied among individuals, with sensitivity for pit bull-type identification ranging from 33% to 75% and specificity ranging from 52% to 100%. The median kappa value for inter-observer agreement with DNA results at each shelter ranged from 0.1 to 0.48 (poor to moderate). Lack of consistency among shelter staff indicated that visual identification of pit bull-type dogs was unreliable. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

7 CFR 52.779 - Freedom from pits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Freedom from pits. 52.779 Section 52.779 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Freedom from pits. (a) General. The factor of freedom from pits refers to the incidence of pits and pit...

3D Modeling of Lacus Mortis Pit Crater with Presumed Interior Tube Structure

NASA Astrophysics Data System (ADS)

Hong, Ik-Seon; Yi, Yu; Yu, Jaehyung; Haruyama, Junichi

2015-06-01

When humans explore the Moon, lunar caves will be an ideal base to provide a shelter from the hazards of radiation, meteorite impact, and extreme diurnal temperature differences. In order to ascertain the existence of caves on the Moon, it is best to visit the Moon in person. The Google Lunar X Prize(GLXP) competition started recently to attempt lunar exploration missions. Ones of those groups competing, plan to land on a pit of Lacus Mortis and determine the existence of a cave inside this pit. In this pit, there is a ramp from the entrance down to the inside of the pit, which enables a rover to approach the inner region of the pit. In this study, under the assumption of the existence of a cave in this pit, a 3D model was developed based on the optical image data. Since this model simulates the actual terrain, the rendering of the model agrees well with the image data. Furthermore, the 3D printing of this model will enable more rigorous investigations and also could be used to publicize lunar exploration missions with ease.

Improving Pit Vehicle Ecology Safety

NASA Astrophysics Data System (ADS)

Koptev, V. Yu; Kopteva, A. V.

2018-05-01

The article discloses the ways to improve the ecological safety of a pit transport: reducing harmful substance concentrations in exhaust gases, implementation of the ecological certificate of the dumping truck, taking into account the operation of the dumping truck actual work, choosing the best model and comparing ecological characteristics of pit lifters at deep pits.

The thermal background determines how the infrared and visual systems interact in pit vipers.

PubMed

Chen, Qin; Liu, Yang; Brauth, Steven E; Fang, Guangzhan; Tang, Yezhong

2017-09-01

The thermal infrared (IR) sensing system of pit vipers is believed to complement vision and provide a substitute imaging system in dark environments. Theoretically, the IR system would best image a scene consisting of a homothermal target in cold surroundings as a bright spot on a dark background. To test this hypothesis, we evaluated how the pit viper ( Gloydius brevicaudus ) discriminates and strikes prey when the background temperature is either higher or lower than that of the prey (approximately 32-33°C) in different parts of the scene. Snakes were tested in a modified predation cage in which background temperatures were set to 26°C on one side and either 33 or 40°C on the opposite side when the eyes, the pit organs or neither sensory system was occluded. When the eyes were blocked, snakes preferred to strike prey on the 26°C side rather than on the 33°C side but showed no bias in the other conditions. Snakes showed no preference for 26 versus 40°C background temperature, although more missed strikes occurred when the eyes were occluded. The results thus revealed that the pit viper IR system can accomplish a 'brightness constancy' computation reflecting the difference between the target and background temperatures, much as the visual system compares the luminance of a figure and the background. Furthermore, the results show that the IR system performs less well for locating prey when the background is warmer than the target. © 2017. Published by The Company of Biologists Ltd.

X-ray off-specular reflectivity studies of electrochemical pitting of Cu surfaces in sodium bicarbonate solution

NASA Astrophysics Data System (ADS)

Feng, Y. P.; Sinha, S. K.; Melendres, C. A.; Lee, D. D.

1996-02-01

We have studied the electrochemically-induced pitting process on a Cu electrode in NaHCO 3 solution using in-situ X-ray off-specular reflectivity measurements. The morphology and growth dynamics of the localized corrosion sites or pits were studied as the applied potential was varied from the cathodic region where the Cu surface is relatively free of oxide films to the anodic region where surface roughening occurs by general corrosion with concomitant formation of an oxide film. Quantitative analysis of the experimental results indicates that early pitting proceeds in favor of nucleation of pit clusters over individual pit growth. It was found that the lateral distribution of the pits is not random but exhibits a short-range order as evidenced by the appearance of a side peak in the transverse off-specular reflectivity. The position, height, and width of the peak was modeled to yield the average size, nearest-neighbor distance (within any one of the clusters), and over-all density of the pits averaged over the entire illuminated surface. In addition, measurements of the longitudinal off-specular reflectivity indicate a bimodal depth distribution for the pits, suggesting a “film breaking” type of pitting mechanism.

Microstructure, Pitting Corrosion Resistance and Impact Toughness of Duplex Stainless Steel Underwater Dry Hyperbaric Flux-Cored Arc Welds

PubMed Central

Hu, Yu; Shen, Xiao-Qin; Wang, Zhong-Min

2017-01-01

Duplex stainless steel multi-pass welds were made at 0.15 MPa, 0.45 MPa, and 0.75 MPa pressure, simulating underwater dry hyperbaric welding by the flux-cored arc welding (FCAW) method, with welds of normal pressure as a benchmark. The purpose of this work was to estimate the effect of ambient pressure on the microstructure, pitting corrosion resistance and impact toughness of the weld metal. The microstructure measurement revealed that the ferrite content in the weld metal made at 0.45 MPa is the lowest, followed by that of 0.75 MPa and 0.15 MPa. The analysis of potentiodynamic polarization tests at 30 °C and 50 °C demonstrated that the pitting corrosion resistance depends on the phases of the lower pitting resistance equivalent numbers (PREN), secondary austenite and ferrite. The weld metal made at 0.45 MPa had the best resistance to pitting corrosion at 30 °C and 50 °C with the highest PRENs of secondary austenite and ferrite. The weld metal made at 0.15 MPa displayed the lowest pitting corrosion resistance at 30 °C with the lowest PREN of secondary austenite, while the weld metal made at 0.75 MPa was the most seriously eroded after being tested at 50 °C for the lowest PREN of ferrite, with large cluster pits seen in ferrite at 50 °C. The impact tests displayed a typical ductile-brittle transition because of the body-centered cubic (BCC) structure of the ferrite when the test temperature was lowered. All the weld metals met the required value of 34 J at −40 °C according to the ASTM A923. The highest ferrite content corresponded to the worst impact toughness, but the highest toughness value did not correspond to the greatest austenite content. With the decreasing of the test temperature, the drop value of absorbed energy was correlated to the ferrite content. Additionally, in this work, the weld metal made at 0.45 MPa had the best combined properties of pitting resistance and impact toughness. PMID:29258262

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palmer, E.

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

Initation of pitting corrosion in martensitic stainless steels. [17-4PH; 13-8Mo; Custom 450

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cieslak, W.R.; Semarge, R.E.; Bovard, F.S.

1986-01-01

The form of localized corrosion known as pitting often initiates preferentially at microstructural inhomogeneities. The pit initiation resistance, therefore, is controlled by the characteristics of the initiation sites, rather than by the bulk material composition. This investigation correlates the pit initiation resistance, as measured by critical pitting potentials, with preferred pit initiation sites for 3 martensitic stainless steels. Pit initiation sites are determined by secondary electron (SE) and backscattered electron (BSE) imaging and energy dispersive and wavelength dispersive spectrometries (EDS and WDS) with a scalling electron microscope (SEM) and an electron probe microanalyzer (EPMA).

Computational fluid dynamics models of conifer bordered pits show how pit structure affects flow.

PubMed

Schulte, Paul J

2012-02-01

• The flow of xylem sap through conifer bordered pits, particularly through the pores in the pit membrane, is not well understood, but is critical for an understanding of water transport through trees. • Models solving the Navier-Stokes equation governing fluid flow were based on the geometry of bordered pits in black spruce (Picea mariana) and scanning electron microscopy images showing details of the pores in the margo of the pit membrane. • Solutions showed that the pit canals contributed a relatively small fraction of resistance to flow, whereas the torus and margo pores formed a large fraction, which depended on the structure of the individual pit. The flow through individual pores in the margo was strongly dependent on pore area, but also on the radial location of the pore with respect to the edge of the torus. • Model results suggest that only a few per cent of the pores in the margo account for nearly half of the flow and these pores tend to be located in the inner region of the margo where their contribution will be maximized. A high density of strands in outer portions of the margo (hence narrower pores) may be more significant for mechanical support of the torus. © 2011 The Author. New Phytologist © 2011 New Phytologist Trust.

Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

PubMed Central

Polizzotto, Matthew L.

2013-01-01

Background: Pit latrines are one of the most common human excreta disposal systems in low-income countries, and their use is on the rise as countries aim to meet the sanitation-related target of the Millennium Development Goals. There is concern, however, that discharges of chemical and microbial contaminants from pit latrines to groundwater may negatively affect human health. Objectives: Our goals were to a) calculate global pit latrine coverage, b) systematically review empirical studies of the impacts of pit latrines on groundwater quality, c) evaluate latrine siting standards, and d) identify knowledge gaps regarding the potential for and consequences of groundwater contamination by latrines. Methods: We used existing survey and population data to calculate global pit latrine coverage. We reviewed the scientific literature on the occurrence of contaminants originating from pit latrines and considered the factors affecting transport of these contaminants. Data were extracted from peer-reviewed articles, books, and reports identified using Web of ScienceSM, PubMed, Google, and document reference lists. Discussion: We estimated that approximately 1.77 billion people use pit latrines as their primary means of sanitation. Studies of pit latrines and groundwater are limited and have generally focused on only a few indicator contaminants. Although groundwater contamination is frequently observed downstream of latrines, contaminant transport distances, recommendations based on empirical studies, and siting guidelines are variable and not well aligned with one another. Conclusions: In order to improve environmental and human health, future research should examine a larger set of contextual variables, improve measurement approaches, and develop better criteria for siting pit latrines. PMID:23518813

Sodium-dependent phosphate cotransporters and phosphate-induced calcification of vascular smooth muscle cells: Redundant roles for PiT-1 and PiT-2

PubMed Central

Crouthamel, Matthew H.; Lau, Wei Ling; Leaf, Elizabeth M.; Chavkin, Nick; Wallingford, Mary C.; Peterson, Danielle F.; Li, Xianwu; Liu, Yonggang; Chin, Michael T.; Levi, Moshe; Giachelli, Cecilia M.

2014-01-01

Objective Elevated serum phosphate has emerged as a major risk factor for vascular calcification. The sodium-dependent phosphate cotransporter, PiT-1, was previously shown to be required for phosphate-induced osteogenic differentiation and calcification of cultured human VSMCs, but its importance in vascular calcification in vivo, as well as the potential role of its homologue, PiT-2, have not been determined. We investigated the in vivo requirement for PiT-1 in vascular calcification using a mouse model of chronic kidney disease, and the potential compensatory role of PiT-2 using in vitro knockdown and over-expression strategies. Approach and Results Mice with targeted deletion of PiT-1 in VSMCs were generated (PiT-1Δsm). PiT-1 mRNA levels were undetectable whereas PiT-2 mRNA levels were increased 2 fold in the vascular aortic media of PiT-1Δsm compared to PiT-1flox/flox control. When arterial medial calcification was induced in PiT-1Δsm and PiT-1flox/flox by chronic kidney disease followed by dietary phosphate loading, the degree of aortic calcification was not different between genotypes, suggesting compensation by PiT-2. Consistent with this possibility, VSMCs isolated from PiT-1Δsm mice had no PiT-1 mRNA expression, increased PiT-2 mRNA levels, and no difference in sodium-dependent phosphate uptake or phosphate-induced matrix calcification compared to PiT-1flox/flox VSMCs. Knockdown of PiT-2 decreased phosphate uptake and phosphate-induced calcification of PiT-1Δsm VSMCs. Furthermore, over-expression of PiT-2 restored these parameters in human PiT-1-deficient VSMCs. Conclusions PiT-2 can mediate phosphate uptake and calcification of VSMCs in the absence of PiT-1. Mechanistically, PiT-1 and PiT-2 appear to serve redundant roles in phosphate-induced calcification of vascular smooth muscle cells. PMID:23968976

The effect of pits of different sizes on ultrasonic shear wave signals

NASA Astrophysics Data System (ADS)

Howard, Richard; Cegla, Frederic

2018-04-01

The use of 0-degree shear waves in NDE and SHM has become more commonplace as the disadvantage of coupling has been eliminated by permanent sensor installations or the use of non-contact transducers, such as EMATs. While the effect of rough surfaces and flat bottom holes on shear waves has been studied in depth, the effect of more complex geometries, such as pitting, has not. In this work, 3D finite element simulations are used to explore the reflection and scattering characteristics of shear bulk waves from pits. Specifically, three scenarios have been investigated, the effect on shear waves of: a sloped backwall; pitting directly under the transducer; and the effect of pits with variable pit position. High speed GPU finite element models enabled a wide range of pit radii and positions to be modeled. Hemispherical pits were used throughout. Key findings of the study are that the anisotropic effects that are clearly visible on sloped reflecting surfaces can also be measured on pits that are located not directly below the center of a shear wave transducer. These anisotropic effects are due to the nature of shear wave polarization. This can potentially be used for better defect characterization purposes.

Distributed fiber optic strain sensing to detect artificial pitting corrosion in stirrups

NASA Astrophysics Data System (ADS)

Zhang, Jiachen; Kancharla, Vinutha; Hoult, Neil A.

2017-04-01

Pitting corrosion is difficult to identify through visual inspection and can lead to sudden structural failures. As such, an experimental study was undertaken to investigate whether distributed fiber optic strain sensors are capable of detecting the locations and strain changes associated with stirrup corrosion in reinforced concrete beams. In comparison to conventional strain gauges, this type of sensor can measure the strain response along the entire length of the fiber optic cable. Two specimens were tested: a control and a deteriorated beam. The deteriorated beam was artificially corroded by reducing the cross sectional area of the closed stirrups by 50% on both sides of the stirrup at the mid-height. This level of area reduction represents severe pitting corrosion. The beams were instrumented with nylon coated fiber optic sensors to measure the distributed strains, and then tested to failure under three point bending. The load deflection behavior of the two specimens was compared to assess the impact of the artificial pitting corrosion on the capacity. Digital Image Correlation was used to locate the extent and trajectory of the crack paths. It was found that the pitting corrosion had no impact on capacity or stiffness. Also, in this investigation the fiber optic sensing system failed to detect the location and strain changes due to pitting corrosion since the shear cracks did not intersect with the pitting location.

CALL FOR ABSTRACTS - PIT LAKES 2004

EPA Science Inventory

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

Electromagnetic Simulations of Ground-Penetrating Radar Propagation near Lunar Pits and Lava Tubes

NASA Technical Reports Server (NTRS)

Zimmerman, M. I.; Carter, L. M.; Farrell, W. M.; Bleacher, J. E.; Petro, N. E.

2013-01-01

Placing an Orion capsule at the Earth-Moon L2 point (EML2) would potentially enable telerobotic operation of a rover on the lunar surface. The Human Exploration Virtual Institute (HEVI) is proposing that rover operations be carried out near one of the recently discovered lunar pits, which may provide radiation shielding for long duration human stays as well as a cross-disciplinary, science-rich target for nearer-term telerobotic exploration. Ground penetrating radar (GPR) instrumentation included onboard a rover has the potential to reveal many details of underground geologic structures near a pit, as well as characteristics of the pit itself. In the present work we employ the full-wave electromagnetic code MEEP to simulate such GPR reflections from a lunar pit and other subsurface features including lava tubes. These simulations will feed forward to mission concepts requiring knowledge of where to hide from harmful radiation and other environmental hazards such as plama charging and extreme diurnal temperatures.

Volume Computation of a Stockpile - a Study Case Comparing GPS and Uav Measurements in AN Open Pit Quarry

NASA Astrophysics Data System (ADS)

Raeva, P. L.; Filipova, S. L.; Filipov, D. G.

2016-06-01

The following paper aims to test and evaluate the accuracy of UAV data for volumetric measurements to the conventional GNSS techniques. For this purpose, an appropriate open pit quarry has been chosen. Two sets of measurements were performed. Firstly, a stockpile was measured by GNSS technologies and later other terrestrial GNSS measurements for modelling the berms of the quarry were taken. Secondly, the area of the whole quarry including the stockpile site was mapped by a UAV flight. Having considered how dynamic our world is, new techniques and methods should be presented in numerous fields. For instance, the management of an open pit quarry requires gaining, processing and storing a large amount of information which is constantly changing with time. Fast and precise acquisition of measurements regarding the process taking place in a quarry is the key to an effective and stable maintenance. In other words, this means getting an objective evaluations of the processes, using up-to-date technologies and reliable accuracy of the results. Often legislations concerning mine engineering state that the volumetric calculations are to present ±3% accuracy of the whole amount. On one hand, extremely precise measurements could be performed by GNSS technologies, however, it could be really time consuming. On the other hand, UAV photogrammetry presents a fast, accurate method for mapping large areas and calculating stockpiles volumes. The study case was performed as a part of a master thesis.

Case history of controlling a landslide at Panluo open-pit mine in China

NASA Astrophysics Data System (ADS)

Wei, Zuoan; Yin, Guangzhi; Wan, Ling; Shen, Louyan

2008-04-01

Controlling of landsides safely and economically is a great challenge to mine operators because landslides are major geological problems especially in open-pit mines. In this paper, a case history at Panluo open-pit mine is presented in detail to share the experiences and lessons with mine operators. Panluo open-pit mine is located in the southwestern Fujian province of China. It is the largest open-pit iron mine in the Fujian province and was planned in 1965 and is in full operation from 1978. In July 1990, an earthquake of magnitude 5.3 in Taiwan Strait and big rainstorms impacted the mine slope, causing tension cracks and rather large-scale failures, and forming a U-shaped landslide. Total potential volume was estimated to be up to 1.0 × 106 m3. This directly threatened the mine production. In order to protect the mine production and the dwellers’ safety around, a dynamic comprehensive method was implemented including geotechnical investigations, in-situ testing and monitoring, stability analysis, and many mitigation and preventive measures. These measures slowed down the development and further occurrence of the landslide. The results showed that the landslides were still active, it was slowed with the control measures and moved rapidly with rainfall and mining down. However, no catastrophic accidents occurred and the pit mining was continued till it was closed at the elevation of 887 m in 2000. As a successful case of landslide control at an open-pit mine for 10 years, this paper reports the controlling measures in details. These experiences of landslide control may be beneficial to other similar mines for landslide control.

Dewatering of the Jenkins open pit uranium mine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Straskraba, V.; Kissinger, L.E.

Mining of low grade uranium sandstones in the Jenkins open pit mine in the Shirley Basin, Wyoming was troubled by slope failures and wet conditions in the pit. Since the mine was expanding toward a river, the possibility of drainage from this river into the mine raised serious concern during the mine planning. A baseline hydrogeologic study was performed and dewatering measures were designed with the help of a numerical mathematical model. A combination of dewatering wells installed from the surface around the perimeter of the pit and horizontal drains in areas of high slope failure potential substantially improved themore » mining conditions and slope stability. This procedure consequently led to the successful ore recovery from the highly saturated sandstone strata. The development of drawdown during the dewatering of two separated aquifers in the overburden was close to that predicted by the model.« less

Atypical pit craters on Mars: new insights from THEMIS, CTX and HiRISE observations

USGS Publications Warehouse

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

2015-01-01

More than 100 pit craters in the Tharsis region of Mars exhibit morphologies, diameters and thermal behaviors that diverge from the much larger bowl-shaped pit craters that occur in most regions across Mars. These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50-350 m, and high depth-to-diameter (d/D) ratios that are usually greater than 0.3 (which is an upper-range value for impacts and bowl-shaped pit craters), and can exceed values of 1.8. Observations by the Mars Odyssey THermal Emission Imaging System (THEMIS) show that APC floor temperatures are warmer at night, and fluctuate with much lower diurnal amplitudes than nearby surfaces or adjacent bowl-shaped pit craters. Kīlauea volcano, Hawai'i, hosts pit craters that formed through subsurface collapse into active volcanic dikes, resulting in pits that can appear morphologically analogous to either APCs or bowl-shaped pit craters. Partially-drained dikes are sometimes exposed within the lower walls and floors of these terrestrial APC analogs and can form extensive cave systems with unique microclimates. Similar caves in martian pit craters are of great interest for astrobiology. This study uses new observations by the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) to refine previous work where seven APCs were described from lower-resolution THEMIS visible-wavelength (VIS) observations. Here, we identify locations of 115 APCs, map their distribution across the Tharsis region, characterize their internal morphologies with high-resolution observations, and discuss possible formation mechanisms.

Parturition pit: the bony imprint of vaginal birth.

PubMed

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

2016-09-01

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

Parturition Pit: The Bony Imprint of Vaginal Birth

PubMed Central

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

2017-01-01

Purpose To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. Materials and Methods We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. Results 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p<0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p<0.0001). No males had pits. Conclusion Our study indicates that parturition pits are associated prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists. PMID:27270921

105. ARAIII. Interior view of ARA608 highbay pit in 1983 ...

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

105. ARA-III. Interior view of ARA-608 high-bay pit in 1983 modified to contain high-temperature, high-pressure autoclave and furnace test area. Ineel photo no. 81-109. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

Morphology and Evolution of Sublimation Pits on Pluto

NASA Astrophysics Data System (ADS)

Abu-Hashmeh, N.; Conrad, J. W.; Nimmo, F.; Moore, J. M.; Stern, A.; Olkin, C.; Weaver, H. A., Jr.; Ennico Smith, K.; Young, L. A.

2017-12-01

Pluto's Sputnik Planitia region hosts a geologically young surface of nitrogen ice that exhibits striking pitted terrain (Moore et al., Science 351, 2016). These pits are most likely formed by sublimation due to incident sunlight, similar to the southern polar cap of Mars (Byrne and Ingersoll, Science 299, 2003); however, their evolution over time has resulted in unique morphological characteristics. Motivated by this, we used the high-resolution mosaic strips captured by New Horizons' Long Range Reconnaissance Imager (LORRI) to map sublimation pits in the southernmost region of Sputnik Planitia. Statistical data shows pit orientations appearing North-South dominant; their morphology also indicates extensional evolution along the major axis caused by further sublimation and contact-coalescence processes. Qualitative analysis of the region yielded indications of an evolutionary path for individual pits that coalesce into each other and exhibit an elongated end-stage. Additionally, densely-pitted regions generally appear to correlate with regions containing longer pits, implying that coalescence may be an important process for elongation. We also model the evolution geometry through competing effects of diffusion (viscous relaxation) and retreat (sublimation) (Buhler and Ingersoll, LPSC Abstract #1746, 2017). The model demonstrates single-pit and coalescing-pit evolutions that influence overall length, as well as a potential ability for the pit center to move in space while the pit morphology evolves.

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

NASA Astrophysics Data System (ADS)

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

2016-03-01

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

The Python pit organ: imaging and immunocytochemical analysis of an extremely sensitive natural infrared detector.

PubMed

Grace, M S; Church, D R; Kelly, C T; Lynn, W F; Cooper, T M

1999-01-01

The Python infrared-sensitive pit organ is a natural infrared imager that combines high sensitivity, ambient temperature function, microscopic dimensions, and self-repair. We are investigating the spectral sensitivity and signal transduction process in snake infrared-sensitive neurons, neither of which is understood. For example, it is unknown whether infrared receptor neurons function on a thermal or a photic mechanism. We imaged pit organs in living Python molurus and Python regius using infrared-sensitive digital video cameras. Pit organs were significantly more absorptive and/or emissive than surrounding tissues in both 3-5 microns and 8-12 microns wavelength ranges. Pit organs exhibited greater absorption/emissivity in the 8-12 microns range than in the 3-5 microns range. To directly test the relationship between photoreceptors and pit organ infrared-sensitive neurons, we performed immunocytochemistry using antisera directed against retinal photoreceptor opsins. Retinal photoreceptors were labeled with antisera specific for retinal opsins, but these antisera failed to label terminals of infrared-sensitive neurons in the pit organ. Infrared-receptive neurons were also distinguished from retinal photoreceptors on the basis of their calcium-binding protein content. These results indicate that the pit organ absorbs infrared radiation in two major atmospheric transmission windows, one of which (8-12 microns) matches emission of targeted prey, and that infrared receptors are biochemically distinct from retinal photoreceptors. These results also provide the first identification of prospective biochemical components of infrared signal transduction in pit organ receptor neurons.

Pits and Channels of Hebrus Valles

NASA Image and Video Library

2017-01-26

The drainages in this image are part of Hebrus Valles, an outflow channel system likely formed by catastrophic floods. Hebrus Valles is located in the plains of the Northern lowlands, just west of the Elysium volcanic region. Individual channels range from several hundred meters to several kilometers wide and form multi-threaded (anastamosing) patterns. Separating the channels are streamlined forms, whose tails point downstream and indicate that channel flow is to the north. The channels seemingly terminate in an elongated pit that is approximately 1875 meters long and 1125 meters wide. Using the shadow that the wall has cast on the floor of the pit, we can estimate that the pit is nearly 500 meters deep. The pit, which formed after the channels, exposes a bouldery layer below the dusty surface mantle and is underlain by sediments. Boulders several meters in diameter litter the slopes down into the pit. Pits such as these are of interest as possible candidate landing sites for human exploration because they might retain subsurface water ice (Schulze-Makuch et al. 2016, 6th Mars Polar Conf.) that could be utilized by future long-term human settlements. http://photojournal.jpl.nasa.gov/catalog/PIA11704

Faulted Layers in Collapse Pits

NASA Image and Video Library

2016-04-06

This image shows a set of coalesced collapse pits in western Valles Marineris as seen by NASA Mars Reconnaissance Orbiter. Fine layers are exposed in the walls of the pits, and in some places those layers are displaced by faults.

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

USGS Publications Warehouse

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

2010-01-01

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

Microvasculature of crotaline snake pit organs: possible function as a heat exchange mechanism.

PubMed

Amemiya, F; Nakano, M; Goris, R C; Kadota, T; Atobe, Y; Funakoshi, K; Hibiya, K; Kishida, R

1999-01-01

The infrared sensory membranes of the pit organs of pit vipers have an extremely rich capillary vasculature, which has been noted passim in the literature, but never illustrated or studied in detail. We rendered the pit vasculature visible in various ways, namely, by microinjection of India ink, by a combination of ink and succinate dehydrogenase staining, and by making resin casts for scanning electron microscope study. We also used transmission electron microscopy for identifying the types (arterioles, venules, capillaries) of blood vessels. Then we compared the pit vasculature with that of the retina and the dermis. Good visualization of the vasculature was obtained with both ink and resin injection. Arterioles, venules, and capillaries could be distinguished with all methods used. The monolayer vasculature was denser in the pit membrane than in the retina or skin. Each loop of the network enclosed a small number of infrared receptors so that all receptors were in contact with a capillary on at least one side. The forward-looking areas of the pit had a denser network than side-looking areas. Since infrared rays cause nerve impulses by raising the temperature of individual receptors, the capillary network functions not only as a supplier of energy but also as a cooling mechanism to reduce afterimages. Thus the denser network in the forward-looking areas causes these areas to be more sensitive and have better image resolution than the rest of the membrane.

Distribution, formation mechanisms, and significance of lunar pits

NASA Astrophysics Data System (ADS)

Wagner, Robert V.; Robinson, Mark S.

2014-07-01

Lunar Reconnaissance Orbiter Camera images reveal the presence of steep-walled pits in mare basalt (n = 8), impact melt deposits (n = 221), and highland terrain (n = 2). Pits represent evidence of subsurface voids of unknown extents. By analogy with terrestrial counterparts, the voids associated with mare pits may extend for hundreds of meters to kilometers in length, thereby providing extensive potential habitats and access to subsurface geology. Because of their small sizes relative to the local equilibrium crater diameters, the mare pits are likely to be post-flow features rather than volcanic skylights. The impact melt pits are indirect evidence both of extensive subsurface movement of impact melt and of exploitable sublunarean voids. Due to the small sizes of pits (mare, highland, and impact melt) and the absolute ages of their host materials, it is likely that most pits formed as secondary features.

Light-extraction efficiency and forward voltage in GaN-based light-emitting diodes with different patterns of V-shaped pits

NASA Astrophysics Data System (ADS)

Wang, Min-Shuai; Huang, Xiao-Jing

2013-08-01

We present a new method of making a textured V-pit surface for improving the light extraction efficiency in GaN-based light-emitting diodes and compare it with the usual low-temperature method for p-GaN V-pits. Three types of GaN-based light-emitting diodes (LEDs) with surface V-pits in different densities and regions were grown by metal—organic chemical vapor deposition. We achieved the highest output power and lowest forward voltage values with the p-InGaN V-pit LED. The V-pits enhanced the light output power values by 1.45 times the values of the conventional LED owing to an enhancement of the light scattering probability and an effective reduction of Mg-acceptor activation energy. Moreover, this new technique effectively solved the higher forward voltage problem of the usual V-pit LED.

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

NASA Astrophysics Data System (ADS)

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

2014-06-01

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

Temperature measurement

MedlinePlus

... this page: //medlineplus.gov/ency/article/003400.htm Temperature measurement To use the sharing features on this page, please enable JavaScript. The measurement of body temperature can help detect illness. It can also monitor ...

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

PubMed

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

2014-12-01

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

Relationship between Microstructure and Corrosion Behavior of Martensitic High Nitrogen Stainless Steel 30Cr15Mo1N at Different Austenitizing Temperatures.

PubMed

Jiang, Zhouhua; Feng, Hao; Li, Huabing; Zhu, Hongchun; Zhang, Shucai; Zhang, Binbin; Han, Yu; Zhang, Tao; Xu, Dake

2017-07-27

The relationship between microstructure and corrosion behavior of martensitic high nitrogen stainless steel 30Cr15Mo1N at different austenitizing temperatures was investigated by microscopy observation, electrochemical measurement, X-ray photoelectron spectroscopy analysis and immersion testing. The results indicated that finer Cr-rich M₂N dispersed more homogeneously than coarse M 23 C₆, and the fractions of M 23 C₆ and M₂N both decreased with increasing austenitizing temperature. The Cr-depleted zone around M 23 C₆ was wider and its minimum Cr concentration was lower than M₂N. The metastable pits initiated preferentially around coarse M 23 C₆ which induced severer Cr-depletion, and the pit growth followed the power law. The increasing of austenitizing temperature induced fewer metastable pit initiation sites, more uniform element distribution and higher contents of Cr, Mo and N in the matrix. In addition, the passive film thickened and Cr₂O₃, Cr 3+ and CrN enriched with increasing austenitizing temperature, which enhanced the stability of the passive film and repassivation ability of pits. Therefore, as austenitizing temperature increased, the metastable and stable pitting potentials increased and pit growth rate decreased, revealing less susceptible metastable pit initiation, larger repassivation tendency and higher corrosion resistance. The determining factor of pitting potentials could be divided into three stages: dissolution of M 23 C₆ (below 1000 °C), dissolution of M₂N (from 1000 to 1050 °C) and existence of a few undissolved precipitates and non-metallic inclusions (above 1050 °C).

Relationship between Microstructure and Corrosion Behavior of Martensitic High Nitrogen Stainless Steel 30Cr15Mo1N at Different Austenitizing Temperatures

PubMed Central

Jiang, Zhouhua; Feng, Hao; Zhu, Hongchun; Zhang, Shucai; Zhang, Binbin; Han, Yu; Zhang, Tao; Xu, Dake

2017-01-01

The relationship between microstructure and corrosion behavior of martensitic high nitrogen stainless steel 30Cr15Mo1N at different austenitizing temperatures was investigated by microscopy observation, electrochemical measurement, X-ray photoelectron spectroscopy analysis and immersion testing. The results indicated that finer Cr-rich M2N dispersed more homogeneously than coarse M23C6, and the fractions of M23C6 and M2N both decreased with increasing austenitizing temperature. The Cr-depleted zone around M23C6 was wider and its minimum Cr concentration was lower than M2N. The metastable pits initiated preferentially around coarse M23C6 which induced severer Cr-depletion, and the pit growth followed the power law. The increasing of austenitizing temperature induced fewer metastable pit initiation sites, more uniform element distribution and higher contents of Cr, Mo and N in the matrix. In addition, the passive film thickened and Cr2O3, Cr3+ and CrN enriched with increasing austenitizing temperature, which enhanced the stability of the passive film and repassivation ability of pits. Therefore, as austenitizing temperature increased, the metastable and stable pitting potentials increased and pit growth rate decreased, revealing less susceptible metastable pit initiation, larger repassivation tendency and higher corrosion resistance. The determining factor of pitting potentials could be divided into three stages: dissolution of M23C6 (below 1000 °C), dissolution of M2N (from 1000 to 1050 °C) and existence of a few undissolved precipitates and non-metallic inclusions (above 1050 °C). PMID:28773221

Distribution, morphology, and origins of Martian pit crater chains

NASA Astrophysics Data System (ADS)

Wyrick, Danielle; Ferrill, David A.; Morris, Alan P.; Colton, Shannon L.; Sims, Darrell W.

2004-06-01

Pit craters are circular to elliptical depressions found in alignments (chains), which in many cases coalesce into linear troughs. They are common on the surface of Mars and similar to features observed on Earth and other terrestrial bodies. Pit craters lack an elevated rim, ejecta deposits, or lava flows that are associated with impact craters or calderas. It is generally agreed that the pits are formed by collapse into a subsurface cavity or explosive eruption. Hypotheses regarding the formation of pit crater chains require development of a substantial subsurface void to accommodate collapse of the overlying material. Suggested mechanisms of formation include: collapsed lava tubes, dike swarms, collapsed magma chamber, substrate dissolution (analogous to terrestrial karst), fissuring beneath loose material, and dilational faulting. The research described here is intended to constrain current interpretations of pit crater chain formation by analyzing their distribution and morphology. The western hemisphere of Mars was systematically mapped using Mars Orbiter Camera (MOC) images to generate ArcView™ Geographic Information System (GIS) coverages. All visible pit crater chains were mapped, including their orientations and associations with other structures. We found that pit chains commonly occur in areas that show regional extension or local fissuring. There is a strong correlation between pit chains and fault-bounded grabens. Frequently, there are transitions along strike from (1) visible faulting to (2) faults and pits to (3) pits alone. We performed a detailed quantitative analysis of pit crater morphology using MOC narrow angle images, Thermal Emission Imaging System (THEMIS) visual images, and Mars Orbiter Laser Altimeter (MOLA) data. This allowed us to determine a pattern of pit chain evolution and calculate pit depth, slope, and volume. Volumes of approximately 150 pits from five areas were calculated to determine volume size distribution and regional

Relationship Between Foveal Cone Specialization and Pit Morphology in Albinism

PubMed Central

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

2014-01-01

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

The effect of normal pulsed Nd-YAG laser irradiation on pits and fissures in human teeth.

PubMed

Bahar, A; Tagomori, S

1994-01-01

The effects of normal pulsed Nd-YAG laser irradiation on the acid resistance of human dental enamel of pits and fissures, the cleaning of the pit and fissure contents and fluoride uptake into deep pits and fissures were examined. The acid resistance of the pit and fissure enamel was evaluated by the amount of dissolved calcium per square millimeter of the surface area. The pit and fissure enamel treated with laser irradiation obtained an acid resistance 30% higher than that of the unlased controls. The cleaning effect of laser irradiation on the pit and fissure contents was compared with chemicomechanical and mechanical methods. The laser irradiation was found to clean the pits and fissures to a greater depth without alterating the shape of pits and fissures, compared with the other two methods. The distribution of calcium, phosphorus and fluoride in the enamel of the pits and fissures was then measured by electron probe microanalyzer. At the entrance and in the deep part of the pits and fissures, the fluoride content of the enamel treated with acidulated phosphate fluoride after laser irradiation was higher than that of the enamel treated with acidulated phosphate fluoride alone. These results thus suggest that Nd-YAG laser irradiation might be effective in increasing the acid resistance of the pit and fissure enamel, while removing the pit and fissure debris contents and increasing the fluoride uptake into the pit and fissure enamel.

