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Sample records for crown inclination measured

  1. Colour measurements of all ceramic crown systems.

    PubMed

    Rosenstiel, S F; Porter, S S; Johnston, W M

    1989-09-01

    The objectives of this study were: (i) to determine variability among colour parameters of five different ceramic crown systems; and (ii) to measure the effect of using coloured luting agents on restoration colour. The crown systems studied were Cerestore, Dicor, Hi-Ceram, Renaissance, and Vitadur-N. Five crowns for each system were made according to manufacturer's instructions with the same nominal shade (Vita Lumin Vacuum A2) to fit an Ivorine central incisor tooth. Restoration thickness was adjusted to within +/- 0.1 mm (+/- 0.05 mm in the mid-facial area where colour measurements were to be made) with the aid of a dial calliper prior to glazing or, in the case of Dicor, surface staining. Where a core was part of the system this was fabricated to the minimum recommended thickness. The crowns were cemented using luting agents of five different colours in a randomly chosen sequence. The colour of each restoration/cement combination was measured three times using a small-area colorimeter (Minolta CR-121). The variance of each colour parameter (L*, a*, b*) was statistically compared for each crown system using an analysis of variance procedure, as was the effect of the cement. Observed differences were related to visual perception by using the colour difference formula. There were statistically significant differences among the variances of the crown systems and the cements, with significant interactions between crown systems and direction of colour and between cement and direction of colour. Restorations made with different ceramic crown systems had noticeably different colour despite having the same nominal shade. Changing the shade of the luting agent had a perceivable effect on Dicor crowns and, to a lesser extent, on Vitadur-N crowns but not on the other systems due, presumably, to the opacity of their core materials. PMID:2809851

  2. Measurements of turbulent inclined plane dual jets

    NASA Astrophysics Data System (ADS)

    Wang, C. S.; Lin, Y. F.; Sheu, M. J.

    1993-11-01

    Measurements of mean velocities, flow direction, velocity fluctuations and Reynolds shear stress were made with a split film probe of hot wire anemometer to investigate the interactions created by two air jets issuing from two identical plane inclined nozzles. The reverse flow was detected by using the split film probe and observed by flow visualization. Experimental results with an inclined angle of 9° are presented in the paper. Some experimental results with an inclined angle of 27° are presented to investigate the effect of inclination on the flow field. Mean velocities approach self-preservation in both the converging region and the combining region. Velocity fluctuations and Reynolds shear stress approach self-preservation in the combining region only. The spreads of jet and the square of the decay of maximum mean velocity increase linearly as the distance from the nozzle exit increases.

  3. Bioinspired dynamic inclination measurement using inertial sensors.

    PubMed

    Vikas, Vishesh; Crane, Carl

    2015-06-01

    Biologically, the vestibular feedback is critical to the ability of human body to balance in different conditions. This balancing ability inspires analysis of the reference equilibrium position in dynamic environments. The research proposes and experimentally validates the concept of equilibrium for the human body modeled as an inverted pendulum, which is instrumental in explaining why we align the body along the surface normal when standing on a surface but not on an incline, and tend to lean backward or forward on non-static surfaces e.g. accelerating or decelerating bus. This equilibrium position--the dynamic equilibrium axis--is dependent only on the acceleration of surface of contact (e.g. gravity) and acts as the reference to the orientation measurements. The research also draws design inspiration from the two human ears--symmetry and plurality of inertial sensors. The vestibular dynamic inclinometer and planar vestibular dynamic inclinometer consist of multiple (two or four) symmetrically placed accelerometers and a gyroscope. The sensors measure the angular acceleration and absolute orientation, not the change in orientation, from the reference equilibrium position and are successful in separating gravity from motion for objects moving on ground. The measurement algorithm is an analytical solution that is not time-recursive, independent of body dynamics and devoid of integration errors. The experimental results for the two sensor combinations validate the theoretically (kinematics) derived analytical solution of the measurement algorithm. PMID:25879912

  4. Analysis of inclined showers measured with LOPES

    NASA Astrophysics Data System (ADS)

    Lopes Collaboration; Saftoiu, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

    2009-06-01

    In the present study, we analyze the radio signal from inclined air showers recorded by LOPES-30 in coincidence with KASCADE-Grande. LOPES-30 consists of 30 East-West oriented digital antennas, which are amplitude calibrated by an external source. Radio emission from air showers is considered a geomagnetic effect. Inclined events provide a larger range of values for geomagnetic angle (angle between shower axis and geomagnetic field direction) than vertical showers and thus more information on the emission processes can be gathered. In order to have the geometry of the air shower we use the reconstruction provided by the KASCADE-Grande particle detectors array. Analyzing events observed by both LOPES and the extended part of the KASCADE array, Grande, gives the possibility to test in particular the capability and efficiency of radio detection of more distant events. The results are compared with a previous analysis of inclined events recorded by the initial 10 antenna set-up, LOPES-10, in coincidence with the Grande array.

  5. Standardisation of crown-rump length measurement.

    PubMed

    Ioannou, C; Sarris, I; Hoch, L; Salomon, L J; Papageorghiou, A T

    2013-09-01

    Correct estimation of gestational age is essential for any study of ultrasound biometry and for everyday clinical practice. However, inconsistency in pregnancy dating may occur through differences in measurement methods or errors during measurement. In the INTERGROWTH-21(st) Project, pregnancies are dated by the last menstrual period, provided that it is certain and associated with a regular menstrual cycle, and the gestational age by dates concurs with a first-trimester ultrasound crown-rump length (CRL) estimation. Hence, there was a need to standardise CRL measurement methodology across the study sites in this international, multicentre project to avoid systematic differences in dating. To achieve uniformity we undertook the following steps: the ultrasound technique was standardised by disseminating an illustrated, operating manual describing CRL plane landmarks and calliper application, and posters describing the correct acquisition technique were disseminated for quick reference. To ensure that all ultrasonographers understood the methodology, they forwarded a log-book to the INTERGROWTH-21(st) Ultrasound Coordinating Unit, containing the answers to a written test on the manual material and five images of a correctly acquired CRL. Interpretation of CRL was also standardised by ensuring that the same CRL regression formula was used across all study sites. These methods should minimise potential systematic errors in dating associated with pooling data from different health institutions, and represent a model for standardising CRL measurement in future studies. PMID:23678951

  6. Avian orientation at steep angles of inclination: experiments with migratory white-crowned sparrows at the magnetic North Pole.

    PubMed

    Akesson, S; Morin, J; Muheim, R; Ottosson, U

    2001-09-22

    The Earth's magnetic field and celestial cues provide animals with compass information during migration. Inherited magnetic compass courses are selected based on the angle of inclination, making it difficult to orient in the near vertical fields found at high geomagnetic latitudes. Orientation cage experiments were performed at different sites in high Arctic Canada with adult and young white-crowned sparrows (Zonotrichia leucophrys gambelii) in order to investigate birds' ability to use the Earth's magnetic field and celestial cues for orientation in naturally very steep magnetic fields at and close to the magnetic North Pole. Experiments were performed during the natural period of migration at night in the local geomagnetic field under natural clear skies and under simulated total overcast conditions. The experimental birds failed to select a meaningful magnetic compass course under overcast conditions at the magnetic North Pole, but could do so in geomagnetic fields deviating less than 3 degrees from the vertical. Migratory orientation was successful at all sites when celestial cues were available. PMID:11564346

  7. Towards an optimized method of olive tree crown volume measurement.

    PubMed

    Miranda-Fuentes, Antonio; Llorens, Jordi; Gamarra-Diezma, Juan L; Gil-Ribes, Jesús A; Gil, Emilio

    2015-01-01

    Accurate crown characterization of large isolated olive trees is vital for adjusting spray doses in three-dimensional crop agriculture. Among the many methodologies available, laser sensors have proved to be the most reliable and accurate. However, their operation is time consuming and requires specialist knowledge and so a simpler crown characterization method is required. To this end, three methods were evaluated and compared with LiDAR measurements to determine their accuracy: Vertical Crown Projected Area method (VCPA), Ellipsoid Volume method (VE) and Tree Silhouette Volume method (VTS). Trials were performed in three different kinds of olive tree plantations: intensive, adapted one-trunked traditional and traditional. In total, 55 trees were characterized. Results show that all three methods are appropriate to estimate the crown volume, reaching high coefficients of determination: R2 = 0.783, 0.843 and 0.824 for VCPA, VE and VTS, respectively. However, discrepancies arise when evaluating tree plantations separately, especially for traditional trees. Here, correlations between LiDAR volume and other parameters showed that the Mean Vector calculated for VCPA method showed the highest correlation for traditional trees, thus its use in traditional plantations is highly recommended. PMID:25658396

  8. Towards an Optimized Method of Olive Tree Crown Volume Measurement

    PubMed Central

    Miranda-Fuentes, Antonio; Llorens, Jordi; Gamarra-Diezma, Juan L.; Gil-Ribes, Jesús A.; Gil, Emilio

    2015-01-01

    Accurate crown characterization of large isolated olive trees is vital for adjusting spray doses in three-dimensional crop agriculture. Among the many methodologies available, laser sensors have proved to be the most reliable and accurate. However, their operation is time consuming and requires specialist knowledge and so a simpler crown characterization method is required. To this end, three methods were evaluated and compared with LiDAR measurements to determine their accuracy: Vertical Crown Projected Area method (VCPA), Ellipsoid Volume method (VE) and Tree Silhouette Volume method (VTS). Trials were performed in three different kinds of olive tree plantations: intensive, adapted one-trunked traditional and traditional. In total, 55 trees were characterized. Results show that all three methods are appropriate to estimate the crown volume, reaching high coefficients of determination: R2 = 0.783, 0.843 and 0.824 for VCPA, VE and VTS, respectively. However, discrepancies arise when evaluating tree plantations separately, especially for traditional trees. Here, correlations between LiDAR volume and other parameters showed that the Mean Vector calculated for VCPA method showed the highest correlation for traditional trees, thus its use in traditional plantations is highly recommended. PMID:25658396

  9. Online measurement system for the surface inclination of metal workpieces

    NASA Astrophysics Data System (ADS)

    Yin, Peng; Sun, Changku; Wang, Peng; Yang, Qian

    2013-12-01

    The online measurement of the metal surfaces' parameters plays an important role in many industrial fields. Because the surfaces of the machined metal pieces have the characteristics of strong reflection and high possibilities of scattered disturbing irradiation points, this paper designs an online measurement system based on the measurement principles of linear structured light to detect whether the parameters of the machined metal surfaces' height difference and inclination fulfill the compliance requirements, in which the grayscale gravity algorithm is applied to extract the sub-pixel coordinates of the center of laser, the least squares method is employed to fit the data and the Pauta criterion is utilized to remove the spurious points. The repeat accuracy of this system has been tested. The experimental results prove that the precision of inclination is 0.046° RMS under the speed of 40mm/sec, and the precision of height difference is 0.072mm RMS, which meets the design expectations. Hence, this system can be applied to online industrial detection of high speed and high precision.

  10. The orbital inclination of Cygnus XR-1 measured polarimetrically

    SciTech Connect

    Dolan, J.F.; Tapia, S.; Steward Observatory, Tucson, AZ )

    1989-09-01

    The X-ray binary Cyg XR-1/HDE 226868 was observed polarimetrically over one orbit at three different optical wavelengths. The standard theory of Brown, et al. (1978) is used to derive an orbital inclination i = 62 deg (+5 deg, -37 deg), where the error is the 90-percent-confidence interval derived by the method of Simmons, et al. (1980). The value of the orbital inclination is significantly lower than values based on polarimetric observations. The difference is a result of the observational protocols used. A bias toward larger values of the inclination caused by the tidal distortion of the primary is still found in the present result. The inclination derived corresponds to a mass of the compact component of 6.3 solar masses, above the maximum mass of any degenerate configuration consistent with general relativity except a black hole. 37 refs.

  11. Volumetric velocity measurements of vortex rings from inclined exits

    NASA Astrophysics Data System (ADS)

    Troolin, Daniel R.; Longmire, Ellen K.

    2010-03-01

    Vortex rings were generated by driving pistons within circular cylinders of inner diameter D = 72.8 mm at a constant velocity U 0 over a distance L = D. The Reynolds number, U 0 L/(2ν), was 2500. The flow downstream of circular and inclined exits was examined using volumetric 3-component velocimetry (V3V). The circular exit yields a standard primary vortex ring that propagates downstream at a constant velocity and a lingering trailing ring of opposite sign associated with the stopping of the piston. By contrast, the inclined nozzle yields a much more complicated structure. The data suggest that a tilted primary vortex ring interacts with two trailing rings; one associated with the stopping of the piston, and the other associated with the asymmetry of the cylinder exit. The two trailing ring structures, which initially have circulation of opposite sign, intertwine and are distorted and drawn through the center of the primary ring. This behavior was observed for two inclination angles. Increased inclination was associated with stronger interactions between the primary and trailing vortices as well as earlier breakdown.