Corrosion pitting of SiC by molten salts

NASA Technical Reports Server (NTRS)

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

1986-01-01

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

Non-destructive measurement of demineralization and remineralization in the occlusal pits and fissures of extracted 3rd molars with PS-OCT

NASA Astrophysics Data System (ADS)

Lee, Chulsung; Hsu, Dennis J.; Le, Michael H.; Darling, Cynthia L.; Fried, Daniel

2009-02-01

Previous studies have demonstrated that Polarization Sensitive Optical Coherence Tomography (PS-OCT) can be used to image the remineralization of early artificial caries lesion on smooth enamel surfaces of human and bovine teeth. However, most new dental decay is found in the pits and fissures of the occlusal surfaces of posterior dentition and it is in these high risk areas where the performance of new caries imaging devices need to be investigated. The purpose of this study was to demonstrate that PS-OCT can be used to measure the subsequent remineralization of artificial lesions produced in the pits and fissures of extracted 3rd molars. A PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of occlusal surfaces exposed to a demineralizing solution at pH-4.5 followed by a fluoride containing remineralizing solution at pH-7.0 containing 2-ppm fluoride. The integrated reflectivity was calculated to a depth of 200-µm in the entire lesion area using an automated image processing algorithm. Although a well-defined surface zone was clearly resolved in only a few of the samples that underwent remineralization, the PS-OCT measurements indicated a significant (p<0.05) reduction in the integrated reflectivity between the severity of the lesions that were exposed to the remineralization solution and those that were not. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth. These results show that PS-OCT can be used to non-destructively monitor the remineralization potential of anti-caries agents in the important pits and fissures of the occlusal surface.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okada, Narihito, E-mail: nokada@yamaguchi-u.ac.jp; Kashihara, Hiroyuki; Sugimoto, Kohei

2015-01-14

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

Effect of Aging on Precipitation Behavior and Pitting Corrosion Resistance of SAF2906 Super Duplex Stainless Steel

NASA Astrophysics Data System (ADS)

Li, Jianchun; Li, Guoping; Liang, Wei; Han, Peide; Wang, Hongxia

2017-09-01

The effect of aging temperature and holding time on the precipitation of secondary phases and pitting corrosion resistance of SAF2906 super duplex stainless steel was examined. Chromium nitride and σ phase were observed to preferentially precipitate at the ferrite/austenite interface. An amount of nitrides was also observed within the ferrite grain. The precipitation of chromium nitride occurred before the σ phase. The increase in aging temperature and holding time did not affect the concentration of the nitrides but increased the area fraction of the σ phase at a faster rate. The Cr2N precipitation in SAF2906 is more evident than that of the other duplex stainless steels. The variation tendency of the precipitation concentrations is primarily consistent with the prediction results of Thermo-Calc software. The electrochemical results showed that Cr2N and σ phase significantly reduced the pitting potential. Scanning electron microscope observations revealed that pits appear mainly in regions adjacent to sigma phase and Cr2N.

Pit initiation on nitinol in simulated physiological solutions.

PubMed

Pound, Bruce G

2018-05-01

Inclusions appear to play a crucial role in the initiation of pitting on nitinol, but the reason remains unclear. Furthermore, it has not been established whether the type of inclusion is a central factor. In this study, potentiodynamic polarization together with scanning electron microscopy and energy dispersive X-ray spectroscopy were used to provide more insight into the initiation of pits on electropolished nitinol wire. Corrosion was limited to a single primary pit on each of the few wire samples that exhibited breakdown. The pit contained numerous Ti 2 NiO x inclusions, but secondary pits that developed within the primary pit provided evidence that these inclusions were the sites of pit initiation. Although several theories have been proposed to account for pit initiation at inclusions in mechanically polished and electropolished nitinol, titanium depletion in the adjacent alloy matrix appears to provide the most viable explanation. The key factor appears to be the size of the inclusion and therefore the extent of titanium depletion in the alloy matrix. The type of inclusion evidently plays a secondary role at most. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1605-1610, 2018. © 2017 Wiley Periodicals, Inc.

Pits on Ascraeus

NASA Technical Reports Server (NTRS)

2005-01-01

24 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows collapse pits and troughs on the lower northeast flank of the giant martian volcano, Ascraeus Mons. Layers of volcanic rock are evident in some of the pit and valley walls, and boulders the size of houses and trucks that were liberated from these walls by gravity can be seen on the floors of the depressions.

Location near: 13.6oN, 102.6oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

Measuring Temperature Reading

NASA Technical Reports Server (NTRS)

2003-01-01

There are two requirements for taking a measurement of something. The first is a tool for taking a measurement. The second is scale for making sense of the numbers of the measurement. For example, a ruler is often used to measure short lengths. It is the tool for measurement. On the ruler are one or more number scales with equally spaced numbers. These numbers can be compared with numbers from any other ruler that is accurately set to the same scale. Measuring length is far simpler than measuring temperature. While there is evidence of tools for measuring length at various times in human history, tools and scales for measuring temperature do not appear until more recent human history. Early thermometers, called thermoscopes, first appear in the 1500's. They were crude instruments that were not at all accurate. Most did not even have a number scale associated with them. This made them useless for most practical purposes. Gabriel Fahrenheit created the first accurate thermometer in 1714, and the Fahrenheit temperature scale followed it in 1724. The thermometer s accuracy was based on its use of mercury, a silver colored substance that remains liquid over a wide range of temperatures but expands or contracts in a standard, predictable way with changes in temperature. To set the scale, Fahrenheit created the coldest temperature that he could. He mixed equal parts of ice, water, and salt, and then used this as the zero point, 0 degrees, of his scale. He intended to make 30 degrees the freezing point of water and 90 degrees the temperature of the human body, but he had to later revise these temperatures to be 32 degrees and 96 degrees. In the final version of the scale, the temperature of the human body became 98.6 degrees. 19th century thermoscope

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

PubMed Central

Jenkins, Marion W.; Cumming, Oliver; Cairncross, Sandy

2015-01-01

Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed. PMID:25734790

Investigation on the pitting of potato starch granules during high frequency ultrasound treatment.

PubMed

Bai, Wenzhe; Hébraud, Pascal; Ashokkumar, Muthupandian; Hemar, Yacine

2017-03-01

In this paper, the pitting of potato starch granules in aqueous suspensions (1%) by high-frequency high-power ultrasound (850kHz at a power of 0.2W, 2W or 3.7W; and also 500kHz and 1MHz at a power of 2W) is reported. The number of pits per starch granules was found to be independent of the amylose content of starches, and the surface properties of starch granules as modified through SDS and ethanol washing. At 850kHz, the maximum number of pits per starch granule, for both normal and waxy starches, did not exceed 11. However, a close inspection of fractionated starch granules based on their sizes showed that there is an optimum granule size for which a maximum pit number is obtained. For example, starch granules with diameter size range of ∼15 to ∼30μm had a maximum pit number (between 10 and 20 pits per granule) when sonicated (2W, 850kHz and 30min); while sonication of small (<10μm) and very large (>45μm) granules resulted in a smaller number of pits per granule (∼5). Further, the maximum number of pits per granules is also found to be proportional to the ultrasound frequency, with values of approximately 7, 10 and 11 at 0.50, 0.85, and 1MHz, respectively. FTIR measurements did not show any breakup of starch molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

Experiment Research on Hot-Rolling Processing of Nonsmooth Pit Surface.

PubMed

Gu, Yun-Qing; Fan, Tian-Xing; Mou, Jie-Gang; Yu, Wei-Bo; Zhao, Gang; Wang, Evan

2016-01-01

In order to achieve the nonsmooth surface drag reduction structure on the inner polymer coating of oil and gas pipelines and improve the efficiency of pipeline transport, a structural model of the machining robot on the pipe inner coating is established. Based on machining robot, an experimental technique is applied to research embossing and coating problems of rolling-head, and then the molding process rules under different conditions of rolling temperatures speeds and depth are analyzed. Also, an orthogonal experiment analysis method is employed to analyze the different effects of hot-rolling process apparatus on the embossed pits morphology and quality of rolling. The results also reveal that elevating the rolling temperature or decreasing the rolling speed can also improve the pit structure replication rates of the polymer coating surface, and the rolling feed has little effect on replication rates. After the rolling-head separates from the polymer coating, phenomenon of rebounding and refluxing of the polymer coating occurs, which is the reason of inability of the process. A continuous hot-rolling method for processing is used in the robot and the hot-rolling process of the processing apparatus is put in a dynamics analysis.

Experiment Research on Hot-Rolling Processing of Nonsmooth Pit Surface

PubMed Central

Gu, Yun-qing; Fan, Tian-xing; Mou, Jie-gang; Yu, Wei-bo; Zhao, Gang; Wang, Evan

2016-01-01

In order to achieve the nonsmooth surface drag reduction structure on the inner polymer coating of oil and gas pipelines and improve the efficiency of pipeline transport, a structural model of the machining robot on the pipe inner coating is established. Based on machining robot, an experimental technique is applied to research embossing and coating problems of rolling-head, and then the molding process rules under different conditions of rolling temperatures speeds and depth are analyzed. Also, an orthogonal experiment analysis method is employed to analyze the different effects of hot-rolling process apparatus on the embossed pits morphology and quality of rolling. The results also reveal that elevating the rolling temperature or decreasing the rolling speed can also improve the pit structure replication rates of the polymer coating surface, and the rolling feed has little effect on replication rates. After the rolling-head separates from the polymer coating, phenomenon of rebounding and refluxing of the polymer coating occurs, which is the reason of inability of the process. A continuous hot-rolling method for processing is used in the robot and the hot-rolling process of the processing apparatus is put in a dynamics analysis. PMID:27022235

Involvement of the pituitary-specific transcription factor pit-1 in somatolactotrope cell growth and death: an approach using dominant-negative pit-1 mutants.

PubMed

Pellegrini, Isabelle; Roche, Cathy; Quentien, Marie-Helene; Ferrand, Mireille; Gunz, Ginette; Thirion, Sylvie; Bagnis, Claude; Enjalbert, Alain; Franc, Jean-Louis

2006-12-01

The anterior pituitary-specific transcription factor Pit-1 was initially identified and cloned as a transactivator of the prolactin (PRL) and GH genes and later as a regulator of the TSHb gene. It was found to be a major developmental regulator, because natural Pit-1 gene mutations cause a dwarf phenotype in mice and cause combined pituitary hormone deficiency associated with pituitary hypoplasia in humans. To further investigate the growth-promoting effects of Pit-1, we used a strategy based on the use of dominant-negative Pit-1 mutants as an alternative means of inactivating endogenous Pit-1 functions. R271W, a Pit-1 mutant identified in one allele in patients with severe combined pituitary hormone deficiency, and Pit-1Delta1-123, a deletion mutant in which only the DNA binding domain of Pit-1 is conserved, were generated, and their ability to abolish the effects of the endogenous native Pit-1 in the differentiated proliferating somatolactotrope GH4C1 cell line was investigated. Enforced expression of the dominant-negative mutants in GH4C1 cells using recombinant lentiviral vectors decreased the levels of expression of known Pit-1 target genes such as PRL and GH, abolished the hormone release, and reduced cell viability by decreasing the growth rate and inducing apoptosis via a caspase-independent pathway. These results show for the first time that the growth-promoting effects of Pit-1 are at least partly due to the fact that this transcription factor prevents apoptotic cell death.

Catastrophic windthrow in the Southern Appalachians: characteristics of pits and mounds and initial vegetation responses

Treesearch

Barton D. Clinton; Corey R. Baker

2000-01-01

We characterized pit and mound (PM) topography resulting from catastrophic wind in the Coweeta Basin, and located 48 PM’s across a variety of forest types. Our measurements included pit length, width, and depth; and mound height, thickness, and width. Species of fallen trees were...

Polar Cap Pits

NASA Technical Reports Server (NTRS)

2005-01-01

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

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

Failure Analysis of Pitted Copper Pipes Used in Underground Water and Preventive Measures

NASA Astrophysics Data System (ADS)

Nam, Gi-ho; Lee, Jong-kwon; Kim, Kyung-ja

2018-05-01

This study performed an experiment on the causes of pitting corrosion in a copper tubing used for a sprinkler system. Corrosion products of a copper tubing that sustained pitting corrosion were collected and cultured in Culture medium [Luria-Bertani, Brain heart infusion, Tryptic soy broth (TSB), R2A]. Four types of bacteria were found through identification: Micrococcus luteus sp (species)., Staphylococcus sp., Sphingomonas sp., and Bacillus sp. The copper toxicity test was performed for each microorganism. Among the four microorganisms, Micrococcus luteus sp. showed good growth in the environment containing copper ions. On the immersion test, changes in pH and Optical density were measured; On the inductively coupled plasma optical emission spectrometry test, the copper concentration of each culture medium was measured. The surface of each copper sample was observed using a scanning electron microscope. The corrosion potential of a copper sample, after 48 h exposure of the TSB medium containing Micrococcus luteus sp., was measured using a potentiodynamic polarization experiment. The next experiment was conducted to prevent microbial corrosion by suppressing the growth of microorganisms. Six 30 ml TSB culture media with controlled pH value of 4, 5, 6, 7, 8, and 9 through HCl and NaOH were manufactured. Then the microorganisms were cultured in 37 °C 133 rpm, of which the growth status was checked every 24 h for 3 days. It was found that microorganisms did not grow on culture media with the pH value of 6 and lower. The same experiment conducted on culture media controlled with acetic acid, nitric acid, and sulfuric acid, also showed no growth of microorganisms on media with pH value of 6 and lower. Six 5 ml TSB culture media each containing 0.5, 0.25, 0.125, 0.0625, 0.0312%, and 0.0156% NaOCl and NaOBr as germicides were manufactured. 0.01 μl of microorganisms were inoculated on the media and cultured in 37 °C for 48 h. It was found that microorganisms did not

Failure Analysis of Pitted Copper Pipes Used in Underground Water and Preventive Measures

NASA Astrophysics Data System (ADS)

Nam, Gi-ho; Lee, Jong-kwon; Kim, Kyung-ja

2018-03-01

This study performed an experiment on the causes of pitting corrosion in a copper tubing used for a sprinkler system. Corrosion products of a copper tubing that sustained pitting corrosion were collected and cultured in Culture medium [Luria-Bertani, Brain heart infusion, Tryptic soy broth (TSB), R2A]. Four types of bacteria were found through identification: Micrococcus luteus sp (species)., Staphylococcus sp., Sphingomonas sp., and Bacillus sp. The copper toxicity test was performed for each microorganism. Among the four microorganisms, Micrococcus luteus sp. showed good growth in the environment containing copper ions. On the immersion test, changes in pH and Optical density were measured; On the inductively coupled plasma optical emission spectrometry test, the copper concentration of each culture medium was measured. The surface of each copper sample was observed using a scanning electron microscope. The corrosion potential of a copper sample, after 48 h exposure of the TSB medium containing Micrococcus luteus sp., was measured using a potentiodynamic polarization experiment. The next experiment was conducted to prevent microbial corrosion by suppressing the growth of microorganisms. Six 30 ml TSB culture media with controlled pH value of 4, 5, 6, 7, 8, and 9 through HCl and NaOH were manufactured. Then the microorganisms were cultured in 37 °C 133 rpm, of which the growth status was checked every 24 h for 3 days. It was found that microorganisms did not grow on culture media with the pH value of 6 and lower. The same experiment conducted on culture media controlled with acetic acid, nitric acid, and sulfuric acid, also showed no growth of microorganisms on media with pH value of 6 and lower. Six 5 ml TSB culture media each containing 0.5, 0.25, 0.125, 0.0625, 0.0312%, and 0.0156% NaOCl and NaOBr as germicides were manufactured. 0.01 μl of microorganisms were inoculated on the media and cultured in 37 °C for 48 h. It was found that microorganisms did not

Study on the Accident-causing of Foundation Pit Engineering

NASA Astrophysics Data System (ADS)

Shuicheng, Tian; Xinyue, Zhang; Pengfei, Yang; Longgang, Chen

2018-05-01

With the development of high-rise buildings and underground space, a large number of foundation pit projects have occurred. Frequent accidents of it cause great losses to the society, how to reduce the frequency of pit accidents has become one of the most urgent problems to be solved. Therefore, analysing the influencing factors of foundation pit engineering accidents and studying the causes of foundation pit accidents, which of great significance for improving the safety management level of foundation pit engineering and reducing the incidence of foundation pit accidents. Firstly, based on literature review and questionnaires, this paper selected construction management, survey, design, construction, supervision and monitoring as research factors, we used the AHP method and the Dematel method to analyze the weights of various influencing factors to screen indicators to determine the ultimate system of accidents caused by foundation pit accidents; Secondly, SPSS 21.0 software was used to test the reliability and validity of the recovered questionnaire data. AMOS 7.0 software was used to fit, evaluate, and explain the set model; Finally, this paper analysed the influencing factors of foundation pit engineering accidents, corresponding management countermeasures and suggestions were put forward.

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

PubMed Central

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

2013-01-01

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

Pit formation observed in a multilayer dielectric coating as a result of simulated space environmental exposure

NASA Astrophysics Data System (ADS)

Fuqua, Peter D.; Presser, Nathan; Barrie, James D.; Meshishnek, Michael J.; Coleman, Dianne J.

2002-06-01

Certain spaceborne telescope designs require that dielectric-coated lenses be exposed to the energetic electrons and protons associated with the space environment. Test coupons that were exposed to a simulated space environment showed extensive pitting as a result of dielectric breakdown. A typical pit was 50-100 mum at the surface and extended to the substrate material, in which a 10-mum-diameter melt region was found. Pitting was not observed on similar samples that had also been overcoated with a transparent conductive thin film. Measurement of the bidirectional reflectance distribution transfer function showed that pitting caused a fivefold to tenfold increase in the scattering of visible light.

Seasonal variations of snow chemistry and mineral dust in the snow pit at GV7, Antarctica

NASA Astrophysics Data System (ADS)

Kang, Jung-Ho; Hwang, Heejin; Han, Yongchoul; Hong, Sang Bum; Lee, Khanghyun; Do Hur, Soon; Frezzotti, Massimo; Narcisi, Biancamaria

2015-04-01

We conducted the scientific ice coring project led by PNRA and KOPRI during the 2013/2014 Italian-Korean Antarctic Expedition in the framework of International Partnerships in Ice Core Science (IPICS) to understand the climatic variability in the last 2000 years. In the part of project, we collected a 3.0 m-depth snow pit at the site of GV7 (S 70° 41'17.1", E 158° 51'48.9", 1950 m a.s.l.), Antarctica. Here, we present the results obtained from the analysis of the water isotope compositions, the major ion concentrations, and the mineral dust concentrations from the snow pit. Snow densities and temperatures also measured in the field. At KOPRI, the samples were melted, then the stable water isotopes, major ions, and particle size distribution were analyzed with the cavity ring-down spectrometers (L1102-i, Piccaro), ion chromatography (ICS-2100, Thermo), and coulter counter (Multisizer 3, Beckman Coulter), respectively. The δ18O varies between -38.3 and -24.1o with a mean value of -31.0o. The δD ranges between -331 and -186o with a mean value of -243o. Among the ion concentrations (Na+, Ca2+, Mg2+, Cl-, SO42-, CH3SO3-(MSA)) from the snow pit, MSA concentrations show a clear seasonal variation. The mineral dust in the pit characterized with the differences of the concentration and the particle size distribution by the seasonality. These data allow us to assume about 4.5 years of snow deposition covered from 2009 to 2013 by these oscillations of the isotopes and geochemical characteristics.

Application of Universal Thermal Climate Index (UTCI) for assessment of occupational heat stress in open-pit mines.

PubMed

Nassiri, Parvin; Monazzam, Mohammad Reza; Golbabaei, Farideh; Dehghan, Somayeh Farhang; Rafieepour, Athena; Mortezapour, Ali Reza; Asghari, Mehdi

2017-10-07

The purpose of this article is to examine the applicability of Universal Thermal Climate Index (UTCI) index as an innovative index for evaluating of occupational heat stress in outdoor environments. 175 workers of 12 open-pit mines in Tehran, Iran were selected for this research study. First, the environmental variables such as air temperature, wet-bulb temperature, globe temperature, relative humidity and air flow rate were measured; then UTCI, wet-bulb globe temperature (WBGT) and heat stress index (HSI) indices were calculated. Simultaneously, physiological parameters including heart rate, oral temperature, tympanic temperature and skin temperature of workers were measured. UTCI and WBGT are positively significantly correlated with all environmental parameters (p<0.03), except for air velocity (r<-0.39; p>0.05). Moreover, a strong significant relationship was found between UTCI and WBGT (r=0.95; p<0.001). The significant positive correlations exist between physiological parameters including oral temperature, tympanic and skin temperatures and heart rate and both the UTCI and WBGT indices (p<0.029). The highest correlation coefficient has been found between the UTCI and physiological parameters. Due to the low humidity and air velocity (~<1 m/s) in understudied mines, UTCI index appears to be appropriate to assess the occupational heat stress in these outdoor workplaces.

[Pit-picking surgery for pilonidal disease].

PubMed

Iesalnieks, I; Deimel, S; Kienle, K; Schlitt, H J; Zülke, C

2011-10-01

The pit-picking method was first described by J. Bascom in 1980, however, this minimally invasive technique is used only by a minority of surgeons yet. Surgery was performed under local anesthesia. All primary pits in the midline were removed by excising a border of skin of <1 mm and a 1 cm long incision was made parallel to one side of the cleft to open the chronic abscess cavity. No specific postoperative wound care was given. Pit-picking surgery was carried out 157 times in a total of 153 patients (126 males) between June 2007 and November 2010. Follow-up information was available in 123 cases and 21 patients (17%) developed disease recurrence after a mean follow-up time of 7.1 months. By multivariate analysis, a body mass index (BMI) >25 kg/m(2) (p=0.019) and duration of the disease of ≥6 months (p=0.017) were statistically significantly associated with disease recurrence after pit-picking surgery. The recurrence occurred more often in male than in female patients (20% versus 4.5%, p=0.12) Patients with pilonidal disease can be successfully treated by the pit-picking procedure in more than 80% of selected cases. Female patients and non-overweight male patients with short-term disease benefit most from this treatment method.

The comparative morphology of pit organs in elasmobranchs.

PubMed

Peach, M B; Marshall, N J

2009-06-01

The pit organs of elasmobranchs (sharks, skates and rays) are free neuromasts of the mechanosensory lateral line system. Pit organs, however, appear to have some structural differences from the free neuromasts of bony fishes and amphibians. In this study, the morphology of pit organs was investigated by scanning electron microscopy in six shark and three ray species. In each species, pit organs contained typical lateral line hair cells with apical stereovilli of different lengths arranged in an "organ-pipe" configuration. Supporting cells also bore numerous apical microvilli taller than those observed in other vertebrate lateral line organs. Pit organs were either covered by overlapping denticles, located in open grooves bordered by denticles, or in grooves without associated denticles. The possible functional implications of these morphological features, including modification of water flow and sensory filtering properties, are discussed.

Correlation between evolution of inclusions and pitting corrosion in 304 stainless steel with yttrium addition.

PubMed

Shi, Weining; Yang, Shufeng; Li, Jingshe

2018-03-19

Effects of the evolution of inclusions on the pitting corrosion resistance of 304 stainless steel with different contents of the rare-earth element yttrium (Y) were studied using thermodynamic calculations, accelerated immersion tests, and electrochemical measurements. The experimental results showed that regular Y 2 O 3 inclusions demonstrated the best pitting resistance, followed in sequence by (Al,Mn)O inclusions, the composite inclusions, and irregular Y 2 O 3 inclusions. The pitting resistance first decreased, then increased, and then decreased again with increasing Y content, because sulfide inclusions were easily generated when the Y content was low and YN inclusions were easily generated at higher Y contents. The best pitting corrosion resistance was obtained for 304 stainless steel with addition of 0.019% Y.

Measurements of evaporation from a mine void lake and testing of modelling approaches

NASA Astrophysics Data System (ADS)

McJannet, David; Hawdon, Aaron; Van Niel, Tom; Boadle, Dave; Baker, Brett; Trefry, Mike; Rea, Iain

2017-12-01

Pit lakes often form in the void that remains after open cut mining operations cease. As pit lakes fill, hydrological and geochemical processes interact and these need to be understood for appropriate management actions to be implemented. Evaporation is important in the evolution of pit lakes as it acts to concentrate various constituents, controls water level and changes the thermal characteristics of the water body. Despite its importance, evaporation from pit lakes is poorly understood. To address this, we used an automated floating evaporation pan and undertook measurements at a pit lake over a 12 month period. We also developed a new procedure for correcting floating pan evaporation estimates to lake evaporation estimates based on surface temperature differences. Total annual evaporation was 2690 mm and reflected the strong radiation inputs, high temperatures and low humidity experienced in this region. Measurements were used to test the performance of evaporation estimates derived using both pan coefficient and aerodynamic modelling techniques. Daily and monthly evaporation estimates were poorly reproduced using pan coefficient techniques and their use is not recommended for such environments. Aerodynamic modelling was undertaken using a range of input datasets that may be available to those who manage pit lake systems. Excellent model performance was achieved using over-water or local over-land meteorological observations, particularly when the sheltering effects of the pit were considered. Model performance was reduced when off-site data were utilised and differences between local and off-site vapor pressure and wind speed were found to be the major cause.

Weathering pits as indicators of the relative age of granite surfaces in the Cairngorm mountains, Scotland

USGS Publications Warehouse

Hall, A.M.; Phillips, W.M.

2006-01-01

Weathering pits 1-140 cm deep occur on granite surfaces in the Cairngorms associated with a range of landforms, including tors, glacially exposed slabs, large erratics and blockfields. Pit depth is positively correlated with cosmogenic exposure age, and both measures show consistent relationships on individual rock landforms. Rates of pit deepening are non-linear and a best fit is provided by the sigmoidal function D = b1+ exp(b2+b3/t). The deepest pits occur on unmodified tor summits, where 10 Be exposure ages indicate that surfaces have been exposed to weathering for a minimum of 52-297 ka. Glacially exposed surfaces with pits 10-46 cm deep have given 10 Be exposure durations of 21-79 ka, indicating exposure by glacial erosion before the last glacial cycle. The combination of cosmogenic exposure ages with weathering pit depths greatly extends the area over which inferences can be made regarding the ages of granite surfaces in the Cairngorms. Well-developed weathering pits on glacially exposed surfaces in other granite areas are potential indicators of glacial erosion before the Last Glacial Maximum. ?? Swedish Society for Anthropology and Geography.

Pitted rock surfaces on Mars: A mechanism of formation by transient melting of snow and ice

NASA Astrophysics Data System (ADS)

Head, James W.; Kreslavsky, Mikhail A.; Marchant, David R.

2011-09-01

Pits in rocks on the surface of Mars have been observed at several locations. Similar pits are observed in rocks in the Mars-like hyperarid, hypothermal stable upland zone of the Antarctic Dry Valleys; these form by very localized chemical weathering due to transient melting of small amounts of snow on dark dolerite boulders preferentially heated above the melting point of water by sunlight. We examine the conditions under which a similar process might explain the pitted rocks seen on the surface of Mars (rock surface temperatures above the melting point; atmospheric pressure exceeding the triple point pressure of H2O; an available source of solid water to melt). We find that on Mars today each of these conditions is met locally and regionally, but that they do not occur together in such a way as to meet the stringent requirements for this process to operate. In the geological past, however, conditions favoring this process are highly likely to have been met. For example, increases in atmospheric water vapor content (due, for example, to the loss of the south perennial polar CO2 cap) could favor the deposition of snow, which if collected on rocks heated to above the melting temperature during favorable conditions (e.g., perihelion), could cause melting and the type of locally enhanced chemical weathering that can cause pits. Even when these conditions are met, however, the variation in heating of different rock facets under Martian conditions means that different parts of the rock may weather at different times, consistent with the very low weathering rates observed on Mars. Furthermore, as is the case in the stable upland zone of the Antarctic Dry Valleys, pit formation by transient melting of small amounts of snow readily occurs in the absence of subsurface active layer cryoturbation.

Corrosion pitting and environmentally assisted small crack growth

PubMed Central

Turnbull, Alan

2014-01-01

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

Torus-margo pits help conifers compete with angiosperms.

PubMed

Pittermann, Jarmila; Sperry, John S; Hacke, Uwe G; Wheeler, James K; Sikkema, Elzard H

2005-12-23

The unicellular conifer tracheid should have greater flow resistance per length (resistivity) than the multicellular angiosperm vessel, because its high-resistance end-walls are closer together. However, tracheids and vessels had comparable resistivities for the same diameter, despite tracheids being over 10 times shorter. End-wall pits of tracheids averaged 59 times lower flow resistance on an area basis than vessel pits, owing to the unique torus-margo structure of the conifer pit membrane. The evolution of this membrane was as hydraulically important as that of vessels. Without their specialized pits, conifers would have 38 times the flow resistance, making conifer-dominated ecosystems improbable in an angiosperm world.

Volume Measurements of Laser-generated Pits for in Situ Geochronology Using KArLE (Potassium-Argon Laser Experiment)

NASA Technical Reports Server (NTRS)

French, R. A.; Cohen, B. A.; Miller, J. S.

2014-01-01

KArLE (Potassium-­-Argon Laser Experiment) has been developed for in situ planetary geochronology using the K - Ar (potassium-­-argon) isotope system, where material ablated by LIBS (Laser-­-Induced Breakdown Spectroscopy) is used to calculate isotope abundances. We are determining the accuracy and precision of volume measurements of these pits using stereo and laser microscope data to better understand the ablation process for isotope abundance calculations. If a characteristic volume can be determined with sufficient accuracy and precision for specific rock types, KArLE will prove to be a useful instrument for future planetary rover missions.

Enhanced ID Pit Sizing Using Multivariate Regression Algorithm

NASA Astrophysics Data System (ADS)

Krzywosz, Kenji

2007-03-01

EPRI is funding a program to enhance and improve the reliability of inside diameter (ID) pit sizing for balance-of plant heat exchangers, such as condensers and component cooling water heat exchangers. More traditional approaches to ID pit sizing involve the use of frequency-specific amplitude or phase angles. The enhanced multivariate regression algorithm for ID pit depth sizing incorporates three simultaneous input parameters of frequency, amplitude, and phase angle. A set of calibration data sets consisting of machined pits of various rounded and elongated shapes and depths was acquired in the frequency range of 100 kHz to 1 MHz for stainless steel tubing having nominal wall thickness of 0.028 inch. To add noise to the acquired data set, each test sample was rotated and test data acquired at 3, 6, 9, and 12 o'clock positions. The ID pit depths were estimated using a second order and fourth order regression functions by relying on normalized amplitude and phase angle information from multiple frequencies. Due to unique damage morphology associated with the microbiologically-influenced ID pits, it was necessary to modify the elongated calibration standard-based algorithms by relying on the algorithm developed solely from the destructive sectioning results. This paper presents the use of transformed multivariate regression algorithm to estimate ID pit depths and compare the results with the traditional univariate phase angle analysis. Both estimates were then compared with the destructive sectioning results.

VOC identification and inter-comparison from laboratory biomass burning using PTR-MS and PIT-MS

Treesearch

C. Warneke; J. M. Roberts; P. Veres; J. Gilman; W. C. Kuster; I. Burling; R. Yokelson; J. A. de Gouw

2011-01-01

Volatile organic compounds (VOCs) emitted from fires of biomass commonly found in the southeast and southwest U.S. were investigated with PTR-MS and PIT-MS, which are capable of fast measurements of a large number of VOCs. Both instruments were calibrated with gas standards and mass dependent calibration curves are determined. The sensitivity of the PIT-MS linearly...

Evaluation of pitting corrosion resistance of high-alloyed stainless steels welds for FGD plants in Korea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baek, K.K.; Sung, H.J.; Im, C.S.

1998-12-31

For successful application of high-alloyed stainless steels for Flue Gas Desulfurization (FGD) plants, pitting corrosion resistance of arc welds of N-added 6%Mo austenitic stainless steels (UNS N 08367) and super duplex stainless steels (UNS S 32550) made with various filler metals were evaluated using the Green Death solution. For Gas Tungsten Arc (GTA) and Gas Metal Arc (GMA) welds of N 08367, Critical Pitting Temperature (CPT) of base metal was 65--70 C, whereas weld made by ERNiCrMo-3 filler metal yielded CPT of 50 C. Welds made by ERNiCrMo-10 or ERNiCrMo-4 filler metals showed CPT of 60--65 C and 65--70C, respectively.more » For GTA and GMA welds of S 32550, CPT of welds made by ERNiCrMo-3 was 45--50 C, indicating that the filler metal can provide pitting corrosion resistance matching the S 32550 alloy. Thus, a proper pitting corrosion resistance of weldments of high-alloy stainless steels can be achieved by selecting filler metals having at least +10 higher Pitting Resistance Equivalent Number (PRE{sub N}) value than the base metal regardless of the type of arc welding process. The over-alloyed filler metals would compensate preferential segregation of Cr, MO along the dendrite boundary, which made the dendrite core more susceptible to pitting. Nitrogen addition to the GTA welds of N 08367 made with ERNiCrMo-3 failed to improve pitting corrosion resistance, which was attributed to the precipitation of nitrogen in the weld metal in the form of Nb-nitride.« less

Imaging and Information Processing of Pitting-Corroded Aluminum Alloy Panels with Surface Metrology Methods

DTIC Science & Technology

2014-12-23

positioned outside the sealed chamber by passing extension cables through the bulkhead in the chamber. Temperature and relative humidity were acquired at...inside the chamber was varied in temperature and humidity to promote corrosion. Panels 1-3 were removed 133, 209 and 286 hours from the experiment...indicated that, the nucleated pits, as those general non- visible ones in Panel 1, usually took regular morphological forms, such as hemi-spherical, near

Pits in Polar Cap

NASA Technical Reports Server (NTRS)

2006-01-01

This full-frame image from the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter shows faults and pits in Mars' north polar residual cap that have not been previously recognized.

The faults and depressions between them are similar to features seen on Earth where the crust is being pulled apart. Such tectonic extension must have occurred very recently because the north polar residual cap is very young, as indicated by the paucity of impact craters on its surface. Alternatively, the faults and pits may be caused by collapse due to removal of material beneath the surface. The pits are aligned along the faults, either because material has drained into the subsurface along the faults or because gas has escaped from the subsurface through them.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

Molten salt corrosion of SiC: Pitting mechanism

NASA Technical Reports Server (NTRS)

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

1985-01-01

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

COPPER PITTING AND PINHOLE LEAK RESEARCH STUDY

EPA Science Inventory

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

PIT tags increase effectiveness of freshwater mussel recaptures

USGS Publications Warehouse

Kurth, J.; Loftin, C.; Zydlewski, Joseph D.; Rhymer, Judith

2007-01-01

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

7 CFR 52.807 - Freedom from pits.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AND THE EGG PRODUCTS INSPECTION ACT PROCESSED FRUITS AND VEGETABLES, PROCESSED PRODUCTS THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted... means pitted cherries that are substantially free from any adhering sirup, sugar, or other packing...

7 CFR 52.807 - Freedom from pits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AND THE EGG PRODUCTS INSPECTION ACT PROCESSED FRUITS AND VEGETABLES, PROCESSED PRODUCTS THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Frozen Red Tart Pitted... means pitted cherries that are substantially free from any adhering sirup, sugar, or other packing...

Pitting and Stress Corrosion Cracking Susceptibility of Nanostructured Al-Mg Alloys in Natural and Artificial Environments

NASA Astrophysics Data System (ADS)

Sharma, Mala M.; Ziemian, Constance W.

2008-12-01

The stress corrosion cracking (SCC) behavior of two developmental nanocrystalline 5083 alloys with varied composition and processing conditions was studied. The results were compared to a commercial aluminum AA 5083 (H111) alloy. The pitting densities, size and depths, and residual tensile strengths were measured after alternate immersion in artificial seawater and atmospheric exposure under different loading conditions. Optical and scanning electron microscopy (SEM) with EDX was used to analyze the fracture surfaces of failed specimen after removal at selected intervals and tensile testing. One of the nanostructured Al-Mg alloys exhibited significantly superior pitting resistance when compared to conventional microstructured AA 5083. Under conditions where pitting corrosion showed up as local tunnels toward phase inclusions, transgranular cracking was observed, whereas under conditions when pitting corrosion evolved along grain boundaries, intergranular cracking inside the pit was observed. Pit initiation resistance of the nano alloys appears to be better than that of the conventional alloys. However, long-term pit propagation is a concern and warrants further study. The objective of this investigation was to obtain information regarding the role that ultra-fine microstructures play in their degradation in marine environments and to provide insight into the corrosion mechanisms and damage processes of these alloys.

Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae).

PubMed

Krochmal, Aaron R; Bakken, George S; LaDuc, Travis J

2004-11-01

Pitvipers (Viperidae: Crotalinae) possess thermal radiation receptors, the facial pits, which allow them to detect modest temperature fluctuations within their environments. It was previously thought that these organs were used solely to aid in prey acquisition, but recent findings demonstrated that western diamondback rattlesnakes (Crotalus atrox) use them to direct behavioral thermoregulation, suggesting that facial pits might be general purpose organs used to drive a suite of behaviors. To investigate this further, we conducted a phylogenetic survey of viperine thermoregulatory behavior cued by thermal radiation. We assessed this behavior in 12 pitviper species, representing key nodes in the evolution of pitvipers and a broad range of thermal environments, and a single species of true viper (Viperidae: Viperinae), a closely related subfamily of snakes that lack facial pits but possess a putative thermal radiation receptor. All pitviper species were able to rely on their facial pits to direct thermoregulatory movements, while the true viper was unable to do so. Our results suggest that thermoregulatory behavior cued by thermal radiation is a universal role of facial pits and probably represents an ancestral trait among pitvipers. Further, they establish behavioral thermoregulation as a plausible hypothesis explaining the evolutionary origin of the facial pit.

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

NASA Astrophysics Data System (ADS)

Ford, Murray R.

2014-06-01

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

Least tern and piping plover nesting at sand pits in Nebraska

USGS Publications Warehouse

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

1993-01-01

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

Perspective—Localized Corrosion: Passive Film Breakdown vs Pit Growth Stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frankel, G. S.; Li, Tianshu; Scully, J. R.

2017-02-24

A debate about the critical step in localized corrosion has raged for decades. Some researchers focus on the composition and structure of the passive film associated with the initial breakdown of the film, whereas others consider that the susceptibility to pitting is controlled by the pit growth kinetics and the stabilization of pit growth. The basis for a unified theory of pitting is presented here in which pit stability considerations are controlling under aggressive conditions (harsh electrolytes and extreme environments and/or susceptible microstructures) and the passive film properties and protectiveness are the critical factors in less extreme environments and/or formore » less susceptible alloys.« less

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

USDA-ARS?s Scientific Manuscript database

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

Speed, Acceleration, Chameleons and Cherry Pit Projectiles

ERIC Educational Resources Information Center

Planinsic, Gorazd; Likar, Andrej

2012-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Netoff, D.I.; Shroba, R.R.

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

Perforated Pit Membranes in Imperforate Tracheary Elements of Some Angiosperms

PubMed Central

SANO, YUZOU; JANSEN, STEVEN

2006-01-01

• Background and Aims The structure of pit membranes in angiosperms has not been fully examined and our understanding about the structure is incomplete. Therefore, this study aims to illustrate the micromorphology of pit membranes in fibres and tracheids of woody species from various families. • Methods Specimens from ten species from ten genera and eight families were prepared using two techniques and examined by field-emission scanning electron microscopy. • Key Results Interfibre pit membranes with an average diameter of <4 µm were frequently perforated or appeared to be very porous. In contrast, pit membranes in imperforate tracheary elements with distinctly bordered pits and an average diameter of ≥4 µm were homogeneous and densely packed with microfibrils. These differences were observed consistently not only among species but also within a single species in which different types of imperforate tracheary elements were present. • Conclusions This study demonstrates that the structure of interfibre pit membranes differs among cell types and the differences are closely associated with the specialization of the fibre cells. It is suggested that perforated pit membranes between specialized fibres contribute to the dehydration of the fibre cells at or soon after maturation. PMID:16520339

Gullies in a Central Pit Crater

NASA Image and Video Library

2015-10-14

Sometimes a central pit forms inside some Martian craters, especially when there substantial ground ice. Such is the case in this observation from NASA Mars Reconnaissance Orbiter spacecraft. Sometimes what we call "mass wasting" processes (think small avalanches or landslides) occur on the slopes of the central pit. We took this image to search for any recent activity that would add to or modify previously identified gullies. http://photojournal.jpl.nasa.gov/catalog/PIA20005

Construction integrity assessment report (ETN-98-0005) S-Farm overground transfer (OGT) system valve pit 241-S-B to valve pit 241-S-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

HICKS, D.F.

1999-08-12

The S-Farm overground transfer (OGT) line will bypass the existing line(s), between valve pits 241-S-B and 241-S-D that no longer meet system requirements. The new OGT line will provide a waste transfer pipeline between these valve pits in support of saltwell pumping activities. The length of the OGT line is approximately 180 ft from pit to pit. The primary pipe is nominal 1-in. diameter stainless steel (SST) braided Ethylene-propylene Diene Monomer (EPDM) hose. The encasement pipe is a nominal 3-in., flanged, SST pipe made up of several different length pipe spool pieces (drawing H-2-829564, sh. 1 and sh. 2). Themore » OGT line slopes from valve pit 241-S-B toward valve pit 241-S-D. At each end, the primary and encasement pipe connect to a pit entry spool piece. The pit entry spool pieces are constructed of prefabricated SST materials. These spool pieces allow for the separation of the primary and encasement pipelines after the pipes have entered the valve pits (drawing H-2-818280, sh. 2). The pit entry spool pieces also allow for leak detection of the encasement pipe at each end (drawing H-2-829564, sh. 2). The OGT encasement pipeline is supported above ground by adjustable height unistrut brackets and precast concrete bases (drawing H-2-829654, sh. 1). The pipeline is heat-traced and insulated. The heat tracing and insulation supply and retain latent heat that prevents waste solidification during transfers and provides freeze protection. The total length of the pipeline is above ground, thereby negating the need for cathodic corrosion protection. This Construction Integrity Assessment Report (CIAR) is prepared by Fluor Daniel Northwest for Numatec Hanford Corporation/Lockheed Martin Hanford Corporation, the operations contractor, and the U. S. Department of Energy, the system owner. The CIAR is intended to verify that construction was performed in accordance with the provisions of Washington Administrative Code, WAC-173-303-640 (3) (c), (e), (f) and (h).« less

A Single Base Difference between Pit-1 Binding Sites at the hGH Promoter and Locus Control Region Specifies Distinct Pit-1 Conformations and Functions

PubMed Central

Shewchuk, Brian M.; Ho, Yugong; Liebhaber, Stephen A.; Cooke, Nancy E.

2006-01-01

Activation of the human growth hormone (hGH-N) gene in pituitary somatotropes is mediated by a locus control region (LCR). This LCR is composed of DNase I-hypersensitive sites (HS) located −14.5 kb to −32 kb relative to the hGH-N promoter. HSI, at −14.5 kb, is the dominant determinant of hGH-N expression and is essential for establishment of a 32-kb domain of histone acetylation that encompasses the active hGH locus. This activity is conferred by three binding sites for the POU domain transcription factor Pit-1. These Pit-1 elements are sufficient to activate hGH-N expression in the mouse pituitary. In contrast, Pit-1 sites at the hGH-N promoter are consistently unable to mediate similar activity. In the present study, we demonstrate that the functional difference between the promoter-proximal and the HSI Pit-1 binding sites can be attributed in part to a single base difference. This base affects the conformation of the Pit-1/DNA complex, and reciprocal exchange of the divergent bases between the two sets of Pit-1 elements results in a partial reversal of their transgenic activities. These data support a model in which the Pit-1 binding sites in the hGH LCR allosterically program the bound Pit-1 complex for chromatin activating functions. PMID:16914737

Upper Extremity Injuries in NASCAR Drivers and Pit Crew: An Epidemiological Study.

PubMed

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

2016-02-01

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

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

USGS Publications Warehouse

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

2003-01-01

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

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution.

PubMed

Sizemore, H G; Platz, T; Schorghofer, N; Prettyman, T H; De Sanctis, M C; Crown, D A; Schmedemann, N; Neesemann, A; Kneissl, T; Marchi, S; Schenk, P M; Bland, M T; Schmidt, B E; Hughson, K H G; Tosi, F; Zambon, F; Mest, S C; Yingst, R A; Williams, D A; Russell, C T; Raymond, C A

2017-07-16

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

USGS Publications Warehouse

Sizemore, H.G.; Platz, Thomas; Schorghofer, Norbert; Prettyman, Thomas; De Sanctis, Maria Christina; Crown, David A.; Schmedemann, Nico; Nessemann, Andeas; Kneissl, Thomas; Simone Marchi,; Schenk, Paul M.; Bland, Michael T.; Schmidt, B.E.; Hughson, Kynan H.G.; Tosi, F.; Zambon, F; Mest, S.C.; Yingst, R.A.; Williams, D.A.; Russell, C.T.; Raymond, C.A.

2017-01-01

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Light scattering from laser induced pit ensembles on high power laser optics

DOE PAGES

Feigenbaum, Eyal; Elhadj, Selim; Matthews, Manyalibo J.

2015-01-01

Far-field light scattering characteristics from randomly arranged shallow Gaussian-like shaped laser induced pits, found on optics exposed to high energy laser pulses, is studied. Closed-form expressions for the far-field intensity distribution and scattered power are derived for individual pits and validated using numerical calculations of both Fourier optics and FDTD solutions to Maxwell’s equations. It is found that the scattered power is proportional to the square of the pit width and approximately also to the square of the pit depth, with the proportionality factor scaling with pit depth. As a result, the power scattered from shallow pitted optics is expectedmore » to be substantially lower than assuming complete scattering from the total visible footprint of the pits.« less

Fish assemblages in borrow-pit lakes of the Lower Mississippi River

USGS Publications Warehouse

Miranda, Leandro E.; Killgore, K. J.; Hoover, J.J.

2013-01-01

Borrow-pit lakes encompass about a third of the lentic water habitats (by area) in the active floodplain of the Lower Mississippi River, yet little is known about their fish assemblages. We investigated whether fish assemblages supported by borrow-pit lakes resembled those in oxbow lakes to help place the ecological relevance of borrow-pit lakes in context with that of natural floodplain lakes. In all, we collected 75 fish species, including 65 species in eight borrow-pit lakes, 52 species in four riverside oxbow lakes, and 44 species in eight landside oxbow lakes. Significant differences in several species richness metrics were evident between borrow-pit lakes and landside oxbow lakes but not between borrow-pit lakes and riverside oxbow lakes. All three lake types differed in fish assemblage composition. Borrow-pit lakes and riverside oxbow lakes tended to include a greater representation of fish species that require access to diverse environments, including lentic, lotic, and palustrine habitats; fish assemblages in landside oxbow lakes included a higher representation of lacustrine species. None of the fish species collected in borrow-pit lakes was federally listed as threatened or endangered, but several were listed as species of special concern by state governments in the region, suggesting that borrow-pit lakes provide habitat for sensitive riverine and wetland fish species. Differences in fish assemblages among borrow-pit lakes were linked to engineered morphologic features, suggesting that diversity in engineering can contribute to diversity in fish assemblages; however, more research is needed to match engineering designs with fish assemblage structures that best meet conservation needs.

High-temperature-measuring device

DOEpatents

Not Available

1981-01-27

A temperature measuring device for very high design temperatures (to 2000/sup 0/C) is described. The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensonally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

High temperature measuring device

DOEpatents

Tokarz, Richard D.

1983-01-01

A temperature measuring device for very high design temperatures (to 2,000.degree. C.). The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensionally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

Infrared nanospectroscopy reveals the chemical nature of pit membranes in water-conducting cells of the plant xylem.

PubMed

Pereira, Luciano; Flores-Borges, Denisele; Bittencourt, Paulo; Mayer, Juliana; Kiyota, Eduardo; Araújo, Pedro; Jansen, Steven; Freitas, Raul; Oliveira, Rafael; Mazzafera, Paulo

2018-06-05

In the xylem of angiosperm plants, microscopic pits through the secondary cell walls connect the water-conducting vessels. Cellulosic meshes originated from primary walls and middle lamella between adjacent vessels, called pit membrane, separates one conduit from another. The intricate structure of the nano-sized pores in pit membranes enables the passage of water under negative pressure without hydraulic failure due to obstruction by gas bubbles (i.e., embolism) under normal conditions or mild drought stress. Since the chemical composition of pit membranes affects embolism formation and bubble behavior, we directly measured pit membrane composition in Populus nigra wood. Here, we characterized the chemical composition of cell wall structures by synchrotron infrared nanospectroscopy and atomic force microscopy-infrared nanospectroscopy with high spatial resolution. Characteristic peaks of cellulose, phenolic compounds, and proteins were found in the intervessel pit membrane of P. nigra wood. In addition, vessel to parenchyma pit membranes and developing cell walls of the vascular cambium showed clear signals of cellulose, proteins, and pectin. We did not find a distinct peak of lignin and other compounds in these structures. Our investigation of the complex chemical composition of intervessel pit membranes furthers our understanding of the flow of water and bubbles between neighboring conduits. The advances presented here pave the way for further label-free studies related to the nano-chemistry of plant cell components. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

Real-time electronic monitoring of a pitted and leaking gas gathering pipeline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asperger, R.G.; Hewitt, P.G.

1986-08-01

Hydrogen patch, flush electrical resistance, and flush linear polarization proves wre used with flush coupons to monitor corrosion rates in a pitted and leaking sour gas gathering line. Four inhibitors were evaluated in stopping the leaks. Inhibitor residuals and the amount and ratio of water and condensate in the lines were measured at five locations along the line. The best inhibitor reduced reduced the pit-leak frequency by over a factor of 10. Inhibitor usage rate was optimized using the hydrogen patch current as a measure of the instantaneous corrosion rate. Improper pigging was identified as a cause of corrosion transients.more » This problem is discussed in relation to the pigging of pipelines in stratified flow where moving fluids are the carriers for continuously injected corrosion inhibitors.« less

Construction risk assessment of deep foundation pit in metro station based on G-COWA method

NASA Astrophysics Data System (ADS)

You, Weibao; Wang, Jianbo; Zhang, Wei; Liu, Fangmeng; Yang, Diying

2018-05-01

In order to get an accurate understanding of the construction safety of deep foundation pit in metro station and reduce the probability and loss of risk occurrence, a risk assessment method based on G-COWA is proposed. Firstly, relying on the specific engineering examples and the construction characteristics of deep foundation pit, an evaluation index system based on the five factors of “human, management, technology, material and environment” is established. Secondly, the C-OWA operator is introduced to realize the evaluation index empowerment and weaken the negative influence of expert subjective preference. The gray cluster analysis and fuzzy comprehensive evaluation method are combined to construct the construction risk assessment model of deep foundation pit, which can effectively solve the uncertainties. Finally, the model is applied to the actual project of deep foundation pit of Qingdao Metro North Station, determine its construction risk rating is “medium”, evaluate the model is feasible and reasonable. And then corresponding control measures are put forward and useful reference are provided.

Temperature correction in conductivity measurements

USGS Publications Warehouse

Smith, Stanford H.

1962-01-01

Electrical conductivity has been widely used in freshwater research but usual methods employed by limnologists for converting measurements to conductance at a given temperature have not given uniformly accurate results. The temperature coefficient used to adjust conductivity of natural waters to a given temperature varies depending on the kinds and concentrations of electrolytes, the temperature at the time of measurement, and the temperature to which measurements are being adjusted. The temperature coefficient was found to differ for various lake and stream waters, and showed seasonal changes. High precision can be obtained only by determining temperature coefficients for each water studied. Mean temperature coefficients are given for various temperature ranges that may be used where less precision is required.

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

PubMed Central

Platz, T.; Schorghofer, N.; Prettyman, T. H.; De Sanctis, M. C.; Crown, D. A.; Schmedemann, N.; Neesemann, A.; Kneissl, T.; Marchi, S.; Schenk, P. M.; Bland, M. T.; Schmidt, B. E.; Hughson, K. H. G.; Tosi, F.; Zambon, F.; Mest, S. C.; Yingst, R. A.; Williams, D. A.; Russell, C. T.; Raymond, C. A.

2017-01-01

Abstract Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice‐rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization. PMID:28989206

Pitting of Space Shuttle's Inconel Honeycomb Conical Seal Panel

NASA Technical Reports Server (NTRS)

Zimmerman, Frank; Gentz, Steven J.; Miller, James B.

2006-01-01

This paper describes the approach, findings, conclusions and recommendations associated with the investigation of the conical seal pitting. It documents the cause and contributing factors of the pitting, the means used to isolate each contributor, and the supporting evidence for the primary cause of the pitting. Finally, the selection, development and verification of the repair procedure used to restore the conical seal panel is described with supporting process and metallurgical rationale for selection.

Mapping sand and gravel pits in the Patuxent River watershed

NASA Technical Reports Server (NTRS)

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

1981-01-01

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

Pit above the lesser tuberosity in axial view radiography.

PubMed

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

2015-02-01

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

Race- and Sex-Related Differences in Retinal Thickness and Foveal Pit Morphology

PubMed Central

Wagner-Schuman, Melissa; Dubis, Adam M.; Nordgren, Rick N.; Lei, Yuming; Odell, Daniel; Chiao, Hellen; Weh, Eric; Fischer, William; Sulai, Yusufu; Dubra, Alfredo

2011-01-01

Purpose. To examine sex- and race-associated differences in macular thickness and foveal pit morphology by using spectral-domain optical coherence tomography (SD-OCT). Methods. One hundred eighty eyes of 90 healthy patients (43 women, 47 men) underwent retinal imaging with spectral-domain OCT. The lateral scale of each macular volume scan was corrected for individual differences in axial length by ocular biometry. From these corrected volumes, Early Treatment Diabetic Retinopathy Study (ETDRS) grids of retinal thickness were generated and compared between the groups. Foveal morphology was measured with previously described algorithms. Results. Compared with the Caucasians, the Africans and African Americans had reduced central subfield thickness. Central subfield thickness was also reduced in the women compared with the men, although the women also showed significant thinning in parafoveal regions. There was no difference between the sexes in foveal pit morphology; however, the Africans/African Americans had significantly deeper and broader foveal pits than the Caucasians. Conclusions. Previous studies have reported race- and sex-associated differences in macular thickness, and the inference has been that these differences represent similar anatomic features. However, the data on pit morphology collected in the present study reveal an important and significant variation. Between the sexes, the differences are due to global variability in retinal thickness, whereas the variation in thickness observed between the races appears to be driven by differences in foveal pit morphology. These differences have important implications for the use of SD-OCT in detecting and diagnosing retinal disease. PMID:20861480

Deep sulcal landmarks: algorithmic and conceptual improvements in the definition and extraction of sulcal pits.

PubMed

Auzias, G; Brun, L; Deruelle, C; Coulon, O

2015-05-01

Recent interest has been growing concerning points of maximum depth within folds, the sulcal pits, that can be used as reliable cortical landmarks. These remarkable points on the cortical surface are defined algorithmically as the outcome of an automatic extraction procedure. The influence of several crucial parameters of the reference technique (Im et al., 2010) has not been evaluated extensively, and no optimization procedure has been proposed so far. Designing an appropriate optimization framework for these parameters is mandatory to guarantee the reproducibility of results across studies and to ensure the feasibility of sulcal pit extraction and analysis on large cohorts. In this work, we propose a framework specifically dedicated to the optimization of the parameters of the method. This optimization framework relies on new measures for better quantifying the reproducibility of the number of sulcal pits per region across individuals, in line with the assumptions of one-to-one correspondence of sulcal roots across individuals which is an explicit aspect of the sulcal roots model (Régis et al., 2005). Our procedure benefits from a combination of improvements, including the use of a convenient sulcal depth estimation and is methodologically sound. Our experiments on two different groups of individuals, with a total of 137 subjects, show an increased reliability across subjects in deeper sulcal pits, as compared to the previous approach, and cover the entire cortical surface, including shallower and more variable folds that were not considered before. The effectiveness of our method ensures the feasibility of a systematic study of sulcal pits on large cohorts. On top of these methodological advances, we quantify the relationship between the reproducibility of the number of sulcal pits per region across individuals and their respective depth and demonstrate the relatively high reproducibility of several pits corresponding to shallower folds. Finally, we report new

Acquired pit of the optic nerve: a risk factor for progression of glaucoma.

PubMed

Ugurlu, S; Weitzman, M; Nduaguba, C; Caprioli, J

1998-04-01

To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma. In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression. Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02). Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.

Quantifying the Dynamic Interactions Between a Clathrin-Coated Pit and Cargo Molecules

NASA Astrophysics Data System (ADS)

Weigel, Aubrey; Tamkun, Michael; Krapf, Diego

2014-03-01

Clathrin-mediated endocytosis is a major pathway of internalization of cargo in eukaryotic cells. This process involves the recruitment of cargo molecules into a growing clathrin-coated pit (CCP). However, cargo-CCP interactions are difficult to study because CCPs display a large degree of lifetime heterogeneity and the interactions with cargo molecules evolve over time. We use single-molecule total internal reflection fluorescence (TIRF) microscopy, in combination with automatic detection and tracking algorithms, to directly visualize the recruitment of individual voltage-gated potassium channels into forming CCPs in living cells. Contrary to widespread ideas, cargo often escapes from a pit before abortive CCP termination or endocytic vesicle production. By measuring tens of thousands of capturing events, we build the distribution of capture times and the times that cargo remains confined to a CCP. An analytical stochastic model is developed and compared to the measured distributions. Due to the dynamic nature of the pit, the model is non-Markovian and it displays long-tail power law statistics. Our findings identify one source of the large heterogeneities observed in CCP maturation and provide a mechanism for the anomalous diffusion of proteins in the plasma membrane. This work was supported by National Science Foundation Grant PHY-0956714.

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

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

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

Noncontact Temperature Measurement

NASA Technical Reports Server (NTRS)

Lee, Mark C. (Editor)

1988-01-01

Noncontact temperature measurement has been identified as one of the eight advanced technology development (ATD) areas to support the effort of the Microgravity Science and Applications Division in developing six Space Station flight experiment facilities. This two-day workshop was an opportunity for all six disciplines to present their requirements on noncontact temperature measurement and to discuss state-of-the-art developments. Multi-color pyrometry, laser pyrometry and radiometric imaging techniques are addressed.

Cavitation Resistance in Seedless Vascular Plants: The Structure and Function of Interconduit Pit Membranes1[W][OPEN

PubMed Central

Brodersen, Craig; Jansen, Steven; Choat, Brendan; Rico, Christopher; Pittermann, Jarmila

2014-01-01

Plant water transport occurs through interconnected xylem conduits that are separated by partially digested regions in the cell wall known as pit membranes. These structures have a dual function. Their porous construction facilitates water movement between conduits while limiting the spread of air that may enter the conduits and render them dysfunctional during a drought. Pit membranes have been well studied in woody plants, but very little is known about their function in more ancient lineages such as seedless vascular plants. Here, we examine the relationships between conduit air seeding, pit hydraulic resistance, and pit anatomy in 10 species of ferns (pteridophytes) and two lycophytes. Air seeding pressures ranged from 0.8 ± 0.15 MPa (mean ± sd) in the hydric fern Athyrium filix-femina to 4.9 ± 0.94 MPa in Psilotum nudum, an epiphytic species. Notably, a positive correlation was found between conduit pit area and vulnerability to air seeding, suggesting that the rare-pit hypothesis explains air seeding in early-diverging lineages much as it does in many angiosperms. Pit area resistance was variable but averaged 54.6 MPa s m−1 across all surveyed pteridophytes. End walls contributed 52% to the overall transport resistance, similar to the 56% in angiosperm vessels and 64% in conifer tracheids. Taken together, our data imply that, irrespective of phylogenetic placement, selection acted on transport efficiency in seedless vascular plants and woody plants in equal measure by compensating for shorter conduits in tracheid-bearing plants with more permeable pit membranes. PMID:24777347

Understanding of surface pit formation mechanism of GaN grown in MOCVD based on local thermodynamic equilibrium assumption

NASA Astrophysics Data System (ADS)

Zhi-Yuan, Gao; Xiao-Wei, Xue; Jiang-Jiang, Li; Xun, Wang; Yan-Hui, Xing; Bi-Feng, Cui; De-Shu, Zou

2016-06-01

Frank’s theory describes that a screw dislocation will produce a pit on the surface, and has been evidenced in many material systems including GaN. However, the size of the pit calculated from the theory deviates significantly from experimental result. Through a careful observation of the variations of surface pits and local surface morphology with growing temperature and V/III ratio for c-plane GaN, we believe that Frank’s model is valid only in a small local surface area where thermodynamic equilibrium state can be assumed to stay the same. If the kinetic process is too vigorous or too slow to reach a balance, the local equilibrium range will be too small for the center and edge of the screw dislocation spiral to be kept in the same equilibrium state. When the curvature at the center of the dislocation core reaches the critical value 1/r 0, at the edge of the spiral, the accelerating rate of the curvature may not fall to zero, so the pit cannot reach a stationary shape and will keep enlarging under the control of minimization of surface energy to result in a large-sized surface pit. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204009 and 61204011) and the Beijing Municipal Natural Science Foundation, China (Grant No. 4142005).

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

NASA Technical Reports Server (NTRS)

Ma, LI; Hoeppner, David W.

1994-01-01

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

Fast Track Characterization of Highly Radioactive Waste Pits Combining Off-the-Shelf Robotics with Innovative Investigation Protocols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chabeuf, Jean-Michel; Boya, Didier

The investigation and characterization of radioactive waste pits and effluent storage tanks represents a substantial and challenging step in the overall decommissioning programme launched by AREVA NC in 1998 on the site of Marcoule on behalf of the French Atomic Energy commission. Physical ,radiological and regulatory constraints, combined with a tight schedule, have lead our teams to use proven conventional instrumentation and robotics in innovative configurations . One such investigation, conducted on a particularly challenging radioactive effluent storage pit, is described below. The 'H' pit is a stainless steel clad concrete cavity, located in the second basement of the de-claddingmore » building of Marcoule site. It was used for forty years as buffer storage for high activity effluents and has a length of 5 meters, a width of 3 meters , a height of 2.5 meters, and is topped by lead plates over 5 cm thick and The bottom of the cavity is covered with a layer of mud containing mainly graphite, diatoms and resins. The mud level ranges from about 20 centimeters to over 50 centimeters. The overall mud volume is around 2.4 cubic meters. Ambient dose rates above the lead plates exceed 10 mSv/h. The main purpose of our investigation was to characterize the muds for future recovery and conditioning prior to decontaminating the pit. The history of the pit together with the varying mud altimetry lead us to believe that sedimentation had probably occurred throughout the years. We thus decided to combine dose rate measurements using IF104 probes, gamma spectroscopy with CdTe probes and sample collections at different depths to ensure the representativeness and full characterization of the muds. Poor access, ambient dose rates have lead us to conceive a robotic arm, mounted on an shaft which can be modified to fit a wide range of pits and tanks. Custom built robotic tools with maximum manoeuvrability generally involve costs and delays far exceeding our purposes. SIT, a

Methodology of selecting dozers for lignite open pit mines in Serbia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stojanovic, D.; Ignjatovic, D.; Kovacevic, S.

1996-12-31

Apart from the main production processes (coal and overburden mining, rail conveyors transportation and storage of excavated masses) performed by great-capacity mechanization at open pit mines, numerous and different auxiliary works, that often have crucial influence on both the work efficiency of main equipment and the maintenance of optimum technical conditions of machines and plants covering technological system of open pit, are present. Successful realization of work indispensably requires a proper and adequate selection of auxiliary machines according to their type quantity, capacity, power etc. thus highly respecting specific conditions existing at each and every open pit mine. A dozermore » is certainly the most important and representative auxiliary machine at single open pit mine. It is widely used in numerous works that, in fact, are preconditions for successful work of the main mechanization and consequently the very selection of a dozer ranges among the most important operations when selecting mechanization. This paper presents the methodology of dozers selection when lignite open pit mines are concerned. A mathematical model defining the volume of work required for dozers to perform at open pit mines and consequently the number of necessary dozers was designed. The model underwent testing in practice at big open pit mines and can be used in design of future open pits mines.« less

Containerless high temperature property measurements

NASA Technical Reports Server (NTRS)

Nordine, Paul C.; Weber, J. K. Richard; Krishnan, Shankar; Anderson, Collin D.

1991-01-01

Containerless processing in the low gravity environment of space provides the opportunity to increase the temperature at which well controlled processing of and property measurements on materials is possible. This project was directed towards advancing containerless processing and property measurement techniques for application to materials research at high temperatures in space. Containerless high temperature material property studies include measurements of the vapor pressure, melting temperature, optical properties, and spectral emissivities of solid boron. The reaction of boron with nitrogen was also studied by laser polarimetric measurement of boron nitride film growth. The optical properties and spectral emissivities were measured for solid and liquid silicon, niobium, and zirconium; liquid aluminum and titanium; and liquid Ti-Al alloys of 5 to 60 atomic pct. titanium. Alternative means for noncontact temperature measurement in the absence of material emissivity data were evaluated. Also, the application of laser induced fluorescence for component activity measurements in electromagnetic levitated liquids was studied, along with the feasibility of a hybrid aerodynamic electromagnetic levitation technique.

VITRECTOMY FOR MACULAR RETINOSCHISIS WITHOUT A DETECTABLE OPTIC DISK PIT.

PubMed

Haruta, Masatoshi; Yamakawa, Ryoji

2017-05-01

To evaluate the efficacy of vitrectomy in the treatment of macular retinoschisis without a detectable optic disk pit. This retrospective interventional case series included eight patients with acquired, unilateral macular retinoschisis with or without foveal detachment. Patients with an optic disk pit, vitreomacular traction, or high myopia were excluded. Six of the eight patients underwent vitrectomy with internal limiting membrane peeling and fluid-air exchange. The surgical outcome was evaluated in terms of the improvement in the macular anatomy and the best-corrected visual acuity. During vitrectomy, all the six eyes were confirmed to have preexisting posterior vitreous detachment. Macular retinoschisis was resolved or reduced in all the six eyes after vitrectomy. The mean central foveal thickness showed significant improvement at the time of the patient's final visit after vitrectomy. The mean best-corrected visual acuity was 20/52 before surgery and 20/31 at the final visit. Vitrectomy might be effective for the treatment of macular retinoschisis without an optic disk pit. Although clinically similar to optic pit maculopathy except for the absence of pit, our intraoperative observations of the posterior hyaloid membrane suggest that maculopathy without optic disk pit has a distinct pathogenesis.

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

NASA Technical Reports Server (NTRS)

Woo, Simon S.

2011-01-01

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

Dual-wavelengths photoacoustic temperature measurement

NASA Astrophysics Data System (ADS)

Liao, Yu; Jian, Xiaohua; Dong, Fenglin; Cui, Yaoyao

2017-02-01

Thermal therapy is an approach applied in cancer treatment by heating local tissue to kill the tumor cells, which requires a high sensitivity of temperature monitoring during therapy. Current clinical methods like fMRI near infrared or ultrasound for temperature measurement still have limitations on penetration depth or sensitivity. Photoacoustic temperature sensing is a newly developed temperature sensing method that has a potential to be applied in thermal therapy, which usually employs a single wavelength laser for signal generating and temperature detecting. Because of the system disturbances including laser intensity, ambient temperature and complexity of target, the accidental errors of measurement is unavoidable. For solving these problems, we proposed a new method of photoacoustic temperature sensing by using two wavelengths to reduce random error and increase the measurement accuracy in this paper. Firstly a brief theoretical analysis was deduced. Then in the experiment, a temperature measurement resolution of about 1° in the range of 23-48° in ex vivo pig blood was achieved, and an obvious decrease of absolute error was observed with averagely 1.7° in single wavelength pattern while nearly 1° in dual-wavelengths pattern. The obtained results indicates that dual-wavelengths photoacoustic sensing of temperature is able to reduce random error and improve accuracy of measuring, which could be a more efficient method for photoacoustic temperature sensing in thermal therapy of tumor.

Progressive Retinal Nerve Fiber Layer Atrophy Associated With Enlarging Peripapillary Pit.

PubMed

Lee, Eun Ji; Kim, Tae-Woo

2017-02-01

To report a case in which progressive retinal nerve fiber layer (RNFL) atrophy was observed along with enlargement of the peripapillary pit. A 34-year-old male was diagnosed with primary open-angle glaucoma and followed up for 4 years with regular ophthalmic examinations. Both eyes were myopic (-10 D, OD and -10.5 D, OS), and untreated intraocular pressures were 18 mm Hg (OD) and 16 mm Hg (OS). A subtle depression of the superotemporal peripapillary area was deepened and emerged as a peripapillary pit during the follow-up period. With the enlargement of the peripapillary pit, a RNFL defect at the location of pit widened and thinned continuously. The enlargement of the pit was documented by the spectral-domain optical coherence tomography posterior pole scanning. Progressive RNFL atrophy was observed with enlargement of the peripapillary pit. The finding suggests that tensile stress derived from the scleral stretching may have significant influence on the integrity of the RNFL.

Mechanism of water-stress induced cavitation in conifers: bordered pit structure and function support the hypothesis of seal capillary-seeding.

PubMed

Delzon, Sylvain; Douthe, Cyril; Sala, Anna; Cochard, Herve

2010-12-01

Resistance to water-stress induced cavitation is an important indicator of drought tolerance in woody species and is known to be intimately linked to the anatomy of the xylem. However, the actual mechanical properties of the pit membrane are not well known and the exact mode of air-seeding by which cavitation occurs is still uncertain. We examined the relationship between cavitation resistance and bordered pit structure and function in 40 coniferous species. Xylem pressure inducing 50% loss of hydraulic conductance (P(50), a proxy for cavitation resistance) varied widely among species, from -2.9 to -11.3 MPa. The valve effect of the pit membrane, measured as a function of margo flexibility and torus overlap, explained more variation in cavitation-resistance than simple anatomical traits such as pit membrane, pit aperture or torus size. Highly cavitation resistant species exhibited both a high flexibility of the margo and a large overlap between the torus and the pit aperture, allowing the torus to tightly seal the pit aperture. Our results support the hypothesis of seal capillary-seeding as the most likely mode of air-seeding, and suggest that the adhesion of the torus to the pit border may be the main determinant of cavitation resistance in conifers. © 2010 Blackwell Publishing Ltd.

Mechanism of water-stress induced cavitation in conifers: bordered pit structure and function support the hypothesis of seal capillary-seeding

PubMed Central

DELZON, SYLVAIN; DOUTHE, CYRIL; SALA, ANNA; COCHARD, HERVE

2010-01-01

Resistance to water-stress induced cavitation is an important indicator of drought tolerance in woody species and is known to be intimately linked to the anatomy of the xylem. However, the actual mechanical properties of the pit membrane are not well known and the exact mode of air-seeding by which cavitation occurs is still uncertain. We examined the relationship between cavitation resistance and bordered pit structure and function in 40 coniferous species. Xylem pressure inducing 50% loss of hydraulic conductance (P50, a proxy for cavitation resistance) varied widely among species, from −2.9 to −11.3 MPa. The valve effect of the pit membrane, measured as a function of margo flexibility and torus overlap, explained more variation in cavitation-resistance than simple anatomical traits such as pit membrane, pit aperture or torus size. Highly cavitation resistant species exhibited both a high flexibility of the margo and a large overlap between the torus and the pit aperture, allowing the torus to tightly seal the pit aperture. Our results support the hypothesis of seal capillary-seeding as the most likely mode of air-seeding, and suggest that the adhesion of the torus to the pit border may be the main determinant of cavitation resistance in conifers. PMID:20636490

Relationship between the Foveal Avascular Zone and Foveal Pit Morphology

PubMed Central

Dubis, Adam M.; Hansen, Benjamin R.; Cooper, Robert F.; Beringer, Joseph; Dubra, Alfredo; Carroll, Joseph

2012-01-01

Purpose. To assess the relationship between foveal pit morphology and size of the foveal avascular zone (FAZ). Methods. Forty-two subjects were recruited. Volumetric images of the macula were obtained using spectral domain optical coherence tomography. Images of the FAZ were obtained using either a modified fundus camera or an adaptive optics scanning light ophthalmoscope. Foveal pit metrics (depth, diameter, slope, volume, and area) were automatically extracted from retinal thickness data, whereas the FAZ was manually segmented by two observers to extract estimates of FAZ diameter and area. Results. Consistent with previous reports, the authors observed significant variation in foveal pit morphology. The average foveal pit volume was 0.081 mm3 (range, 0.022 to 0.190 mm3). The size of the FAZ was also highly variable between persons, with FAZ area ranging from 0.05 to 1.05 mm2 and FAZ diameter ranging from 0.20 to 1.08 mm. FAZ area was significantly correlated with foveal pit area, depth, and volume; deeper and broader foveal pits were associated with larger FAZs. Conclusions. Although these results are consistent with predictions from existing models of foveal development, more work is needed to confirm the developmental link between the size of the FAZ and the degree of foveal pit excavation. In addition, more work is needed to understand the relationship between these and other anatomic features of the human foveal region, including peak cone density, rod-free zone diameter, and Henle fiber layer. PMID:22323466

An in situ trap capacitance measurement and ion-trapping detection scheme for a Penning ion trap facility.

PubMed

Reza, Ashif; Banerjee, Kumardeb; Das, Parnika; Ray, Kalyankumar; Bandyopadhyay, Subhankar; Dam, Bivas

2017-03-01

This paper presents the design and implementation of an in situ measurement setup for the capacitance of a five electrode Penning ion trap (PIT) facility at room temperature. For implementing a high Q resonant circuit for the detection of trapped electrons/ions in a PIT, the value of the capacitance of the trap assembly is of prime importance. A tunable Colpitts oscillator followed by a unity gain buffer and a low pass filter is designed and successfully implemented for a two-fold purpose: in situ measurement of the trap capacitance when the electric and magnetic fields are turned off and also providing RF power at the desired frequency to the PIT for exciting the trapped ions and subsequent detection. The setup is tested for the in situ measurement of trap capacitance at room temperature and the results are found to comply with those obtained from measurements using a high Q parallel resonant circuit setup driven by a standard RF signal generator. The Colpitts oscillator is also tested successfully for supplying RF power to the high Q resonant circuit, which is required for the detection of trapped electrons/ions.