  12. MEASUREMENTS OF STELLAR INCLINATIONS FOR KEPLER PLANET CANDIDATES

    SciTech Connect

    Hirano, Teruyuki; Taruya, Atsushi; Suto, Yasushi; Sanchis-Ojeda, Roberto; Winn, Joshua N.; Takeda, Yoichi; Narita, Norio

    2012-09-01

    We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period P{sub s} inferred from the flux variation due to starspots and the projected rotational velocity Vsin I{sub s} and stellar radius obtained by a high-resolution spectroscopy, we attempt to estimate the inclination I{sub s} of the stellar spin axis with respect to the line of sight. For transiting planetary systems, in which planetary orbits are edge-on seen from us, the stellar inclination I{sub s} can be a useful indicator of a spin-orbit alignment/misalignment. We newly conducted spectroscopic observations with Subaru/HDS for 15 Kepler Object of Interest (KOI) systems, whose light curves show periodic flux variations. Detailed analyses of their light curves and spectra revealed that some of them are binaries, or the flux variations are too coherent to be caused by starspots, and consequently we could constrain stellar inclinations I{sub s} for eight systems. Among them, KOI-262 and 280 are in good agreement with I{sub s} 90 Degree-Sign suggesting a spin-orbit alignment, while at least one system, KOI-261, shows a possible spin-orbit misalignment. We also obtain a small I{sub s} for KOI-1463, but the transiting companion seems to be a star rather than a planet. The results for KOI-257, 269, 367, and 974 are ambiguous and can be explained with either misalignments or moderate differential rotation. Since our method can be applied to any system having starspots regardless of the planet size, future observations will allow for the expansion of the parameter space in which the spin-orbit relations are investigated.

  13. Measurements of Stellar Inclinations for Kepler Planet Candidates

    NASA Astrophysics Data System (ADS)

    Hirano, Teruyuki; Sanchis-Ojeda, Roberto; Takeda, Yoichi; Narita, Norio; Winn, Joshua N.; Taruya, Atsushi; Suto, Yasushi

    2012-09-01

    We present an investigation of spin-orbit angles for planetary system candidates reported by Kepler. By combining the rotational period Ps inferred from the flux variation due to starspots and the projected rotational velocity Vsin Is and stellar radius obtained by a high-resolution spectroscopy, we attempt to estimate the inclination Is of the stellar spin axis with respect to the line of sight. For transiting planetary systems, in which planetary orbits are edge-on seen from us, the stellar inclination Is can be a useful indicator of a spin-orbit alignment/misalignment. We newly conducted spectroscopic observations with Subaru/HDS for 15 Kepler Object of Interest (KOI) systems, whose light curves show periodic flux variations. Detailed analyses of their light curves and spectra revealed that some of them are binaries, or the flux variations are too coherent to be caused by starspots, and consequently we could constrain stellar inclinations Is for eight systems. Among them, KOI-262 and 280 are in good agreement with Is = 90° suggesting a spin-orbit alignment, while at least one system, KOI-261, shows a possible spin-orbit misalignment. We also obtain a small Is for KOI-1463, but the transiting companion seems to be a star rather than a planet. The results for KOI-257, 269, 367, and 974 are ambiguous and can be explained with either misalignments or moderate differential rotation. Since our method can be applied to any system having starspots regardless of the planet size, future observations will allow for the expansion of the parameter space in which the spin-orbit relations are investigated.

  14. Olive Crown Porosity Measurement Based on Radiation Transmittance: An Assessment of Pruning Effect.

    PubMed

    Castillo-Ruiz, Francisco J; Castro-Garcia, Sergio; Blanco-Roldan, Gregorio L; Sola-Guirado, Rafael R; Gil-Ribes, Jesus A

    2016-01-01

    Crown porosity influences radiation interception, air movement through the fruit orchard, spray penetration, and harvesting operation in fruit crops. The aim of the present study was to develop an accurate and reliable methodology based on transmitted radiation measurements to assess the porosity of traditional olive trees under different pruning treatments. Transmitted radiation was employed as an indirect method to measure crown porosity in two olive orchards of the Picual and Hojiblanca cultivars. Additionally, three different pruning treatments were considered to determine if the pruning system influences crown porosity. This study evaluated the accuracy and repeatability of four algorithms in measuring crown porosity under different solar zenith angles. From a 14° to 30° solar zenith angle, the selected algorithm produced an absolute error of less than 5% and a repeatability higher than 0.9. The described method and selected algorithm proved satisfactory in field results, making it possible to measure crown porosity at different solar zenith angles. However, pruning fresh weight did not show any relationship with crown porosity due to the great differences between removed branches. A robust and accurate algorithm was selected for crown porosity measurements in traditional olive trees, making it possible to discern between different pruning treatments. PMID:27213391

  15. Olive Crown Porosity Measurement Based on Radiation Transmittance: An Assessment of Pruning Effect

    PubMed Central

    Castillo-Ruiz, Francisco J.; Castro-Garcia, Sergio; Blanco-Roldan, Gregorio L.; Sola-Guirado, Rafael R.; Gil-Ribes, Jesus A.

    2016-01-01

    Crown porosity influences radiation interception, air movement through the fruit orchard, spray penetration, and harvesting operation in fruit crops. The aim of the present study was to develop an accurate and reliable methodology based on transmitted radiation measurements to assess the porosity of traditional olive trees under different pruning treatments. Transmitted radiation was employed as an indirect method to measure crown porosity in two olive orchards of the Picual and Hojiblanca cultivars. Additionally, three different pruning treatments were considered to determine if the pruning system influences crown porosity. This study evaluated the accuracy and repeatability of four algorithms in measuring crown porosity under different solar zenith angles. From a 14° to 30° solar zenith angle, the selected algorithm produced an absolute error of less than 5% and a repeatability higher than 0.9. The described method and selected algorithm proved satisfactory in field results, making it possible to measure crown porosity at different solar zenith angles. However, pruning fresh weight did not show any relationship with crown porosity due to the great differences between removed branches. A robust and accurate algorithm was selected for crown porosity measurements in traditional olive trees, making it possible to discern between different pruning treatments. PMID:27213391

  16. Application of Replica Technique and SEM in Accuracy Measurement of Ceramic Crowns

    NASA Astrophysics Data System (ADS)

    Trifkovic, B.; Budak, I.; Todorovic, A.; Hodolic, J.; Puskar, T.; Jevremovic, D.; Vukelic, D.

    2012-01-01

    The paper presents a comparative study of the measuring values of the marginal gap related to the ceramic crowns made by dental CAD/CAM system using the replica technique and SEM. The study was conducted using three experimental groups, which consisted of ceramic crowns manufactured by the Cerec CAD/CAM system. The scanning procedure was carried out using three specialized dental 3D digitization systems from the Cerec family - two types of extraoral optical scanning systems and an intraoral optical scanner. Measurements of the marginal gap were carried out using the replica technique and SEM. The comparison of aggregate values of the marginal gap using the replica technique showed a statistically significant difference between the systems. The measured values of marginal gaps of ceramic crowns using the replica technique were significantly lower compared to those measured by SEM. The results indicate that the choice of technique for measuring the accuracy of ceramic crowns influences the final results of investigation.

  17. Comparison of femoral inclination angle measurements in dysplastic and nondysplastic dogs of different breeds.

    PubMed

    Sarierler, M

    2004-01-01

    In this study, inclination angle of the femoral head and neck was measured on 484 limbs of 242 dogs belonging to 7 breeds, examined for hip dysplasia. These inclination angles were compared according to age, sex and joint laxity, evaluated with Subluxation Index (SI) and Norberg angle (NA) results. The findings indicate that (a) there was a minimal (nonsignificant) difference in femoral inclination angle between the dysplastic and nondysplastic dogs belonging to 7 breeds; (b) although there was no significant difference in femoral inclination angle between the nondysplastic dogs belonging to 4 breeds (Pointer, Irish Setter, Golden Retriever and German Shepherd), a significant difference was observed between Doberman and Labrador, and between Anatolian Karabash and the other six breeds (p < 0.001). Age and sex did not affect the femoral neck angle. PMID:15168756

  18. Measuring relative-story displacement and local inclination angle using multiple position-sensitive detectors.

    PubMed

    Matsuya, Iwao; Katamura, Ryuta; Sato, Maya; Iba, Miroku; Kondo, Hideaki; Kanekawa, Kiyoshi; Takahashi, Motoichi; Hatada, Tomohiko; Nitta, Yoshihiro; Tanii, Takashi; Shoji, Shuichi; Nishitani, Akira; Ohdomari, Iwao

    2010-01-01

    We propose a novel sensor system for monitoring the structural health of a building. The system optically measures the relative-story displacement during earthquakes for detecting any deformations of building elements. The sensor unit is composed of three position sensitive detectors (PSDs) and lenses capable of measuring the relative-story displacement precisely, even if the PSD unit was inclined in response to the seismic vibration. For verification, laboratory tests were carried out using an Xθ-stage and a shaking table. The static experiment verified that the sensor could measure the local inclination angle as well as the lateral displacement. The dynamic experiment revealed that the accuracy of the sensor was 150 μm in the relative-displacement measurement and 100 μrad in the inclination angle measurement. These results indicate that the proposed sensor system has sufficient accuracy for the measurement of relative-story displacement in response to the seismic vibration. PMID:22163434

  19. First Measurements of the Inclined Boron Layer Thermal-Neutron Detector for Reflectometry

    SciTech Connect

    Clonts, Lloyd G; Crow, Lowell; Van Vuure, Thorwald L; Robertson, Lee; Riedel, Richard A; Richards, John D; Cooper, Ronald G; Remec, Igor; Ankner, John Francis; Browning, Jim

    2010-01-01

    A prototype detector based on the inclined boron layer principle is introduced. For typical measurement conditions at the Liquids Reflectometer at the Spallation Neutron Source, its count rate capability is shown to be superior to that of the current detector by nearly two orders of magnitude.

  20. Alternative approaches for measuring oat crown rust to improve resistance mapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Precise and accurate disease assessment can improve mapping of QTL conferring resistance. We have used two new methods to assess crown rust resistance in the Ogle/TAM O-301 oat mapping population: 1) single-race field trials in isolation chambers and 2) a molecular assay to measure the development...

  1. Measurement of a three-dimensional flow with a single rotating inclined hot wire

    NASA Astrophysics Data System (ADS)

    Algifri, A. H.; Bhardwaj, R. K.; Rao, Y. V. N.

    1988-11-01

    Response equations for determining the mean velocity components, turbulence intensities and Reynolds stresses have been derived for an inclined single hot wire probe which is oriented in the flow field at desired locations. The analysis contains no limitations to any turbulence intensity as it makes use of the squared voltages and has no simplification or dropping of higher order terms. The results obtained by using the derived expressions are in good agreement with those obtained by other measurement techniques.

  2. Utilizing CAD/CAM to Measure Total Occlusal Convergence of Preclinical Dental Students' Crown Preparations.

    PubMed

    Mays, Keith A; Crisp, H Alex; Vos, Paul

    2016-01-01

    Traditionally, faculty assessment of preclinical crown preparations occurs by visualizing preparation features. However, contemporary CAD/CAM tools have the ability to more precisely evaluate preparation features, which is beneficial for psychomotor development. Taper is one of the most challenging features to objectively assess. The aim of this study was twofold: first, to validate the software's ability to distinguish differences in taper, and second, to compare traditional faculty assessment with digital assessment of taper. In the study, 30 all-metal crown preparations were created on typodont teeth with varying degrees of axial reduction and placed into three groups based on amount of taper (minimum, moderate, or excessive). Each tooth was scanned with the D4D scanner, and the taper was analyzed using E4D Compare. A second experiment used 50 crown preparations of tooth #19, which were done as a formative exercise. A comparison faculty assessment with CAD/CAM assessments of taper was performed. The results showed that when the taper was varied, E4D Compare was able to distinguish those differences; the Tukey post-hoc test revealed a significant difference (p=0.001). The qualitative analysis comparing faculty grading to CAD/CAM grading demonstrated a trend for CAD/CAM to be more precise. These results suggest that E4D Compare is an effective means of quantitatively measuring the amount of total occlusal convergence or taper on a crown preparation and that digital assessment may be more precise than faculty visual grading. PMID:26729690

  3. An error compensation method of laser displacement sensor in the inclined surface measurement

    NASA Astrophysics Data System (ADS)

    Li, Feng; Xiong, Zhongxing; Li, Bin

    2015-10-01

    Laser triangulation displacement sensor is an important tool in non-contact displacement measurement which has been widely used in the filed of freeform surface measurement. However, measurement accuracy of such optical sensors is very likely to be influenced by the geometrical shape and face properties of the inspected surfaces. This study presents an error compensation method for the measurement of inclined surfaces using a 1D laser displacement sensor. The effect of the incident angle on the measurement results was investigated by analyzing the laser spot projected on the inclined surface. Both the shape and the light intensity distribution of the spot will be influenced by the incident angle, which lead to the measurement error. As the beam light spot size is different at different measurement position according to Gaussian beam propagating laws, the light spot projectted on the inclinde surface will be an ellipse approximatively. It's important to note that this ellipse isn't full symmetrical because the spot size of Gaussian beam is different at different position. By analyzing the laws of the shape change, the error compensation model can be established. This method is verified through the measurement of an ceramic plane mounted on a high-accuracy 5-axis Mikron UCP 800 Duro milling center. The results show that the method is effective in increasing the measurement accuracy.

  4. A compendium of AGN inclinations with corresponding UV/optical continuum polarization measurements

    NASA Astrophysics Data System (ADS)

    Marin, F.

    2014-06-01

    The anisotropic nature of active galactic nuclei (AGN) is thought to be responsible for the observational differences between type-1 (pole-on) and type-2 (edge-on) nearby Seyfert-like galaxies. In this picture, the detection of emission and/or absorption features is directly correlated to the inclination of the system. The AGN structure can be further probed by using the geometry-sensitive technique of polarimetry, yet the pairing between observed polarization and Seyfert type remains poorly examined. Based on archival data, I report here the first compilation of 53 estimated AGN inclinations matched with ultraviolet/optical continuum polarization measurements. Corrections, based on the polarization of broad emission lines, are applied to the sample of Seyfert-2 AGN to remove dilution by starburst light and derive information about the scattered continuum alone. The resulting compendium agrees with past empirical results, i.e. type-1 AGN show low polarization degrees (P ≤ 1 per cent) predominantly associated with a polarization position angle parallel to the projected radio axis of the system, while type-2 objects show stronger polarization percentages (P > 7 per cent) with perpendicular polarization angles. The transition between type-1 and type-2 inclination occurs between 45° and 60° without noticeable impact on P. The compendium is further used as a test to investigate the relevance of four AGN models. While an AGN model with fragmented regions matches observations better than uniform models, a structure with a failed dusty wind along the equator and disc-born, ionized, polar outflows is by far closer to observations. However, although the models correctly reproduce the observed dichotomy between parallel and perpendicular polarization, as well as correct polarization percentages at type-2 inclinations, further work is needed to account for some highly polarized type-1 AGN.

  5. Slip resistance of winter footwear on snow and ice measured using maximum achievable incline

    PubMed Central

    Hsu, Jennifer; Shaw, Robert; Novak, Alison; Li, Yue; Ormerod, Marcus; Newton, Rita; Dutta, Tilak; Fernie, Geoff

    2016-01-01

    Abstract Protective footwear is necessary for preventing injurious slips and falls in winter conditions. Valid methods for assessing footwear slip resistance on winter surfaces are needed in order to evaluate footwear and outsole designs. The purpose of this study was to utilise a method of testing winter footwear that was ecologically valid in terms of involving actual human testers walking on realistic winter surfaces to produce objective measures of slip resistance. During the experiment, eight participants tested six styles of footwear on wet ice, on dry ice, and on dry ice after walking over soft snow. Slip resistance was measured by determining the maximum incline angles participants were able to walk up and down in each footwear–surface combination. The results indicated that testing on a variety of surfaces is necessary for establishing winter footwear performance and that standard mechanical bench tests for footwear slip resistance do not adequately reflect actual performance. Practitioner Summary: Existing standardised methods for measuring footwear slip resistance lack validation on winter surfaces. By determining the maximum inclines participants could walk up and down slopes of wet ice, dry ice, and ice with snow, in a range of footwear, an ecologically valid test for measuring winter footwear performance was established. PMID:26555738

  6. Slip resistance of winter footwear on snow and ice measured using maximum achievable incline.

    PubMed

    Hsu, Jennifer; Shaw, Robert; Novak, Alison; Li, Yue; Ormerod, Marcus; Newton, Rita; Dutta, Tilak; Fernie, Geoff

    2016-05-01

    Protective footwear is necessary for preventing injurious slips and falls in winter conditions. Valid methods for assessing footwear slip resistance on winter surfaces are needed in order to evaluate footwear and outsole designs. The purpose of this study was to utilise a method of testing winter footwear that was ecologically valid in terms of involving actual human testers walking on realistic winter surfaces to produce objective measures of slip resistance. During the experiment, eight participants tested six styles of footwear on wet ice, on dry ice, and on dry ice after walking over soft snow. Slip resistance was measured by determining the maximum incline angles participants were able to walk up and down in each footwear-surface combination. The results indicated that testing on a variety of surfaces is necessary for establishing winter footwear performance and that standard mechanical bench tests for footwear slip resistance do not adequately reflect actual performance. Practitioner Summary: Existing standardised methods for measuring footwear slip resistance lack validation on winter surfaces. By determining the maximum inclines participants could walk up and down slopes of wet ice, dry ice, and ice with snow, in a range of footwear, an ecologically valid test for measuring winter footwear performance was established. PMID:26555738

  7. Direct measurement of hematite individual particle anisotropy: implications for inclination shallowing in red bed DRMs.

    NASA Astrophysics Data System (ADS)

    Bilardello, D.; Kodama, K. P.

    2007-12-01

    Methods to correct for the observed inclination shallowing in sedimentary rocks have been proposed that are based on either models of the geomagnetic field and the resulting directional distribution of paleomagnetic vectors or the magnetic anisotropy of the magnetic minerals carrying the remanence. One limitation of the anisotropy method for hematite-bearing red beds has been the isolation and determination of a rock's detrital hematite individual particle anisotropy. Up to now, our red bed inclination shallowing corrections have been dependent on estimates of hematite individual particle anisotropy using data fit to theoretical correction curves. We have developed a technique for preferentially extracting the detrital hematite particles in a sample in order to directly measure their individual particle anisotropy. The method involves crushing of the sample followed by ball milling and sieving to ensure that the rock particles are smaller than 4Φ. The resulting slurry was then placed in an ultrasonic cleaner for at least 24 hours and finally centrifuged at 1000 rpm for 20 minutes in order to separate the dense, gray iron oxide particles from the red pigmentary grains. The gray, iron oxide-rich slurry was collected by hand and circulated in a magnetic extraction apparatus. The magnetic separate was then collected over a period of two to three weeks. Small amounts of the magnetic separates where mixed in a slow-drying epoxy resin for 24 hours and placed in a DC magnetic field (100 mT to 180 mT) in order to align the grains. The bulk IRM anisotropy of the epoxy samples provides an average individual particle anisotropy for the magnetic grains. Separates were collected from samples of the Mauch Chunk Fm. of Pennsylvania, the Maringouin and the Shepody Fms of New Brunswick/ Nova Scotia and the Kapusaliang Fm. of northwestern China. IRM acquisitions experiments were performed in fields of up to 1.2 T in order to identify the magnetic mineralogies present. Remanence

  8. Measurement of Interfacial Profiles of Wavy Film Flow on Inclined Wall

    NASA Astrophysics Data System (ADS)

    Rosli, N.; Amagai, K.

    2016-02-01

    Falling liquid films on inclined wall present in many industrial processes such as in food processing, seawater desalination and electronic devices manufacturing industries. In order to ensure an optimal efficiency of the operation in these industries, a fundamental study on the interfacial flow profiles of the liquid film is of great importance. However, it is generally difficult to experimentally predict the interfacial profiles of liquid film flow on inclined wall due to the instable wavy flow that usually formed on the liquid film surface. In this paper, the liquid film surface velocity was measured by using a non-intrusive technique called as photochromic dye marking method. This technique utilizes the color change of liquid containing the photochromic dye when exposed to the UV light source. The movement of liquid film surface marked by the UV light was analyzed together with the wave passing over the liquid. As a result, the liquid film surface was found to slightly shrink its gradual movement when approached by the wave before gradually move again after the intersection with the wave.

  9. Measurements of the energy deposit of inclined muon bundles in the CWD NEVOD

    NASA Astrophysics Data System (ADS)

    Kokoulin, R. P.; Bogdanov, A. G.; Dushkin, L. I.; Khokhlov, S. S.; Khomyakov, V. A.; Kindin, V. V.; Kovylyaeva, E. A.; Mannocchi, G.; Petrukhin, A. A.; Saavedra, O.; Shutenko, V. V.; Trinchero, G.; Yashin, I. I.

    2015-08-01

    First results of investigations of the energy deposits of inclined muon bundles in the ground-based Cherenkov water detector NEVOD are presented. As a measure of the muon bundle energy deposit, the total number of photoelectrons detected by PMTs of the Cherenkov calorimeter is used. For each event, the local muon density at the observation point and the muon bundle arrival direction are estimated from the data of the coordinate-tracking detector DECOR. Registration of the bundles in a wide range of zenith angles allows to explore the interval of primary particle energies from ∼ 1016 to ∼ 1018 eV. Measurement results are compared with CORSIKA based simulations of EAS muon component. It is found that the mean energy of muons detected in the bundles rapidly increases with the zenith angle and reaches about 500 GeV near the horizon.

  10. Root type matters: measurements of water uptake by seminal, crown and lateral roots of maize

    NASA Astrophysics Data System (ADS)

    Ahmed, Mutez Ali; Zarebanadkouki, Mohsen; Kaestner, Anders; Carminati, Andrea

    2016-04-01

    Roots play a key role in water acquisition and are a significant component of plant adaptation to different environmental conditions. Although maize (Zea mays L.) is one of the most important crops worldwide, there is limited information on the function of different root segments and types in extracting water from soils. Aim of this study was to investigate the location of root water uptake in mature maize. We used neutron radiography to image the spatial distribution of maize roots and trace the transport of injected deuterated water (D2O) in soil and roots. Maize plants were grown in aluminum containers filled with a sandy soil that was kept homogeneously wet throughout the experiment. When the plants were five weeks-old, we injected D2O into selected soil regions. The transport of D2O was simulated using a diffusion-convection numerical model. By fitting the observed D2O transport we quantified the diffusion coefficient and the water uptake of the different root segments. The model was initially developed and tested with two weeks-old maize (Ahmed et. al. 2015), for which we found that water was mainly taken up by lateral roots and the water uptake of the seminal roots was negligible. Here, we used this method to measure root water uptake in a mature maize root system. The root architecture of five weeks-old maize consisted of primary and seminal roots with long laterals and crown (nodal) roots that emerged from the above ground part of the plant two weeks after planting. The crown roots were thicker than the seminal roots and had fewer and shorter laterals. Surprisingly, we found that the water was mainly taken up by the crown roots and their laterals, while the lateral roots of seminal roots, which were the main location of water uptake of younger plants, stopped to take up water. Interestingly, we also found that in contrast to the seminal roots, the crown roots were able to take up water also from their distal segments. We conclude that for the two weeks

  11. Shear-Sensitive Liquid Crystal Coating Method: Surface-Inclination Effects on Shear Vector Measurements

    NASA Technical Reports Server (NTRS)

    Reda, Daniel C.; Wilder, Michael C.; Nixon, David (Technical Monitor)

    1998-01-01

    The shear-sensitive liquid crystal coating (SSLCC) method is an image-based technique for both visualizing dynamic surface-flow phenomena, such as transition and separation, and for measuring the continuous shear-stress vector distribution acting on an aerodynamic surface. Under proper lighting and viewing conditions (discussed below), the coating changes color in response to an applied aerodynamic shear. This color-change response is continuous and reversible, with a response time of milliseconds, and is a function of both the shear magnitude and the shear vector orientation relative to the observer. The liquid crystal phase of matter is a weakly-ordered, viscous, non-Newtonian fluid state that exists between the nonuniform liquid phase and the ordered solid phase of certain organic compounds. Cholesteric liquid crystal compounds possess a helical molecular arrangement that selectively scatters white light, incident along the helical axis, as a three-dimensional spectrum. This property is linked to the helical pitch length, which is within the range of wavelengths in the visible spectrum. The pitch length, and hence the wavelength of the scattered light, is influenced by shear stress normal to the helical axis. This unique optical property produces a measurable color change in response to an applied shearing force. The full-surface shear stress vector measurement method, developed at NASA-Ames, is schematically illustrated. As with the visualization method, the coated test surface is illuminated from the normal direction with white light and the camera is positioned at an above-plane view angle of approximately 30 deg. Experiments have been initiated at NASA Ames to begin the process of quantifying surface-inclination (surface-curvature) effects on shear vector measurement accuracy. In preliminary experiments, surface-inclination angles theta(sub x), theta(sub y) of 0, +/-5, +/-10, and +/-15 deg were employed. In this arrangement, white-light illumination was

  12. Applicability of non-destructive substitutes for leaf area in different stands of Norway spruce (Picea abies L. Karst.) focusing on traditional forest crown measures

    PubMed Central

    Laubhann, Daniel; Eckmüllner, Otto; Sterba, Hubert

    2010-01-01

    Since individual tree leaf area is an important measure for productivity as well as for site occupancy, it is of high interest in many studies about forest growth. The exact determination of leaf area is nearly impossible. Thus, a common way to get information about leaf area is to use substitutes. These substitutes are often variables which are collected in a destructive way which is not feasible for long term studies. Therefore, this study aimed at testing the applicability of using substitutes for leaf area which could be collected in a non-destructive way, namely crown surface area and crown projection area. In 8 stands of Norway spruce (Picea abies L. Karst.), divided into three age classes and two thinning treatments, a total of 156 trees were felled in order to test the relationship between leaf area and crown surface area and crown projection area, respectively. Individual tree leaf area of the felled sample trees was estimated by 3P-branch sampling with an accuracy of ±10%. Crown projection area and crown surface area were compared with other, more commonly used, but destructive predictors of leaf area, namely sapwood area at different heights on the bole. Our investigations confirmed findings of several studies that sapwood area is the most precise measure for leaf area because of the high correlation between sapwood area and the leaf area. But behind sapwood area at crown base and sapwood area at three tenth of the tree height the predictive ability of crown surface area was ranked third and even better than that of sapwood area at breast height (R2 = 0.656 compared with 0.600). Within the stands leaf area is proportional to crown surface area. Using the pooled data of all stands a mixed model approach showed that additionally to crown surface area dominant height and diameter at breast height (dbh) improved the leaf area estimates. Thus, taking dominant height and dbh into account, crown surface area can be recommended for estimating the leaf area of

  13. Crown Gall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crown gall disease occurs on diverse dicotyledonous and gymnospermous plant species worldwide. Reports of crown gall on hop date back to at least 1929, and the disease has been reported from most countries where hop is or has been grown commercially. The epidemiology of the causal bacterium, Agrob...