Pluto: Pits and mantles on uplands north and east of Sputnik Planitia

NASA Astrophysics Data System (ADS)

Howard, Alan D.; Moore, Jeffrey M.; White, Oliver L.; Umurhan, Orkan M.; Schenk, Paul M.; Grundy, William M.; Schmitt, Bernard; Philippe, Sylvain; McKinnon, William B.; Spencer, John R.; Beyer, Ross A.; Stern, S. Alan; Ennico, Kimberly; Olkin, Cathy B.; Weaver, Harold A.; Young, Leslie A.; New Horizons Science Team

2017-09-01

The highlands region north and east of Sputnik Planitia can be subdivided into seven terrain types based on their physiographic expression. The northern rough uplands are characterized by jagged uplands and broad troughs, and it may contain a deeply-eroded ancient mantle. Dissected terrain has been interpreted to have been eroded by paleo-glaciation. The smooth uplands and pits terrain contains broad, rolling uplands surrounding complexes of pits, some of which contain smooth floors. The uplands are mantled by smooth-surfaced deposits possibly derived from adjacent pits through low-power explosive cryovolcanism or through slow vapor condensation. The eroded smooth uplands appear to have originally been smooth uplands and pits terrain modified by small-scale sublimation pitting. The bright pitted uplands features intricate texturing by reticulate ridges that may have originated by sublimation erosion, volatile condensation, or both. The bladed terrain is characterized by parallel ridges oriented north-south and is discussed in a separate paper. The dark uplands are mantled with reddish deposits that may be atmospherically deposited tholins. Their presence has affected long-term landform evolution. Widespread pit complexes occur on most of the terrain units. Most appear to be associated with tectonic lineations. Some pits are floored by broad expanses of ices, whereas most feature deep, conical depressions. A few pit complexes are enclosed by elevated rims of uncertain origin.

Laser Pyrometer For Spot Temperature Measurements

NASA Technical Reports Server (NTRS)

Elleman, D. D.; Allen, J. L.; Lee, M. C.

1988-01-01

Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

Pits, pipes, ponds--and me.

PubMed

Mara, Duncan

2013-05-01

My life in low-cost sanitation and low-cost wastewater treatment and the use of treated wastewater in agriculture and aquaculture really has been 'pits, pipes and ponds' - 'pits' are low-cost sanitation technologies (LCST) such as VIP latrines and pour-flush toilets; 'pipes' are low-cost sewerage, principally condominial (simplified) sewerage; and 'ponds' are low-cost wastewater treatment systems, especially waste stabilization ponds, and the use of treated wastewater in agriculture and aquaculture. 'Pits' were mainly working on World Bank LCST research projects, with fieldwork principally in Zimbabwe, 'pipes' were working on condominial sewerage projects in Brazil and disseminating this LCST to a wider global audience, and 'ponds' were waste stabilization ponds, with fieldwork mainly in Brazil, Colombia, Portugal and the United Kingdom, the development of aerated rock filters to polish facultative-pond effluents, and the human-health aspects of treated wastewater use in agriculture and aquaculture, with fieldwork in Brazil and the UK, and the application of quantitative microbial risk analysis. The paper provides a professional perspective and lessons from historical developments and gives recommended future directions based on my career working on low-cost sanitation technologies and treated wastewater use in agriculture and aquaculture. Copyright © 2013 Elsevier Ltd. All rights reserved.

Pit Crater - False Color

NASA Image and Video Library

2015-06-18

The THEMIS VIS camera contains 5 filters. Data from different filters can be combined in multiple ways to create a false color image. This image from NASA 2001 Mars Odyssey spacecraft shows the central pit of an unnamed crater south of Coprates Catena.

A proposed origin for palimpsests and anomalous pit craters on Ganymede and Callisto

NASA Technical Reports Server (NTRS)

Croft, S. K.

1983-01-01

The hypothesis that palimpsests and anomalous pit craters are essentially pristine crater forms derived from high-velocity impacts and/or impacts into an ice crust with preimpact temperatures near melting is explored. The observational data are briefly reviewed, and an impact model is proposed for the direct formation of a palimpsest from an impact when the modification flow which produces the final crater is dominated by 'wet' fluid flow, as opposed to the 'dry' granular flow which produces normal craters. Conditions of 'wet' modification occur when the volume of impact melt remaining in the transient crater attains a volume comparable to the transient crater. The normal crater-palimpsest transition is found to occur for sufficiently large impacts or sufficiently fast impactors. The range of crater diameters and morphological characteristics inferred from the impact model is consistent with the observed characteristics of palimpsests and anomalous pit craters.

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

PubMed

Strømman, G; Rosseland, B O; Skipperud, L; Burkitbaev, L M; Uralbekov, B; Heier, L S; Salbu, B

2013-09-01

Kurday in Kazhakstan and Taboshar in Tajikistan were U mining sites operated during the 1950s and 1960s as part of the USSR nuclear weapon program. Today, they represent sources of potential U contamination of the environment. Within both mining sites, open pits from which U ore was extracted have been filled with water due to ground water inflow and precipitation. These artificial pit lakes contain fish consumed occasionally by the local people, and wild and domestic animals are using the water for drinking purposes. To assess the potential impact from U in these pit lakes, field work was performed in 2006 in Kurday and 2006 and 2008 in Taboshar. Results show that the U concentration in the lake waters were relatively high, about 1 mg/L in Kurday Pit Lake and about 3 mg/L in Taboshar Pit Lake. The influence of U-bearing materials on the lakes and downstream waters were investigated by measuring the U concentration and the (234)U/(238)U activity ratios. In both Kurday and Taboshar, the ratios increased distinctively from about 1 at the pit lakes to >1.5 far downstream the lakes. The concentrations of (238)U in gill, liver, muscle and bones in fish from the pit lakes were much higher than in the reference fish. Peak concentration of U was seen in bones (13 mg/kg w.w.), kidney (9.1 mg/kg w.w.) and gills (8.9 mg/kg w.w.) from Cyprinus auratus caught in the Taboshar Pit Lake. Bioconcentration factors (BCF) calculated for organs from fish caught in the Taboshar Pit Lake, with the same tendency seen in the Kurday Pit Lake, showed that U accumulates most in bone (BCF = 4.8 L/kg w.w.), gills (BCF = 3.6 L/kg w.w.), kidney (BCF = 3.6 L/kg w.w.), and liver (BCF = 2.5 L/kg w.w.), while least was accumulated in the muscle (BCF = 0.12 L/kg w.w.). Copyright © 2012 Elsevier Ltd. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, I.-Y.; Seo, H.-S.; Ahn, B.-S.

2010-03-12

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

An Autoregulatory Pathway Establishes the Definitive Chromatin Conformation at the Pit-1 Locus

PubMed Central

Cooke, Nancy E.; Liebhaber, Stephen A.

2015-01-01

The transcription factor Pit-1 (POU1-F1) plays a dominant role in cell lineage expansion and differentiation in the anterior pituitary. Prior studies of the mouse Pit-1 (mPit-1) gene revealed that this master regulatory locus is activated at embryonic day 13.5 (E13.5) by an early enhancer (EE), whereas its subsequent expression throughout adult life is maintained by a more distal definitive enhancer (DE). Here, we demonstrate that the sequential actions of these two enhancers are linked to corresponding shifts in their proximities to the Pit-1 promoter. We further demonstrate that the looping of the definitive enhancer to the mPit-1 promoter is critically dependent on a self-sustaining autoregulatory mechanism mediated by the Pit-1 protein. These Pit-1-dependent actions are accompanied by localized recruitment of CBP and enrichment for H3K27 acetylation within the Pit-1 locus. These data support a model in which the sequential actions of two developmentally activated enhancers are linked to a corresponding shift in higher-order chromatin structures. This shift establishes an autoregulatory circuit that maintains durable expression of Pit-1 throughout adult life. PMID:25691665

Simulation of Fatigue Crack Initiation at Corrosion Pits With EDM Notches

NASA Technical Reports Server (NTRS)

Smith, Stephen W.; Newman, John A.; Piascik, Robert S.

2003-01-01

Uniaxial fatigue tests were conducted to compare the fatigue life of laboratory produced corrosion pits, similar to those observed in the shuttle main landing gear wheel bolt-hole, and an electro-discharged-machined (EDM) flaw. EDM Jaws are used to simulate corrosion pits during shuttle wheel (dynamometer) testing. The aluminum alloy, (AA 7050) laboratory fatigue tests were conducted to simulate the local stress level contained in the wheel bolt-hole. Under this high local stress condition, the EDM notch produced a fatigue life similar to test specimens containing corrosion pits of similar size. Based on the laboratory fatigue test results, the EDM Jaw (semi-circular disc shaped) produces a local stress state similar to corrosion pits and can be used to simulate a corrosion pit during the shuttle wheel dynamometer tests.

Phosphate Uptake-Independent Signaling Functions of the Type III Sodium-Dependent Phosphate Transporter, PiT-1, in Vascular Smooth Muscle Cells

PubMed Central

Chavkin, Nicholas W.; Jun Chia, Jia; Crouthamel, Matthew H.; Giachelli, Cecilia M.

2015-01-01

Vascular calcification (VC) is prevalent in chronic kidney disease and elevated serum inorganic phosphate (Pi) is a recognized risk factor. The type III sodium-dependent phosphate transporter, PiT-1, is required for elevated Pi-induced osteochondrogenic differentiation and matrix mineralization in vascular smooth muscle cells (VSMCs). However, the molecular mechanism(s) by which PiT-1 promotes these processes is unclear. In the present study, we confirmed that the Pi concentration required to induce osteochondrogenic differentiation and matrix mineralization of mouse VSMCs was well above that required for maximal Pi uptake, suggesting a signaling function of PiT-1 that was independent of Pi transport. Elevated Pi-induced signaling via ERK1/2 phosphorylation was abrogated in PiT-1 deficient VSMCs, but could be rescued by wild-type (WT) and a Pi transport-deficient PiT-1 mutant. Furthermore, both WT and transport-deficient PiT-1 mutants promoted osteochondrogenic differentiation as measured by decreased SM22α and increased osteopontin mRNA expression. Finally, compared to vector alone, expression of transport-deficient PiT-1 mutants promoted VSMC matrix mineralization, but not to the extent observed with PiT-1 WT. These data suggest that both Pi uptake-dependent and -independent functions of PiT-1 are important for VSMC processes mediating vascular calcification. PMID:25684711

Atomic force microscopy of atomic-scale ledges and etch pits formed during dissolution of quartz

NASA Technical Reports Server (NTRS)

Gratz, A. J.; Manne, S.; Hansma, P. K.

1991-01-01

The processes involved in the dissolution and growth of crystals are closely related. Atomic force microscopy (AFM) of faceted pits (called negative crystals) formed during quartz dissolution reveals subtle details of these underlying physical mechanisms for silicates. In imaging these surfaces, the AFM detected ledges less than 1 nm high that were spaced 10 to 90 nm apart. A dislocation pit, invisible to optical and scanning electron microscopy measurements and serving as a ledge source, was also imaged. These observations confirm the applicability of ledge-motion models to dissolution and growth of silicates; coupled with measurements of dissolution rate on facets, these methods provide a powerful tool for probing mineral surface kinetics.

Noncontact true temperature measurement, 2

NASA Technical Reports Server (NTRS)

Lee, Mark C.; Allen, James L.

1988-01-01

A laser pyrometer was developed for acquiring the true temperature of a levitated sample. The reflectivity is measured by first expanding the laser beam to cover the entire cross-sectional surface of the diffuse target. The reflectivity calibration of this system is determined from the surface emissivity of a target with a blackbody cavity. The emissivity of the real target can then be calculated. The overall system constant is obtained by passively measuring the radiance of the blackbody cavity (emissivity = 1.0) at a known, arbitrary temperature. Since the photosensor used is highly linear over the entire operating temperature range, the true temperature of the target can then be computed. The latest results available from this on-going research indicate that true temperatures thus obtained are in very good quantitative agreement with thermocouple measured temperatures.

Survival and growth of juvenile Pacific lampreys tagged with passive integrated transponders (PIT) in freshwater and seawater

USGS Publications Warehouse

Mesa, Matthew G.; Copeland, Elizabeth S.; Christiansen, Helena E.; Gregg, Jacob L.; Roon, Sean R.; Hershberger, Paul K.

2012-01-01

Tagging methods are needed for both adult and juvenile life stages of Pacific lampreys Lampetra tridentata to better understand their biology and factors contributing to their decline. We developed a safe and efficient technique for tagging juvenile Pacific lampreys with passive integrated transponder (PIT) tags. We tested the short-term survival of PIT-tagged juvenile lampreys in freshwater at four temperatures (9, 12, 15, and 18°C) and their long-term growth and survival in seawater. For both experiments there was little to no tag loss, and juvenile lampreys in freshwater showed high survival at all temperatures at 7 d (95–100%) and 14 d (88–100%) posttagging. Prolonged holding (40 d) resulted in significantly lower survival (28–79%) at warmer temperatures (12–18°C). For juvenile lampreys tagged in freshwater and then transitioned to seawater, survival was 97% for tagged fish until day 94, and at the end of 6 months, survival was about 58% for both tagged and control fish. About half of the tagged and control fish that survived in seawater grew, but there was no difference in growth between the two groups. In freshwater, but not in seawater, most fish that died had an aquatic fungal infection. In both experiments, survival increased with increasing fish length at tagging. Our results indicate that tags similar in size to a 9-mm PIT tag are a feasible option for tagging metamorphosed juvenile lampreys migrating downstream and that when fungal infections are mitigated—as in seawater—long-term (at least 6 months) survival of tagged juvenile lampreys is high.

Railroad Rails Containing Electrode-Induced Pitting from Pressure Electric Welding

DOT National Transportation Integrated Search

2018-04-18

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

Pit-chain in Noctis Labyrinthus

NASA Image and Video Library

2002-12-20

These pit-chain features in this NASA Mars Odyssey image of south Noctis Labryinthus are oriented parallel to grabens in the area, suggesting that tensional stresses may have been responsible for their formation.

Nucleation sites of Ge nanoislands grown on pit-patterned Si substrate prepared by electron-beam lithography

NASA Astrophysics Data System (ADS)

Smagina, Zh. V.; Zinovyev, V. A.; Rudin, S. A.; Novikov, P. L.; Rodyakina, E. E.; Dvurechenskii, A. V.

2018-04-01

Regular pit-patterned Si(001) substrates were prepared by electron-beam lithography followed by plasma chemical etching. The geometry of the pits was controlled by varying the etching conditions and the electron-beam exposure duration. It was shown that the location of three-dimensional (3D) Ge nanoislands subsequently grown on the pit-patterned Si substrates depends on the shape of the pit bottom. In the case of pits having a sharp bottom, 3D Ge islands nucleate inside the pits. For pits with a wide flat bottom, the 3D Ge island nucleation takes place at the pit periphery. This effect is attributed to the strain relaxation depending not only on the initial pit shape, but also on its evolution during the Ge wetting layer deposition. It was shown by Monte Carlo simulations that in the case of a pit with a pointed bottom, the relaxation is most effective inside the pit, while for a pit with a wide bottom, the most relaxed area migrates during Ge deposition from the pit bottom to its edges, where 3D Ge islands nucleate.

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

PubMed

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

2015-07-02

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

Thermospheric temperature measurement technique.

NASA Technical Reports Server (NTRS)

Hueser, J. E.; Fowler, P.

1972-01-01

A method for measurement of temperature in the earth's lower thermosphere from a high-velocity probes is described. An undisturbed atmospheric sample is admitted to the instrument by means of a free molecular flow inlet system of skimmers which avoids surface collisions of the molecules prior to detection. Measurement of the time-of-flight distribution of an initially well-localized group of nitrogen metastable molecular states produced in an open, crossed electron-molecular beam source, yields information on the atmospheric temperature. It is shown that for high vehicle velocities, the time-of-flight distribution of the metastable flux is a sensitive indicator of atmospheric temperature. The temperature measurement precision should be greater than 94% at the 99% confidence level over the range of altitudes from 120-170 km. These precision and altitude range estimates are based on the statistical consideration of the counting rates achieved with a multichannel analyzer using realistic values for system parameters.

Temperature Measurement Aid

NASA Technical Reports Server (NTRS)

1979-01-01

NASA's Ames Research Center has designed a simple but medically important device--one which holds temperature probes, called thermistors, to a person's skin without affecting the characteristics of the skin segment being measured. The device improves the accuracy of skin surface temperature measurements, valuable data in health evaluation. The need for such a device was recognized in the course of life science experiments at Ames. In earlier methods, the sensing head of the temperature probe was affixed to the patient's skin by tape or elastic bands. This created a heat variance which altered skin temperature readings. The Ames-developed thermistor holder is a plastic ring with tab extensions, shown in the upper photo on the chest, arm and leg of the patient undergoing examination. The ring holds the sensing head of the temperature probe and provides firm, constant pressure between the skin and the probe. The tabs help stabilize the ring and provide attachment points for the fastening tape or bands, which do not directly touch the sensor. With this new tool, it is possible to determine more accurately the physiological effects of strenuous exercise, particularly on the treadmill. The holder is commercially available from Yellow Springs Instrument Company, Inc., Yellow Springs, Ohio, which is producing the device under a NASA patent license.

Structure and function of bordered pits: new discoveries and impacts on whole-plant hydraulic function.

PubMed

Choat, Brendan; Cobb, Alexander R; Jansen, Steven

2008-01-01

Bordered pits are cavities in the lignified cell walls of xylem conduits (vessels and tracheids) that are essential components in the water-transport system of higher plants. The pit membrane, which lies in the center of each pit, allows water to pass between xylem conduits but limits the spread of embolism and vascular pathogens in the xylem. Averaged across a wide range of species, pits account for > 50% of total xylem hydraulic resistance, indicating that they are an important factor in the overall hydraulic efficiency of plants. The structure of pits varies dramatically across species, with large differences evident in the porosity and thickness of pit membranes. Because greater porosity reduces hydraulic resistance but increases vulnerability to embolism, differences in pit structure are expected to correlate with trade-offs between efficiency and safety of water transport. However, trade-offs in hydraulic function are influenced both by pit-level differences in structure (e.g. average porosity of pit membranes) and by tissue-level changes in conduit allometry (average length, diameter) and the total surface area of pit membranes that connects vessels. In this review we address the impact of variation in pit structure on water transport in plants from the level of individual pits to the whole plant.

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

PubMed

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

2014-06-05

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

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

PubMed Central

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

2014-01-01

Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water. PMID:28788679

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

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

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

Pitted keratolysis*

PubMed Central

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

2016-01-01

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

Phosphate (Pi)-regulated heterodimerization of the high-affinity sodium-dependent Pi transporters PiT1/Slc20a1 and PiT2/Slc20a2 underlies extracellular Pi sensing independently of Pi uptake.

PubMed

Bon, Nina; Couasnay, Greig; Bourgine, Annabelle; Sourice, Sophie; Beck-Cormier, Sarah; Guicheux, Jérôme; Beck, Laurent

2018-02-09

Extracellular phosphate (P i ) can act as a signaling molecule that directly alters gene expression and cellular physiology. The ability of cells or organisms to detect changes in extracellular P i levels implies the existence of a P i -sensing mechanism that signals to the body or individual cell. However, unlike in prokaryotes, yeasts, and plants, the molecular players involved in P i sensing in mammals remain unknown. In this study, we investigated the involvement of the high-affinity, sodium-dependent P i transporters PiT1 and PiT2 in mediating P i signaling in skeletal cells. We found that deletion of PiT1 or PiT2 blunted the P i -dependent ERK1/2-mediated phosphorylation and subsequent gene up-regulation of the mineralization inhibitors matrix Gla protein and osteopontin. This result suggested that both PiTs are necessary for P i signaling. Moreover, the ERK1/2 phosphorylation could be rescued by overexpressing P i transport-deficient PiT mutants. Using cross-linking and bioluminescence resonance energy transfer approaches, we found that PiT1 and PiT2 form high-abundance homodimers and P i -regulated low-abundance heterodimers. Interestingly, in the absence of sodium-dependent P i transport activity, the PiT1-PiT2 heterodimerization was still regulated by extracellular P i levels. Of note, when two putative P i -binding residues, Ser-128 (in PiT1) and Ser-113 (in PiT2), were substituted with alanine, the PiT1-PiT2 heterodimerization was no longer regulated by extracellular P i These observations suggested that P i binding rather than P i uptake may be the key factor in mediating P i signaling through the PiT proteins. Taken together, these results demonstrate that P i -regulated PiT1-PiT2 heterodimerization mediates P i sensing independently of P i uptake. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Pits and Scarps

NASA Image and Video Library

2015-04-08

Lessing crater can be seen in the lower left of this image. Instead of the typical central peak found in a complex crater on Mercury, Lessing sports a central pit, likely formed by volcanic activity. A large tectonic scarp that formed when the planet's interior cooled and contracted can be seen running through a crater near the center of the image. http://photojournal.jpl.nasa.gov/catalog/PIA19276

Pitting Corrosion Behaviour of New Corrosion-Resistant Reinforcement Bars in Chloride-Containing Concrete Pore Solution

PubMed Central

Liu, Yao; Chu, Hong-yan; Wang, Danqian; Ma, Han; Sun, Wei

2017-01-01

In this study, the pitting behaviour of a new corrosion-resistant alloy steel (CR) is compared to that of low-carbon steel (LC) in a simulated concrete pore solution with a chloride concentration of 5 mol/L. The electrochemical behaviour of the bars was characterised using linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS). The pitting profiles were detected by reflective digital holographic microscopy (DHM), scanning electron microscopy (SEM), and the chemical components produced in the pitting process were analysed by X-ray energy dispersive spectroscopy (EDS). The results show that the CR bars have a higher resistance to pitting corrosion than the LC bars. This is primarily because of the periodic occurrence of metastable pitting during pitting development. Compared to the pitting process in the LC bars, the pitting depth grows slowly in the CR bars, which greatly reduces the risk of pitting. The possible reason for this result is that the capability of the CR bars to heal the passivation film helps to restore the metastable pits to the passivation state. PMID:28777327

Bordered pit structure and function determine spatial patterns of air-seeding thresholds in xylem of Douglas-fir (Pseudotsuga menziesii; Pinaceae) trees.

Treesearch

J.C. Domec; B. Lachenbruch; F.C. Meinzer

2006-01-01

The air-seeding hypothesis predicts that xylem embolism resistance is linked directly to bordered pit functioning. We tested this prediction in trunks, roots, and branches at different vertical and radial locations in young and old trees of Pseudotsuga menziesii. Dimensions of bordered pits were measured from light and scanning electron micrographs...

New Developments in Nb3Sn PIT Strand: The Effects of Titanium and Second Phase Additions on the Superconducting Properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Motowidlo, L.R.; Ghosh, A.; Distin, J.

2011-08-03

We report the effect of titanium on the transport properties of multifilament PIT strand. In addition, the effect of second phase yttrium additions on the microstructure and the bulk pinning force are reported for PIT Nb{sub 3}Sn mono-core wires. High resolution SEM, EDS, magnetization, and transport measurements were utilized to evaluate the superconducting properties.

Effect of Annealing Temperature on the Mechanical and Corrosion Behavior of a Newly Developed Novel Lean Duplex Stainless Steel.

PubMed

Guo, Yanjun; Hu, Jincheng; Li, Jin; Jiang, Laizhu; Liu, Tianwei; Wu, Yanping

2014-09-12

The effect of annealing temperature (1000-1150 °C) on the microstructure evolution, mechanical properties, and pitting corrosion behavior of a newly developed novel lean duplex stainless steel with 20.53Cr-3.45Mn-2.08Ni-0.17N-0.31Mo was studied by means of optical metallographic microscopy (OMM), scanning electron microscopy (SEM), magnetic force microscopy (MFM), scanning Kelvin probe force microscopy (SKPFM), energy dispersive X-ray spectroscopy (EDS), uniaxial tensile tests (UTT), and potentiostatic critical pitting temperature (CPT). The results showed that tensile and yield strength, as well as the pitting corrosion resistance, could be degraded with annealing temperature increasing from 1000 up to 1150 °C. Meanwhile, the elongation at break reached the maximum of 52.7% after annealing at 1050 °C due to the effect of martensite transformation induced plasticity (TRIP). The localized pitting attack preferentially occurred at ferrite phase, indicating that the ferrite phase had inferior pitting corrosion resistance as compared to the austenite phase. With increasing annealing temperature, the pitting resistance equivalent number (PREN) of ferrite phase dropped, while that of the austenite phase rose. Additionally, it was found that ferrite possessed a lower Volta potential than austenite phase. Moreover, the Volta potential difference between ferrite and austenite increased with the annealing temperature, which was well consistent with the difference of PREN.

Effect of Annealing Temperature on the Mechanical and Corrosion Behavior of a Newly Developed Novel Lean Duplex Stainless Steel

PubMed Central

Guo, Yanjun; Hu, Jincheng; Li, Jin; Jiang, Laizhu; Liu, Tianwei; Wu, Yanping

2014-01-01

The effect of annealing temperature (1000–1150 °C) on the microstructure evolution, mechanical properties, and pitting corrosion behavior of a newly developed novel lean duplex stainless steel with 20.53Cr-3.45Mn-2.08Ni-0.17N-0.31Mo was studied by means of optical metallographic microscopy (OMM), scanning electron microscopy (SEM), magnetic force microscopy (MFM), scanning Kelvin probe force microscopy (SKPFM), energy dispersive X-ray spectroscopy (EDS), uniaxial tensile tests (UTT), and potentiostatic critical pitting temperature (CPT). The results showed that tensile and yield strength, as well as the pitting corrosion resistance, could be degraded with annealing temperature increasing from 1000 up to 1150 °C. Meanwhile, the elongation at break reached the maximum of 52.7% after annealing at 1050 °C due to the effect of martensite transformation induced plasticity (TRIP). The localized pitting attack preferentially occurred at ferrite phase, indicating that the ferrite phase had inferior pitting corrosion resistance as compared to the austenite phase. With increasing annealing temperature, the pitting resistance equivalent number (PREN) of ferrite phase dropped, while that of the austenite phase rose. Additionally, it was found that ferrite possessed a lower Volta potential than austenite phase. Moreover, the Volta potential difference between ferrite and austenite increased with the annealing temperature, which was well consistent with the difference of PREN. PMID:28788201

Phosphate assimilation in Rhizobium (Sinorhizobium) meliloti: identification of a pit-like gene.

PubMed

Bardin, S D; Voegele, R T; Finan, T M

1998-08-01

Rhizobium meliloti mutants defective in the phoCDET-encoded phosphate transport system form root nodules on alfalfa plants that fail to fix nitrogen (Fix-). We have previously reported that two classes of second-site mutations can suppress the Fix- phenotype of phoCDET mutants to Fix+. Here we show that one of these suppressor loci (sfx1) contains two genes, orfA and pit, which appear to form an operon transcribed in the order orfA-pit. The Pit protein is homologous to various phosphate transporters, and we present evidence that three suppressor mutations arose from a single thymidine deletion in a hepta-thymidine sequence centered 54 nucleotides upstream of the orfA transcription start site. This mutation increased the level of orfA-pit transcription. These data, together with previous biochemical evidence, show that the orfA-pit genes encode a Pi transport system that is expressed in wild-type cells grown with excess Pi but repressed in cells under conditions of Pi limitation. In phoCDET mutant cells, orfA-pit expression is repressed, but this repression is alleviated by the second-site suppressor mutations. Suppression increases orfA-pit expression compensating for the deficiencies in phosphate assimilation and symbiosis of the phoCDET mutants.

Engineered river flow-through to improve mine pit lake and river values.

PubMed

McCullough, Cherie D; Schultze, Martin

2018-05-30

Mine pit lakes may develop at mine closure when mining voids extend below groundwater levels and fill with water. Acid and metalliferous drainage (AMD) and salinity are common problems for pit lake water quality. Contaminated pit lake waters can directly present significant risk to both surrounding and regional communities and natural environmental values and limit beneficial end use opportunities. Pit lake waters can also discharge into surface and groundwater; or directly present risks to wildlife, stock and human end users. Riverine flow-through is increasingly proposed to mitigate or remediate pit lake water contamination using catchment scale processes. This paper presents the motivation and key processes and considerations for a flow-through pit lake closure strategy. International case studies as precedent and lessons for future application are described from pit lakes that use or propose flow-through as a key component of their mine closure design. Chemical and biological processes including dilution, absorption and flocculation and sedimentation can sustainably reduce pit lake contaminant concentrations to acceptable levels for risk and enable end use opportunities to be realised. Flow-through may be a valid mine closure strategy for pit lakes with poor water quality. However, maintenance of existing riverine system values must be foremost. We further suggest that decant river water quality may, in some circumstances, be improved; notably in examples of meso-eutrophic river waters flowing through slightly acidic pit lakes. Flow-through closure strategies must be scientifically justifiable and risk-based for both lake and receptors potentially affected by surface and groundwater transport. Due to the high-uncertainty associated with this complex strategy, biotic and physico-chemical attributes of both inflow and decant river reaches as well as lake should be well monitored. Monitoring should directly feed into an adaptive management framework discussed with

Bed conduction impact on fiber optic distributed temperature sensing water temperature measurements

NASA Astrophysics Data System (ADS)

O'Donnell Meininger, T.; Selker, J. S.

2015-02-01

Error in distributed temperature sensing (DTS) water temperature measurements may be introduced by contact of the fiber optic cable sensor with bed materials (e.g., seafloor, lakebed, streambed). Heat conduction from the bed materials can affect cable temperature and the resulting DTS measurements. In the Middle Fork John Day River, apparent water temperature measurements were influenced by cable sensor contact with aquatic vegetation and fine sediment bed materials. Affected cable segments measured a diurnal temperature range reduced by 10% and lagged by 20-40 min relative to that of ambient stream temperature. The diurnal temperature range deeper within the vegetation-sediment bed material was reduced 70% and lagged 240 min relative to ambient stream temperature. These site-specific results illustrate the potential magnitude of bed-conduction impacts with buried DTS measurements. Researchers who deploy DTS for water temperature monitoring should understand the importance of the environment into which the cable is placed on the range and phase of temperature measurements.

Zebrafish pit1 mutants lack three pituitary cell types and develop severe dwarfism.

PubMed

Nica, Gabriela; Herzog, Wiebke; Sonntag, Carmen; Hammerschmidt, Matthias

2004-05-01

The Pou domain transcription factor Pit-1 is required for lineage determination and cellular commitment processes during mammalian adenohypophysis development. Here we report the cloning and mutational analysis of a pit1 homolog from zebrafish. Compared with mouse, zebrafish pit1 starts to be expressed at a much earlier stage of adenohypophysis development. However, as in the mouse, expression is restricted to a subset of pituitary cell types, excluding proopiomelanocortin (pomc)-expressing cells (corticotropes, melanotropes) and possibly gonadotropes. We could identify two N-ethyl-N-nitrosourea-induced zebrafish pit1 null mutants. Most mutants die during larval stages, whereas survivors develop severe dwarfism. Mutant larvae lack lactotropes, somatotropes, and thyrotropes, although the adenohypophysis is of normal size, without any sign of increased apoptosis rates. Instead, mutant embryos initiate ectopic expression of pomc in pit1-positive cells, leading to an expansion of the Pomc lineage. Similarly, the number of gonadotropes seems increased, as indicated by the expression of gsualpha, a marker for thyrotropes and gonadotropes. In pit1 mutants, the total number of gsualpha-positive cells is normal despite the loss of gsualpha and tshbeta coexpressing cells. Together, these data suggest a transfating of the Pit1 lineage to the Pomc and possibly the gonadotroph lineages in the mutant, and a pomc- and gonadotropin-repressive role of Pit1 during normal zebrafish development. This is different from mouse, for which a repressive role of Pit-1 has only been reported for the gonadotropin Lhbeta, but not for Pomc. In sum, our data point to both conserved and class-specific aspects of Pit1 function during pituitary development in different vertebrate species.

Pit membranes of Ephedra resemble gymnosperms more than angiosperms

Treesearch

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

2014-01-01

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

Integrated Emissivity And Temperature Measurement

DOEpatents

Poulsen, Peter

2005-11-08

A multi-channel spectrometer and a light source are used to measure both the emitted and the reflected light from a surface which is at an elevated temperature relative to its environment. In a first method, the temperature of the surface and emissivity in each wavelength is calculated from a knowledge of the spectrum and the measurement of the incident and reflected light. In the second method, the reflected light is measured from a reference surface having a known reflectivity and the same geometry as the surface of interest and the emitted and the reflected light are measured for the surface of interest. These measurements permit the computation of the emissivity in each channel of the spectrometer and the temperature of the surface of interest.

Structural graph-based morphometry: A multiscale searchlight framework based on sulcal pits.

PubMed

Takerkart, Sylvain; Auzias, Guillaume; Brun, Lucile; Coulon, Olivier

2017-01-01

Studying the topography of the cortex has proved valuable in order to characterize populations of subjects. In particular, the recent interest towards the deepest parts of the cortical sulci - the so-called sulcal pits - has opened new avenues in that regard. In this paper, we introduce the first fully automatic brain morphometry method based on the study of the spatial organization of sulcal pits - Structural Graph-Based Morphometry (SGBM). Our framework uses attributed graphs to model local patterns of sulcal pits, and further relies on three original contributions. First, a graph kernel is defined to provide a new similarity measure between pit-graphs, with few parameters that can be efficiently estimated from the data. Secondly, we present the first searchlight scheme dedicated to brain morphometry, yielding dense information maps covering the full cortical surface. Finally, a multi-scale inference strategy is designed to jointly analyze the searchlight information maps obtained at different spatial scales. We demonstrate the effectiveness of our framework by studying gender differences and cortical asymmetries: we show that SGBM can both localize informative regions and estimate their spatial scales, while providing results which are consistent with the literature. Thanks to the modular design of our kernel and the vast array of available kernel methods, SGBM can easily be extended to include a more detailed description of the sulcal patterns and solve different statistical problems. Therefore, we suggest that our SGBM framework should be useful for both reaching a better understanding of the normal brain and defining imaging biomarkers in clinical settings. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling pitting corrosion of iron exposed to alkaline solutions containing nitrate and nitrite

NASA Astrophysics Data System (ADS)

Chen, Lifeng

2001-07-01

Pitting corrosion could be extremely serious for dilute high-level radioactive waste stored or processed in carbon steel tanks at the Savannah River Site. In these solutions, nitrate is an aggressive ion with respect to pitting of carbon steel while nitrite can be used as an inhibitor. Excessive additions of nitrite increase the risk of generating unstable nitrogen compounds during waste processing, and insufficient additions of nitrite could increase the risk of corrosion-induced failure. Thus there are strong incentives to obtain a fundamental understanding of the role of nitrite in pitting corrosion prevention with these solution chemistries. In this dissertation, both a 1-D and a 2-D model are used to study the pitting mechanism as a function of nitrite/nitrate ratios. The 1-D model used BAND(J) to test a reaction mechanism for the passivation behavior by comparing the predicted Open Circuit Potential (OCP) with OCP data from experiments at different NO2-/NO3- ratio. The model predictions are compared with Cyclic Potentiodynamic Polarization (CPP) experiments. A 2-D model was developed for the propagation of a pit in iron by writing subroutines for finite element software of GAMBIT and FIDAP. Geometrically distributed anodic and cathodic reactions are assumed. The results show three partial explanations describing the inhibition influence of nitrite to iron corrosion: the competing reduction reaction of nitrate to nitrite, the formation of Fe(OH)+, and the function of the porous film. The current distributions and the effect of porosity of the film on pH are also explained. The calculation results also show that rate of pit growth decreases as the pit diameter increases until it reaches a constant value. The profile of the local current density on the pit wall is parabolic for small pits and it changes to a linear distribution for large pits. The model predicts that addition of nitrite will decrease the production of ferrous ions and those can prevent iron from

INTERACTIVE PIT LAKES 2004 CONFERENCE

EPA Science Inventory

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

Temperature measuring device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lauf, R.J.; Bible, D.W.; Sohns, C.W.

1999-10-19

Systems and methods are described for a wireless instrumented silicon wafer that can measure temperatures at various points and transmit those temperature readings to an external receiver. The device has particular utility in the processing of semiconductor wafers, where it can be used to map thermal uniformity on hot plates, cold plates, spin bowl chucks, etc. without the inconvenience of wires or the inevitable thermal perturbations attendant with them.

Temperature measuring device

DOEpatents

Lauf, Robert J.; Bible, Don W.; Sohns, Carl W.

1999-01-01

Systems and methods are described for a wireless instrumented silicon wafer that can measure temperatures at various points and transmit those temperature readings to an external receiver. The device has particular utility in the processing of semiconductor wafers, where it can be used to map thermal uniformity on hot plates, cold plates, spin bowl chucks, etc. without the inconvenience of wires or the inevitable thermal perturbations attendant with them.

Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete.

PubMed

Ferguson, David P; Davis, Adam M; Lightfoot, J Timothy

2015-03-01

Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

The convection stack - a device for ridding pit toilets of bad odor

Treesearch

J. Alan Wagar

1962-01-01

One of the common problems on outdoor recreation areas is that pit toilets smell bad. Flush plumbing is one answer to the problem. But pit toilets are needed in many places where modern sewage systems are economically or physically impractical. To reduce the smell of the pit toilet, one simple, safe, and inexpensive device that can be used is the convection stack....

Evaluation of methods for attaching PIT tags and biotelemetry devices to freshwater mussels

USGS Publications Warehouse

Young, S.P.; Isely, J.J.