  14. Crown gall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crown gall is uncommon in alfalfa. The disease has been reported from alfalfa stands in the Imperial Valley of California, but rare infected plants can be found occasionally in other parts of the U.S. Symptoms: The galls or tumor-like overgrowths form on the crown branches at or slightly below t...

  15. Inclination distributions and size measurements of hemlock and red spruce needles

    NASA Technical Reports Server (NTRS)

    Kimes, Daniel S.; Smith, J. A.

    1991-01-01

    Needle inclination angle distributions were plotted for 5 and 10 deg intervals for two hemlock trees and one red spruce. The distributions for the hemlock and spruce were similar, with the peak normal angle occurring between 10 and 20 deg. These distributions are between two theoretical (planophile and spherical) leaf angle distributions. The results can be used as an input to radiative transfer models that require a distribution of the orientation of the scattering elements of the canopy.

  16. Inclined cross-stream stereo particle image velocimetry measurements in turbulent boundary layers

    NASA Astrophysics Data System (ADS)

    Hutchins, N.; Hambleton, W. T.; Marusic, Ivan

    2005-10-01

    This work can be viewed as a reprise of Head & Bandyopadhyay's (J. Fluid Mech. vol. 107, p. 297) original boundary-layer visualization study although in this instance we make use of stereo particle image velocimetry (PIV), techniques to obtain a quantitative view of the turbulent structure. By arranging the laser light-sheet and image plane of a stereo PIV system in inclined spanwise/wall-normal planes (inclined at both 45(°) and 135(°) to the streamwise axis) a unique quantitative view of the turbulent boundary layer is obtained. Experiments are repeated across a range of Reynolds numbers, Re_{tau} {≈} 690-2800. Despite numerous experimental challenges (due to the large out-of-plane velocity components), mean flow and Reynolds stress profiles indicate that the salient features of the turbulent flow have been well resolved. The data are analysed with specific attention to a proposed hairpin eddy model. In-plane two-dimensional swirl is used to identify vortical eddy structures piercing the inclined planes. The vast majority of this activity occurs in the 135(°) plane, indicating an inclined eddy structure, and Biot-Savart law calculations are carried out to aid in the discussion. Conditional averaging and linear stochastic estimation results also support the presence of inclined eddies, arranged about low-speed regions. In the 135(°) plane, instantaneous swirl patterns exhibit a predisposition for counter-rotating vortex pairs (arranged with an ejection at their confluence). Such arrangements are consistent with the hairpin packet model. Correlation and scaling results show outer-scaling to be the correct way to quantify the characteristic spanwise length scale across the log and wake regions of the boundary layers (for the range of Reynolds numbers tested). A closer investigation of two-point velocity correlation contours indicates the occurrence of a distinct two-regime behaviour, in which contours (and hence streamwise velocity fluctuations) either appear

  17. A High-Precision, Optical Polarimeter to Measure Inclinations of High Mass X-Ray Binaries

    NASA Astrophysics Data System (ADS)

    Wiktorowicz, Sloane; Matthews, K.; Kulkarni, S. R.

    2007-12-01

    While most astrophysical objects require many parameters in order to be fully described, black holes are unique in that only three parameters are required: mass, spin, and charge. Of these, mass and spin are enough to describe the black hole's gravitational field and event horizon location. Therefore, theory and observation may jointly pursue one or two quantities to uncover the progenitor star's history. Constraints on black hole mass exist for high mass X-ray binaries, such as Cygnus X-1, which is thought to consist of a 40 ± 10 solar mass O9.7Iab star and a 13.5-29 solar mass black hole (Ziolkowski 2005). While the constraints on the mass of the compact object are tight enough to declare that it is a black hole, they are sufficiently loose as to prohibit precise modeling of the progenitor star's mass. We have built an optical polarimeter for the Hale 5-m telescope at Mt. Palomar to provide an independent method for determining black hole mass. Degree of polarization will vary for an edge-on system, while position angle of net polarization will vary for a face-on system. Therefore, by monitoring the linear polarimetric variability of the binary, inclination can be estimated. Coupled with the known mass function of the binary from radial velocity work (Gies et al. 2003), inclination estimates constrain the mass of the black hole. Our polarimeter, POLISH (POLarimeter for Inclination Studies of High mass x-ray binaries), has achieved linear polarimetric precision of less than 10 parts per million on bright, unpolarized standard stars. We will also present results for polarized standard stars and Cygnus X-1 itself. This instrument has been funded by an endowment from the Moore Foundation.

  18. Analysis of the dental morphology of Plio-pleistocene hominids. I. Mandibular molars: crown area measurements and morphological traits.

    PubMed Central

    Wood, B A; Abbott, S A

    1983-01-01

    This study has used accurate measurements of crown area and precise assessments of the morphological traits of mandibular molars in an attempt to define the metrical and morphological characteristics of early hominid taxa. A total of 196 Plio-Pleistocene hominid molars were either allocated to one of six informal taxonomic groups or considered as individual cases. Accurate measurements of crown base area made from occlusal photographs have enabled us to estimate the effects of interproximal wear on crown areas. The average correction factor over the three molar types is around 2-4% with a maximum of 6%. The patterns of distribution of extra cusps show interesting differences between taxa. None of the M-1S in the two groups of 'gracile' hominids from East and South Africa bears a C6, but it is common in the two 'robust' taxa. The distribution of a C7 is the reverse of this, it being rare in the robust' taxa, and more common in the 'gracile' groups. There is thus no simple relationship between cusp number and tooth size. Our observations on the protostylid suggest that though it is more common in the 'robust' australopithecines than the 'graciles', when it does occur it is more strongly expressed in the 'gracile' group. The combination of simple metrical data, and the assessment of morphological traits, can help in the classification of enigmatic or incomplete specimens. Some isolated teeth from the collection at Koobi Fora can confidently be assigned to Australopithecus boisei, and useful guides have been provided for taxonomic assessment of the skull KNM-ER 1805, and the mandibles KNM-ER 1506 and 1820. PMID:6403498

  19. Detailed measurements of local heat transfer coefficient in the entrance to normal and inclined film cooling holes

    SciTech Connect

    Gillespie, D.R.H.; Byerley, A.R.; Ireland, P.T.; Wang, Z.; Jones, T.V.; Kohler, S.T.

    1996-04-01

    The local heat transfer inside the entrance to large-scale models of film cooling holes has been measured using the transient heat transfer technique. The method employs temperature-sensitive liquid crystals to measure the surface temperature of large-scale perspex models. Full distributions of local Nusselt number were calculated based on the cooling passage centerline gas temperature ahead of the cooling hole. The circumferentially averaged Nusselt number was also calculated based on the local mixed bulk driving gas temperature to aid interpretation of the results, and to broaden the potential application of the data. Data are presented for a single film cooling hole inclined at 90 and 150 deg to the coolant duct wall. Both holes exhibited entry length heat transfer levels that were significantly lower than those predicted by entry length data in the presence of crossflow. The reasons for the comparative reduction are discussed in terms of the interpreted flow field.

  20. Crown wart

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crown wart has been found widely distributed in Australia, New Zealand, and European countries. It has been recorded sporadically in India (Punjab), South Africa, South America (Ecuador, Chile, Peru), Panama, Mexico, and Canada (British Columbia). In the United States, it has been found more frequ...

  1. Dental crowns

    MedlinePlus

    ... cover a tooth Replace a misshapen tooth or dental implant Correct a misaligned tooth Talk to your dentist ... the tooth pulled and replaced with a tooth implant. Your crown could chip or crack: If you grind your teeth or clench your jaw, you may need to ...

  2. Ductile cutting of silicon microstructures with surface inclination measurement and compensation by using a force sensor integrated single point diamond tool

    NASA Astrophysics Data System (ADS)

    Chen, Yuan-Liu; Cai, Yindi; Shimizu, Yuki; Ito, So; Gao, Wei; Ju, Bing-Feng

    2016-02-01

    This paper presents a measurement and compensation method of surface inclination for ductile cutting of silicon microstructures by using a diamond tool with a force sensor based on a four-axis ultra-precision lathe. The X- and Y-directional inclinations of a single crystal silicon workpiece with respect to the X- and Y-motion axes of the lathe slides were measured respectively by employing the diamond tool as a touch-trigger probe, in which the tool-workpiece contact is sensitively detected by monitoring the force sensor output. Based on the measurement results, fabrication of silicon microstructures can be thus carried out directly along the tilted silicon workpiece by compensating the cutting motion axis to be parallel to the silicon surface without time-consuming pre-adjustment of the surface inclination or turning of a flat surface. A diamond tool with a negative rake angle was used in the experiment for superior ductile cutting performance. The measurement precision by using the diamond tool as a touch-trigger probe was investigated. Experiments of surface inclination measurement and ultra-precision ductile cutting of a micro-pillar array and a micro-pyramid array with inclination compensation were carried out respectively to demonstrate the feasibility of the proposed method.

  3. Heat transfer measurements to a gas turbine cooling passage with inclined ribs

    SciTech Connect

    Wang, Z.; Ireland, P.T.; Kohler, S.T.; Chew, J.W.

    1998-01-01

    The local heat transfer coefficient distribution over all four walls of a large-scale model of a gas turbine cooling passage have been measured in great detail. A new method of determining the heat transfer coefficient to the rib surface has been developed and the contribution of the rib, at 5% blockage, to the overall roughened heat transfer coefficient was found to be considerable. The vortex-dominated flow field was interpreted from the detailed form of the measured local heat transfer contours. Computational Fluid Dynamics calculations support this model of the flow and yield friction factors that agree with measured values. Advances in the heat transfer measuring technique and data analysis procedure that confirm the accuracy of the transient method are described in full.

  4. Measuring and modelling seasonal patterns of carbohydrate storage and mobilization in the trunks and root crowns of peach trees

    PubMed Central

    Da Silva, David; Qin, Liangchun; DeBuse, Carolyn; DeJong, Theodore M.

    2014-01-01

    Background and Aims Developing a conceptual and functional framework for simulating annual long-term carbohydrate storage and mobilization in trees has been a weak point for virtually all tree models. This paper provides a novel approach for solving this problem using empirical field data and details of structural components of simulated trees to estimate the total carbohydrate stored over a dormant season and available for mobilization during spring budbreak. Methods The seasonal patterns of mobilization and storage of non-structural carbohydrates in bark and wood of the scion and rootstock crowns of the trunks of peach (Prunus persica) trees were analysed subsequent to treatments designed to maximize differences in source–sink behaviour during the growing season. Mature peach trees received one of three treatments (defruited and no pruning, severe pruning to 1·0 m, and unthinned with no pruning) in late winter, just prior to budbreak. Selected trees of each treatment were harvested at four times (March, June, August and November) and slices of trunk and root crown tissue above and below the graft union were removed for carbohydrate analysis. Inner bark and xylem tissues from the first to fifth rings were separated and analysed for non-structural carbohydrates. Data from these experiments were then used to estimate the amount of non-structural carbohydrates available for mobilization and to parameterize a carbohydrate storage sub-model in the functional–structural L-PEACH model. Key Results The mass fraction of carbohydrates in all sample tissues decreased from March to June, but the decrease was greatest in the severely pruned and unthinned treatments. November carbohydrate mass fractions in all tissues recovered to values similar to those in the previous March, except in the older xylem rings of the severely pruned and unthinned treatment. Carbohydrate storage sink capacity in trunks was empirically estimated from the mean maximum measured trunk non

  5. Motor Performance Assessment in Parkinson’s Disease: Association between Objective In-Clinic, Objective In-Home, and Subjective/Semi-Objective Measures

    PubMed Central

    Toosizadeh, Nima; Mohler, Jane; Lei, Hong; Parvaneh, Saman; Sherman, Scott; Najafi, Bijan

    2015-01-01

    Advances in wearable technology allow for the objective assessment of motor performance in both in-home and in-clinic environments and were used to explore motor impairments in Parkinson’s disease (PD). The aims of this study were to: 1) assess differences between in-clinic and in-home gait speed, and sit-to-stand and stand-to-sit duration in PD patients (in comparison with healthy controls); and 2) determine the objective physical activity measures, including gait, postural balance, instrumented Timed-up-and-go (iTUG), and in-home spontaneous physical activity (SPA), with the highest correlation with subjective/semi-objective measures, including health survey, fall history (fallers vs. non-fallers), fear of falling, pain, Unified Parkinson's Disease Rating Scale, and PD stage (Hoehn and Yahr). Objective assessments of motor performance were made by measuring physical activities in the same sample of PD patients (n = 15, Age: 71.2±6.3 years) and age-matched healthy controls (n = 35, Age: 71.9±3.8 years). The association between in-clinic and in-home parameters, and between objective parameters and subjective/semi-objective evaluations in the PD group was assessed using linear regression-analysis of variance models and reported as Pearson correlations (R). Both in-home SPA and in-clinic assessments demonstrated strong discriminatory power in detecting impaired motor function in PD. However, mean effect size (0.94±0.37) for in-home measures was smaller compared to in-clinic assessments (1.30±0.34) for parameters that were significantly different between PD and healthy groups. No significant correlation was observed between identical in-clinic and in-home parameters in the PD group (R = 0.10–0.25; p>0.40), while the healthy showed stronger correlation in gait speed, sit-to-stand duration, and stand-to-sit duration (R = 0.36–0.56; p<0.03). This suggests a better correlation between supervised and unsupervised motor function assessments in healthy controls

  6. All-ceramic crowns.

    PubMed

    Lehner, C R; Schärer, P

    1992-06-01

    Despite the good appearance and biocompatibility of dental porcelains, failures are still of considerable concern because of some limited properties common to all-ceramic crown systems. As in the years before, pertinent scientific articles published between November 1990 and December 1991 focused on strengthening mechanisms and compared fracture toughness for different ceramic systems by using various test methods. Some evaluated the clinical implications thereon for seating and loading crowns and measured wear against different ceramic surface conditions. Recently introduced with pleasing aesthetic qualities, IPS-Empress (Ivoclar, Schaan, Liechtenstein), a new European leucite-reinforced glass-ceramic, has finally drawn attention in some journals and has been reviewed with promising in vitro test results. Using a simple press-molding technique, well-fitting crowns, inlays, and veneers can be fabricated without an additional ceramming procedure. Again, only long-term clinical trials will validate achievements compared with other all-ceramic systems and with well-established metal ceramics. PMID:1325848

  7. Internal dynamics of a free-surface viscoplastic flow down an inclined plane: experimental results through PIV measurements

    NASA Astrophysics Data System (ADS)

    Freydier, Perrine; Chambon, Guillaume; Naaim, Mohamed

    2015-04-01

    Debris flows constitute one of the most important natural hazards throughout the mountainous regions of the world, causing significant damages and economic losses. These mass are composed of particles of all sizes from clay to boulders suspended in a viscous fluid. An important goal resides in developing models that are able to accurately predict the hydraulic properties of debris flows. First, these flows are generally represented using models based on a momentum integral approach that consists in assuming a shallow flow and in depth averaging the local conservation equations. These models take into account closure terms depending on the shape of the velocity profile inside the flow. Second, the specific migration mechanisms of the suspended particles, which have a strong influence on the propagation of the surges, also depend on the internal dynamics within the flow. However, to date, few studies concerning the internal dynamics in particular in the vicinity of the front, of such flows have been carried out. The aim of this study is to document the internal dynamics in free-surface viscoplastic flows down an inclined channel. The rheological studies concerning natural muddy debris flows, rich in fine particles, have shown that these materials can be modeled, at least as a first approximation as non-Newtonian viscoplastic fluids. Experiments are conducted in an inclined channel whose bottom is constituted by an upward-moving conveyor belt with controlled velocity. Carbopol microgel has been used as a homogeneous transparent viscoplastic fluid. This experimental setup allows generating and monitoring stationary gravity-driven surges in the laboratory frame. We use PIV technique (Particle Image Velocimetry) to obtain velocity fields both in the uniform zone and within the front zone where flow thickness is variable and where recirculation takes place. Experimental velocity profiles and determination of plug position will be presented and compared to theoretical

  8. 2. VIEW SOUTH, INCLINE PLANE CAR, INCLINE PLANE TRACK, UPPER ...

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

    2. VIEW SOUTH, INCLINE PLANE CAR, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  9. Weatherford Inclined Wellbore Construction

    SciTech Connect

    Schulte, R.

    2002-08-19

    The Rocky Mountain Oilfield Testing Center (RMOTC) has recently completed construction of an inclined wellbore with seven (7) inch, twenty-three (23) pound casing at a total depth of 1296 feet. The inclined wellbore is near vertical to 180 feet with a build angle of approximately 4.5 degrees per hundred feet thereafter. The inclined wellbore was utilized for further proprietary testing after construction and validation. The wellbore is available to other companies requiring a cased hole environment with known deviation out to fifty degrees (50) from vertical. The wellbore may also be used by RMOTC for further deepening into the fractured shales of the Steele and Niobrara formation.

  10. Measurements of stellar inclinations for Kepler planet candidates. II. Candidate spin-orbit misalignments in single- and multiple-transiting systems

    SciTech Connect

    Hirano, Teruyuki; Sanchis-Ojeda, Roberto; Winn, Joshua N.; Takeda, Yoichi; Narita, Norio; Takahashi, Yasuhiro H.

    2014-03-01

    We present a test for spin-orbit alignment for the host stars of 25 candidate planetary systems detected by the Kepler spacecraft. The inclination angle of each star's rotation axis was estimated from its rotation period, rotational line broadening, and radius. The rotation periods were determined using the Kepler photometric time series. The rotational line broadening was determined from high-resolution optical spectra with the Subaru High Dispersion Spectrograph. Those same spectra were used to determine the star's photospheric parameters (effective temperature, surface gravity, metallicity), which were then interpreted with stellar-evolutionary models to determine stellar radii. We combine the new sample with the seven stars from our previous work on this subject, finding that the stars show a statistical tendency to have inclinations near 90°, in alignment with the planetary orbits. Possible spin-orbit misalignments are seen in several systems, including three multiple-planet systems (KOI-304, 988, 2261). Ideally, these systems should be scrutinized with complementary techniques, such as the Rossiter-McLaughlin effect, starspot-crossing anomalies, or asteroseismology, but the measurements will be difficult owing to the relatively faint apparent magnitudes and small transit signals in these systems.

  11. Crown ethers in graphene

    SciTech Connect

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; Gallego, Nidia C.; Pantelides, Sokrates T.; Pennycook, Stephen J.; Moyer, Bruce A.; Chisholm, Matthew F.

    2014-11-13

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.

  12. Crown ethers in graphene

    DOE PAGESBeta

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; Gallego, Nidia C.; Pantelides, Sokrates T.; Pennycook, Stephen J.; Moyer, Bruce A.; Chisholm, Matthew F.

    2014-11-13

    Crown ethers, introduced by Pedersen1, are at their most basic level neutral rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted special attention for their ability to selectively incorporate various atoms2 or molecules within the cavity formed by the ring3-6. This property has led to the use of crown ethers and their compounds in a wide range of chemical and biological applications7,8. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity9,10. In this Letter, we report atomic-resolution images of the same basicmore » structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar and thus uniquely suited for the many applications that crown ethers are known for. First-principles calculations show that the close similarity of the structures seen in graphene with those of crown ether molecules also extends to their selectivity towards specific metal cations depending on the ring size. Atoms (or molecules) incorporated within the crown ethers in graphene offer a simple environment that can be easily and systematically probed and modeled. Thus, we expect that this discovery will introduce a new wave of investigations and applications of chemically functionalized graphene.« less

  13. Crown ethers in graphene

    NASA Astrophysics Data System (ADS)

    Guo, Junjie; Lee, Jaekwang; Contescu, Cristian I.; Gallego, Nidia C.; Pantelides, Sokrates T.; Pennycook, Stephen J.; Moyer, Bruce A.; Chisholm, Matthew F.

    2014-11-01

    Crown ethers are at their most basic level rings constructed of oxygen atoms linked by two- or three-carbon chains. They have attracted attention for their ability to selectively incorporate various atoms or molecules within the cavity formed by the ring. However, crown ethers are typically highly flexible, frustrating efforts to rigidify them for many uses that demand higher binding affinity and selectivity. Here we present atomic-resolution images of the same basic structures of the original crown ethers embedded in graphene. This arrangement constrains the crown ethers to be rigid and planar. First-principles calculations show that the close similarity of the structures should also extend to their selectivity towards specific metal cations. Crown ethers in graphene offer a simple environment that can be systematically tested and modelled. Thus, we expect that our finding will introduce a new wave of investigations and applications of chemically functionalized graphene.

  14. Measuring social desirability across language and sex: A comparison of Marlowe-Crowne Social Desirability Scale factor structures in English and Mandarin Chinese in Malaysia.

    PubMed

    Kurz, A Solomon; Drescher, Christopher F; Chin, Eu Gene; Johnson, Laura R

    2016-06-01

    Malaysia is a Southeast Asian country in which multiple languages are prominently spoken, including English and Mandarin Chinese. As psychological science continues to develop within Malaysia, there is a need for psychometrically sound instruments that measure psychological phenomena in multiple languages. For example, assessment tools for measuring social desirability could be a useful addition in psychological assessments and research studies in a Malaysian context. This study examined the psychometric performance of the English and Mandarin Chinese versions of the Marlowe-Crowne Social Desirability Scale when used in Malaysia. Two hundred and eighty-three students (64% female; 83% Chinese, 9% Indian) from two college campuses completed the Marlowe-Crowne Social Desirability Scale in their language of choice (i.e., English or Mandarin Chinese). Proposed factor structures were compared with confirmatory factor analysis, and multiple indicators-multiple causes models were used to examine measurement invariance across language and sex. Factor analyses supported a two-factor structure (i.e., Attribution and Denial) for the measure. Invariance tests revealed the scale was invariant by sex, indicating that social desirability can be interpreted similarly across sex. The scale was partially invariant by language version, with some non-invariance observed within the Denial factor. Non-invariance may be related to differences in the English and Mandarin Chinese languages, as well as cultural differences. Directions for further research include examining the measurement of social desirability in other contexts where both English and Mandarin Chinese are spoken (i.e., China) and further examining the causes of non-invariance on specific items. PMID:27168227

  15. PRECISE TULLY-FISHER RELATIONS WITHOUT GALAXY INCLINATIONS

    SciTech Connect

    Obreschkow, D.; Meyer, M.

    2013-11-10

    Power-law relations between tracers of baryonic mass and rotational velocities of disk galaxies, so-called Tully-Fisher relations (TFRs), offer a wealth of applications in galaxy evolution and cosmology. However, measurements of rotational velocities require galaxy inclinations, which are difficult to measure, thus limiting the range of TFR studies. This work introduces a maximum likelihood estimation (MLE) method for recovering the TFR in galaxy samples with limited or no information on inclinations. The robustness and accuracy of this method is demonstrated using virtual and real galaxy samples. Intriguingly, the MLE reliably recovers the TFR of all test samples, even without using any inclination measurements—that is, assuming a random sin i-distribution for galaxy inclinations. Explicitly, this 'inclination-free MLE' recovers the three TFR parameters (zero-point, slope, scatter) with statistical errors only about 1.5 times larger than the best estimates based on perfectly known galaxy inclinations with zero uncertainty. Thus, given realistic uncertainties, the inclination-free MLE is highly competitive. If inclination measurements have mean errors larger than 10°, it is better not to use any inclinations than to consider the inclination measurements to be exact. The inclination-free MLE opens interesting perspectives for future H I surveys by the Square Kilometer Array and its pathfinders.

  16. The acrylic jacket crown.

    PubMed

    Bell, A M

    1975-04-01

    An attempt has been made to cover briefly the many applications of the acrylic jacket crown. It is readily understandable that this type of restoration has many shortcomings but at the same time it has many useful and important applications in dentistry when properly employed. It is hoped that the specialist and generalist alike will have found some new and useful applications of the acrylic jacket crown. PMID:1090464

  17. 3. INCLINE PLANE CAR INTERIOR, UPPER COMPARTMENT. Monongahela Incline ...

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

    3. INCLINE PLANE CAR INTERIOR, UPPER COMPARTMENT. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  18. First Results from Colorado Student Space Weather Experiment (CSSWE): Differential Flux Measurements of Energetic Particles in a Highly Inclined Low Earth Orbit

    NASA Astrophysics Data System (ADS)

    Li, X.; Palo, S. E.; Kohnert, R.; Gerhardt, D.; Blum, L. W.; Schiller, Q.; Turner, D. L.; Tu, W.