2008-01-01

We evaluated methods to attach PIT tags and transmitters to freshwater mussels. Mussels received externally-mounted PIT tags using cyanoacrylate or underwater epoxy, and a sub-group of those with PIT tags attached using cyanoacrylate also received dummy transmitters. Tag retention and survival were 100% after a 30 day laboratory observation period for each method. During the subsequent 18 months of field observation, underwater epoxy and cyanoacrylate proved to be adequate adhesives for attaching PIT tags and transmitters. Epoxy performed best with 100% PIT tag retention. Cyanoacrylate also provided high retention rates of PIT tags and transmitters, >90%. Mortality was minimal at 4.7% for all relocated mussels over 18 months. All mortalities were those tagged with cyanoacrylate. Three of the mortalities occurred among mussels fitted with dummy transmitters, and seven among PIT tags only. Percent recapture of the different tag/adhesive combinations ranged from 48 - 77.5% during 6- and 18-month surveys. Results suggest both adhesives provide a reliable method for external attachment of tags during freshwater mussel research; however, epoxy may be better suited because of slightly higher tag retention and reduced emersion times during attachment. Copyright ?? 2008 Malacological Society of Australasia.

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

NASA Astrophysics Data System (ADS)

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

2018-06-01

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

Quantitative Correlation of 7B04 Aluminum Alloys Pitting Corrosion Morphology Characteristics with Stress Concentration Factor

NASA Astrophysics Data System (ADS)

Liu, Zhiguo; Yan, Guangyao; Mu, Zhitao; Li, Xudong

2018-01-01

The accelerated pitting corrosion test of 7B04 aluminum alloy specimen was carried out according to the spectrum which simulated airport environment, and the corresponding pitting corrosion damage was obtained and was defined through three parameters A and B and C which respectively denoted the corrosion pit surface length and width and corrosion pit depth. The ratio between three parameters could determine the morphology characteristics of corrosion pits. On this basis the stress concentration factor of typical corrosion pit morphology under certain load conditions was quantitatively analyzed. The research shows that the corrosion pits gradually incline to be ellipse in surface and moderate in depth, and most value of B/A and C/A lies in 1 between 4 and few maximum exceeds 4; The stress concentration factor Kf of corrosion pits is obviously affected by the its morphology, the value of Kf increases with corrosion pits depth increasement under certain corrosion pits surface geometry. Also, the value of Kf decreases with surface width increasement under certain corrosion pits depth. The research conclusion can set theory basis for corrosion fatigue life analysis of aircraft aluminum alloy structure.

Electronic structures of GeSi nanoislands grown on pit-patterned Si(001) substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Han, E-mail: Dabombyh@aliyun.com; Yu, Zhongyuan

2014-11-15

Patterning pit on Si(001) substrate prior to Ge deposition is an important approach to achieve GeSi nanoislands with high ordering and size uniformity. In present work, the electronic structures of realistic uncapped pyramid, dome, barn and cupola nanoislands grown in (105) pits are systematically investigated by solving Schrödinger equation for heavy-hole, which resorts to inhomogeneous strain distribution and nonlinear composition-dependent band parameters. Uniform, partitioned and equilibrium composition profile (CP) in nanoisland and inverted pyramid structure are simulated separately. We demonstrate the huge impact of composition profile on localization of heavy-hole: wave function of ground state is confined near pit facetsmore » for uniform CP, at bottom of nanoisland for partitioned CP and at top of nanoisland for equilibrium CP. Moreover, such localization is gradually compromised by the size effect as pit filling ratio or pit size decreases. The results pave the fundamental guideline of designing nanoislands on pit-patterned substrates for desired applications.« less

Pitting corrosion of titanium. The relationship between pitting potential and competitive anion adsorption at the oxide film/electrolyte interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basame, S.B.; White, H.S.

2000-04-01

The potential-dependent breakdown of the native oxide film ({approximately}20 {angstrom} thick) on titanium has been investigated in aqueous Br{sup {minus}} solutions and in solutions that contain a mixture of Br{sup {minus}} and anions that inhibit oxide breakdown (i.e., Cl{sup {minus}}, I{sup {minus}}, SO{sub 4}{sup 2{minus}}, Fe(CN){sub 6}{sup 4{minus}}, and Fe(CN){sub 6}{sup 3{minus}}). The oxide film is unstable in neutral pH solutions containing only Br{sup {minus}}, resulting in the formation of stable corrosion pits at relatively low potentials ({approximately}1.4 V vs. Ag/AgCl). The pitting potential, E{sub p}, is strongly dependent upon the concentration of Br{sup {minus}}, and can be modeled usingmore » a Langmuir isotherm to describe the adsorption of Br{sup {minus}} at the oxide film/electrolyte interface. Addition of a second anion inhibits oxide film breakdown, as indicated by a large positive shift in E{sub p} and a decrease in the number of stable corrosion pits. The dependence of E{sub p} on the relative concentrations of Br{sup {minus}} and the inhibitor anion is consistent with competitive adsorption of the anions. Equilibrium adsorption coefficients for I{sup {minus}}, Br{sup {minus}}, and Cl{sup {minus}} are estimated from the dependence of E{sub p} on anion concentration. The results are used to establish a physical basis for the anomalously low pitting potential for titanium in aqueous Br{sup {minus}} solutions.« less

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

NASA Technical Reports Server (NTRS)

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

1983-01-01

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

Shallow V-Shape Nanostructured Pit Arrays in Germanium Using Aqua Regia Electroless Chemical Etching

PubMed Central

Chaabane, Ibtihel; Banerjee, Debika; Touayar, Oualid; Cloutier, Sylvain G.

2017-01-01

Due to its high refractive index, reflectance is often a problem when using Germanium for optoelectronic devices integration. In this work, we propose an effective and low-cost nano-texturing method for considerably reducing the reflectance of bulk Germanium. To do so, uniform V-shape pit arrays are produced by wet electroless chemical etching in a 3:1 volume ratio of highly-concentrated hydrochloridric and nitric acids or so-called aqua regia bath using immersion times ranging from 5 to 60 min. The resulting pit morphology, the crystalline structure of the surface and the changes in surface chemistry after nano-patterning are all investigated. Finally, broadband near-infrared reflectance measurements confirm a significant reduction using this simple wet etching protocol, while maintaining a crystalline, dioxide-free, and hydrogen-passivated surface. It is important to mention that reflectance could be further reduced using deeper pits. However, most optoelectronic applications such as photodetectors and solar cells require relatively shallow patterning of the Germanium to allow formation of a pn-junction close to the surface. PMID:28773215

Temperature measurement systems in wearable electronics

NASA Astrophysics Data System (ADS)

Walczak, S.; Gołebiowski, J.

2014-08-01

The aim of this paper is to present the concept of temperature measurement system, adapted to wearable electronics applications. Temperature is one of the most commonly monitored factor in smart textiles, especially in sportswear, medical and rescue products. Depending on the application, measured temperature could be used as an initial value of alert, heating, lifesaving or analysis system. The concept of the temperature measurement multi-point system, which consists of flexible screen-printed resistive sensors, placed on the T-shirt connected with the central unit and the power supply is elaborated in the paper.

Influence of copper recovery on the water quality of the acidic Berkeley Pit lake, Montana, U.S.A.

PubMed

Tucci, Nicholas J; Gammons, Christopher H

2015-04-07

The Berkeley Pit lake in Butte, Montana, formed by flooding of an open-pit copper mine, is one of the world's largest accumulations of acidic, metal-rich water. Between 2003 and 2012, approximately 2 × 10(11) L of pit water, representing 1.3 lake volumes, were pumped from the bottom of the lake to a copper recovery plant, where dissolved Cu(2+) was precipitated on scrap iron, releasing Fe(2+) back to solution and thence back to the pit. Artificial mixing caused by this continuous pumping changed the lake from a meromictic to holomictic state, induced oxidation of dissolved Fe(2+), and caused subsequent precipitation of more than 2 × 10(8) kg of secondary ferric compounds, mainly schwertmannite and jarosite, which settled to the bottom of the lake. A large mass of As, P, and sulfate was also lost from solution. These unforeseen changes in chemistry resulted in a roughly 25-30% reduction in the lake's calculated and measured total acidity, which represents a significant potential savings in the cost of lime treatment, which is not expected to commence until 2023. Future monitoring is needed to verify that schwertmannite and jarosite in the pit sediment do not convert to goethite, a process which would release stored acidity back to the water column.

Dose-Dependent Dual Role of PIT-1 (POU1F1) in Somatolactotroph Cell Proliferation and Apoptosis

PubMed Central

Jullien, Nicolas; Roche, Catherine; Brue, Thierry; Figarella-Branger, Dominique; Graillon, Thomas; Barlier, Anne; Herman, Jean-Paul

2015-01-01

To test the role of wtPIT-1 (PITWT) or PIT-1 (R271W) (PIT271) in somatolactotroph cells, we established, using inducible lentiviral vectors, sublines of GH4C1 somatotroph cells that allow the blockade of the expression of endogenous PIT-1 and/or the expression of PITWT or PIT271, a dominant negative mutant of PIT-1 responsible for Combined Pituitary Hormone Deficiency in patients. Blocking expression of endogenous PIT-1 induced a marked decrease of cell proliferation. Overexpressing PITWT twofold led also to a dose-dependent decrease of cell proliferation that was accompanied by cell death. Expression of PIT271 induced a strong dose-dependent decrease of cell proliferation accompanied by a very pronounced cell death. These actions of PIT271 are independent of its interaction/competition with endogenous PIT-1, as they were unchanged when expression of endogenous PIT-1 was blocked. All these actions are specific for somatolactotroph cells, and could not be observed in heterologous cells. Cell death induced by PITWT or by PIT271 was accompanied by DNA fragmentation, but was not inhibited by inhibitors of caspases, autophagy or necrosis, suggesting that this cell death is a caspase-independent apoptosis. Altogether, our results indicate that under normal conditions PIT-1 is important for the maintenance of cell proliferation, while when expressed at supra-normal levels it induces cell death. Through this dual action, PIT-1 may play a role in the expansion/regression cycles of pituitary lactotroph population during and after lactation. Our results also demonstrate that the so-called “dominant-negative” action of PIT271 is independent of its competition with PIT-1 or a blockade of the actions of the latter, and are actions specific to this mutant variant of PIT-1. PMID:25822178

Evaluation of manometric temperature measurement, a process analytical technology tool for freeze-drying: part I, product temperature measurement.

PubMed

Tang, Xiaolin; Nail, Steven L; Pikal, Michael J

2006-02-10

This study examines the factors that may cause systematic errors in the manometric temperature measurement (MTM) procedure used to evaluate product temperature during primary drying. MTM was conducted during primary drying using different vial loads, and the MTM product temperatures were compared with temperatures directly measured by thermocouples. To clarify the impact of freeze-drying load on MTM product temperature, simulation of the MTM vapor pressure rise was performed, and the results were compared with the experimental results. The effect of product temperature heterogeneity in MTM product temperature determination was investigated by comparing the MTM product temperatures with directly measured thermocouple product temperatures in systems differing in temperature heterogeneity. Both the simulated and experimental results showed that at least 50 vials (5 mL) were needed to give sufficiently rapid pressure rise during the MTM data collection period (25 seconds) in the freeze dryer, to allow accurate determination of the product temperature. The product temperature is location dependent, with higher temperature for vials on the edge of the array and lower temperature for the vials in the center of the array. The product temperature heterogeneity is also dependent upon the freeze-drying conditions. In product temperature heterogeneous systems, MTM measures a temperature close to the coldest product temperature, even if only a small fraction of the samples have the coldest product temperature. The MTM method is valid even at very low product temperature (-45 degrees C).

Evaluation of manometric temperature measurement, a process analytical technology tool for freeze-drying: Part I, product temperature measurement.

PubMed

Tang, Xiaolin; Nail, Steven L; Pikal, Michael J

2006-03-01

This study examines the factors that may cause systematic errors in the manometric temperature measurement (MTM) procedure used to evaluate product temperature during primary drying. MTM was conducted during primary drying using different vial loads, and the MTM product temperatures were compared with temperatures directly measured by thermocouples. To clarify the impact of freeze-drying load on MTM product temperatures, simulation of the MTM vapor pressure rise was performed, and the results were compared with the experimental results. The effect of product temperature heterogeneity in MTM product temperature determination was investigated by comparing the MTM product temperatures with directly measured thermocouple product temperatures in systems differing in temperature heterogeneity. Both the simulated and experimental results showed that at least 50 vials (5 mL) were needed to give sufficiently rapid pressure rise during the MTM data collection period (25 seconds) in the freeze dryer, to allow accurate determination of the product temperature. The product temperature is location dependent, with higher temperature for vials on the edge of the array and lower temperature for the vials in the center of the array. The product temperature heterogeneity is also dependent upon the freeze-drying conditions. In product temperature heterogeneous systems, MTM measures a temperature close to the coldest product temperature, even, if only a small fraction of the samples have the coldest product temperature. The MTM method is valid even at very low product temperature (-45°C).

Rationale and concept for a lunar pit reconnaissance probe

NASA Astrophysics Data System (ADS)

Dorrington, G. E.

2018-04-01

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

Dynamic interactions of the asialoglycoprotein receptor subunits with coated pits. Enhanced interactions of H2 following association with H1.

PubMed

Katzir, Z; Nardi, N; Geffen, I; Fuhrer, C; Henis, Y I

1994-08-26

Lateral mobility studies comparing native and mutated membrane proteins, combined with treatments that alter clathrin lattice structure, can measure membrane protein-coated pit interactions in intact cells (Fire, E., Zwart, D., Roth, M. G., and Henis, Y. I. (1991) J. Cell Biol. 115, 1585-1594). We applied this approach to study the interactions of the H1 and H2 human asialoglycoprotein receptor subunits with coated pits. The lateral mobilities of singly expressed and coexpressed H1 and H2B (the H2 species that reaches the cell surface) were measured by fluorescence photobleaching recovery. They were compared with mutant proteins, H1(5A) (Tyr-5 replaced by Ala) and H2(5A) (Phe-5 replaced by Ala). While the mobile fractions of H1, H2B, and their mutants were similar, the lateral diffusion rate (measured by D, the lateral diffusion coefficient) was significantly slower for H1, whether expressed alone or with H2B. Coexpression with H1 reduced D of H2B to that of H1. Disruption of the clathrin lattices by hypertonic medium elevated D of H1, H1(5A), H2B, and H2(5A) to the same final level, without affecting their mobile fractions. Cytosol acidification, which retains altered clathrin lattices attached to the membrane and prevents coated vesicle formation, immobilized part of the H1 molecules, reflecting stable entrapment in "frozen" coated pits. H1(5A), H2B, and H2(5A) were not affected; however, coexpression of H2B with H1 conferred the sensitivity to cytosol acidification on H2B. Our results suggest that H1 lateral mobility is inhibited by dynamic interactions with coated pits in which Tyr-5 is involved. H2B resembles H1(5A) rather than H1, and its interactions with coated pits are weaker; efficient interaction of H2B with coated pits depends on complex formation with H1.

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

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

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

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3765 Pit and fissure sealant and...

Measuring Poisson Ratios at Low Temperatures

NASA Technical Reports Server (NTRS)

Boozon, R. S.; Shepic, J. A.

1987-01-01

Simple extensometer ring measures bulges of specimens in compression. New method of measuring Poisson's ratio used on brittle ceramic materials at cryogenic temperatures. Extensometer ring encircles cylindrical specimen. Four strain gauges connected in fully active Wheatstone bridge self-temperature-compensating. Used at temperatures as low as liquid helium.

Algorithms for detecting cherry pits on the basis of transmittance mode hyperspectral data

NASA Astrophysics Data System (ADS)

Siedliska, Anna; Zubik, Monika; Baranowski, Piotr; Mazurek, Wojciech

2017-10-01

The suitability of the hyperspectral transmittance imaging technique was assessed in terms of detecting the internal intrusions (pits and their fragments) in cherries. Herein, hyperspectral transmission images were acquired in the visible and near-infrared range (450-1000 nm) from pitted and intact cherries of three popular cultivars: `Łutówka', `Pandy 103', and `Groniasta', differing by soluble solid content. The hyperspectral transmittance data of fresh cherries were used to determine the influence of differing soluble solid content in fruit tissues on pit detection effectiveness. Models for predicting the soluble solid content of cherries were also developed. The principal component analysis and the second derivative pre-treatment of the hyperspectral data were used to construct the supervised classification models. In this study, five classifiers were tested for pit detection. From all the classifiers studied, the best prediction accuracies for the whole pit or pit fragment detection were obtained via the backpropagation neural networks model (87.6% of correctly classified instances for the training/test set and 81.4% for the validation set). The accuracy of distinguishing between drilled and intact cherries was close to 96%. These results showed that the hyperspectral transmittance imaging technique is feasible and useful for the non-destructive detection of pits in cherries.

Groundwater and surface water interaction in flow-through gravel pit lakes.

NASA Astrophysics Data System (ADS)

Nella Mollema, Pauline; Antonellini, Marco

2015-04-01

Gravel pits are excavated in aquifers to fulfill the need for construction materials. Flow-through lakes form when the gravel pits are below the water table and fill with groundwater. In certain areas there are more than 60 of these lakes close together and their presence changes the drainage patterns and water- and hydrochemical budgets of a watershed. In flow-through gravel pit lakes, groundwater mixes with surface water and interacts with the atmosphere; outflow occurs only via groundwater. The lifespan of gravel pit lakes may be up to thousands of years as their depth to surface ratio is typically large and sedimentation rates are low. We have studied two gravel pit lake systems, a fluvial freshwater system in the Netherlands and a coastal brackish lake system in Italy. One Dutch gravel pit lake studied in detail is in part artificially replenished with Meuse River water for drinking water production that occurs downstream of the lake by water pumps. The Italian gravel pit lakes are fed by brackish groundwater that is a mix of freshwater from precipitation, Apennine Rivers and brackish (Holocene) Adriatic Sea water. Here, the drainage system of the low lying land enhances groundwater flow into the lake. Surface water evaporation is larger in temperate and Mediterranean climates than the actual evapotranspiration of pre-existing grassland and forests. The lakes, therefore, cause a loss of freshwater. The creation of water surfaces allows algae and other flora and fauna to develop. In general, water becomes gradually enriched in certain chemical constituents on its way through the hydrological cycle, especially as groundwater due to water-rock interactions. When groundwater ex-filtrates into gravel pit lakes, the natural flow of solutes towards the sea is interrupted. Hydrochemical analysis of ground- and surface waters, as well as chemical analysis of lake bottom sediments and stable H and O isotope data, show that gravel pit lake water is characterized (among

Pits, rifts and slumps: the summit structure of Piton de la Fournaise

NASA Astrophysics Data System (ADS)

Carter, Adam; van Wyk de Vries, Benjamin; Kelfoun, Karim; Bachèlery, Patrick; Briole, Pierre

2007-06-01

A clear model of structures and associated stress fields of a volcano can provide a framework in which to study and monitor activity. We propose a volcano-tectonic model for the dynamics of the summit of Piton de la Fournaise (La Reunion Island, Indian Ocean). The summit contains two main pit crater structures (Dolomieu and Bory), two active rift zones, and a slumping eastern sector, all of which contribute to the actual fracture system. Dolomieu has developed over 100 years by sudden large collapse events and subsequent smaller drops that include terrace formation. Small intra-pit collapse scars and eruptive fissures are located along the southern floor of Dolomieu. The western pit wall of Dolomieu has a superficial inward dipping normal fault boundary connected to a deeper ring fault system. Outside Dolomieu, an oval extension zone containing sub-parallel pit-related fractures extends to a maximum distance of 225 m from the pit. At the summit the main trend for eruptive fissures is N80°, normal to the north south rift zone. The terraced structure of Dolomieu has been reproduced by analogue models with a roof to width ratio of approximately 1, suggesting an original magma chamber depth of about 1 km. Such a chamber may continue to act as a storage location today. The east flank has a convex concave profile and is bounded by strike-slip fractures that define a gravity slump. This zone is bound to the north by strike-slip fractures that may delineate a shear zone. The southern reciprocal shear zone is probably marked by an alignment of large scoria cones and is hidden by recent aa lavas. The slump head intersects Dolomieu pit and may slide on a hydrothermally altered layer known to be located at a depth of around 300 m. Our model has the summit activity controlled by the pit crater collapse structure, not the rifts. The rifts become important on the mid-flanks of the cone, away from pit-related fractures. On the east flank the superficial structures are controlled

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conditioner. (a) Identification. A pit and fissure sealant and conditioner is a device composed of resin, such...

21 CFR 872.3765 - Pit and fissure sealant and conditioner.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pit and fissure sealant and conditioner. 872.3765 Section 872.3765 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... conditioner. (a) Identification. A pit and fissure sealant and conditioner is a device composed of resin, such...

Study of Etching Pits in a Large-grain Single Cell Bulk Niobium Cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Xin; Ciovati, Gianluigi; Reece, Charles E.

2009-11-01

Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitativelymore » low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed crystal structure surrounding the pits via crystal phase orientation mapping, while 3D profilometry gave information on the depth and size of the pits. In addition, a survey of the samples by energy dispersive X-ray analysis (EDX) did not show any significant contamination of the samples surface.« less

Structural Design and Monitoring Analysis of Foundation Pit Support in Yiwu Huishang Tiandi

NASA Astrophysics Data System (ADS)

Zhang, Chunsu

2017-08-01

Huishang Tiandi deep foundation pit in Yiwu is a two-story basement,which is located in the downtown area and adjacent to the city center main traffic trunk. The surrounding environment is too com-plex to slope. The excavation depth is large, the formation is weak and complex, and the groundwater level is high.In order to ensure the safety of the foundation wall and the surrounding environment, the deformation of the foundation pit support is strictly controlled, and the deformation and internal force of the foundation supporting structure and the surrounding building are monitored.The deformation law of the foundation pit is obtained through the analysis of the horizontal displacement, the deformation rate of the supporting struc-ture, the surrounding environment of the foundation pit and the internal force of the anchor cable. The relia-bility and rationality of the design of foundation pit support are verified. It is of reference value for the de-sign and construction of other deep foundation pit engineering in Yiwu area.

A South Polar Pit or an Impact Crater?

NASA Image and Video Library

2017-05-30

This observation from NASA's Mars Reconnaissance Orbiter show it is late summer in the Southern hemisphere, so the Sun is low in the sky and subtle topography is accentuated in orbital images. We see many shallow pits in the bright residual cap of carbon dioxide ice (also called "Swiss cheese terrain"). There is also a deeper, circular formation that penetrates through the ice and dust. This might be an impact crater or it could be a collapse pit. https://photojournal.jpl.nasa.gov/catalog/PIA21636

Ablation layers to prevent pitting in laser peening

DOEpatents

Hackel, Lloyd A

2016-08-09

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

Loss of PiT-1 Results in Abnormal Endocytosis in the Yolk Sac Visceral Endoderm

PubMed Central

Wallingford, Mary C.; Giachelli, Cecilia M.

2014-01-01

PiT-1 protein is a transmembrane sodium-dependent phosphate (Pi) transporter. PiT-1 knock out (KO) embryos die from largely unknown causes by embryonic day (E) 12.5. We tested the hypothesis that PiT-1 is required for endocytosis in the embryonic yolk sac (YS) visceral endoderm (VE). Here we present data supporting that PiT-1 KO results in a YS remodeling defect and decreased endocytosis in the YS VE. The remodeling defect is not due to an upstream cardiomyocyte requirement for PiT-1, as SM22αCre-specific KO of PiT-1 in the developing heart and the YS mesodermal layer (ME) does not recapitulate the PiT-1 global KO phenotype. Furthermore, we find that high levels of PiT-1 protein localize to the YS VE apical membrane. Together these data support that PiT-1 is likely required in YS VE. During normal development maternal immunoglobulin (IgG) is endocytosed into YS VE and accumulates in the apical side of the VE in a specialized lysosome termed the apical vacuole (AV). We have identified a reduction in PiT-1 KO VE cell height and a striking loss of IgG accumulation in the PiT-1 KO VE. The endocytosis genes Tfeb, Lamtor2 and Snx2 are increased at the RNA level. Lysotracker Red staining reveals a loss of distinct AVs, and yolk sacs incubated ex vivo with phRODO Green Dextran for Endocytosis demonstrate a functional loss of endocytosis. As yolk sac endocytosis is controlled in part by microautophagy, but expression of LC3 had not been examined, we investigated LC3 expression during yolk sac development and found stage-specific LC3 RNA expression that is predominantly from the YS VE layer at E9.5. Normalized LC3-II protein levels are decreased in the PiT-1 KO YS, supporting a requirement for PiT-1 in autophagy in the YS. Therefore, we propose the novel idea that PiT-1 is central to the regulation of endocytosis and autophagy in the YS VE. PMID:25138534

High-Sensitivity Temperature Measurement

ERIC Educational Resources Information Center

Leadstone, G. S.

1978-01-01

Describes a method of measuring small temperature differences that amount to a .01K, using an arrangement of a copper-constantan thermocouple, a microamplifier and a galvanometer, as an indirect way of measuring heat energy. (GA)

The Kelvin and Temperature Measurements

PubMed Central

Mangum, B. W.; Furukawa, G. T.; Kreider, K. G.; Meyer, C. W.; Ripple, D. C.; Strouse, G. F.; Tew, W. L.; Moldover, M. R.; Johnson, B. Carol; Yoon, H. W.; Gibson, C. E.; Saunders, R. D.

2001-01-01

The International Temperature Scale of 1990 (ITS-90) is defined from 0.65 K upwards to the highest temperature measurable by spectral radiation thermometry, the radiation thermometry being based on the Planck radiation law. When it was developed, the ITS-90 represented thermodynamic temperatures as closely as possible. Part I of this paper describes the realization of contact thermometry up to 1234.93 K, the temperature range in which the ITS-90 is defined in terms of calibration of thermometers at 15 fixed points and vapor pressure/temperature relations which are phase equilibrium states of pure substances. The realization is accomplished by using fixed-point devices, containing samples of the highest available purity, and suitable temperature-controlled environments. All components are constructed to achieve the defining equilibrium states of the samples for the calibration of thermometers. The high quality of the temperature realization and measurements is well documented. Various research efforts are described, including research to improve the uncertainty in thermodynamic temperatures by measuring the velocity of sound in gas up to 800 K, research in applying noise thermometry techniques, and research on thermocouples. Thermometer calibration services and high-purity samples and devices suitable for “on-site” thermometer calibration that are available to the thermometry community are described. Part II of the paper describes the realization of temperature above 1234.93 K for which the ITS-90 is defined in terms of the calibration of spectroradiometers using reference blackbody sources that are at the temperature of the equilibrium liquid-solid phase transition of pure silver, gold, or copper. The realization of temperature from absolute spectral or total radiometry over the temperature range from about 60 K to 3000 K is also described. The dissemination of the temperature scale using radiation thermometry from NIST to the customer is achieved by

Surface Temperature Measurement Using Hematite Coating

NASA Technical Reports Server (NTRS)

Bencic, Timothy J. (Inventor)

2015-01-01

Systems and methods that are capable of measuring temperature via spectrophotometry principles are discussed herein. These systems and methods are based on the temperature dependence of the reflection spectrum of hematite. Light reflected from these sensors can be measured to determine a temperature, based on changes in the reflection spectrum discussed herein.

Investigation on Aging σ-Phase Precipitation Kinetics and Pitting Corrosion of 22 Pct Cr Economical Duplex Stainless Steel with Mn Addition

NASA Astrophysics Data System (ADS)

Yang, Yinhui; Qian, Hao

2018-05-01

The influence of Mn addition on σ-phase precipitation kinetics and pitting corrosion of Fe-22Cr-1.9Ni-2.3Mo-0.2N-xMn low nickel type duplex stainless steel was investigated by medium- and high-temperature aging treatments of 600 °C and 800 °C. The microstructure analysis showed that the fine rod-shaped and coarsening dendritelike σ-phase precipitates formed at 600 °C and 800 °C, respectively, and the precipitate growth with the higher temperature was accelerated due to the partition of Mn, but Mn is not a strong σ-phase forming element like Cr, Mo during aging treatment at these two temperatures. At an early aging time of 800 °C, more precipitated nuclei with more Mn addition promote refinement of σ precipitates in later aging time. The kinetic behavior at 600 °C and 800 °C is related to diffusion-controlled growth of σ phase, and the σ-phase nucleation and growth are enhanced with more Mn addition and higher aging temperature due to a faster Mn diffusion rate. The difference in precipitation morphology for two aging temperatures was attributed to the different nucleation modes caused by kinetics parameter n variation. Increasing the aging temperature from 600 °C to 800 °C increased the susceptibility to pitting with higher Mn addition due to faster σ-phase precipitation kinetics.

New Onset Migraine Associated With a Civilian Burn Pit.

PubMed

Chalela, Julio A

2017-05-01

Deployed service members exposed to burn pit smoke can experience a multitude of symptoms. Respiratory symptoms after burn pit smoke exposure are well recognized, but neurologic symptoms are less well recognized. There are reports of migraines triggered by odors but no specific reports of new onset migraines triggered by exposure to burn pit smoke. Clinicians encountering patients with new onset migraines in the deployed setting face the dilemma of evacuating the patients to perform neuroimaging or keeping them in theatre. Retrospective case series study and review of the literature. Three patients with new onset headache after exposure to open burn pit smoke are described. The headaches met established criteria to be classified as migraine with aura in two patients and migraine without aura in one patient. The migraines were triggered by exposure to the burn pit smoke and relieved by avoidance of the smoke. The patients did not have history of migraine and had normal neurological examinations. Computed tomography performed in one patient and optic nerve insonation performed in all three patients were normal. The patients responded well to triptans and antiemetic medicines. Nociceptive odors can trigger classic migraines in adults without prior history of migraine. The temporal association between exposure to the odor and the development of the headache, the absence of abnormalities on neurologic examination, and the response to triptans help establish the diagnosis. Activation of the trigeminal system leading to release of pain-related neuropeptides may mediate the migrainous symptoms. Evacuation for advanced neuroimaging or specialized consultation can be avoided if the above-mentioned criteria are met. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

Site-controlled crystalline InN growth from the V-pits of a GaN substrate

NASA Astrophysics Data System (ADS)

Kuo, Chien-Ting; Hsu, Lung-Hsing; Lai, Yung-Yu; Cheng, Shan-Yun; Kuo, Hao-Chung; Lin, Chien-Chung; Cheng, Yuh-Jen

2017-05-01

A site-controlled crystalline InN growth from the V-pits of a GaN substrate was investigated. The V- pits were fabricated by epitaxial lateral growth of GaN over SiO2 disks patterned on a sapphire substrate. InN crystals were found to preferably grow on the inclined {10-11} crystal planes of the V-pits. A V-pit size of 1 μm or less can provide precise site-controlled InN nucleation at the V-pit bottom, while no InN was grown on the rest of the exposed GaN surfaces. The site-controlled nucleation is attributed to the low surface energy point created by the converging six {10-11} crystal facets at the V-pit bottom. When In source supply is below a certain value, this V-pit bottom is the only location able to aggregate enough active sources to start nucleation, thereby providing site-controlled crystal growth.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boomer, Kayle D.; Engeman, Jason K.; Gunter, Jason R.

2014-01-20

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

Elimination of trench defects and V-pits from InGaN/GaN structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smalc-Koziorowska, Julita; Grzanka, Ewa; Czernecki, Robert

2015-03-09

The microstructural evolution of InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor phase epitaxy was studied as a function of the growth temperature of the GaN quantum barriers (QBs). We observed the formation of basal stacking faults (BSFs) in GaN QBs grown at low temperature. The presence of BSFs terminated by stacking mismatch boundaries (SMBs) leads to the opening of the structure at the surface into a V-shaped trench loop. This trench may form above an SMB, thereby terminating the BSF, or above a junction between the SMB and a subsequent BSF. Fewer BSFs and thus fewer trench defectsmore » were observed in GaN QBs grown at temperatures higher than 830 °C. Further increase in the growth temperature of the GaN QBs led to the suppression of the threading dislocation opening into V-pits.« less

PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

EPA Science Inventory

Exposed, open pit mine highwalls contribute significantly to the production of acid mine

drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

A new C-terminal located mutation (V272ter) in the PIT-1 gene manifesting with severe congenital hypothyroidism. Possible functionality of the PIT-1 C-terminus.

PubMed

Blankenstein, O; Mühlenberg, R; Kim, C; Wüller, S; Pfäffle, R; Heimann, G

2001-01-01

We describe a newborn with clinical signs of severe hypothyroidism and combined pituitary hormone deficiency due to a new mutation in the PIT-1 gene. Endocrine stimulation test revealed a deficiency for PRL, TSH and GH, suggesting a defect in the pituitary transcription factor PIT-1. Genetic analysis of the PIT-1 gene was performed by exon-specific PCR, followed by SSCP mutation screening and DNA sequencing of the abnormal migrating fragments. DNA sequencing revealed a new mutation (V272ter) in direct neighborhood to a known mutational hot spot (R271W) in the C-terminal part of the PIT-1 molecule. Whereas the R271W mutation has a dominant negative effect on the mutant protein, the newly described mutation is inherited in an autosomal-recessive way. The biological consequences of these two different mutations are discussed. Copyright 2002 S. Karger AG, Basel

Wetland mitigation in abandoned gravel pits.

DOT National Transportation Integrated Search

2010-03-01

It is becoming increasingly difficult to provide on-site mitigation for wetland impacts due to road construction in : northeastern Minnesota counties that retain greater than 80 percent of their pre-settlement wetlands. Abandoned : gravel pits are on...

Non-Standard Gearing as the Possibility of Increasing Resistance to Pitting

NASA Astrophysics Data System (ADS)

Kopiláková, Beáta; Bošanský, Miroslav

2014-12-01

In this article are shown the influence of the type non-standard gearing to reduce damage to the pitting. The introduction of the article describes a fundamental difference between the involute and non-involute gearing and the influence of some parameters, especially of the slip ratio to damage of gearing. The paper describes the principle of evaluation pitting by makrofoto graphical method, too and also shows the basic results of the experiment, which was executed on two types of gearing (HCR gearing and C-C gearing) on the Niemanńs stend in term of the damage to pitting.

Designing local solutions for emptying pit latrines in low-income urban settlements (Malawi)

NASA Astrophysics Data System (ADS)

Chipeta, W. C.; Holm, R. H.; Kamanula, J. F.; Mtonga, W. E.; de los Reyes, F. L.

2017-08-01

A lack of effective options in local technology poses challenges when onsite household sanitation facilities are eventually filled to capacity in unplanned settlement areas within Mzuzu City, located in northern Malawi. Vacuum trucks currently dominate the market but focus on emptying septic tanks in the more easily accessible planned settlement areas, rather than servicing the pit latrines common in unplanned settlement areas. As a result, households in the unplanned settlement areas within Mzuzu rely primarily on manual pit emptying (i.e., shoveling by hand) or digging a new pit latrine. These practices have associated health risks and are limited by space constraints. This research focused on filling the technological gap through the design, development, and testing of a pedal powered modified Gulper pump using locally available materials and fabrication. A modified pedal powered Gulper technology was developed and demonstrated to be capable of lifting fecal sludge from a depth of 1.5 m with a mean flow rate of 0.00058 m3/s. If the trash content was low, a typical pit latrine with a volume of 1-4 m3 could be emptied within 1-2 h. Based on the findings in our research Phase IV, the pedal powered Gulper modification is promising as a potential emptying technology for lined pit latrines in unplanned settlement areas. The success rate of the technology is about 17% (5 out 30 sampled lined pit latrines were successful) and reflects the difficulty in finding a single technology that can work well in all types of pit latrines with varying contents. We note that cost should not be the only design criteria and acknowledge the challenge of handling trash in pit latrines.

Automated measurement of cattle surface temperature and its correlation with rectal temperature

PubMed Central

Ren, Kang; Chen, XiaoLi; Lu, YongQiang; Wang, Dong

2017-01-01

The body temperature of cattle varies regularly with both the reproductive cycle and disease status. Establishing an automatic method for monitoring body temperature may facilitate better management of reproduction and disease control in cattle. Here, we developed an Automatic Measurement System for Cattle’s Surface Temperature (AMSCST) to measure the temperature of metatarsus by attaching a special shell designed to fit the anatomy of cattle’s hind leg. Using AMSCST, the surface temperature (ST) on the metatarsus of the hind leg was successively measured during 24 hours a day with an interval of one hour in three tested seasons. Based on ST and rectal temperature (RT) detected by AMSCST and mercury thermometer, respectively, a linear mixed model was established, regarding both the time point and seasonal factors as the fixed effects. Unary linear correlation and Bland-Altman analysis results indicated that the temperatures measured by AMSCST were closely correlated to those measured by mercury thermometer (R2 = 0.998), suggesting that the AMSCST is an accurate and reliable way to detect cattle’s body temperature. Statistical analysis showed that the differences of STs among the three seasons, or among the different time points were significant (P<0.05), and the differences of RTs among the different time points were similarly significant (P<0.05). The prediction accuracy of the mixed model was verified by 10-fold cross validation. The average difference between measured RT and predicted RT was about 0.10 ± 0.10°C with the association coefficient of 0.644, indicating the feasibility of this model in measuring cattle body temperature. Therefore, an automated technology for accurately measuring cattle body temperature was accomplished by inventing an optimal device and establishing the AMSCST system. PMID:28426682

Remitting Seronegative Symmetrical Synovitis with Pitting Edema Syndrome in a Chronic Hemodialysis Patient

PubMed Central

Yamada, Shunsuke; Fuyuno, Seiya; Eriguchi, Masahiro; Tsuruya, Kazuhiko; Kitazono, Takanari

2012-01-01

A 75-year-old male who was undergoing chronic hemodialysis developed abrupt-onset pitting edema and pain in the dorsum of both hands and feet. Biochemical analysis disclosed increased C-reactive protein, and negative rheumatoid factor and antinuclear antibody. Radiological examination showed no bony erosion. Computed tomography and gallium scintigraphy revealed no active infection or neoplasms. The clinical diagnosis was remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome. The pitting edema and inflammatory response quickly subsided after low-dose prednisolone therapy. This case demonstrates that RS3PE syndrome could be a differential diagnosis in elderly patients undergoing dialysis who develop pitting edema and joint pain. PMID:22431931

Properties of hydrocarbon- and salt-contaminated flare pit soils in northeastern British Columbia (Canada).