    2012-12-01

    The Colorado Student Space Weather Experiment (CSSWE) is a 3-unit (10cm x 10cm x 30cm) CubeSat mission funded by the National Science Foundation, scheduled for launch into a low-Earth, polar orbit after August 14th, 2012 as a secondary payload under NASA's Educational Launch of Nanosatellites (ELaNa) program. The science objectives of CSSWE are to investigate the relationship of the location, magnitude, and frequency of solar flares to the timing, duration, and energy spectrum of solar energetic particles (SEP) reaching Earth, and to determine the precipitation loss and the evolution of the energy spectrum of radiation belt electrons. CSSWE contains a single science payload, the Relativistic Electron and Proton Telescope integrated little experiment (REPTile), which is a miniaturization of the Relativistic Electron and Proton Telescope (REPT) built at the Laboratory for Atmospheric and Space Physics (LASP). The REPT instrument will fly onboard the NASA/Radiation Belt Storm Probes (RBSP) mission, which consists of two identical spacecraft scheduled to launch after August 23rd, 2012 that will go through the heart of the radiation belts in a low inclination orbit. CSSWE's REPTile is designed to measure the directional differential flux of protons ranging from 10 to 40 MeV and electrons from 0.5 to >3 MeV. Such differential flux measurements have significant science value, and a number of engineering challenges were overcome to enable these clean measurements to be made under the mass and power limits of a CubeSat. The CSSWE is an ideal class project, providing training for the next generation of engineers and scientists over the full life-cycle of a satellite project. We will report the first results from this exciting mission.

  19. Use of IQRF technology for detection of construction inclination

    NASA Astrophysics Data System (ADS)

    Martin, Pies; Radovan, Hajovsky

    2016-06-01

    This paper deals with the application of wireless measurement of inclination of objects located at mining dumps. Measurement of inclination uses a set of sensors including a gyroscope, an accelerometer and a magnetometer. Measured data is processed by AHRS algorithm that, once applied, allows getting more precise information on rotation of the object in the area compared to unprocessed data from accelerometer or gyroscope. Measurement chain consists of two parts. The first one is a wireless module reading the data from particular sensors via I2C bus and sends it consequently to a computer that performs evaluation and visualization of inclination. Communication among particular devices is ensured by IQRF technology working within ISM band of 868MHz. Application of this approach for measurement of inclination is a reasonable choice in case of measurement of inclination by inclinometers.

  20. Photoelectric inclination sensor

    NASA Astrophysics Data System (ADS)

    Kato, Hisao; Kojima, Masahiko; Hayashi, Morihiko; Sasaki, Shunji

    1986-06-01

    A new photoelectric inclination sensor consisting of a light emitting diode (LED) spirit level mounted on a photodiode array is introduced. Light from the LED projects a bubble in the level and throws a shadow onto the surface of the array composed of four equivalent square-shaped diodes, isolated from each other by a cross on a wafer. When the transducer is kept horizontal, the area of the shadow in each diode is exactly equivalent. By taking the difference output positioned obliquely in the array, the water level in the two-dimensional plane is detected. This transducer detects the two-dimensional water level accurately, can be compact, and the response is fast.

  1. The Ballistic Cart on an Incline Revisited.

    ERIC Educational Resources Information Center

    Serway, Raymond A.; And Others

    1995-01-01

    Presents the theory behind the mechanics demonstration that involves projecting a ball vertically upward from a ballistic cart moving along an inclined plane. The measured overshoot is believed to be due, in part, to the presence of rolling friction and the inertial properties of the cart wheels. (JRH)

  2. Motion of an inclined cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2015-09-01

    We consider in this paper the motion of an inclined cylinder on an inclined plane. At low inclined plane angles, the cylinder rolls without slipping across the incline, in a direction perpendicular to its long axis. At steeper angles, long cylinders follow a straight line path in a direction that veers away from the low angle path. Short cylinders follow a curved path. These effects are described in terms of a transition from rolling to sliding as the incline angle is increased. The results help to explain why a vehicle normally turns in the direction that the wheels are pointing and why a vehicle can veer away from that direction on a slippery surface.

  3. Marginal and Internal Fit of Conventional Metal-Ceramic and Lithium Disilicate CAD/CAM Crowns.

    PubMed

    Nam, Se-Jin; Yoon, Mi-Jung; Kim, Won-Hee; Ryu, Gil-Ju; Bang, Min-Ki; Huh, Jung-Bo

    2015-01-01

    This study aimed to evaluate and compare the marginal and internal gap widths of lithium disilicate computer-aided design / computer-assisted manufacture (LDC) crowns and conventionally produced porcelain-fused-to-metal (PFM) crowns. A convenience sample of 21 patients treated with a single restoration was selected. PFM and LDC crowns were fabricated for each selected abutment tooth, following traditional crown preparation. Silicone replicas were produced, and internal gaps and marginal gaps were measured. Internal gaps were significantly larger for the axial and occlusal surfaces of LDC crowns than for those of PFM crowns (P < .001). Marginal gaps were not significantly different (P > .05). Both LDC crowns and PFM crowns showed clinically acceptable marginal fit. PMID:26340013

  4. Relationships between Migration to Urban Settings and Children's Creative Inclinations

    ERIC Educational Resources Information Center

    Shi, Baoguo; Lu, Yongli; Dai, David Yun; Lin, Chongde

    2013-01-01

    In this study, 909 5th- and 6th-grade children were recruited as participants, and questionnaires were used to investigate the relationships between migration to urban settings and children's creative inclinations. The study was broken down to 2 parts. Study 1 compared scores on measures of creative inclinations among migrant, rural, and urban…

  5. An Investigation Into the Integrity of Fit of Provisional Crowns Using Current Proprietary Temporary Crown Materials.

    PubMed

    Taylor, Philip D; Georgakis, Georgios; Niggli, Jason

    2016-06-01

    Three methods of direct provisional crown construction were investigated for accuracy of marginal fit. A modified proprietary crown coping was compared to Bis GMA and isobutyl methacrylate resin provisional crowns with margins modified by using a flowable composite and 'bead on' isobutyl methacrylate respectively. Measurement was at 50x magnification at seven sites over the fit surface. Data was analyzed using SPSS version 13.0.1 and measurement compared using the Mann Whitney test set at a significance level of 0.05. Reliability was checked using the Bland Altman test. Statistical significant differences were found between the three groups. The order of best fit was Bis-GMA and flowable composite > isobutyl methacrylate with 'bead on' margins > Bis-GMA modified implant temporary coping. The clinical significance is that the Bis GMA and flowable composite combination can be used with equal confidence to traditional methods of temporarisation. PMID:27424335

  6. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns.

    PubMed

    Lameira, Deborah Pacheco; Buarque e Silva, Wilkens Aurélio; Andrade e Silva, Frederico; De Souza, Grace M

    2015-01-01

    The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37 °C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength. PMID:26576423

  7. Three-Dimensional Vortex Structure in Jets from Inclined Nozzles

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Longmire, E. K.

    1996-11-01

    Flow visualization and particle image velocimetry measurements were performed on round jets exiting nozzles with inclines from 0 to 45 deg at a Reynolds number of 9000. Results from natural jets and jets forced with single frequencies corresponding to StD = 0.25 and 0.5 will be presented. In the natural case, the nozzle incline caused a mild increase in the radial spreading in the plane of azimuthal symmetry. The forcing amplified the asymmetric radial spreading by altering the vortex structure. In general, inclined vortex rings rolled up at an angle slightly smaller than the nozzle incline angle. As the rings moved downstream, they migrated away from the jet centerline, and their incline angle increased until breakdown occurred. For StD = 0.5, the rings did not pair, and the maximum incline angle observed was 49 deg. Forcing at StD = 0.25 yielded a pairing where the pairing location moved upstream with increasing nozzle incline angle. The nature of the pairing, which was also dependent on the nozzle incline angle, will be described.

  8. Clinical assessment of enamel wear caused by monolithic zirconia crowns.

    PubMed

    Stober, T; Bermejo, J L; Schwindling, F S; Schmitter, M

    2016-08-01

    The purpose of this study was to measure enamel wear caused by antagonistic monolithic zirconia crowns and to compare this with enamel wear caused by contralateral natural antagonists. Twenty monolithic zirconia full molar crowns were placed in 20 patients. Patients with high activity of the masseter muscle at night (bruxism) were excluded. For analysis of wear, vinylpolysiloxane impressions were prepared after crown incorporation and at 6-, 12-, and 24-month follow-up. Wear of the occlusal contact areas of the crowns, of their natural antagonists, and of two contralateral natural antagonists (control teeth) was measured by use of plaster replicas and a 3D laser-scanning device. Differences of wear between the zirconia crown antagonists and the control teeth were investigated by means of two-sided paired Student's t-tests and linear regression analysis. After 2 years, mean vertical loss was 46 μm for enamel opposed to zirconia, 19-26 μm for contralateral control teeth and 14 μm for zirconia crowns. Maximum vertical loss was 151 μm for enamel opposed to zirconia, 75-115 μm for control teeth and 60 μm for zirconia crowns. Statistical analysis revealed significant differences between wear of enamel by zirconia-opposed teeth and by control teeth. Gender, which significantly affected wear, was identified as a possible confounder. Monolithic zirconia crowns generated more wear of opposed enamel than did natural teeth. Because of the greater wear caused by other dental ceramics, the use of monolithic zirconia crowns may be justified. PMID:27198539

  9. Turner syndrome isochromosome karyotype correlates with decreased dental crown width.

    PubMed

    Rizell, S; Barrenäs, M-L; Andlin-Sobocki, A; Stecksén-Blicks, C; Kjellberg, H

    2012-04-01

    The aim of this project was to study possible influences of Turner syndrome (TS) karyotype and the number of X chromosomes with intact short arm (p-arm) on dental crown width. Primary and permanent mesio-distal crown width was measured on plaster casts from 112 TS females. The influence on crown width of four karyotypes: 1. monosomy (45,X), 2. mosaic (45,X/46,XX), 3. isochromosome, and 4. other, and the number of intact X chromosomal p-arms were investigated. In comparisons between karyotypes, statistically significant differences were found for isochromosome karyotype maxillary second premolars, canines, laterals, mandibular first premolars, and canines, indicating that this karyotype was the most divergent as shown by the most reduced crown width. When each karyotype group were compared versus controls, all teeth in the isochromosome group were significantly smaller than controls (P < 0.01-0.001). The 45,X/46,XX karyotype expressed fewer and smaller differences from controls, while 45,X individuals seemed to display an intermediate tooth width compared with 45,X/46,XX and isochromosomes. No significant difference in crown width was found comparing the groups with one or two intact X chromosomal p-arms. Both primary and permanent teeth proved to have a significantly smaller crown width in the entire group of TS females compared to healthy females. We conclude that the isochromosome group deviates most from other karyotypes and controls, exhibiting the smallest dental crown width, while individuals with 45,X/46,XX mosaicism seemed to have a less affected crown width. An influence of the number of intact p-arms on crown width could not be demonstrated in this study. PMID:21303812

  10. Evaluation of marginal fit of 2 CAD-CAM anatomic contour zirconia crown systems and lithium disilicate glass-ceramic crown

    PubMed Central

    Ji, Min-Kyung; Park, Ji-Hee; Park, Sang-Won; Yun, Kwi-Dug; Oh, Gye-Jeong

    2015-01-01

    PURPOSE This study was to evaluate the marginal fit of two CAD-CAM anatomic contour zirconia crown systems compared to lithium disilicate glass-ceramic crowns. MATERIALS AND METHODS Shoulder and deep chamfer margin were formed on each acrylic resin tooth model of a maxillary first premolar. Two CAD-CAM systems (Prettau®Zirconia and ZENOSTAR®ZR translucent) and lithium disilicate glass ceramic (IPS e.max®press) crowns were made (n=16). Each crown was bonded to stone dies with resin cement (Rely X Unicem). Marginal gap and absolute marginal discrepancy of crowns were measured using a light microscope equipped with a digital camera (Leica DFC295) magnified by a factor of 100. Two-way analysis of variance (ANOVA) and post-hoc Tukey's HSD test were conducted to analyze the significance of crown marginal fit regarding the finish line configuration and the fabrication system. RESULTS The mean marginal gap of lithium disilicate glass ceramic crowns (IPS e.max®press) was significantly lower than that of the CAD-CAM anatomic contour zirconia crown system (Prettau®Zirconia) (P<.05). Both fabrication systems and finish line configurations significantly influenced the absolute marginal discrepancy (P<.05). CONCLUSION The lithium disilicate glass ceramic crown (IPS e.max®press) had significantly smaller marginal gap than the CAD-CAM anatomic contour zirconia crown system (Prettau®Zirconia). In terms of absolute marginal discrepancy, the CAD-CAM anatomic contour zirconia crown system (ZENOSTAR®ZR translucent) had under-extended margin, whereas the CAD-CAM anatomic contour zirconia crown system (Prettau®Zirconia) and lithium disilicate glass ceramic crowns (IPS e.max®press) had overextended margins. PMID:26330973

  11. The Effect of Changes in Lower Incisor Inclination on Gingival Recession

    PubMed Central

    Kamak, Gulen; Kamak, Hasan; Keklik, Hakan; Gurel, Hakan Gurcan

    2015-01-01

    Aim. Orthodontic treatment may promote development of recessions. The mechanism by which orthodontic treatment influences occurrence of recessions remains unclear. The aim of this study was to test the hypothesis that a change of mandibular incisor inclination promotes development of labial gingival recessions. Materials and Methods. The study sample comprised dental casts and lateral cephalograms obtained from 109 subjects before orthodontic treatment (Tb) and after orthodontic treatment (Ta). Depending on the change of lower incisor inclination during treatment, the subjects were divided into three groups: Retroclination (R), Stable Position (S), and Proclination (P). The presence of gingival recessions of mandibular incisors and clinical crown heights were assessed on plaster models. Results and Conclusions. From Tb to Ta, Inc_Incl showed a statistically significant change in the R, P, and S groups (p < 0.05). Increase of clinical crown heights of the lower incisors (42, 4, and 31) was not statistically significant in any group. The only statistically significant intergroup difference was the greater increase of the clinical crown height of tooth number 32 in the P group in comparison with the R group (p = 0.049). The change of lower incisor inclination during treatment did not lead to development of labial gingival recessions in the study sample. PMID:25961071

  12. Resonance capture at arbitrary inclination

    NASA Astrophysics Data System (ADS)

    Namouni, F.; Morais, M. H. M.