PubMed

Arocena, J M; Rutherford, P M

2005-07-01

Many contaminated sites in Canada are associated with flare pits generated during past petroleum extraction operations. Flare pits are located adjacent to well sites, compressor stations and batteries and are often subjected to the disposal of wastes from the flaring of gas, liquid hydrocarbons and brine water. This study was conducted to evaluate the physical, chemical, electrical and mineral properties of three flare pit soils as compared to adjacent control soils. Results showed that particle size distribution, pH, total N, cation exchange capacity, exchangeable Mg(2+), and sodium adsorption ratio were similar in soils from flare pits and control sites. Total C, exchangeable Ca(2+), K(+) and Na(+), soluble Ca(2+), Mg(2+), K(+) and Na(+) and electrical conductivity were higher in flare pit soils compared to control soils. X-ray diffraction and scanning electron microscopic analyses showed the presence of gypsum [CaSO(4).2H(2)O], dolomite [CaMg(CO(3))(2)], pyrite [FeS(2)], jarosite [KFe(3)(OH)(6)(SO(4))(2)], magnesium sulphate, oxides of copper and iron+copper in salt efflorescence observed in flare pit soils. Soils from both flare pits and control sites contained mica, kaolonite and 2:1 expanding clays. The salt-rich materials altered the ionic equilibria in the flare pit soils; K(Mg-Ca) selectivity coefficients in control soils were higher compared to contaminated soils. The properties of soils (e.g., high electrical conductivity) affected by inputs associated with oil and gas operations might render flare pit soils less conducive to the establishment and growth of common agricultural crops and forest trees.

[Maculopathy in case of the pit of the disc].

PubMed

Kolár, P

2005-09-01

The pit of the disc is a congenital anomaly of the optic nerve disc. The prevalence is 1/11 000 patients. On the affected side, the optic disc is in 85% of cases larger than the disc of the other healthy eye. The pit of the disc is very often associated with the presence of the cilioretinal artery. Maculopathy in congenital pit of the optic nerve disc was described in the early 30's of the last century by Calhoun. The average age of the patients is roughly 30 years of age (20-40 years). The complementary examination method, which may help to clarify anatomical conditions of the macular region, is the optical coherence tomography. The defect of the optic disc of different depth caused by the pit and maculopathy caused by retinoschisis communicating with the temporal rim of the disc are found. This case report refers to a 29 years old man with disturbing relative central scotoma and decreased vision for one month in his right eye, who underwent classical three-ports pars plana vitrectomy with expansive gas tamponade. On the basis of differential diagnosis discretion, the temporally localized pit of the disc accompanied by maculopathy due to retonoschisis was detemined. The surgical treatment by means of three-ports pars plana vitrectomy and peeling of the inner limiting membrane with expansive gas tamponade restored in our patient the physiological macular structure followed by improvement of the best-corrected visual acuity. No complications were noticed during the surgery or after it as well. Among the differential diagnoses, it is necessary to eliminate other possible causes of maculopathy in young patients as well as other congenital anomalies of the optic disc, which may be related to the maculopathy. Maculopathy following the pit of the optic nerve disc represents relatively rare diagnostic entity. According to the literature, the natural course of this disease results in very low final best-corrected visual acuity, often worse than 5/50 (0,1 or 20/200). The

Millennium Open Pit Mine, Alberta, Canada

NASA Image and Video Library

2007-11-26

Near Fort McMurray, Alberta, Canada, on the east bank of the Athabasca River, are found the Steepbank and Millennium open pit mines. These images were acquired by NASA Terra satellite on September 22, 2000 and July 31, 2007.

Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits

PubMed Central

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

2015-01-01

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

Flyover Modeling of Planetary Pits - Undergraduate Student Instrument Project

NASA Astrophysics Data System (ADS)

Bhasin, N.; Whittaker, W.

2015-12-01

On the surface of the moon and Mars there are hundreds of skylights, which are collapsed holes that are believed to lead to underground caves. This research uses Vision, Inertial, and LIDAR sensors to build a high resolution model of a skylight as a landing vehicle flies overhead. We design and fabricate a pit modeling instrument to accomplish this task, implement software, and demonstrate sensing and modeling capability on a suborbital reusable launch vehicle flying over a simulated pit. Future missions on other planets and moons will explore pits and caves, led by the technology developed by this research. Sensor software utilizes modern graph-based optimization techniques to build 3D models using camera, LIDAR, and inertial data. The modeling performance was validated with a test flyover of a planetary skylight analog structure on the Masten Xombie sRLV. The trajectory profile closely follows that of autonomous planetary powered descent, including translational and rotational dynamics as well as shock and vibration. A hexagonal structure made of shipping containers provides a terrain feature that serves as an appropriate analog for the rim and upper walls of a cylindrical planetary skylight. The skylight analog floor, walls, and rim are modeled in elevation with a 96% coverage rate at 0.25m2 resolution. The inner skylight walls have 5.9cm2 color image resolution and the rims are 6.7cm2 with measurement precision superior to 1m. The multidisciplinary student team included students of all experience levels, with backgrounds in robotics, physics, computer science, systems, mechanical and electrical engineering. The team was commited to authentic scientific experimentation, and defined specific instrument requirements and measurable experiment objectives to verify successful completion.This work was made possible by the NASA Undergraduate Student Instrument Project Educational Flight Opportunity 2013 program. Additional support was provided by the sponsorship of an

Standardized emissions inventory methodology for open-pit mining areas.

PubMed

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

2011-08-01

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

Retrospective Analysis of Mosh-Pit-Related Injuries.

PubMed

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

2017-12-01

Moshing is a violent form of dancing found world-wide at rock concerts, festivals, and electronic dance music events. It involves crowd surfing, shoving, and moving in a circular rotation. Moshing is a source of increased morbidity and mortality. The goal of this study was to report epidemiologic information on patient presentation rate (PPR), transport to hospital rate (TTHR), and injury patterns from patients who participated in mosh-pits. Materials and Methods Subjects were patrons from mosh-pits seeking medical care at a single venue. The events reviewed were two national concert tours which visited this venue during their tour. The eight distinct events studied occurred between 2011 and 2014. Data were collected retrospectively from prehospital patient care reports (PCRs). A single Emergency Medical Service (EMS) provided medical care at this venue. The following information was gathered from each PCR: type of injury, location of injury, treatment received, alcohol or drug use, Advanced Life Support/ALS interventions required, age and gender, disposition, minor or parent issues, as well as type of activity engaged in when injured. Attendance for the eight events ranged from 5,100 to 16,000. Total patient presentations ranged from 50 to 206 per event. Patient presentations per ten thousand (PPTT) ranged from 56 to 130. The TTHR per 10,000 ranged from seven to 20. The mean PPTT was 99 (95% CI, 77-122) and the median was 98. The mean TTHR was 16 (95% CI, 12-29) and the median TTHR was 17. Patients presenting from mosh-pits were more frequently male (57.6%; P<.004). The mean age was 20 (95% CI, 19-20). Treatment received was overwhelmingly at the Basic Life Support (BLS) level (96.8%; P<.000001). General moshing was the most common activity leading to injury. Crowd surfing was the next most significant, accounting for 20% of presentations. The most common body part injured was the head (64% of injuries). This retrospective review of mosh-pit-associated injury

90. ARAIII. GCRE reactor building (ARA608) mechanical loop pit. Shows ...

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

90. ARA-III. GCRE reactor building (ARA-608) mechanical loop pit. Shows nitrogen gas compressor in foreground, piping installations on walls of pit, and other details. February 24, 1959. Ineel photo no. 59-880. Photographer: Ken Mansfield. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

Detection of pit fragments in fresh cherries using near infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

NIR spectroscopy in the wavelength region from 900nm to 2600nm was evaluated as the basis for a rapid, non-destructive method for the detection of pits and pit fragments in fresh cherries. Partial Least Squares discriminant analysis (PLS-DA) following various spectral pretreatments was applied to sp...

Body Temperature Measurements for Metabolic Phenotyping in Mice.

PubMed

Meyer, Carola W; Ootsuka, Youichirou; Romanovsky, Andrej A

2017-01-01

Key Points Rectal probing is subject to procedural bias. This method is suitable for first-line phenotyping, provided probe depth and measurement duration are standardized. It is also useful for detecting individuals with out-of-range body temperatures (during hypothermia, torpor).The colonic temperature attained by inserting the probe >2 cm deep is a measure of deep (core) body temperature.IR imaging of the skin is useful for detecting heat leaks and autonomous thermoregulatory alterations, but it does not measure body temperature.Temperature of the hairy or shaved skin covering the inter-scapular brown adipose tissue can be used as a measure of BAT thermogenesis. However, obtaining such measurements of sufficient quality is very difficult, and interpreting them can be tricky. Temperature differences between the inter-scapular and lumbar areas can be a better measure of the thermogenic activity of inter-scapular brown adipose tissue.Implanted probes for precise determination of BAT temperature (changes) should be fixed close to the Sulzer's vein. For measurement of BAT thermogenesis, core body temperature and BAT temperature should be recorded simultaneously.Tail temperature is suitable to compare the presence or absence of vasoconstriction or vasodilation.Continuous, longitudinal monitoring of core body temperature is preferred over single probing, as the readings are taken in a non-invasive, physiological context.Combining core body temperature measurements with metabolic rate measurements yields insights into the interplay between heat production and heat loss (thermal conductance), potentially revealing novel thermoregulatory phenotypes. Endothermic organisms rely on tightly balanced energy budgets to maintain a regulated body temperature and body mass. Metabolic phenotyping of mice, therefore, often includes the recording of body temperature. Thermometry in mice is conducted at various sites, using various devices and measurement practices, ranging from

Morphological Evolution of Pit-Patterned Si(001) Substrates Driven by Surface-Energy Reduction

NASA Astrophysics Data System (ADS)

Salvalaglio, Marco; Backofen, Rainer; Voigt, Axel; Montalenti, Francesco

2017-09-01

Lateral ordering of heteroepitaxial islands can be conveniently achieved by suitable pit-patterning of the substrate prior to deposition. Controlling shape, orientation, and size of the pits is not trivial as, being metastable, they can significantly evolve during deposition/annealing. In this paper, we exploit a continuum model to explore the typical metastable pit morphologies that can be expected on Si(001), depending on the initial depth/shape. Evolution is predicted using a surface-diffusion model, formulated in a phase-field framework, and tackling surface-energy anisotropy. Results are shown to nicely reproduce typical metastable shapes reported in the literature. Moreover, long time scale evolutions of pit profiles with different depths are found to follow a similar kinetic pathway. The model is also exploited to treat the case of heteroepitaxial growth involving two materials characterized by different facets in their equilibrium Wulff's shape. This can lead to significant changes in morphologies, such as a rotation of the pit during deposition as evidenced in Ge/Si experiments.

Morphological Evolution of Pit-Patterned Si(001) Substrates Driven by Surface-Energy Reduction.

PubMed

Salvalaglio, Marco; Backofen, Rainer; Voigt, Axel; Montalenti, Francesco

2017-09-29

Lateral ordering of heteroepitaxial islands can be conveniently achieved by suitable pit-patterning of the substrate prior to deposition. Controlling shape, orientation, and size of the pits is not trivial as, being metastable, they can significantly evolve during deposition/annealing. In this paper, we exploit a continuum model to explore the typical metastable pit morphologies that can be expected on Si(001), depending on the initial depth/shape. Evolution is predicted using a surface-diffusion model, formulated in a phase-field framework, and tackling surface-energy anisotropy. Results are shown to nicely reproduce typical metastable shapes reported in the literature. Moreover, long time scale evolutions of pit profiles with different depths are found to follow a similar kinetic pathway. The model is also exploited to treat the case of heteroepitaxial growth involving two materials characterized by different facets in their equilibrium Wulff's shape. This can lead to significant changes in morphologies, such as a rotation of the pit during deposition as evidenced in Ge/Si experiments.

Research on horizontal displacement monitoring method of deep foundation pit based on laser projecting sensing technology

NASA Astrophysics Data System (ADS)

Liu, Peng; Xie, Shulin; Zhang, Lixiao; Zhou, Guangyi; Zhao, Xuefeng

2018-03-01

A certain level of horizontal displacement will occur during excavation or subsequent construction of deep foundation pit. If the support is improper and the horizontal displacement of the foundation pit is too large, it will cause collapse and even affect the buildings around the foundation pit, which will endanger people's life and property. Therefore, the horizontal displacement monitoring of deep foundation pit becomes more and more important. At present, the electronic total station is often used to monitor the horizontal displacement of the foundation pit, but this monitoring method is expensive, prone to accidental errors, and can not be used for real-time monitoring. Therefore, a method of monitoring the horizontal displacement of deep foundation pit by using laser projection sensing technique is proposed in this paper. The horizontal displacement of the foundation pit is replaced by the displacement of the laser spot emitted by the laser, and the horizontal displacement of the foundation pit can be obtained by identifying the displacement of the laser spot projected on the screen. A series of experiments show that the accuracy of this monitoring method meets the engineering requirements and greatly reduces the cost, which provides a new technology for the displacement monitoring of deep foundation pit.

Pit chains on Enceladus signal the recent tectonic dissection of the ancient cratered terrains

NASA Astrophysics Data System (ADS)

Martin, Emily S.; Kattenhorn, Simon A.; Collins, Geoffrey C.; Michaud, Robert L.; Pappalardo, Robert T.; Wyrick, Danielle Y.

2017-09-01

Enceladus is the first outer solar system body on which pit chains have been positively identified. We map the global distribution of pit chains and show that pit chains are among the youngest tectonic features on Enceladus's surface, concentrated in the cratered plains centered on Enceladus's Saturnian and anti-Saturnian hemispheres. Pit chains on Enceladus are interpreted as the surface expressions of subsurface dilational fractures underlying a cover of unconsolidated material, which we infer to be a geologically young cover of loose regolith that mantles the surface of Enceladus. A widespread layer of regolith may act to insulate the surface, which has implications for the thermal state of Enceladus's ice shell. The widespread distribution of pit chains across the cratered plains indicates that this ancient surface has recently been tectonically active.

Measuring nanowire thermal conductivity at high temperatures

NASA Astrophysics Data System (ADS)

Wang, Xiaomeng; Yang, Juekuan; Xiong, Yucheng; Huang, Baoling; Xu, Terry T.; Li, Deyu; Xu, Dongyan

2018-02-01

This work extends the micro-thermal-bridge method for thermal conductivity measurements of nanowires to high temperatures. The thermal-bridge method, based on a microfabricated device with two side-by-side suspended membranes with integrated platinum resistance heaters/thermometers, has been used to determine thermal conductivity of various nanowires/nanotubes/nanoribbons at relatively low temperatures. However, to date, thermal conductivity characterization of nanowires at temperatures above 600 K has seldom been reported presumably due to several technical difficulties including the instability of the microfabricated thermometers, radiation heat loss, and the effect of the background conductance on the measurement. Here we report on our attempt to address the aforementioned challenges and demonstrate thermal conductivity measurement of boron nanoribbons up to 740 K. To eliminate high temperature resistance instability, the device is first annealed at 1023 K for 5 min in an argon atmosphere. Two radiation shields are installed in the measurement chamber to minimize radiation heat loss from the measurement device to the surroundings; and the temperature of the device at each set point is calibrated by an additional thermocouple directly mounted on the chip carrier. The effect of the background conductance is eliminated by adopting a differential measurement scheme. With all these modifications, we successfully measured the thermal conductivity of boron nanoribbons over a wide temperature range from 27 K to 740 K. The measured thermal conductivity increases monotonically with temperature and reaches a plateau of ~2.5 W m-1 K-1 at approximately 400 K, with no clear signature of Umklapp scattering observed in the whole measurement temperature range.

Manipulation of nanoscale V-pits to optimize internal quantum efficiency of InGaN multiple quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chiao-Yun; Li, Heng; Shih, Yang-Ta

2015-03-02

We systematically investigated the influence of nanoscale V-pits on the internal quantum efficiency (IQE) of InGaN multiple quantum wells (MQWs) by adjusting the underlying superlattices (SLS). The analysis indicated that high barrier energy of sidewall MQWs on V-pits and long diffusion distance between the threading dislocation (TD) center and V-pit boundary were crucial to effectively passivate the non-radiative centers of TDs. For a larger V-pit, the thicker sidewall MQW on V-pit would decrease the barrier energy. On the contrary, a shorter distance between the TD center and V-pit boundary would be observed in a smaller V-pit, which could increase themore » carrier capturing capability of TDs. An optimized V-pit size of approximately 200–250 nm in our experiment could be concluded for MQWs with 15 pairs SLS, which exhibited an IQE value of 70%.« less

Evidence for Recent Liquid Water on Mars: Gullies at 70oS in Polar Pit Walls

NASA Technical Reports Server (NTRS)

2000-01-01

[figure removed for brevity, see original site]

Gully landforms proposed to have been caused by geologically-recent seepage and runoff of liquid water on Mars are found in the most unlikely places. They typically occur in areas that are quite cold--well below freezing--all year round. Like the old adage about moss on trees, nearly all of them form on slopes that face away from sunlight. Most of the gullies occur at latitudes between 30o and 70o.

The highest latitude at which martian gullies have been found is around 70o-75oS on the walls of pits developed in the south polar pitted plains. If you were at this same latitude on Earth, you would be in Antarctica. This region spends much of the winter--which lasts approximately 6 months on Mars--in darkness and at temperatures cold enough to freeze carbon dioxide (around -130oC or -200oF). Nevertheless, gullies with very sharp, deep, v-shaped channels are seen on the pit walls (above, left).

Based upon the locations of the tops of the channels on the slope shown here, the inferred site of liquid seepage is located at a layer in the pit wall about 1/3 of the way down from the top of the MOC image. The channels start wide and taper downslope. The area above the channels is layered and has been eroded by mass movement--dry avalanching of debris--to form a pattern of chutes and ridges on the upper slope of the pit wall. The top layer appears to have many boulders in it (each about the size of a small house), these boulders are left behind on the upper slopes of the pit wall as debris is removed.

Centered near 70.7oS, 355.7oW, the MOC image was acquired July 14, 1999, and covers an area approximately 2.8 km (1.7 mi) wide by 2.1 km (1.3 mi) high. Sunlight illuminates the MOC image from the upper left and north is toward the upper left. The context view (right) is from the Viking 2 orbiter and was acquired in 1977. The Viking picture is illuminated from the top/upper left; north is toward the upper right. The

3D Modeling of Landslide in Open-pit Mining on Basis of Ground-based LIDAR Data

NASA Astrophysics Data System (ADS)

Hu, H.; Fernandez-Steeger, T. M.; Azzam, R.; Arnhardt, C.

2009-04-01

Slope stability is not only an important problem which is related to production and safety in open-pit mining, but also very complex task. There are three main reasons which affect the slope stability as follows: geotechnical factors: Geological structure, lithologic characteristics, water, cohesion, friction, etc.; climate factors: Rainfall and temperature; and external factors: Open-pit mining process, explosion vibration, dynamic load, etc.. The 3rd reason, as a specially one in open-pit mining, not only causes some dynamic problems but also induces the fast geometry changing which must be considered in the following research using numerical simulation and stability analysis. Recently, LIDAR technology has been applied in many fields and places in the world wide. Ground-based LIDAR technology with high accuracy up to 3mm increasingly accommodates to monitoring landslides and detecting changing. LIDAR data collection and preprocessing research have been carried out by Department of Engineering Geology and Hydrogeology at RWTH Aachen University. LIDAR data, so-called a point-cloud of mass data in high density can be obtained in short time for the sensitive open-pit mining area by using ground-based LIDAR. To obtain a consistent surface model, it is necessary to set up multiple scans with the ground-based LIDAR. The framework of data preprocessing which can be implemented by Poly-Works is introduced as follows: gross error detection and elimination, integration of reference frame, model fusion of different scans (re-sampled in overlap region), data reduction without removing the useful information which is a challenge and research front in LIDAR data processing. After data preprocessing, 3D surface model can be directly generated in Poly-Works or generated in other software by building the triangular meshes. The 3D surface landslide model can be applied to further researches such as: real time landslide geometry monitoring due to the fast data collection and

Pitting Behavior of L415 Pipeline Steel in Simulated Leaching Liquid Environment

NASA Astrophysics Data System (ADS)

Wan, H. X.; Yang, X. J.; Liu, Z. Y.; Song, D. D.; Du, C. W.; Li, X. G.

2017-02-01

The corrosion behavior and laws of the west-east gas pressure pipeline of L415 steel were studied in simulated leaching liquid. The failure of the L415 steel during the pressure testing process was investigated using electrochemical polarization, electrochemical impedance spectroscopy, and immersion test. The corrosion rate of the L415 steel increased with ion concentration in the leaching liquid. This rate reached about 0.8 mm a-1 and belonged to the severe corrosion grade. Pitting corrosion was observed in various simulated solutions with different aggressive species concentrations. The original ion concentration in the leaching liquid (1×) is the key factor influencing pitting initiation and development. Pitting showed easy nucleation, and its growth rate was relatively slow, in the basic simulating solution of the leach liquid (i.e., the ion content is compactable to the real condition in the rust on the inner steel pipe surface). Pitting was also highly sensitive and easily grew in the solution with doubled ion concentration in the basic simulating solution (2×). A uniform corrosion, instead of pitting, mainly occurred when the ion concentration was up to 10× of the basic solution.

Dynamic interactions between Pit-1 and C/EBPalpha in the pituitary cell nucleus.

PubMed

Demarco, Ignacio A; Voss, Ty C; Booker, Cynthia F; Day, Richard N

2006-11-01

The homeodomain (HD) transcription factors are a structurally conserved family of proteins that, through networks of interactions with other nuclear proteins, control patterns of gene expression during development. For example, the network interactions of the pituitary-specific HD protein Pit-1 control the development of anterior pituitary cells and regulate the expression of the hormone products in the adult cells. Inactivating mutations in Pit-1 disrupt these processes, giving rise to the syndrome of combined pituitary hormone deficiency. Pit-1 interacts with CCAAT/enhancer-binding protein alpha (C/EBPalpha) to regulate prolactin transcription. Here, we used the combination of biochemical analysis and live-cell microscopy to show that two different point mutations in Pit-1, which disrupted distinct activities, affected the dynamic interactions between Pit-1 and C/EBPalpha in different ways. The results showed that the first alpha-helix of the POU-S domain is critical for the assembly of Pit-1 with C/EBPalpha, and they showed that DNA-binding activity conferred by the HD is critical for the final intranuclear positioning of the metastable complex. This likely reflects more general mechanisms that govern cell-type-specific transcriptional control, and the results from the analysis of the point mutations could indicate an important link between the mislocalization of transcriptional complexes and disease processes.

Rarity of PIT1 involvement in children from Russia with combined pituitary hormone deficiency.

PubMed

Fofanova, O V; Takamura, N; Kinoshita, E; Yoshimoto, M; Tsuji, Y; Peterkova, V A; Evgrafov, O V; Dedov, I I; Goncharov, N P; Yamashita, S

1998-06-05

To ascertain the molecular background of combined pituitary hormone deficiency, screening for mutations in the pituitary-specific transcription factor (Pit-1/GHF-1) gene (PIT1) was performed on a cohort of 15 children from Russia with combined growth hormone (GH)/prolactin (Prl)/thyroid-stimulating hormone (TSH) deficiency. The group of patients, suspected of PIT1 mutations, consisted of four familial cases (seven patients) and eight sporadic cases. All had complete GH deficiency and complete or partial Prl and TSH deficiency. Direct sequencing of all six exons of PIT1 and its promoter region showed a C to T transition mutation at codon 14 of exon 1 in a 3 8/12-year-old girl. This novel PIT1 mutation results in a proline to leucine substitution (P14L). The patient was heterozygous for mutant and normal alleles. The heterozygous P14L mutation was also present in her mother as well as in her maternal aunt and grandmother, all of whom were phenotypically normal. There was no mutation in the father's DNA, suggesting the need for reevaluation of genomic imprinting. In other children of our series, no mutation in PIT1 or in its promotor region was identified. This is the first report on the analysis of PIT1 and its promoter region in Russian children with GH/Prl/TSH deficiency. However, as the involvement of PIT1 mutation is rare in Russia, the other negative cases need to be analyzed for another candidate gene responsible for combined GH/Pr/TSH deficiency.

Study on Electro-Polishing Process by Niobium-Plate Sample With Artificial Pits

DOE Office of Scientific and Technical Information (OSTI.GOV)

T. Saeki, H. Hayano, S. Kato, M. Nishiwaki, M. Sawabe, W.A. Clemens, R.L. Geng, R. Manus, P.V. Tyagi

2011-07-01

The Electro-polishing (EP) process is the best candidate of final surface-treatment for the production of ILC cavities. Nevertheless, the development of defects on the inner-surface of the Superconducting RF cavity during EP process has not been studied by experimental method. We made artificial pits on the surface of a Nb-plate sample and observed the development of the pit-shapes after each step of 30um-EP process where 120um was removed by EP in total. This article describes the results of this EP-test of Nb-sample with artificial pits.

Acoustical Measurement Of Furnace Temperatures

NASA Technical Reports Server (NTRS)

Parthasarathy, Shakkottai; Venkateshan, Shakkottai P.

1989-01-01

Simple probes withstand severe conditions, yet give spatially-resolved temperature readings. Prototype acoustical system developed to measure temperatures from ambient to 1,800 degree F in such structures as large industrial lime kilns and recovery-boiler furnaces. Pulses of sound reflected from obstructions in sensing tube. Speed of sound and temperature in each segment deduced from travel times of pulses.

Pit-a-Pat: A Smart Electrocardiogram System for Detecting Arrhythmia.

PubMed

Park, Juyoung; Lee, Kuyeon; Kang, Kyungtae

2015-10-01

Electrocardiogram (ECG) telemonitoring is one of the most promising applications of medical telemetry. However, previous approaches to ECG telemonitoring have largely relied on public databases of ECG results. In this article we propose a smart ECG system called Pit-a-Pat, which extracts features from ECG signals and detects arrhythmia. It is designed to run on an Android™ (Google, Mountain View, CA) device, without requiring modifications to other software. We implemented the Pit-a-Pat system using a commercial ECG device, and the experimental results demonstrate the effectiveness and accuracy of Pit-a-Pat for monitoring the ECG signal and analyzing the cardiac activity of a mobile patient. The proposed system allows monitoring of cardiac activity with automatic analysis, thereby providing a convenient, inexpensive, and ubiquitous adjunct to personal healthcare.

Enhancement in transport critical current density of ex situ PIT Ag/(Ba, K)Fe2As2 tapes achieved by applying a combined process of flat rolling and uniaxial pressing

NASA Astrophysics Data System (ADS)

Togano, Kazumasa; Gao, Zhaoshun; Matsumoto, Akiyoshi; Kumakura, Hiroaki

2013-11-01

We report that the transport critical current density Jc of ex situ powder-in-tube (PIT) processed (Ba, K)Fe2As2 (Ba-122) tapes can be significantly enhanced by applying uniaxial cold pressing at the final stage of deformation. The tapes were prepared by packing high quality precursor powder into a Ag tube, cycles of rolling and intermediate annealing, and pressing followed by the final heat treatment for sintering. The Jc values in applied magnetic fields were increased by almost one order of magnitude compared to the tapes processed without pressing, exceeding 104 A cm-2 at 4.2 K. We achieved the highest Jc (at 4.2 K and 10 T) of 2.1×104 A cm-2 among PIT-processed Fe-based wires and tapes reported so far. The Jc-H curves measured at higher temperatures maintain small field dependence up to around 20 K, suggesting that these tapes are promising for applications at higher temperatures as well as at liquid helium temperature. The microstructure investigations reveal that there are two possible causes of the large Jc enhancement by pressing: one is densification and the other is the change of crack structure. Optimization of processing parameters such as the reduction ratio of rolling and pressing is expected to yield further Jc enhancement.

Advantages and limitations for users of double pit pour-flush latrines: a qualitative study in rural Bangladesh.

PubMed

Hussain, Faruqe; Clasen, Thomas; Akter, Shahinoor; Bawel, Victoria; Luby, Stephen P; Leontsini, Elli; Unicomb, Leanne; Barua, Milan Kanti; Thomas, Brittany; Winch, Peter J

2017-05-25

In rural Bangladesh, India and elsewhere, pour-flush pit latrines are the most common sanitation system. When a single pit latrine becomes full, users must empty it themselves and risk exposure to fresh feces, pay an emptying service to remove pit contents or build a new latrine. Double pit pour-flush latrines may serve as a long-term sanitation option including high water table areas because the pits do not need to be emptied immediately and the excreta decomposes into reusable soil. Double pit pour-flush latrines were implemented in rural Bangladesh for 'hardcore poor' households by a national NGO, BRAC. We conducted interviews, focus groups, and spot checks in two low-income, rural areas of Bangladesh to explore the advantages and limitations of using double pit latrines compared to single pit latrines. The rural households accepted the double pit pour-flush latrine model and considered it feasible to use and maintain. This latrine design increased accessibility of a sanitation facility for these low-income residents and provided privacy, convenience and comfort, compared to open defecation. Although a double pit latrine is more costly and requires more space than a single pit latrine the households perceived this sanitation system to save resources, because households did not need to hire service workers to empty pits or remove decomposed contents themselves. In addition, the excreta decomposition process produced a reusable soil product that some households used in homestead gardening. The durability of the latrine superstructures was a problem, as most of the bamboo-pole superstructure broke after 6-18 months of use. Double pit pour-flush latrines are a long-term improved sanitation option that offers users several important advantages over single pit pour-flush latrines like in rural Bangladesh which can also be used in areas with high water table. Further research can provide an understanding of the comparative health impacts and effectiveness of the model

Pitted Landforms in Southern Hellas Planitia

NASA Image and Video Library

2015-03-25

This image is of a portion of the Southern plains region within Hellas, the largest impact basin on Mars, with a diameter of about 2300 kilometers 1400 miles, as observed by NASA Mars Reconnaissance Orbiter. There are three main phenomena apparent in this image. First, the faint dark streaks that criss-cross the terrain are dust devil tracks that clear the bright dust along their way. Second, the subtle overall bumpy "basketball" texture of the surface is formed by repeated seasonal freezing and thawing of the ice-rich regolith and is common at higher latitudes. Third, the large, elliptical, scalloped depressions are common in permafrost terrains in both hemispheres, where thick, latitude-dependent sedimentary mantles comprise the surface units. These mantles are composed of ice-rich sediments that degrade as the ice sublimates away and is heated either by the Sun or by locally higher geothermal gradients. Sublimation, or the direct change in phase from ice to gas, occurs on Mars because of its low density atmosphere. These depressions have steeper pole-facing slopes, whereas the equator-facing slopes gently fade into the surrounding terrain. At full resolution (see close up view), numerous sublimation pits and networks of polygonal cracks are visible on the steeper, unstable pole-ward facing slopes. The overall morphology of this terrain is characteristic of what is called "thermokarstic degradation processes," which is a term used to describe the formation of pits in an ice-rich terrain due to loss of ice creating pits and collapse features. http://photojournal.jpl.nasa.gov/catalog/PIA19350

Spectroscopic temperature measurements in interior ballistic environments

NASA Astrophysics Data System (ADS)

Klingenberg, G.; Mach, H.

1984-11-01

Spectroscopic temperature measurements during the interior ballistic cycle of a 20 mm test fixture gun and inside the muzzle flash of a 7.62 mm rifle are described. The investigation yields information on temperature distribution in the burning propellant charge of the 20 mm test fixture and on radial temperature profiles in the 7.62 mm muzzle flash region. A technique to obtain temperature during the ignition and combustion within the 20 mm propellant charge is presented. Additional in-bore measurements by quartz windows mounted into bores along the barrel and emission-absorption measurements inside the muzzle flash of the 20 mm test fixture yield a complete temperature profile for the gun system. Spectroscopic infrared measurements inside the muzzle flash of a 7.62 mm rifle complete the investigation.

86. ARAIII. GCRE reactor building (ARA608) showing mechanical loop pit ...

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

86. ARA-III. GCRE reactor building (ARA-608) showing mechanical loop pit after building shell had been erected. Beyond pit are demineralized water surge tank and heat exchanger. Camera facing northeast. December 22, 1958. Ineel photo no. 58-6427. Photographer: Ken Mansfield. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

Superswollen microemulsions stabilized by shear and trapped by a temperature quench.

PubMed

Roger, Kevin; Olsson, Ulf; Zackrisson-Oskolkova, Malin; Lindner, Peter; Cabane, Bernard

2011-09-06

We studied the solubilization of oil in the C(16)E(8)/hexadecane/H(2)O system. Close to the phase inversion temperature (PIT), the system, at equilibrium, can form either homogeneous states (i.e., microemulsions) at high surfactant concentrations or three-phase states at lower concentrations. We show that, under gentle shear, at a line we named the clearing boundary (CB), located a few degrees below the PIT, the system is homogeneous regardless of the surfactant concentration. We relate this shift of the microemulsion boundary to shear-induced disruption of the asymmetric bicontinuous structure. Although this state quickly relaxes to equilibrium when shear is stopped, we show that it is still possible to trap it into a metastable state through a temperature quench. This method is the sub-PIT emulsification that we described in a previous work (Roger Langmuir 2010, 26, 3860-3867). © 2011 American Chemical Society

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

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Gear Fault Detection Effectiveness as Applied to Tooth Surface Pitting Fatigue Damage

NASA Technical Reports Server (NTRS)

Lewicki, David G.; Dempsey, Paula J.; Heath, Gregory F.; Shanthakumaran, Perumal

2009-01-01

A study was performed to evaluate fault detection effectiveness as applied to gear tooth pitting fatigue damage. Vibration and oil-debris monitoring (ODM) data were gathered from 24 sets of spur pinion and face gears run during a previous endurance evaluation study. Three common condition indicators (RMS, FM4, and NA4) were deduced from the time-averaged vibration data and used with the ODM to evaluate their performance for gear fault detection. The NA4 parameter showed to be a very good condition indicator for the detection of gear tooth surface pitting failures. The FM4 and RMS parameters performed average to below average in detection of gear tooth surface pitting failures. The ODM sensor was successful in detecting a significant amount of debris from all the gear tooth pitting fatigue failures. Excluding outliers, the average cumulative mass at the end of a test was 40 mg.

121. Man with temperature probe aimed at armature measuring temperature ...

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

121. Man with temperature probe aimed at armature measuring temperature as armature heats up between the two electrodes. March 27, 1985 - Statue of Liberty, Liberty Island, Manhattan, New York County, NY

Illuminating Anaerobic Microbial Community and Cooccurrence Patterns across a Quality Gradient in Chinese Liquor Fermentation Pit Muds

PubMed Central

Hu, Xiaolong; Du, Hai; Ren, Cong

2016-01-01

Fermentation pit mud, an important reservoir of diverse anaerobic microorganisms, is essential for Chinese strong-aroma liquor production. Pit mud quality, according to its sensory characteristics, can be divided into three grades: degraded, normal, and high quality. However, the relationship between pit mud microbial community and pit mud quality is poorly understood, as are microbial associations within the pit mud ecosystem. Here, microbial communities at these grades were compared using Illumina MiSeq sequencing of the variable region V4 of the 16S rRNA gene. Our results revealed that the pit mud microbial community was correlated with its quality and environmental factors. Species richness, biodiversity, and relative and/or absolute abundances of Clostridia, Clostridium kluyveri, Bacteroidia, and Methanobacteria significantly increased, with corresponding increases in levels of pH, NH4+, and available phosphorus, from degraded to high-quality pit muds, while levels of Lactobacillus, dissolved organic carbon, and lactate significantly decreased, with normal samples in between. Furthermore, 271 pairs of significant and robust correlations (cooccurrence and negative) were identified from 76 genera using network analysis. Thirteen hubs of cooccurrence patterns, mainly under the Clostridia, Bacteroidia, Methanobacteria, and Methanomicrobia, may play important roles in pit mud ecosystem stability, which may be destroyed with rapidly increased levels of lactic acid bacteria (Lactobacillus, Pediococcus, and Streptococcus). This study may help clarify the relationships among microbial community, environmental conditions, and pit mud quality, allow the improvement of pit mud quality by using bioaugmentation and controlling environmental factors, and shed more light on the ecological rules guiding community assembly in pit mud. PMID:26896127

A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel.

PubMed

Yang, Zixuan; Kan, Bo; Li, Jinxu; Qiao, Lijie; Volinsky, Alex A; Su, Yanjing

2017-11-14

Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance.

Dynamin recruitment and membrane scission at the neck of a clathrin-coated pit.

PubMed

Cocucci, Emanuele; Gaudin, Raphaël; Kirchhausen, Tom

2014-11-05

Dynamin, the GTPase required for clathrin-mediated endocytosis, is recruited to clathrin-coated pits in two sequential phases. The first is associated with coated pit maturation; the second, with fission of the membrane neck of a coated pit. Using gene-edited cells that express dynamin2-EGFP instead of dynamin2 and live-cell TIRF imaging with single-molecule EGFP sensitivity and high temporal resolution, we detected the arrival of dynamin at coated pits and defined dynamin dimers as the preferred assembly unit. We also used live-cell spinning-disk confocal microscopy calibrated by single-molecule EGFP detection to determine the number of dynamins recruited to the coated pits. A large fraction of budding coated pits recruit between 26 and 40 dynamins (between 1 and 1.5 helical turns of a dynamin collar) during the recruitment phase associated with neck fission; 26 are enough for coated vesicle release in cells partially depleted of dynamin by RNA interference. We discuss how these results restrict models for the mechanism of dynamin-mediated membrane scission. © 2014 Cocucci et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Floodplain restoration with flood control: fish habitat value of levee borrow pits

USDA-ARS?s Scientific Manuscript database

Earthen flood control levees are often built using soil excavated from borrow pits lying parallel to and riverward of the finished levee. After construction, these pits can provide valuable floodplain habitats, and their value is well established along corridors of larger rivers. However, levee bo...

Noseleaf pit in Egyptian slit-faced bat as a doubly curved reflector

NASA Astrophysics Data System (ADS)

Zhuang, Qiao; Wang, Xiao-Min; Li, Ming-Xuan; Mao, Jie; Wang, Fu-Xun

2012-02-01

Noseleaves in slit-faced bats have been hypothesized to affect the sonar beam. Using numerical methods, we show that the pit in the noseleaf of an Egyptian slit-faced bat has an effect on focusing the acoustic near field as well as shaping the radiation patterns and hence enhancing the directionality. The underlying physical mechanism suggested by the properties of the effect is that the pit acts as a doubly curved reflector. Thanks to the pit the beam shape is overall directional and more selectively widened at the high end of the biosonar frequency range to improve spatial coverage and detectability of targets.

COPPER PITTING CORROSION: A CASE STUDY

EPA Science Inventory

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

Associations of polymorphisms in the Pit-1 gene with growth and carcass traits in Angus beef cattle.

PubMed

Zhao, Q; Davis, M E; Hines, H C

2004-08-01

The Pit-1 gene was studied as a candidate for genetic markers of growth and carcass traits. Angus beef cattle that were divergently selected for high- or low-blood serum IGF-I concentration were used in this study. The single-strand conformation polymorphism method was used to identify polymorphism in the Pit-1 gene including regions from intron 2 to exon 6. Two polymorphisms, Pit1I3H (HinfI) and Pit1I3NL (NlaIII), were detected in intron 3 of the Pit-1 gene. One polymorphism, Pit1I4N (BstNI), was found in intron 4, and a single nucleotide polymorphism, Pit1I5, was found in intron 5. The previously reported polymorphism in exon 6, Pit1E6H (HinfI), was also studied in 416 Angus beef cattle. Associations of the polymorphisms with growth traits, carcass traits, and IGF-I concentration were analyzed using a general linear model procedure. No significant associations were observed between these polymorphisms and growth and carcass traits.

Reliable identification of deep sulcal pits: the effects of scan session, scanner, and surface extraction tool.

PubMed

Im, Kiho; Lee, Jong-Min; Jeon, Seun; Kim, Jong-Heon; Seo, Sang Won; Na, Duk L; Grant, P Ellen

2013-01-01

Sulcal pit analysis has been providing novel insights into brain function and development. The purpose of this study was to evaluate the reliability of sulcal pit extraction with respect to the effects of scan session, scanner, and surface extraction tool. Five subjects were scanned 4 times at 3 MRI centers and other 5 subjects were scanned 3 times at 2 MRI centers, including 1 test-retest session. Sulcal pits were extracted on the white matter surfaces reconstructed with both Montreal Neurological Institute and Freesurfer pipelines. We estimated similarity of the presence of sulcal pits having a maximum value of 1 and their spatial difference within the same subject. The tests showed high similarity of the sulcal pit presence and low spatial difference. The similarity was more than 0.90 and the spatial difference was less than 1.7 mm in most cases according to different scan sessions or scanners, and more than 0.85 and about 2.0 mm across surface extraction tools. The reliability of sulcal pit extraction was more affected by the image processing-related factors than the scan session or scanner factors. Moreover, the similarity of sulcal pit distribution appeared to be largely influenced by the presence or absence of the sulcal pits on the shallow and small folds. We suggest that our sulcal pit extraction from MRI is highly reliable and could be useful for clinical applications as an imaging biomarker.

Compensation of Verdet Constant Temperature Dependence by Crystal Core Temperature Measurement

PubMed Central

Petricevic, Slobodan J.; Mihailovic, Pedja M.

2016-01-01

Compensation of the temperature dependence of the Verdet constant in a polarimetric extrinsic Faraday sensor is of major importance for applying the magneto-optical effect to AC current measurements and magnetic field sensing. This paper presents a method for compensating the temperature effect on the Faraday rotation in a Bi12GeO20 crystal by sensing its optical activity effect on the polarization of a light beam. The method measures the temperature of the same volume of crystal that effects the beam polarization in a magnetic field or current sensing process. This eliminates the effect of temperature difference found in other indirect temperature compensation methods, thus allowing more accurate temperature compensation for the temperature dependence of the Verdet constant. The method does not require additional changes to an existing Δ/Σ configuration and is thus applicable for improving the performance of existing sensing devices. PMID:27706043

Temperature measurement method using temperature coefficient timing for resistive or capacitive sensors

DOEpatents

Britton, Jr., Charles L.; Ericson, M. Nance

1999-01-01

A method and apparatus for temperature measurement especially suited for low cost, low power, moderate accuracy implementation. It uses a sensor whose resistance varies in a known manner, either linearly or nonlinearly, with temperature, and produces a digital output which is proportional to the temperature of the sensor. The method is based on performing a zero-crossing time measurement of a step input signal that is double differentiated using two differentiators functioning as respective first and second time constants; one temperature stable, and the other varying with the sensor temperature.

Temperature measurement method using temperature coefficient timing for resistive or capacitive sensors

DOEpatents

Britton, C.L. Jr.; Ericson, M.N.

1999-01-19

A method and apparatus for temperature measurement especially suited for low cost, low power, moderate accuracy implementation. It uses a sensor whose resistance varies in a known manner, either linearly or nonlinearly, with temperature, and produces a digital output which is proportional to the temperature of the sensor. The method is based on performing a zero-crossing time measurement of a step input signal that is double differentiated using two differentiators functioning as respective first and second time constants; one temperature stable, and the other varying with the sensor temperature. 5 figs.

Effect of sulfur and magnesium on hot ductility and pitting corrosion for Inconel 690 alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, K.; Zhang, B.; Zhang, S.

1995-12-31

A series of hot tensile tests has been performed to study the effect of sulfur and magnesium on hot ductility of Inconel 690 alloy. The hot ductility has been evaluated from the reduction of area in hot tensile tests using a Gleeble testing machine. The value of reduction in area decreased with increasing sulfur content in the temperature range from 900 C to 1,200 C. When sulfur content was larger than 0.0025%, a ductility dip appeared, and the greater the sulfur content, the deeper and wider the ductility dip. The Scanning Electron Microscope (SEM) analyses showed that the fracture appearancesmore » changed gradually from transgranular to intergranular with increasing sulfur content, meanwhile sulfur and titanium segregation were observed at grain boundaries. The ductility dip of 690 alloy with relatively higher sulfur content could be inhibited by adding appropriate amount of magnesium. However, excessive addition led to magnesium precipitation, which was detrimental to hot ductility. The pitting test has also been conducted and the results showed that pitting rate obviously increased with increasing sulfur content.« less

Method and apparatus for optical temperature measurement

DOEpatents

O'Rourke, P.E.; Livingston, R.R.; Prather, W.S.

1994-09-20

A temperature probe and a method for using said probe for temperature measurements based on changes in light absorption by the probe are disclosed. The probe comprises a first and a second optical fiber that carry light to and from the probe, and a temperature sensor material, the absorbance of which changes with temperature, through which the light is directed. Light is directed through the first optical fiber, passes through the temperature sensor material, and is transmitted by a second optical fiber from the material to a detector. Temperature-dependent and temperature-independent factors are derived from measurements of the transmitted light intensity. For each sensor material, the temperature T is a function of the ratio, R, of these factors. The temperature function f(R) is found by applying standard data analysis techniques to plots of T versus R at a series of known temperatures. For a sensor having a known temperature function f(R) and known characteristic and temperature-dependent factors, the temperature can be computed from a measurement of R. Suitable sensor materials include neodymium-doped borosilicate glass, accurate to [+-]0.5 C over an operating temperature range of about [minus]196 C to 400 C; and a mixture of D[sub 2]O and H[sub 2]O, accurate to [+-]0.1 C over an operating range of about 5 C to 90 C. 13 figs.

Method and apparatus for optical temperature measurement

DOEpatents

O'Rourke, Patrick E.; Livingston, Ronald R.; Prather, William S.

1994-01-01

A temperature probe and a method for using said probe for temperature measurements based on changes in light absorption by the probe. The probe comprises a first and a second optical fiber that carry light to and from the probe, and a temperature sensor material, the absorbance of which changes with temperature, through which the light is directed. Light is directed through the first optical fiber, passes through the temperature sensor material, and is transmitted by a second optical fiber from the material to a detector. Temperature-dependent and temperature-independent factors are derived from measurements of the transmitted light intensity. For each sensor material, the temperature T is a function of the ratio, R, of these factors. The temperature function f(R) is found by applying standard data analysis techniques to plots of T versus R at a series of known temperatures. For a sensor having a known temperature function f(R) and known characteristic and temperature-dependent factors, the temperature can be computed from a measurement of R. Suitable sensor materials include neodymium-doped boresilicate glass, accurate to .+-.0.5.degree. C. over an operating temperature range of about -196.degree. C. to 400.degree. C.; and a mixture of D.sub.2 O and H.sub.2 O, accurate to .+-.0.1.degree. C. over an operating range of about 5.degree. C. to 90.degree. C.

Estimation of Methane Emissions from Slurry Pits below Pig and Cattle Confinements

PubMed Central

Petersen, Søren O.; Olsen, Anne B.; Elsgaard, Lars; Triolo, Jin Mi; Sommer, Sven G.

2016-01-01

Quantifying in-house emissions of methane (CH4) from liquid manure (slurry) is difficult due to high background emissions from enteric processes, yet of great importance for correct estimation of CH4 emissions from manure management and effects of treatment technologies such as anaerobic digestion. In this study CH4 production rates were determined in 20 pig slurry and 11 cattle slurry samples collected beneath slatted floors on six representative farms; rates were determined within 24 h at temperatures close to the temperature in slurry pits at the time of collection. Methane production rates in pig and cattle slurry differed significantly at 0.030 and 0.011 kg CH4 kg-1 VS (volatile solids). Current estimates of CH4 emissions from pig and cattle manure management correspond to 0.032 and 0.015 kg CH4 kg-1, respectively, indicating that slurry pits under animal confinements are a significant source. Fractions of degradable volatile solids (VSd, kg kg-1 VS) were estimated using an aerobic biodegradability assay and total organic C analyses. The VSd in pig and cattle slurry averaged 0.51 and 0.33 kg kg-1 VS, and it was estimated that on average 43 and 28% of VSd in fresh excreta from pigs and cattle, respectively, had been lost at the time of sampling. An empirical model of CH4 emissions from slurry was reparameterised based on experimental results. A sensitivity analysis indicated that predicted CH4 emissions were highly sensitive to uncertainties in the value of lnA of the Arrhenius equation, but much less sensitive to uncertainties in VSd or slurry temperature. A model application indicated that losses of carbon in VS as CO2 may be much greater than losses as CH4. Implications of these results for the correct estimation of CH4 emissions from manure management, and for the mitigation potential of treatments such as anaerobic digestion, are discussed. PMID:27529692

Limited mobility of dioxins near San Jacinto super fund site (waste pit) in the Houston Ship Channel, Texas due to strong sediment sorption.

PubMed

Louchouarn, Patrick; Seward, Shaya M; Cornelissen, Gerard; Arp, Hans Peter H; Yeager, Kevin M; Brinkmeyer, Robin; Santschi, Peter H

2018-07-01

Sediments from a waste pit in Houston Ship Channel (HSC) were characterized using a number of molecular markers of natural organic matter fractions (e.g., pyrogenic carbon residues, PAHs, lignins), in addition to dioxins, in order to test the hypothesis that the dispersal and mobility of dioxins from the waste pit in the San Jacinto River is minimal. Station SG-6, sampled at the site of the submerged waste pit, had the highest dioxin/furan concentrations reported for the Houston Ship Channel/Galveston Bay (HSC/GB) system (10,000-46,000 pg/g), which translated into some of the highest reported World Health Organization Toxic Equivalents (TEQs: 2000-11,000 pg/g) in HSC sediments. Using a multi-tracer approach, this study confirmed our hypothesis that sludges from chlorinated pulps are a very likely source of dioxins/furans to this pit. However, this material also contained large quantities of additional hydrophobic organic contaminants (PAHs) and pyrogenic markers (soot-BC, levoglucosan), pointing to the co-occurrence of petroleum hydrocarbons and combustion byproducts. Comparison of dioxin/furan signatures in the waste pit with those from sediments of the HSC and a control site suggests that the remobilization of contaminated particles did not occur beyond the close vicinity of the pit itself. The dioxins/furans in sediments outside the waste pit within the HSC are rather from other diffuse inputs, entering the sedimentary environment through the air and water, and which are comprised of a mixture of industrial and municipal sources. Fingerprinting of waste pit dioxins indicates that their composition is typical of pulp and paper sources. Measured pore water concentrations were 1 order of magnitude lower than estimated values, calculated from a multiphase sorption model, indicating low mobility of dioxins within the waste pit. This is likely accomplished by co-occurring and strong sorbing pyrogenic and petrogenic residues in the waste pit, which tend to keep

Reduced Performance of Prey Targeting in Pit Vipers with Contralaterally Occluded Infrared and Visual Senses

PubMed Central

Chen, Qin; Deng, Huanhuan; Brauth, Steven E.; Ding, Li; Tang, Yezhong

2012-01-01

Both visual and infrared (IR) senses are utilized in prey targeting by pit vipers. Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons. A series of ocular and pit organ occlusion experiments using the short-tailed pit viper (Gloydius brevicaudus) were conducted to investigate the role of visual and IR information during prey targeting. Compared with unoccluded controls, snakes with either both eyes or pit organs occluded performed more poorly in hunting prey although such subjects still captured prey on 75% of trials. Subjects with one eye and one pit occluded on the same side of the face performed as well as those with bilateral occlusion although these subjects showed a significant targeting angle bias toward the unoccluded side. Performance was significantly poorer when only a single eye or pit was available. Interestingly, when one eye and one pit organ were occluded on opposite sides of the face, performance was poorest, the snakes striking prey on no more than half the trials. These results indicate that, visual and infrared information are both effective in prey targeting in this species, although interference between the two modalities occurs if visual and IR information is restricted to opposite sides of the brain. PMID:22606229

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70° F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

Reliability issues in human brain temperature measurement

PubMed Central

2009-01-01

Introduction The influence of brain temperature on clinical outcome after severe brain trauma is currently poorly understood. When brain temperature is measured directly, different values between the inside and outside of the head can occur. It is not yet clear if these differences are 'real' or due to measurement error. Methods The aim of this study was to assess the performance and measurement uncertainty of body and brain temperature sensors currently in use in neurocritical care. Two organic fixed-point, ultra stable temperature sources were used as the temperature references. Two different types of brain sensor (brain type 1 and brain type 2) and one body type sensor were tested under rigorous laboratory conditions and at the bedside. Measurement uncertainty was calculated using internationally recognised methods. Results Average differences between the 26°C reference temperature source and the clinical temperature sensors were +0.11°C (brain type 1), +0.24°C (brain type 2) and -0.15°C (body type), respectively. For the 36°C temperature reference source, average differences between the reference source and clinical thermometers were -0.02°C, +0.09°C and -0.03°C for brain type 1, brain type 2 and body type sensor, respectively. Repeat calibrations the following day confirmed that these results were within the calculated uncertainties. The results of the immersion tests revealed that the reading of the body type sensor was sensitive to position, with differences in temperature of -0.5°C to -1.4°C observed on withdrawing the thermometer from the base of the isothermal environment by 4 cm and 8 cm, respectively. Taking into account all the factors tested during the calibration experiments, the measurement uncertainty of the clinical sensors against the (nominal) 26°C and 36°C temperature reference sources for the brain type 1, brain type 2 and body type sensors were ± 0.18°C, ± 0.10°C and ± 0.12°C respectively. Conclusions The results show that

High-temperature rapid pyrometamorphism induced by a charcoal pit burning: The case of Ricetto, central Italy

NASA Astrophysics Data System (ADS)

Capitanio, Flavio; Larocca, Francesco; Improta, Salvatore

Bulk chemistry and mineralogy of the peculiar rock of Ricetto (Carseolani Mts., Central Apennines, Italy) was studied to resolve its controversial origin: igneous dyke or anthropic product. This hybrid rock consists of a colorless, felsic component made up of glass plus quartz, and a brown, femic component made up of fans and spherulites of diopside, calcic plagioclase, wollastonite, and melilite. Textural relationships indicate very rapid cooling and immiscibility phenomena. The bulk chemistry of the rock is the same as that of the surrounding siliciclastic sandstone. The 14C analysis of a coal fragment from bottom of the body yields the conventional age of 227(+/-50) years. The Ricetto occurrence is an example of pyrometamorphism of a siliceous limestone induced by a charcoal pit burning. The small size of the heat source at Ricetto caused an intense but short-lived melting of the country rock. Prograde metamorphism caused a temperature increase up to 1,000-1,100 °C when melilite crystallization conditions were reached at appreciable P(CO2) and high f(O2). Melting occurred in a close system represented by the simplified equation: 3Cal+16.5Qtz+Ms+Bt-->Mel+Melt+2H2O+3CO2+0.5O2. Diopside+calcic plagioclase+wollastonite formed by melilite breakdown during rapid cooling, through the reaction: 6Mel+6Qtz+0.5O2-->3Di+2An+7Wo. Liquid immiscibility caused the separation between the felsic melt component and the femic melilite-bearing component. Immiscibility was characterized by different fractionation of alumina and alkalies between these two phases. Differences in bulk, glass, and mineral chemistry between the Ricetto and other melilite-bearing pyrometamorphic rocks can be attributed mainly to different protoliths.

Gear Fault Detection Effectiveness as Applied to Tooth Surface Pitting Fatigue Damage

NASA Technical Reports Server (NTRS)

Lewicki, David G.; Dempsey, Paula J.; Heath, Gregory F.; Shanthakumaran, Perumal

2010-01-01

A study was performed to evaluate fault detection effectiveness as applied to gear-tooth-pitting-fatigue damage. Vibration and oil-debris monitoring (ODM) data were gathered from 24 sets of spur pinion and face gears run during a previous endurance evaluation study. Three common condition indicators (RMS, FM4, and NA4 [Ed. 's note: See Appendix A-Definitions D were deduced from the time-averaged vibration data and used with the ODM to evaluate their performance for gear fault detection. The NA4 parameter showed to be a very good condition indicator for the detection of gear tooth surface pitting failures. The FM4 and RMS parameters perfomu:d average to below average in detection of gear tooth surface pitting failures. The ODM sensor was successful in detecting a significant 8lDOunt of debris from all the gear tooth pitting fatigue failures. Excluding outliers, the average cumulative mass at the end of a test was 40 mg.

A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel

PubMed Central

Yang, Zixuan; Kan, Bo; Li, Jinxu; Su, Yanjing; Qiao, Lijie; Volinsky, Alex A.

2017-01-01

Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance. PMID:29135912

MISSE 1 and 2 Tray Temperature Measurements

NASA Technical Reports Server (NTRS)

Harvey, Gale A.; Kinard, William H.

2006-01-01

The Materials International Space Station Experiment (MISSE 1 & 2) was deployed August 10,2001 and retrieved July 30,2005. This experiment is a co-operative endeavor by NASA-LaRC. NASA-GRC, NASA-MSFC, NASA-JSC, the Materials Laboratory at the Air Force Research Laboratory, and the Boeing Phantom Works. The objective of the experiment is to evaluate performance, stability, and long term survivability of materials and components planned for use by NASA and DOD on future LEO, synchronous orbit, and interplanetary space missions. Temperature is an important parameter in the evaluation of space environmental effects on materials. The MISSE 1 & 2 had autonomous temperature data loggers to measure the temperature of each of the four experiment trays. The MISSE tray-temperature data loggers have one external thermistor data channel, and a 12 bit digital converter. The MISSE experiment trays were exposed to the ISS space environment for nearly four times the nominal design lifetime for this experiment. Nevertheless, all of the data loggers provided useful temperature measurements of MISSE. The temperature measurement system has been discussed in a previous paper. This paper presents temperature measurements of MISSE payload experiment carriers (PECs) 1 and 2 experiment trays.

Application of vaginal temperature measurement in bitches.

PubMed

Maeder, B; Arlt, S; Burfeind, O; Heuwieser, W

2012-12-01

Finding innovative, non-invasive methods for continuously measuring body temperature minimizing human interference is important for accurate data collection. The objective of this study was to assess feasibility and accuracy of continuous body temperature measurements with loggers placed in the vaginal cavity of bitches. First, an in vitro experiment was performed to compare values obtained by temperature loggers (n = 26) to a calibrated liquid-in-glass thermometer. The mean differences between the two methods were low. Next, an in vivo experiment was performed using five healthy bitches, and values obtained by the vaginal loggers were compared to measurements collected rectally with digital thermometers. The results show that rectal and vaginal temperatures were correlated. The mean differences between rectal and vaginal temperatures were negligible. We conclude that the utilized temperature loggers provide accurate and reliable data. © 2012 Blackwell Verlag GmbH.

Illuminating Anaerobic Microbial Community and Cooccurrence Patterns across a Quality Gradient in Chinese Liquor Fermentation Pit Muds.

PubMed

Hu, Xiaolong; Du, Hai; Ren, Cong; Xu, Yan

2016-04-01

Fermentation pit mud, an important reservoir of diverse anaerobic microorganisms, is essential for Chinese strong-aroma liquor production. Pit mud quality, according to its sensory characteristics, can be divided into three grades: degraded, normal, and high quality. However, the relationship between pit mud microbial community and pit mud quality is poorly understood, as are microbial associations within the pit mud ecosystem. Here, microbial communities at these grades were compared using Illumina MiSeq sequencing of the variable region V4 of the 16S rRNA gene. Our results revealed that the pit mud microbial community was correlated with its quality and environmental factors. Species richness, biodiversity, and relative and/or absolute abundances of Clostridia,Clostridium kluyveri, Bacteroidia, and Methanobacteria significantly increased, with corresponding increases in levels of pH, NH4 (+), and available phosphorus, from degraded to high-quality pit muds, while levels of Lactobacillus, dissolved organic carbon, and lactate significantly decreased, with normal samples in between. Furthermore, 271 pairs of significant and robust correlations (cooccurrence and negative) were identified from 76 genera using network analysis. Thirteen hubs of cooccurrence patterns, mainly under the Clostridia,Bacteroidia,Methanobacteria, and Methanomicrobia, may play important roles in pit mud ecosystem stability, which may be destroyed with rapidly increased levels of lactic acid bacteria (Lactobacillus,Pediococcus, and Streptococcus). This study may help clarify the relationships among microbial community, environmental conditions, and pit mud quality, allow the improvement of pit mud quality by using bioaugmentation and controlling environmental factors, and shed more light on the ecological rules guiding community assembly in pit mud. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Seedling and Sapling Dynamics of Treefall Pits in Puerto Rico1

Treesearch

Lawrence R. Walker

2000-01-01

Seedling and sapling dynamics in a Puerto Rican rain forest were compared between forest understory and soil pits created by the uprooting of 27 trees during Hurricane Hugo. Soil N and P, organic matter, and soil moisture were lower and bulk densities were higher in the disturbed mineral soils of the pits than in undisturbed forest soils ten months after the hurricane...

Evaluation of Remote Delivery of Passive Integrated Transponder (PIT) Technology to Mark Large Mammals

PubMed Central

Walter, W. David; Anderson, Charles W.; VerCauteren, Kurt C.

2012-01-01

Methods to individually mark and identify free-ranging wildlife without trapping and handling would be useful for a variety of research and management purposes. The use of Passive Integrated Transponder technology could be an efficient method for collecting data for mark-recapture analysis and other strategies for assessing characteristics about populations of various wildlife species. Passive Integrated Transponder tags (PIT) have unique numbered frequencies and have been used to successfully mark and identify mammals. We tested for successful injection of PIT and subsequent functioning of PIT into gelatin blocks using 4 variations of a prototype dart. We then selected the prototype dart that resulted in the least depth of penetration in the gelatin block to assess the ability of PIT to be successfully implanted into muscle tissue of white-tailed deer (Odocoileus virginianus) post-mortem and long-term in live, captive Rocky Mountain elk (Cervus elaphus). The prototype dart with a 12.7 mm (0.5 inch) needle length and no powder charge resulted in the shallowest mean (± SD) penetration depth into gelatin blocks of 27.0 mm (±5.6 mm) with 2.0 psi setting on the Dan-Inject CO2-pressured rifle. Eighty percent of PIT were successfully injected in the muscle mass of white-tailed deer post-mortem with a mean (± SD) penetration depth of 22.2 mm (±3.8 mm; n = 6). We injected PIT successfully into 13 live, captive elk by remote delivery at about 20 m that remained functional for 7 months. We successfully demonstrated that PIT could be remotely delivered in darts into muscle mass of large mammals and remain functional for >6 months. Although further research is warranted to fully develop the technique, remote delivery of PIT technology to large mammals is possible using prototype implant darts. PMID:22984572

Near-Field Microwave Detection of Corrosion Precursor Pitting under Thin Dielectric Coatings in Metallic Substrate

NASA Astrophysics Data System (ADS)

Hughes, D.; Zoughi, R.; Austin, R.; Wood, N.; Engelbart, R.

2003-03-01

Detection of corrosion precursor pitting on metallic surfaces under various coatings and on bare metal is of keen interest in evaluation of aircraft fuselage. Near-field microwave nondestructive testing methods, utilizing open-ended rectangular waveguides and coaxial probes, have been used extensively for detection of surface flaws in metals, both on bare metal and under a dielectric coating. This paper presents the preliminary results of using microwave techniques to detect corrosion precursor pitting under paint and primer, applique and on bare metal. Machined pits of 500 μm diameter were detected using open-ended rectangular waveguides at V-Band under paint and primer and applique, and on bare metal. Using coaxial probes, machined pits with diameters down to 150 μm on bare metal were also detected. Relative pit size and density were shown on a corrosion-pitted sample using open-ended rectangular waveguides at frequencies of 35 GHz to 70 GHz. The use of Boeing's MAUS™ scanning systems provided improved results by alleviating standoff variation and scanning artifact. Typical results of this investigation are also presented.

Non-invasive body temperature measurement of wild chimpanzees using fecal temperature decline.

PubMed

Jensen, Siv Aina; Mundry, Roger; Nunn, Charles L; Boesch, Christophe; Leendertz, Fabian H

2009-04-01

New methods are required to increase our understanding of pathologic processes in wild mammals. We developed a noninvasive field method to estimate the body temperature of wild living chimpanzees habituated to humans, based on statistically fitting temperature decline of feces after defecation. The method was established with the use of control measures of human rectal temperature and subsequent changes in fecal temperature over time. The method was then applied to temperature data collected from wild chimpanzee feces. In humans, we found good correspondence between the temperature estimated by the method and the actual rectal temperature that was measured (maximum deviation 0.22 C). The method was successfully applied and the average estimated temperature of the chimpanzees was 37.2 C. This simple-to-use field method reliably estimates the body temperature of wild chimpanzees and probably also other large mammals.

Device for the alternative option of temperature measurement

NASA Astrophysics Data System (ADS)

Jargus, Jan; Nedoma, Jan; Fajkus, Marcel; Novak, Martin; Cubik, Jakub; Cvejn, Daniel; Vasinek, Vladimir

2017-10-01

Polydimethylsiloxane (PDMS) has good optical properties, and its composition offers the possibility of use in many applications (industry, security device, medicine applications and etc.). We focused on the alternative option of temperature measurement in this article. Our approach is based on measuring changes of chromaticity correlated temperature corresponding to changes in temperature. Described device uses an optical fiber with a defined layer of PDMS and luminophore and we assume that it can find use also in the field of security. The article describes the process of making the prototype of the device and its verification based on laboratory results. The measured temperature depends mainly on the type of optical fiber and the measured temperature range is determined by the thermal resistance of used optical fiber. Using a calibration measurement can determine the value of temperature with an accuracy of +/- 2,5 %.

Non-contact temperature measurement requirements

NASA Technical Reports Server (NTRS)

Higgins, D. B.; Witherow, W. K.

1989-01-01

The Marshall Space Flight Center is involved with levitation experiments for Spacelab, Space Station, and drop tube/tower operations. These experiments have temperature measurement requirements, that of course must be non-contact in nature. The experiment modules involved are the Acoustic Levitator Furnace (ALF), and the Modular Electromagnetic Levitator (MEL). User requirements of the ALF and drop tube are presented. The center also has temperature measurement needs that are not microgravity experiment oriented, but rather are related to the propulsion system for the STS. This requirement will also be discussed.

Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi

PubMed Central

Chirwa, Charles F. C.; Hall, Ralph P.; Krometis, Leigh-Anne H.; Vance, Eric A.; Edwards, Adam; Guan, Ting; Holm, Rochelle H.

2017-01-01

Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology. PMID:28165378

Chemical, Physical, and Biological Factors Shape Littoral Invertebrate Community Structure in Coal-Mining End-Pit Lakes

NASA Astrophysics Data System (ADS)

Luek, Andreas; Rasmussen, Joseph B.

2017-04-01

Aquatic invertebrates form the base of the consumer food web in lakes. In coal-mining end-pit lakes, invertebrates are exposed to an environment with potentially challenging physical and chemical features. We hypothesized that the physical and chemical features of end-pit lakes reduce critical littoral habitat and thus reduce invertebrate diversity, thereby limiting the potential for these lakes to be naturalized. We used a multivariate approach using principle component analysis and redundancy analysis to study relationships between invertebrate community structure, habitat features, and water quality in five end-pit lakes and five natural lakes in the Rocky Mountain foothills of west-central Alberta, Canada. Results show a significantly different invertebrate community structure was present in end-pit lakes as compared with reference lakes in the same region, which could be accounted for by water hardness, conductivity, slope of the littoral zone, and phosphorus concentrations. Habitat diversity in end-pit lakes was also limited, cover provided by macrophytes was scarce, and basin slopes were significantly steeper in pit lakes. Although water chemistry is currently the strongest influencing factor on the invertebrate community, physical challenges of habitat homogeneity and steep slopes in the littoral zones were identified as major drivers of invertebrate community structure. The addition of floating wetlands to the littoral zone of existing pit lakes can add habitat complexity without the need for large-scale alterations to basing morphology, while impermeable capping of waste-rock and the inclusion of littoral habitat in the planning process of new pit lakes can improve the success of integrating new pit lakes into the landscape.

Chemical, Physical, and Biological Factors Shape Littoral Invertebrate Community Structure in Coal-Mining End-Pit Lakes.

PubMed

Luek, Andreas; Rasmussen, Joseph B

2017-04-01

Aquatic invertebrates form the base of the consumer food web in lakes. In coal-mining end-pit lakes, invertebrates are exposed to an environment with potentially challenging physical and chemical features. We hypothesized that the physical and chemical features of end-pit lakes reduce critical littoral habitat and thus reduce invertebrate diversity, thereby limiting the potential for these lakes to be naturalized. We used a multivariate approach using principle component analysis and redundancy analysis to study relationships between invertebrate community structure, habitat features, and water quality in five end-pit lakes and five natural lakes in the Rocky Mountain foothills of west-central Alberta, Canada. Results show a significantly different invertebrate community structure was present in end-pit lakes as compared with reference lakes in the same region, which could be accounted for by water hardness, conductivity, slope of the littoral zone, and phosphorus concentrations. Habitat diversity in end-pit lakes was also limited, cover provided by macrophytes was scarce, and basin slopes were significantly steeper in pit lakes. Although water chemistry is currently the strongest influencing factor on the invertebrate community, physical challenges of habitat homogeneity and steep slopes in the littoral zones were identified as major drivers of invertebrate community structure. The addition of floating wetlands to the littoral zone of existing pit lakes can add habitat complexity without the need for large-scale alterations to basing morphology, while impermeable capping of waste-rock and the inclusion of littoral habitat in the planning process of new pit lakes can improve the success of integrating new pit lakes into the landscape.

Evolution of mud-capped dredge pits following excavation: sediment trapping and slope instability

NASA Astrophysics Data System (ADS)

Obelcz, J.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; O'Connor, M. C.; Wang, J.

2016-02-01

Many fluvial channels incised the Northern Gulf of Mexico inner continental shelf during the late Quaternary. Mud-capped dredge pits (MCDPs), which are generally elongate and deep (8-10 m) excavations, target sandy fluvial channel deposits for coastal restoration projects. The morphological evolution of dredge excavations in noncohesive sandy substrate is well studied, but MCDPs have up to a several-meter-thick veneer of Holocene shelf mud overlying sandy channel deposits. This stratigraphy is hypothesized to result in more complex post-dredge morphology than pit walls simply slumping to the angle of repose shortly after excavation. Numerical modeling of MCDP post-dredge response conducted prior to excavation indicates pit walls may retrogressively fail, which is accounted for in pit design by assigning no-dredge setback buffers from pipelines or cultural and environmental resources. To validate model results and test effectiveness of setback buffers, a geophysical survey of the Sandy Point MCDP (20 km west of the Mississippi River Delta in 10m deep water), where 1.7 million m3 of sandy sediment was excavated in 2012, was conducted May 2015. A total of 84 line-km of high-resolution chirp subbottom and a 27 km2 grid of swath bathymetry and sidescan sonar were collected. The data indicate the dredge pit walls are differentially slumping, with the western pit wall in a more active state of failure than the eastern wall. The western failures morphologically resemble features observed along the muddy Mississippi River Delta Front at water depths of 20-100 m, including bowl-shaped collapse failures and retrogressive stair-stepped slumps; these failures may play a key role in evaluating the distance of setback buffer zone to pipelines. These features indicate the cohesive mud overlying the sandy infill has a prominent role in pit wall stability. A 0.5-1 m thick acoustically transparent package overlies the entire pit floor (interpreted as a possible fluid mud layer

Pitted keratolysis, erythromycin, and hyperhidrosis.

PubMed

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

2014-01-01

Pitted keratolysis (PK) is a plantar skin disorder mainly caused by coryneform bacteria. A common treatment consists of the topical use of erythromycin. Hyperhidrosis is considered a predisposing factor for bacterial proliferation and, consequently, for the onset of PK. The aim of this study was to evaluate the relationship between PK erythromycin and hyperhidrosis. All patients with PK seen in Sant'Andrea Hospital, between January 2009 and December 2011, were collected. PK was clinically and microscopically diagnosed. All patients underwent only topical treatment with erythromycin 3% gel twice daily. At the beginning of the study and after 5 and 10 days of treatment, a clinical evaluation and a gravimetric measurement of plantar sweating were assessed. A total of 97 patients were diagnosed as PK and were included in the study. Gravimetric measurements showed that in 94 of 97 examined patients (96.90%) at the time of the diagnosis, there was a bilateral excessive sweating occurring specifically in the areas affected by PK. After 10 days of antibiotic therapy, hyperhidrosis regressed together with the clinical manifestations. According to these data, we hypothesize that hyperhidrosis is due to an eccrine sweat gland hyperfunction, probably secondary to bacterial infection. © 2013 Wiley Periodicals, Inc.

Growth hormone and Pit-1 expression in bovine fetal lymphoid cells.