    2015-01-01

    Resonance capture is studied numerically in the three-body problem for arbitrary inclinations. Massless particles are set to drift from outside the 1:5 resonance with a Jupiter-mass planet thereby encountering the web of the planet's diverse mean motion resonances. Randomly constructed samples explore parameter space for inclinations from 0 to 180° with 5° increments totalling nearly 6 × 105 numerical simulations. 30 resonances internal and external to the planet's location are monitored. We find that retrograde resonances are unexpectedly more efficient at capture than prograde resonances and that resonance order is not necessarily a good indicator of capture efficiency at arbitrary inclination. Capture probability drops significantly at moderate sample eccentricity for initial inclinations in the range [10°,110°]. Orbit inversion is possible for initially circular orbits with inclinations in the range [60°,130°]. Capture in the 1:1 co-orbital resonance occurs with great likelihood at large retrograde inclinations. The planet's orbital eccentricity, if larger than 0.1, reduces the capture probabilities through the action of the eccentric Kozai-Lidov mechanism. A capture asymmetry appears between inner and outer resonances as prograde orbits are preferentially trapped in inner resonances. The relative capture efficiency of retrograde resonance suggests that the dynamical lifetimes of Damocloids and Centaurs on retrograde orbits must be significantly larger than those on prograde orbits implying that the recently identified asteroids in retrograde resonance, 2006 BZ8, 2008 SO218, 2009 QY6 and 1999 LE31 may be among the oldest small bodies that wander between the outer giant planets.

  13. Eccentricity and inclination of Miranda's orbit

    NASA Technical Reports Server (NTRS)

    Whitaker, E.; Greenberg, R.

    1973-01-01

    Careful re-measurement of all available plates showing Uranus V (Miranda), supplemented by some recently obtained images, shows that this satellite has both a pronounced orbital eccentricity and inclination (to the plane of the other satellites). Observations are sufficient in number and distribution to allow determinations of the precession rates of both pericenter and node, with implications for the dynamical oblateness of Uranus and the gravitational interaction of the satellites. An improved value for the revolution period is a byproduct of the investigation. The success of the study is due to the improved precision of the measures resulting from the adoption of a very simple, direct method of measurement.

  14. Eccentricity and inclination of Miranda's orbit

    NASA Technical Reports Server (NTRS)

    Whitaker, E.; Greenberg, R.

    1973-01-01

    Careful re-measurement of all available plates showing Uranus V (Miranda), supplemented by some recently obtained images, shows that this satellite has both a pronounced orbital eccentricity and inclination (to the plane of the other satellites). Observations are sufficient in number and distribution to allow determinations of the precession rates of both pericenter and node, with implications for the dynamical oblateness of Uranus and the gravitational interaction of the satellites. An improved value for the revolution period is a by-product of the investigation. The success of this study is due to the improved precision of the measures resulting from the adoption of a very simple, direct method of measurement.

  15. Deriving Stellar Inclination of Slow Rotators Using Stellar Activity

    NASA Astrophysics Data System (ADS)

    Dumusque, X.

    2014-12-01

    Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than ~2-2.5 km s-1. By using the new activity simulation SOAP 2.0 which can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit observations of solar-type stars and derive their inclination. For HD 189733, we estimate the stellar inclination to be i=84+6-20 deg, which implies a star-planet obliquity of \\psi =4+18-4 considering previous measurements of the spin-orbit angle. For α Cen B, we derive an inclination of i=45+9-19, which implies that the rotational spin of the star is not aligned with the orbital spin of the α Cen binary system. In addition, assuming that α Cen Bb is aligned with its host star, no transit would occur. The inclination of α Cen B can be measured using 40 radial-velocity measurements, which is remarkable given that the projected rotational velocity of the star is smaller than 1.15 km s-1. Based on observations made with the MOST satellite, the HARPS instrument on the ESO 3.6 m telescope at La Silla Observatory (Chile), and the SOPHIE instrument at the Observatoire de Haute Provence (France).

  16. Deriving stellar inclination of slow rotators using stellar activity

    SciTech Connect

    Dumusque, X.

    2014-12-01

    Stellar inclination is an important parameter for many astrophysical studies. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than ∼2-2.5 km s{sup –1}. By using the new activity simulation SOAP 2.0 which can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit observations of solar-type stars and derive their inclination. For HD 189733, we estimate the stellar inclination to be i=84{sub −20}{sup +6} deg, which implies a star-planet obliquity of ψ=4{sub −4}{sup +18} considering previous measurements of the spin-orbit angle. For α Cen B, we derive an inclination of i=45{sub −19}{sup +9}, which implies that the rotational spin of the star is not aligned with the orbital spin of the α Cen binary system. In addition, assuming that α Cen Bb is aligned with its host star, no transit would occur. The inclination of α Cen B can be measured using 40 radial-velocity measurements, which is remarkable given that the projected rotational velocity of the star is smaller than 1.15 km s{sup –1}.

  17. Synthesis and fluorescence properties of divalent europium-poly(methacrylate containing crown ether structure) complexes

    SciTech Connect

    Higashiyama, N.; Nakamura, H.; Mishima, T.; Shiokawa, J.; Adachi, G. )

    1991-02-01

    This paper reports on divalent europium complexes with poly(methacrylate containing crown ether structure)s, poly(crown ether)s, prepared and their fluorescence properties studied. The polymers used were poly(15-crown-5-methyl methacrylate) (PMA15C5), copoly(15- crown-5-methyl methacrylate-X) (copoly(MA15C5-X)); (X = MMA, EMA, BMA, 2-methoxyethyl methacrylate (MAGI) 3,6,9,12,15- pentaoxahexadecyl methacrylate (MAG5)), poly(18-crown-6- methyl methacrylate) (PMA18C6), and copoly(18-crown-6-methyl methacrylate-MMA) (copoly(MA18C6-MMA)), which were obtained by bulk polymerization. The fluorescence properties of Eu{sup 2+} polymers activated by complexing Eu{sup 2+} ions with crown ether groups were measured in powder form. The Eu{sup 2+}-poly (crown ether)s irradiated by UV light generally gave blue bright emission in the region of 420-465 nm. It was Eu{sup 2+}-copoly(Ma15C5-X); (X = MMA, EMA, and MAG1) that showed the largest emission intensity among the Eu{sup 2+} polymers, and its emission intensity was ca. 20% of that for CaWO{sub 4}:Pb (NBS1026) whose quantum efficiency is about 76%. The intensities of emission for the Eu{sup 2+} polymers containing 15-crown-5 were much larger than that for the ones containing 18-crown-6.

  18. Heliospheric current sheet inclinations predicted from source surface maps

    NASA Technical Reports Server (NTRS)

    Shodhan, S.; Crooker, N. U.; Hughes, W. J.; Siscoe, G. L.

    1994-01-01

    The inclinations of the neutral line at the ecliptic plane derived from source surface model maps of coronal fields are measured for the interval from June 1976 to March 1992. The mean and median values of 53 deg and 57 deg are close to the average inclinations determined earlier from minimum variance analyses of solar wind measurements at sector boundaries, but the mode falls in the 80 deg - 90 deg bin. This result, which is based on the model assumptions implicit in deriving the source surface maps, predicts that the heliospheric current sheet typically intersects the ecliptic plane nearly at right angles, even without steepening by stream interaction regions. High inclinations dominate the solar cycle for about 7 years around solar maximum. Dips to lower inclination occur near solar minimum, but high variance admits a wide range of inclinations throughout the cycle. Compared to the smooth solar cycle variation of the maximum latitudinal excursion of the neutral line, often treated as the tilt angle of a flat heliospheric current sheet, the noisy variation of the inclinations reflects the degree to which the neutral line deviates from a sine wave, implying warps and corrugations in the current sheet. About a third of the time the neutral line so deviates that it doubles back in longitude.

  19. INCLINATION MIXING IN THE CLASSICAL KUIPER BELT

    SciTech Connect

    Volk, Kathryn; Malhotra, Renu

    2011-07-20

    We investigate the long-term evolution of the inclinations of the known classical and resonant Kuiper Belt objects (KBOs). This is partially motivated by the observed bimodal inclination distribution and by the putative physical differences between the low- and high-inclination populations. We find that some classical KBOs undergo large changes in inclination over gigayear timescales, which means that a current member of the low-inclination population may have been in the high-inclination population in the past, and vice versa. The dynamical mechanisms responsible for the time variability of inclinations are predominantly distant encounters with Neptune and chaotic diffusion near the boundaries of mean motion resonances. We reassess the correlations between inclination and physical properties including inclination time variability. We find that the size-inclination and color-inclination correlations are less statistically significant than previously reported (mostly due to the increased size of the data set since previous works with some contribution from inclination variability). The time variability of inclinations does not change the previous finding that binary classical KBOs have lower inclinations than non-binary objects. Our study of resonant objects in the classical Kuiper Belt region includes objects in the 3:2, 7:4, 2:1, and eight higher-order mean motion resonances. We find that these objects (some of which were previously classified as non-resonant) undergo larger changes in inclination compared to the non-resonant population, indicating that their current inclinations are not generally representative of their original inclinations. They are also less stable on gigayear timescales.

  20. Holographic evaluation of the marginal fit of complete crowns loaded at central fossa

    NASA Astrophysics Data System (ADS)

    Chen, Terry Y.; Chang, Guan L.; Wu, Shih H.

    1993-07-01

    In dentistry, the defect of cementation on the margins of crowns accumulates bacterial plaque easily. This can result in recurrent caries and periodontal disease. In this paper holographic interferometry is applied to study the effect of masticatory force on various complete crowns. Four complete molar crowns made from different casting materials (Au, Pd-Ag, Ni-Cr, and PFM) were tested. The horizontal displacements of two points near the margin, measured by the method of multiple observations, could be as large as 15 micrometers under normal load (25 kgw). However, the marginal discrepancy of all four crowns estimated were quite small (< 0.2 micrometers ). This also indicates that the cementation between the crown and the tooth is quite good. Nevertheless, when the load was increased to 45 kgw, a defect of cementation was found on the Pd-Ag crown.

  1. Removal of failed crown and bridge

    PubMed Central

    Rahul, G R.; Poduval, Soorya T.; Shetty, Karunakar

    2012-01-01

    Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched. Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. PMID:24558549

  2. 46 CFR 28.535 - Inclining test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Inclining test. 28.535 Section 28.535 Shipping COAST... VESSELS Stability § 28.535 Inclining test. (a) Except as provided in paragraphs (b) and (c) of this... order to do the calculations required in this subpart must have an inclining test performed. (b)...

  3. Extracting oil palm crown from WorldView-2 satellite image

    NASA Astrophysics Data System (ADS)

    Korom, A.; Phua, M.-H.; Hirata, Y.; Matsuura, T.

    2014-02-01

    Oil palm (OP) is the most commercial crop in Malaysia. Estimating the crowns is important for biomass estimation from high resolution satellite (HRS) image. This study examined extraction of individual OP crown from a WorldView-2 image using twofold algorithms, i.e., masking of Non-OP pixels and detection of individual OP crown based on the watershed segmentation of greyscale images. The study site was located in Beluran district, central Sabah, where matured OPs with the age ranging from 15 to 25 years old have been planted. We examined two compound vegetation indices of (NDVI+1)*DVI and NDII for masking non-OP crown areas. Using kappa statistics, an optimal threshold value was set with the highest accuracy at 90.6% for differentiating OP crown areas from Non-OP areas. After the watershed segmentation of OP crown areas with additional post-procedures, about 77% of individual OP crowns were successfully detected in comparison to the manual based delineation. Shape and location of each crown segment was then assessed based on a modified version of the goodness measures of Möller et al which was 0.3, indicating an acceptable CSGM (combined segmentation goodness measures) agreements between the automated and manually delineated crowns (perfect case is '1').