PubMed

Chen, H T; Schuler, L A; Schultz, R D

1997-11-01

Bovine fetal lymphoid cells were examined for growth hormone (GH) and the transcription factor Pit-1/GHF-1 mRNA. GH and Pit-1/GHF-1 transcripts were detected in thymocytes and splenocytes from fetuses at 60, 90, 120, and 270 d of gestation using reverse transcription-polymerase chain reaction (RT-PCR). Northern analysis indicated that the lymphoid GH mRNA was approximately 350 nucleotides larger than in the pituitary. RT-PCR analysis demonstrated that the coding regions as well as 3' untranslated region of the lymphocyte GH and pituitary transcripts were the same. Analysis of the 5'-untranslated region of the lymphocyte GH mRNA showed that transcription began upstream from the start site in the pituitary gland, suggesting differences in regulation in these tissues. Fetal thymocytes and splenocytes expressed Pit-1/GHF-1 mRNA; however, they contained only the 2.5-kb transcript. The GH and Pit-1/GHF-1 mRNA in fetal lymphoid cells supports the hypothesis that lymphocyte-derived GH may function as an autocrine and/or paracrine factor during the development and maturation of the bovine fetal immune system.

Fabrication of anatomically tapered foveal pits for retinal phantoms for optical coherence tomography

NASA Astrophysics Data System (ADS)

Lee, Gary C. F.; Smith, Gennifer T.; Agrawal, Monica; Ellerbee, Audrey K.

2015-03-01

Optical Coherence Tomography (OCT) has become a standard tool for diagnosing retinal disease in many ophthalmology clinics. Nonetheless, the technical and clinical research communities still lack a standardized phantom that could aid in evaluating and normalizing the various scan protocols and OCT machines employed at different institutions. Existing retinal phantoms designed for OCT imaging mimic some important features of the retina, such as the thickness and scattering properties of its many layers. However, the morphology of the foveal pit and the visible tapering of the retinal layers underlying the surface surrounding the pit remains a challenge to replicate in current phantoms. Recent attempts at creating a realistic foveal pit include molding, ablation and laser etching but have not proved sufficient to replicate this particular anatomical feature. In this work, we demonstrate a new fabrication procedure that is capable of replicating the tapered appearance of the retinal layers near the foveal pit using a combination of spin-coating and replica molding. The ability to create an anatomically correct foveal pit will allow for a new phantom better suited for intra- and inter-system evaluation and for improved testing of retinal segmentation algorithms.

Operational methods of thermodynamics. Volume 1 - Temperature measurement

NASA Astrophysics Data System (ADS)

Eder, F. X.

The principles of thermometry are examined, taking into account the concept of temperature, the Kelvin scale, the statistical theory of heat, negative absolute temperatures, the thermodynamic temperature scale, the thermodynamic temperature scale below 1 K, noise thermometry, temperature scales based on black-body radiation, acoustical thermometry, and the International Practical Temperature Scale 1968. Aspects of practical temperature measurement are discussed, giving attention to thermometers based on the expansion of a gas or a liquid, instruments utilizing the relative thermal expansion of two different metals, devices measuring the vapor pressure of a liquid, thermocouples, resistance thermometers, radiation pyrometers of various types, instruments utilizing the temperature dependence of a number of material characteristics, devices for temperature control, thermometer calibration, and aspects of thermometer installation and inertia. A description is presented of the approaches employed for the measurement of low temperatures.

Measurement of the temperature distribution inside the power cable using distributed temperature system

NASA Astrophysics Data System (ADS)

Jaros, Jakub; Liner, Andrej; Papes, Martin; Vasinek, Vladimir; Mach, Veleslav; Hruby, David; Kajnar, Tomas; Perecar, Frantisek

2015-01-01

Nowadays, the power cables are manufactured to fulfill the following condition - the highest allowable temperature of the cable during normal operation and the maximum allowable temperature at short circuit conditions cannot exceed the condition of the maximum allowable internal temperature. The distribution of the electric current through the conductor leads to the increase of the amplitude of electrons in the crystal lattice of the cables material. The consequence of this phenomenon is the increase of friction and the increase of collisions between particles inside the material, which causes the temperature increase of the carrying elements. The temperature increase is unwanted phenomena, because it is causing losses. In extreme cases, the long-term overload leads to the cable damaging or fire. This paper deals with the temperature distribution measurement inside the power cables using distributed temperature system. With cooperation with Kabex company, the tube containing optical fibers was installed into the center of power cables. These fibers, except telecommunications purposes, can be also used as sensors in measurements carrying out with distributed temperature system. These systems use the optical fiber as a sensor and allow the continual measurement of the temperature along the whole cable in real time with spatial resolution 1 m. DTS systems are successfully deployed in temperature measurement applications in industry areas yet. These areas include construction, drainage, hot water etc. Their advantages are low cost, resistance to electromagnetic radiation and the possibility of real time monitoring at the distance of 8 km. The location of the optical fiber in the center of the power cable allows the measurement of internal distribution of the temperature during overloading the cable. This measurement method can be also used for prediction of short-circuit and its exact location.

Temperature measurement with industrial color camera devices

NASA Astrophysics Data System (ADS)

Schmidradler, Dieter J.; Berndorfer, Thomas; van Dyck, Walter; Pretschuh, Juergen

1999-05-01

This paper discusses color camera based temperature measurement. Usually, visual imaging and infrared image sensing are treated as two separate disciplines. We will show, that a well selected color camera device might be a cheaper, more robust and more sophisticated solution for optical temperature measurement in several cases. Herein, only implementation fragments and important restrictions for the sensing element will be discussed. Our aim is to draw the readers attention to the use of visual image sensors for measuring thermal radiation and temperature and to give reasons for the need of improved technologies for infrared camera devices. With AVL-List, our partner of industry, we successfully used the proposed sensor to perform temperature measurement for flames inside the combustion chamber of diesel engines which finally led to the presented insights.

Using passive integrated transponder (PIT) systems for terrestrial detection of blue-spotted salamanders (Ambystoma laterale) in situ

USGS Publications Warehouse

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

2014-01-01

Pure-diploid Blue-spotted Salamanders (Ambystoma laterale) are the smallest members of the family Ambystomatidae which makes tracking with radio-transmitters difficult because of small battery capacity. Passive integrated transponder (PIT) tags provide another tracking approach for small fossorial animals such as salamanders. We evaluated the use of portable PIT tag readers (PIT packs) to detect PIT tag-implanted pure-diploid Blue-spotted Salamanders in situ. We also examined the detection probability of salamanders with PIT tags held in enclosures in wetland and terrestrial habitats, as well as the underground detection range of PIT packs by scanning for buried tags not implanted into salamanders. Of the 532 PIT tagged salamanders, we detected 6.84% at least once during scanning surveys. We scanned systematically within a 13.37 ha area surrounding a salamander breeding pool on 34 occasions (~119 hours of survey time) and detected PIT tags 74 times. We detected 55% of PITs in tagged salamanders and 45%were expelled tags. We were able to reliably detect buried PIT tags from 1–22cm below the ground surface. Because nearly half the locations represented expelled tags, our data suggest this technique is inappropriate for future studies of pure-diploid Blue-spotted Salamanders, although it may be suitable for polyploid Blue-spotted Salamanders and other ambystomatid species, which are larger in size and may exhibit higher tag retention rates. It may also be prudent to conduct long-term tag retention studies in captivity before tagging and releasing salamanders for in situ study, and to double-mark individuals.

Special Analysis: Disposal Plan for Pit 38 at Technical Area 54, Area G

DOE Office of Scientific and Technical Information (OSTI.GOV)

French, Sean B.; Shuman, Rob

2012-06-26

, efforts have been made to utilize the remaining disposal capacity within MDA G to the greatest extent possible. One approach for doing this has been to dispose of low-activity waste from cleanup operations at LANL in the headspace of selected disposal pits. Waste acceptance criteria (WAC) for the material placed in the headspace of pits 15, 37, and 38 have been developed (LANL, 2010) and the impacts of placing waste in the headspace of these units has been evaluated (LANL, 2012a). The efforts to maximize disposal efficiency have taken on renewed importance because of the disposal demands placed on MDA G by the large volumes of waste that are being generated at LANL by cleanup efforts. For example, large quantities of waste were recently generated by the retrieval of waste formerly disposed of at TA-21, MDA B. A portion of this material has been disposed of in the headspace of pit 38 in compliance with the WAC developed for that disposal strategy; a large amount of waste has also been sent to off-site facilities for disposal. Nevertheless, large quantities of MDA B waste remain that require disposal. An extension of pit 38 was proposed to provide the disposal capacity that will be needed to dispose of institutional waste and MDA B waste through 2013. A special analysis was prepared to evaluate the impacts of the pit extension (LANL, 2012b). The analysis concluded that the disposal unit could be extended with modest increases in the exposures projected for the Area G performance assessment and composite analysis, as long as limits were placed on the radionuclide concentrations in the waste that is placed in the headspace of the pit. Based, in part, on the results of the special analysis, the extension of pit 38 was approved and excavation of the additional disposal capacity was started in May 2012. The special analysis presented here uses performance modeling to identify a disposal plan for the placement of waste in pit 38. The modeling uses a refined design of the disposal

Magnetic Barkhausen noise indications of stress concentrations near pits of various depths

NASA Astrophysics Data System (ADS)

Mandal, K.; Loukas, M. E.; Corey, A.; Atherton, D. L.

1997-11-01

The presence of a defect in a material under stress, changes the local stress distribution around it. This local stress distributions around three circular pits in line pipe steel with depths of 30, 50 and 80% wall thickness were studied nondestructively by magnetic Barkhausen noise measurements and in the presence of different bending stresses. The results show stress concentration factors ˜ 1.5, 1.7 and 2.05, respectively, and are consistent with theoretical predictions.

Persistent pit viper envenomation in a cat.

PubMed

Yankin, Igor; Schaer, Michael; Johnson, Matthew; Meland, Tessa; Londoño, Leonel A

2017-01-01

A 4-year-old female spayed, indoor/outdoor domestic mediumhair cat presented with multiple bleeding puncture wounds and hemorrhagic shock. The cat was diagnosed with suspected pit viper envenomation based on the location and appearance of the bite wounds, as well as the presence of severe coagulopathy with prolonged activated coagulation time (762 s), which responded to antivenom administration. The clinical course of the cat was unique owing to the prolonged clinical signs of envenomation that appeared as intermittent coagulopathy and hemorrhage over a 2 week period. Five vials of antivenom were administered and three units of packed red blood cells were transfused over a 7 day period. The cat made a complete recovery with cessation of hemorrhage and normalization of clotting times. This is the first report of persistent pit viper venom-induced coagulopathy in the feline veterinary literature.

Optic disc pit with sectorial retinitis pigmentosa.

PubMed

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

2013-01-01

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

Improving the spectral measurement accuracy based on temperature distribution and spectra-temperature relationship

NASA Astrophysics Data System (ADS)

Li, Zhe; Feng, Jinchao; Liu, Pengyu; Sun, Zhonghua; Li, Gang; Jia, Kebin

2018-05-01

Temperature is usually considered as a fluctuation in near-infrared spectral measurement. Chemometric methods were extensively studied to correct the effect of temperature variations. However, temperature can be considered as a constructive parameter that provides detailed chemical information when systematically changed during the measurement. Our group has researched the relationship between temperature-induced spectral variation (TSVC) and normalized squared temperature. In this study, we focused on the influence of temperature distribution in calibration set. Multi-temperature calibration set selection (MTCS) method was proposed to improve the prediction accuracy by considering the temperature distribution of calibration samples. Furthermore, double-temperature calibration set selection (DTCS) method was proposed based on MTCS method and the relationship between TSVC and normalized squared temperature. We compare the prediction performance of PLS models based on random sampling method and proposed methods. The results from experimental studies showed that the prediction performance was improved by using proposed methods. Therefore, MTCS method and DTCS method will be the alternative methods to improve prediction accuracy in near-infrared spectral measurement.

Impacts of swine manure pits on groundwater quality

USGS Publications Warehouse

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

2002-01-01

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

Temperature measurement reliability and validity with thermocouple extension leads or changing lead temperature.

PubMed

Jutte, Lisa S; Long, Blaine C; Knight, Kenneth L

2010-01-01

Thermocouples' leads are often too short, necessitating the use of an extension lead. To determine if temperature measures were influenced by extension-lead use or lead temperature changes. Descriptive laboratory study. Laboratory. Experiment 1: 10 IT-21 thermocouples and 5 extension leads. Experiment 2: 5 IT-21 and PT-6 thermocouples. In experiment 1, temperature data were collected on 10 IT-21 thermocouples in a stable water bath with and without extension leads. In experiment 2, temperature data were collected on 5 IT-21 and PT-6 thermocouples in a stable water bath before, during, and after ice-pack application to extension leads. In experiment 1, extension leads did not influence IT-21 validity (P  =  .45) or reliability (P  =  .10). In experiment 2, postapplication IT-21 temperatures were greater than preapplication and application measures (P < .05). Extension leads had no influence on temperature measures. Ice application to leads may increase measurement error.

Dynamic gas temperature measurement system

NASA Technical Reports Server (NTRS)

Elmore, D. L.; Robinson, W. W.; Watkins, W. B.

1983-01-01

A gas temperature measurement system with compensated frequency response of 1 KHz and capability to operate in the exhaust of a gas turbine combustor was developed. Environmental guidelines for this measurement are presented, followed by a preliminary design of the selected measurement method. Transient thermal conduction effects were identified as important; a preliminary finite-element conduction model quantified the errors expected by neglecting conduction. A compensation method was developed to account for effects of conduction and convection. This method was verified in analog electrical simulations, and used to compensate dynamic temperature data from a laboratory combustor and a gas turbine engine. Detailed data compensations are presented. Analysis of error sources in the method were done to derive confidence levels for the compensated data.

Outdoor surface temperature measurement: ground truth or lie?

NASA Astrophysics Data System (ADS)

Skauli, Torbjorn

2004-08-01

Contact surface temperature measurement in the field is essential in trials of thermal imaging systems and camouflage, as well as for scene modeling studies. The accuracy of such measurements is challenged by environmental factors such as sun and wind, which induce temperature gradients around a surface sensor and lead to incorrect temperature readings. In this work, a simple method is used to test temperature sensors under conditions representative of a surface whose temperature is determined by heat exchange with the environment. The tested sensors are different types of thermocouples and platinum thermistors typically used in field trials, as well as digital temperature sensors. The results illustrate that the actual measurement errors can be much larger than the specified accuracy of the sensors. The measurement error typically scales with the difference between surface temperature and ambient air temperature. Unless proper care is taken, systematic errors can easily reach 10% of this temperature difference, which is often unacceptable. Reasonably accurate readings are obtained using a miniature platinum thermistor. Thermocouples can perform well on bare metal surfaces if the connection to the surface is highly conductive. It is pointed out that digital temperature sensors have many advantages for field trials use.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark Krauss and Catherine Birney

2011-05-01

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

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

USGS Publications Warehouse

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

2009-01-01

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

Planetary Pits and Caves: Targets for Science Exploration

NASA Astrophysics Data System (ADS)

Whittaker, W. L.; Boston, P. J.; Cushing, G.; Titus, T. N.; Wagner, R. V.; Colaprete, A.; Haruyama, J.; Jones, H. L.; Blank, J. G.; Mueller, R. P.; Stopar, J. D.; Tabib, W.; Wong, U.

2017-02-01

Planetary pits, caves, and voids are compelling mission destinations for science, exploration, and habitation throughout the solar system. Questions of origins, geology, mineralogy, stratigraphy, gravimetry, aging, and astrobiology abound.

Noncontact Measurement of Humidity and Temperature Using Airborne Ultrasound

NASA Astrophysics Data System (ADS)

Kon, Akihiko; Mizutani, Koichi; Wakatsuki, Naoto

2010-04-01

We describe a noncontact method for measuring humidity and dry-bulb temperature. Conventional humidity sensors are single-point measurement devices, so that a noncontact method for measuring the relative humidity is required. Ultrasonic temperature sensors are noncontact measurement sensors. Because water vapor in the air increases sound velocity, conventional ultrasonic temperature sensors measure virtual temperature, which is higher than dry-bulb temperature. We performed experiments using an ultrasonic delay line, an atmospheric pressure sensor, and either a thermometer or a relative humidity sensor to confirm the validity of our measurement method at relative humidities of 30, 50, 75, and 100% and at temperatures of 283.15, 293.15, 308.15, and 323.15 K. The results show that the proposed method measures relative humidity with an error rate of less than 16.4% and dry-bulb temperature with an error of less than 0.7 K. Adaptations of the measurement method for use in air-conditioning control systems are discussed.

Comparative treatment effectiveness of conventional trench and seepage pit systems.

PubMed

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

2007-03-01

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

A Comprehensive Investigation of Copper Pitting Corrosion in a Drinking Water Distribution System

EPA Science Inventory

Copper pipe pitting is a complicated corrosion process for which exact causes and solutions are uncertain. This paper presents the findings of a comprehensive investigation of a cold water copper pitting corrosion problem in a drinking water distribution system, including a refi...

Temperature Measurements Taken by Phoenix Spacecraft

NASA Image and Video Library

2008-09-30

This chart plots the minimum daily atmospheric temperature measured by NASA Phoenix Mars Lander spacecraft since landing on Mars. As the temperature increased through the summer season, the atmospheric humidity also increased.

Influence of pitting defects on quality of high power laser light field

NASA Astrophysics Data System (ADS)

Ren, Huan; Zhang, Lin; Yang, Yi; Shi, Zhendong; Ma, Hua; Jiang, Hongzhen; Chen, Bo; Yang, XiaoYu; Zheng, Wanguo; Zhu, Rihong

2018-01-01

With the split-step-Fourier-transform method for solving the nonlinear paraxial wave equation, the intensity distribution of the light field when the pits diameter or depth change is obtained by using numerical simulation, include the intensity distribution inside optical element, the beam near-field, the different distances behind the element and the beam far-field. Results show that with the increase of pits diameter or depth, the light field peak intensity and the contrast inside of element corresponding enhancement. The contrast of the intensity distribution of the rear surface of the element will increase slightly. The peak intensity produced by a specific location element downstream of thermal effect will continue to increase, the damage probability in optics placed here is greatly increased. For the intensity distribution of the far-field, increase the pitting diameter or depth will cause the focal spot intensity distribution changes, and the energy of the spectrum center region increase constantly. This work provide a basis for quantitative design and inspection for pitting defects, which provides a reference for the design of optical path arrangement.

Hydrolase treatments help unravel the function of intervessel pits in xylem hydraulics.

PubMed

Dusotoit-Coucaud, Anaïs; Brunel, Nicole; Tixier, Aude; Cochard, Hervé; Herbette, Stéphane

2014-03-01

Intervessel pits are structures that play a key role in the efficiency and safety functions of xylem hydraulics. However, little is known about the components of the pit membrane (PM) and their role in hydraulic functions, especially in resistance to cavitation. We tested the effect of commercial chemicals including a cellulase, a hemicellulase, a pectolyase, a proteinase and DTT on xylem hydraulic properties: vulnerability to cavitation (VC) and conductance. The effects were tested on branch segments from Fagus sylvatica (where the effects on pit structure were analyzed using TEM) and Populus tremula. Cellulose hydrolysis resulted in a sharp increase in VC and a significant increase in conductance, related to complete breakdown of the PM. Pectin hydrolysis also induced a sharp increase in VC but with no effect on conductance or pit structure observable by TEM. The other treatments with hemicellulase, proteinase or DTT showed no effect. This study brings evidence that cellulose and pectins are critical components underpinning VC, and that PM components may play distinct roles in the xylem hydraulic safety and efficiency. © 2013 Scandinavian Plant Physiology Society.

SPERTI Reactor Pit Building (PER605) under construction. Poured concrete foundation ...

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

SPERT-I Reactor Pit Building (PER-605) under construction. Poured concrete foundation will enclosure a "Pit" into which the reactor vessel will be placed. Steel framework has been erected. To left of view is instrument cell (PER-606), constructed of concrete block. Photographer: R.G. Larsen. Date: April 22, 1955. INEEL negative no. 55-1000 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

Body temperature measurements in pigs during general anaesthesia.

PubMed

Musk, G C; Costa, R S; Tuke, J

2016-04-01

The aim was to compare rectal, pharyngeal and oesophageal temperature measurements in anaesthetized pigs. Data were compared using the Bland-Altman method, and correlation coefficients and error measures were calculated. Sixty-six sets of data were collected from 16 pigs weighing 16.2 ± 4.2 kg. The bias (and 95% limit of agreement) for rectal and pharyngeal compared with oesophageal temperature were 0.69 (-1.18 to 2.57) ℃ and 0.22 (-0.84 to 1.28) ℃, respectively. The correlation coefficients for rectal and pharyngeal compared with oesophageal temperature were 0.47 and 0.87, respectively. The absolute error for rectal and pharyngeal compared with oesophageal temperature was 0.7 ± 0.9℃ and 0.2 ± 0.5℃, respectively. Pharyngeal temperature measurement may be more suitable than rectal temperature measurement for estimation of oesophageal temperature during general anaesthesia of pigs. © The Author(s) 2015.

Origin of collapsed pits and branched valleys surrounding the Ius chasma on Mars

NASA Astrophysics Data System (ADS)

Vamshi, G. T.; Martha, T. R.; Vinod Kumar, K.

2014-11-01

Chasma is a deep, elongated and steep sided depression on planetary surfaces. Several hypothesis have been proposed regarding the origin of chasma. In this study, we analysed morphological features in north and south of Ius chasma. Collapsed pits and branched valleys alongwith craters are prominent morphological features surrounding Ius Chasma, which forms the western part of the well known Valles Marineris chasma system on Martian surface. Analysis of images from the High Resolution Stereo Camera (HRSC) in ESA's Mars Express (MEX) with a spatial resolution of 10 m shows linear arrangement of pits north of the Ius chasma. These pits were initially developed along existing narrow linear valleys parallel to Valles Merineris and are conical in shape unlike flat floored impact craters found adjacent to them. The width of conical pits ranges 1-10 km and depth ranges 1-2 km. With more subsidence, size of individual pits increased gradually and finally coalesced together to create a large depression forming a prominent linear valley. Arrangement of pits in this particular fashion can be attributed to collapse of the surface due to l arge hollows created in the subsurface because of the withdrawal of either magma or dry ice. Branched valleys which are prominent morphologic features south of the Ius chasma could have been formed due to groundwater sapping mechanism as proposed by previous researchers. Episodic release of groundwater in large quantity to the surface could have resulted in surface runoff creating V-shaped valleys, which were later modified into U-shaped valleys due to mass wasting and lack of continued surface runoff.

Temperature and heat flux measurements: Challenges for high temperature aerospace application

NASA Technical Reports Server (NTRS)

Neumann, Richard D.

1992-01-01

The measurement of high temperatures and the influence of heat transfer data is not strictly a problem of either the high temperatures involved or the level of the heating rates to be measured at those high temperatures. It is a problem of duration during which measurements are made and the nature of the materials in which the measurements are made. Thermal measurement techniques for each application must respect and work with the unique features of that application. Six challenges in the development of measurement technology are discussed: (1) to capture the character and localized peak values within highly nonuniform heating regions; (2) to manage large volumes of thermal instrumentation in order to efficiently derive critical information; (3) to accommodate thermal sensors into practical flight structures; (4) to broaden the capabilities of thermal survey techniques to replace discrete gages in flight and on the ground; (5) to provide supporting instrumentation conduits which connect the measurement points to the thermally controlled data acquisition system; and (6) to develop a class of 'vehicle tending' thermal sensors to assure the integrity of flight vehicles in an efficient manner.

Building pit dewatering: application of transient analytic elements.

PubMed

Zaadnoordijk, Willem J

2006-01-01

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

53. Photocopied August 1978. DERRICKS AND GENERAL VIEW OF PIT ...

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

53. Photocopied August 1978. DERRICKS AND GENERAL VIEW OF PIT WALLS, POWER HOUSE, NOVEMBER 7, 1900. THE MONOLITHIC BASES OF THESE WALLS PRIOR TO THE ERECTION OF THE PRE-MOULDED BLOCKS APPEAR TO THE RIGHT. ASSEMBLED WALLS ARE ON THE LEFT. NOTE THAT THE MONOLITHIC FLOORS FOR THE TAIL PITS HAVE BEEN POURED IN THE FIVE RACES ON THE RIGHT, BUT NOT IN THE THREE CLOSEST TO THE ALREADY-ASSEMBLED WALLS. (103) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

Direct observation of pitting corrosion evolutions on carbon steel surfaces at the nano-to-micro- scales.

PubMed

Guo, Peng; La Plante, Erika Callagon; Wang, Bu; Chen, Xin; Balonis, Magdalena; Bauchy, Mathieu; Sant, Gaurav

2018-05-22

The Cl - -induced corrosion of metals and alloys is of relevance to a wide range of engineered materials, structures, and systems. Because of the challenges in studying pitting corrosion in a quantitative and statistically significant manner, its kinetics remain poorly understood. Herein, by direct, nano- to micro-scale observations using vertical scanning interferometry (VSI), we examine the temporal evolution of pitting corrosion on AISI 1045 carbon steel over large surface areas in Cl - -free, and Cl - -enriched solutions. Special focus is paid to examine the nucleation and growth of pits, and the associated formation of roughened regions on steel surfaces. By statistical analysis of hundreds of individual pits, three stages of pitting corrosion, namely, induction, propagation, and saturation, are quantitatively distinguished. By quantifying the kinetics of these processes, we contextualize our current understanding of electrochemical corrosion within a framework that considers spatial dynamics and morphology evolutions. In the presence of Cl - ions, corrosion is highly accelerated due to multiple autocatalytic factors including destabilization of protective surface oxide films and preservation of aggressive microenvironments within the pits, both of which promote continued pit nucleation and growth. These findings offer new insights into predicting and modeling steel corrosion processes in mid-pH aqueous environments.

The effect of previous experience on trap construction and movement distance in a pit-building predator.

PubMed

Adar, Shay; Scharf, Inon; Dor, Roi

2016-10-01

Wormlion larvae are sit-and-wait predators that construct cone-shaped pits in sandy patches to capture prey. Wormlions select microhabitats that feature favorable conditions for pit construction, in a similar way to other trap-building predators, like spiders and antlions. We investigated whether wormlions exhibit an experience-based behavioral plasticity in their pit construction behavior. In a laboratory experiment, pit sizes and relocation distances were compared between larvae that experienced either a period of unfavorable conditions, i.e., surface obstacles, shallow or coarse sand, or a period of favorable conditions, i.e., clear, deep, and fine sand and were able to construct pits undisturbed. We expected that wormlions experiencing improving conditions would build larger pits than those experiencing deteriorating conditions. In addition, we expected that larvae experiencing unfavorable conditions would be less choosy in their new microhabitat and move over shorter distances. We observed a certain effect of recent experience on the trap-building behavior; however, it was not consistent among treatments. Additionally, we detected a correlation between larval body mass, relocation distance, and pit area. These findings might suggest that past experience does not influence wormlion foraging behavior in a simple manner but that different types of experience induce different behavioral responses.

Crystal growth and dislocation etch pits observation of chalcopyrite CdSiP2

NASA Astrophysics Data System (ADS)

He, Zhiyu; Zhao, Beijun; Zhu, Shifu; Chen, Baojun; Huang, Wei; Lin, Li; Feng, Bo

2018-01-01

CdSiP2 is the only crystal that can offer Non-critical Phase Matching (NCPM) for a 1064 nm pumped optical parametric oscillation (OPO) with idler output in the 6 μm range. In this paper, a large, crack-free CdSiP2 single crystal measuring 18 mm in diameter and 65 mm in length was successfully grown by the Vertical Bridgman method (MVB) with an explosion-proof quartz ampoule. The results of lattice parameters, element composition and IR transmittance of the as-grown crystal characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS) and Fourier transformation infrared spectrometer (FTIR) showed the as grown crystal crystallized well and the absorption coefficients at 4878 cm-1 and 2500 cm-1 were 0.14 cm-1 and 0.06 cm-1. Moreover, a new etchant composed of Br2, HCl, HNO3, CH3OH and H2O (1:800:800:400:400 in volume ratio) was prepared and the dislocation etch pits on oriented faces of as-grown CdSiP2 crystal were observed for the first time. It is found the etch pits are in rectangular structure on the (1 0 1) face, but in trigonal pyramid structure on (3 1 2) face. According to the quantities of the etch pits, the average densities of dislocation were evaluated to be 2.28 × 105/cm2 and 1.4 × 105/cm2, respectively.

40 CFR 91.309 - Engine intake air temperature measurement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must be...

40 CFR 91.309 - Engine intake air temperature measurement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must be...

40 CFR 91.309 - Engine intake air temperature measurement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must be...

40 CFR 91.309 - Engine intake air temperature measurement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must be...

Optic Disc Pit with Sectorial Retinitis Pigmentosa

PubMed Central

Taskapili, Muhittin; Yilmaz, Tolga; Teke, Mehmet Yasin

2013-01-01

Sectorial retinitis pigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, fluorescein angiography, and multifocal electroretinogram scans confirmed these clinical findings. Visual acuity was decreased due to an atrophic-appearing foveal lesion. No intervention was suggested because of the poor visual potential. To the best of our knowledge, the present study is the first to describe coexistent optic disc pit and sectorial RP in the superior and inferotemporal sectors covering the macula in the same eye with figures. PMID:23781365

Treatment of a mud pit by bioremediation.

PubMed

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

2016-08-01

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

Refunctionalization of the ancient rice blast disease resistance gene Pit by the recruitment of a retrotransposon as a promoter.

PubMed

Hayashi, Keiko; Yoshida, Hitoshi

2009-02-01

The plant genome contains a large number of disease resistance (R) genes that have evolved through diverse mechanisms. Here, we report that a long terminal repeat (LTR) retrotransposon contributed to the evolution of the rice blast resistance gene Pit. Pit confers race-specific resistance against the fungal pathogen Magnaporthe grisea, and is a member of the nucleotide-binding site leucine-rich repeat (NBS-LRR) family of R genes. Compared with the non-functional allele Pit(Npb), the functional allele Pit(K59) contains four amino acid substitutions, and has the LTR retrotransposon Renovator inserted upstream. Pathogenesis assays using chimeric constructs carrying the various regions of Pit(K59) and Pit(Npb) suggest that amino acid substitutions might have a potential effect in Pit resistance; more importantly, the upregulated promoter activity conferred by the Renovator sequence is essential for Pit function. Our data suggest that transposon-mediated transcriptional activation may play an important role in the refunctionalization of additional 'sleeping' R genes in the plant genome.

Temperature Measurement and Numerical Prediction in Machining Inconel 718

PubMed Central

Tapetado, Alberto; Vázquez, Carmen; Miguélez, Henar

2017-01-01

Thermal issues are critical when machining Ni-based superalloy components designed for high temperature applications. The low thermal conductivity and extreme strain hardening of this family of materials results in elevated temperatures around the cutting area. This elevated temperature could lead to machining-induced damage such as phase changes and residual stresses, resulting in reduced service life of the component. Measurement of temperature during machining is crucial in order to control the cutting process, avoiding workpiece damage. On the other hand, the development of predictive tools based on numerical models helps in the definition of machining processes and the obtainment of difficult to measure parameters such as the penetration of the heated layer. However, the validation of numerical models strongly depends on the accurate measurement of physical parameters such as temperature, ensuring the calibration of the model. This paper focuses on the measurement and prediction of temperature during the machining of Ni-based superalloys. The temperature sensor was based on a fiber-optic two-color pyrometer developed for localized temperature measurements in turning of Inconel 718. The sensor is capable of measuring temperature in the range of 250 to 1200 °C. Temperature evolution is recorded in a lathe at different feed rates and cutting speeds. Measurements were used to calibrate a simplified numerical model for prediction of temperature fields during turning. PMID:28665312

Temperature Measurement and Numerical Prediction in Machining Inconel 718.

PubMed

Díaz-Álvarez, José; Tapetado, Alberto; Vázquez, Carmen; Miguélez, Henar

2017-06-30

Thermal issues are critical when machining Ni-based superalloy components designed for high temperature applications. The low thermal conductivity and extreme strain hardening of this family of materials results in elevated temperatures around the cutting area. This elevated temperature could lead to machining-induced damage such as phase changes and residual stresses, resulting in reduced service life of the component. Measurement of temperature during machining is crucial in order to control the cutting process, avoiding workpiece damage. On the other hand, the development of predictive tools based on numerical models helps in the definition of machining processes and the obtainment of difficult to measure parameters such as the penetration of the heated layer. However, the validation of numerical models strongly depends on the accurate measurement of physical parameters such as temperature, ensuring the calibration of the model. This paper focuses on the measurement and prediction of temperature during the machining of Ni-based superalloys. The temperature sensor was based on a fiber-optic two-color pyrometer developed for localized temperature measurements in turning of Inconel 718. The sensor is capable of measuring temperature in the range of 250 to 1200 °C. Temperature evolution is recorded in a lathe at different feed rates and cutting speeds. Measurements were used to calibrate a simplified numerical model for prediction of temperature fields during turning.

PIT Tagging Anurans

USGS Publications Warehouse

McCreary, Brome

2008-01-01

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

Numerical ages of Holocene tributary debris fans inferred from dissolution pitting on carbonate boulders in the Grand Canyon of Arizona

USGS Publications Warehouse

Hereford, R.; Thompson, K.S.; Burke, K.J.

1998-01-01

Carbonate boulders transported down steep tributary channels by debris flow came to rest on Holocene debris fans beside the Colorado River in Grand Canyon National Park. Weakly acidic rainfall and the metabolic activity of blue-green algae have produced roughly hemispheric dissolution pits as much as 2-cm deep on the initially smooth surfaces of the boulders. The average depth of dissolution pits increases with relative age of fan surfaces. The deepening rate averages 2.4 mm/1000 yr (standard error = 0.2 mm/1000 yr), as calculated from several radiometrically dated surfaces and an archeological structure. This linear rate, which appears constant over at least the past 3000 yr, is consistent with field relations limiting the maximum age of the fans and with the physical chemistry of limestone dissolution. Dissolution-pit measurements (n = 6973) were made on 617 boulders on 71 fan surfaces at the 26 largest debris fans in Grand Canyon. Among these fan surfaces, the average pit depth ranges from 1.2 to 17.4 mm, and the resulting pit dissolution ages range from 500 to 7300 cal yr B.P. Most (75%) surfaces are younger than 3000 yr, probably because of removal of older debris fans by the Colorado River. Many of the ages are close to 800, 1600, 2300, 3100, or 4300 cal yr B.P. If not the result of differential preservation of fan surfaces, this clustering implies periods of heightened debris-flow activity and increased precipitation.

Micro-scale temperature measurement method using fluorescence polarization

NASA Astrophysics Data System (ADS)

Tatsumi, K.; Hsu, C.-H.; Suzuki, A.; Nakabe, K.

2016-09-01

A novel method that can measure the fluid temperature in microscopic scale by measuring the fluorescence polarization is described in this paper. The measurement technique is not influenced by the quenching effects which appears in conventional LIF methods and is believed to show a higher reliability in temperature measurements. Experiment was performed using a microchannel flow and fluorescent molecule probes, and the effects of the fluid temperature, fluid viscosity, measurement time, and pH of the solution on the measured fluorescence polarization degree are discussed to understand the basic characteristics of the present method. The results showed that fluorescence polarization is considerably less sensible to these quenching factors. A good correlation with the fluid temperature, on the other hand, was obtained and agreed well with the theoretical values confirming the feasibility of the method.

Pit-1 inhibits BRCA1 and sensitizes human breast tumors to cisplatin and vitamin D treatment

PubMed Central

Seoane, Samuel; Arias, Efigenia; Sigueiro, Rita; Sendon-Lago, Juan; Martinez-Ordoñez, Anxo; Castelao, Esteban; Eiró, Noemí; Garcia-Caballero, Tomás; Macia, Manuel; Lopez-Lopez, Rafael; Maestro, Miguel; Vizoso, Francisco; Mouriño, Antonio; Perez-Fernandez, Roman

2015-01-01

The POU class 1 homeobox 1 (POU1F1, also known as Pit-1), pertaining to the Pit-Oct-Unc (POU) family of transcription factors, has been related to tumor growth and metastasis in breast. However, its role in response to breast cancer therapy is unknown. We found that Pit-1 down-regulated DNA-damage and repair genes, and specifically inhibited BRCA1 gene expression, sensitizing breast cancer cells to DNA-damage agents. Administration of 1α, 25-dihydroxy-3-epi-vitamin D3 (3-Epi, an endogenous low calcemic vitamin D metabolite) reduced Pit-1 expression, and synergized with cisplatin, thus, decreasing cell proliferation and apoptosis in vitro, and reducing tumor growth in vivo. In addition, fifteen primary cultures of human breast tumors showed significantly decreased proliferation when treated with 3-Epi+cisplatin, compared to cisplatin alone. This response positively correlated with Pit-1 levels. Our findings demonstrate that high levels of Pit-1 and reduced BRCA1 levels increase breast cancer cell susceptibility to 3-Epi+cisplatin therapy. PMID:25992773