  4. Extracting Oil Palm Crown from WorldView-2 Satellite Image

    NASA Astrophysics Data System (ADS)

    Korom, A.; Phua, M.-H.; Hirata, Y.; Matsuura, T.

    2014-02-01

    Oil palm (OP) is the most commercial crop in Malaysia. Estimating the crowns is important for biomass estimation from high resolution satellite (HRS) image. This study examined extraction of individual OP crown from a WorldView-2 image using twofold algorithms, i.e., masking of Non-OP pixels and detection of individual OP crown based on the watershed segmentation of greyscale images. The study site was located in Beluran district, central Sabah, where matured OPs with the age ranging from 15 to 25 years old have been planted. We examined two compound vegetation indices of (NDVI+1)*DVI and NDII for masking non-OP crown areas. Using kappa statistics, an optimal threshold value was set with the highest accuracy at 90.6% for differentiating OP crown areas from Non-OP areas. After the watershed segmentation of OP crown areas with additional post-procedures, about 77% of individual OP crowns were successfully detected in comparison to the manual based delineation. Shape and location of each crown segment was then assessed based on a modified version of the goodness measures of [14] which was 0.3, indicating an acceptable CSGM (combined segmentation goodness measures) agreements between the automated and manually delineated crowns (perfect case is '1').

  5. Acoustic signals generated in inclined granular flows

    NASA Astrophysics Data System (ADS)

    Tan, Danielle S.; Jenkins, James T.; Keast, Stephen C.; Sachse, Wolfgang H.

    2015-10-01

    Spontaneous avalanching in specific deserts produces a low-frequency sound known as "booming." This creates a puzzle, because avalanches down the face of a dune result in collisions between sand grains that occur at much higher frequencies. Reproducing this phenomenon in the laboratory permits a better understanding of the underlying mechanisms for the generation of such lower frequency acoustic emissions, which may also be relevant to other dry granular flows. Here we report measurements of low-frequency acoustical signals, produced by dried "sounding" sand (sand capable of booming in the desert) flowing down an inclined chute. The amplitude of the signal diminishes over time but reappears upon drying of the sand. We show that the presence of this sound in the experiments may provide supporting evidence for a previously published "waveguide" explanation for booming. Also, we propose a model based on kinetic theory for a sheared inclined flow in which the flowing layer exhibits "breathing" modes superimposed on steady shearing. The predicted oscillation frequency is of a similar order of magnitude as the measurements, indicating that small perturbations can sustain oscillations of a low frequency. However, the frequency is underestimated, which indicates that the stiffness has been underestimated. Also, the model predicts a discrete spectrum of frequencies, instead of the broadband spectrum measured experimentally.

  6. Experimental investigation of the abrasive crown dynamics in orbital atherectomy.

    PubMed

    Zheng, Yihao; Belmont, Barry; Shih, Albert J

    2016-07-01

    Orbital atherectomy is a catheter-based minimally invasive procedure to modify the plaque within atherosclerotic arteries using a diamond abrasive crown. This study was designed to investigate the crown motion and its corresponding contact force with the vessel. To this end, a transparent arterial tissue-mimicking phantom made of polyvinyl chloride was developed, a high-speed camera and image processing technique were utilized to visualize and quantitatively analyze the crown motion in the vessel phantom, and a piezoelectric dynamometer measured the forces on the phantom during the procedure. Observed under typical orbital atherectomy rotational speeds of 60,000, 90,000, and 120,000rpm in a 4.8mm caliber vessel phantom, the crown motion was a combination of high-frequency rotation at 1000, 1500, and 1660.4-1866.1Hz and low-frequency orbiting at 18, 38, and 40Hz, respectively. The measured forces were also composed of these high and low frequencies, matching well with the rotation of the eccentric crown and the associated orbital motion. The average peak force ranged from 0.1 to 0.4N at different rotational speeds. PMID:27160429

  7. [An automatic extraction algorithm for individual tree crown projection area and volume based on 3D point cloud data].

    PubMed

    Xu, Wei-Heng; Feng, Zhong-Ke; Su, Zhi-Fang; Xu, Hui; Jiao, You-Quan; Deng, Ou

    2014-02-01

    Tree crown projection area and crown volume are the important parameters for the estimation of biomass, tridimensional green biomass and other forestry science applications. Using conventional measurements of tree crown projection area and crown volume will produce a large area of errors in the view of practical situations referring to complicated tree crown structures or different morphological characteristics. However, it is difficult to measure and validate their accuracy through conventional measurement methods. In view of practical problems which include complicated tree crown structure, different morphological characteristics, so as to implement the objective that tree crown projection and crown volume can be extracted by computer program automatically. This paper proposes an automatic untouched measurement based on terrestrial three-dimensional laser scanner named FARO Photon120 using plane scattered data point convex hull algorithm and slice segmentation and accumulation algorithm to calculate the tree crown projection area. It is exploited on VC+6.0 and Matlab7.0. The experiments are exploited on 22 common tree species of Beijing, China. The results show that the correlation coefficient of the crown projection between Av calculated by new method and conventional method A4 reaches 0.964 (p<0.01); and the correlation coefficient of tree crown volume between V(VC) derived from new method and V(C) by the formula of a regular body is 0.960 (p<0.001). The results also show that the average of V(C) is smaller than that of V(VC) at the rate of 8.03%, and the average of A4 is larger than that of A(V) at the rate of 25.5%. Assumed Av and V(VC) as ture values, the deviations of the new method could be attributed to irregularity of the crowns' silhouettes. Different morphological characteristics of tree crown led to measurement error in forest simple plot survey. Based on the results, the paper proposes that: (1) the use of eight-point or sixteen-point projection with

  8. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns

    PubMed Central

    Lameira, Deborah Pacheco; Silva, Wilkens Aurélio Buarque e; Silva, Frederico Andrade e; De Souza, Grace M.

    2015-01-01

    The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (n = 10): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37°C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey's test (P = .05) indicated that monolithic zirconia crowns presented similar fracture strength (PM = 3476.2 N ± 791.7; GM = 3561.5 N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength. PMID:26576423

  9. In-cylinder flows of a motored four-stroke engine with flat-crown and slightly concave-crown pistons

    SciTech Connect

    Huang, R.F.; Yang, H.S.; Yeh, C.-N.

    2008-04-15

    The temporal and spatial evolution processes of the in-cylinder flow structures and turbulence intensities in the symmetry and offset planes of a motored four-valve, four-stroke engine during the intake and compression strokes are diagnosed by using a particle image velocimeter. Two pistons of different crown shapes (flat-crown and slightly concave-crown pistons) are studied. The inception, establishment, and evolution of the tumbling vortical flow structures during the intake and compression strokes are clearly depicted. Quantitative strengths of the rotating vortical flow motions are presented by a dimensionless parameter, the tumble ratio, which can represent the mean angular velocity of the vortices in the target plane. The turbulence intensity of the in-cylinder flow is also calculated by using the measured time-varying velocity data. The results show that the flat-crown piston induces higher bulk-averaged tumble ratio and turbulence intensity than the slightly concave-crown piston does because the tumble ratio and turbulence generated by the flat-crown piston in the offset planes during the compression stroke are particularly large. The engine with the flat-crown piston also presents larger torque and power outputs and lower hydrocarbon emission than that with the slightly concave-crown piston. This might be caused by the enhanced combustion in the engine cylinder due to the stronger tumble ratio and turbulence intensity. (author)

  10. Radium separation through complexation by aqueous crown ethers and ion exchange or solvent extraction

    SciTech Connect

    Chiarizia, R.; Dietz, M.L.; Horwitz, E.P.; Burnett, W.C.

    1997-11-01

    The effect of three water-soluble, unsubstituted crown ethers (15-crown-5 (15C5), 18-crown-6 (18C6) and 21-crown-7 (21C7)) on the uptake of Ca, Sr, Ba and Ra cations by a sulfonic acid cation exchange resin, and on the extraction of the same cations by xylene solutions of dinonylnaphthalenesulfonic acid (HDNNS) from aqueous hydrochloric acid solutions has been investigated. The crown ethers enhance the sorption of the larger cations by the ion exchange resin, thereby improving the resin selectivity over calcium, a result of a synergistic interaction between the crown ether and the ionic functional groups of the resin. Similarly, the extraction of the larger alkaline earth cations into xylene by HDNNS is strongly synergized by the presence of the crown ethers in the aqueous phase. Promising results for intra-Group IIa cation separations have been obtained using each of the three crown ethers as the aqueous ligands and the sulfonic acid cation exchange resin. Even greater separation factors for the radium-calcium couple have been measured with the crown-ethers and HDNNS solutions in the solvent extraction mode. The application of the uptake and extraction results to the development of radium separation schemes is discussed and a possible flowchart for the determination of {sup 226}Ra/{sup 228}Ra in natural waters is presented.

  11. Measurement of the cosmic ray spectrum above 4 × 1018 eV using inclined events detected with the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Pierre Auger Collaboration

    2015-08-01

    A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E-γ with index γ=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0-1.2 (sys))×1019 eV.

  12. Measurement of the cosmic ray spectrum above 4×1018 eV using inclined events detected with the Pierre Auger Observatory

    DOE PAGESBeta

    Aab, Alexander

    2015-08-26

    A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E–γ with index γ=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value inmore » the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0–1.2 (sys))×1019 eV.« less

  13. Measurement of the cosmic ray spectrum above 4×1018 eV using inclined events detected with the Pierre Auger Observatory

    SciTech Connect

    Aab, Alexander

    2015-08-26

    A measurement of the cosmic-ray spectrum for energies exceeding 4×1018 eV is presented, which is based on the analysis of showers with zenith angles greater than 60° detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×1018 eV, the ``ankle'', the flux can be described by a power law E–γ with index γ=2.70 ± 0.02 (stat) ± 0.1 (sys) followed by a smooth suppression region. For the energy (Es) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25 (stat)+1.0–1.2 (sys))×1019 eV.

  14. Legged-locomotion on inclined granular media

    NASA Astrophysics Data System (ADS)

    Rieser, Jennifer; Qian, Feifei; Goldman, Daniel

    Animals traverse a wide variety of complex environments, including situations in which the ground beneath them can yield (e.g. dry granular media in desert dunes). Locomotion strategies that are effective on level granular media can fail when traversing a granular slope. Taking inspiration from successful legged-locomotors in sandy, uneven settings, we explore the ability of a small (15 cm long, 100 g), six-c-shaped legged robot to run uphill in a bed of 1-mm-diameter poppy seeds, using an alternating tripod gait. Our fully automated experiments reveal that locomotor performance can depend sensitively on both environmental parameters such as the inclination angle and volume fraction of the substrate, and robot morphology and control parameters like leg shape, step frequency, and the friction between the feet of the robot and the substrate. We assess performance by measuring the average speed of the robot, and we find that the robot tends to perform better at higher step frequency and lower inclination angles, and that average speed decreases more rapidly with increasing angle for higher step frequency.

  15. Objective assessment of occlusal and coronal characteristics of untreated normals: a measurement study.

    PubMed

    Currim, Simone; Wadkar, Prabodh V

    2004-05-01

    To determine whether tooth shape and position are constant within tooth types, dental casts of 68 Indians (age range, 10-32 years; mean, 18.72 years) were analyzed. The casts were selected from a larger sample and met the following criteria: Class I molar and canine relationships; overjet and overbite within normal limits; well-related vertical, transverse, and anteroposterior relationships with pleasing profiles and well-aligned arches; and no supernumerary teeth or large restorations. None of the subjects had received orthodontic treatment, and all were in good health and exhibited normal growth. Crown angulation, inclination, offset of maxillary molar, curve of Spee, crown facial prominence, horizontal crown contour, and vertical crown contour were assessed. Means, standard deviations, and standard errors were calculated. The measurements were compared with Andrews's data on 120 nonorthodontic normal occlusion casts. The Student t test was used to determine the significance of differences between the 2 sets of data. It was found that teeth of the same tooth type have similar values of horizontal and vertical crown contours. Values for inclination, angulation, and relative prominence were also similar. Hence, we concluded that tooth shape and position are constant for each tooth type. The data from this study were comparable with Andrews's findings. However, from this study, it would be safe to presume that all teeth except the maxillary second molars require alterations in the bracket base inclination value, and that the maxillary lateral incisor, canine, second premolar, and second molar, and the mandibular canine, require alterations in angulation values. PMID:15127027

  16. Chipping Resistance of Graded Zirconia Ceramics for Dental Crowns

    PubMed Central

    Zhang, Y.; Chai, H.; Lee, J.J.-W.; Lawn, B.R.

    2012-01-01

    A serious drawback of veneering porcelains is a pronounced susceptibility to chipping. Glass-infiltrated dense zirconia structures can now be produced with esthetic quality, making them an attractive alternative. In this study, we examined the hypothesis that such infiltrated structures are much more chip-resistant than conventional porcelains, and at least as chip-resistant as non-infiltrated zirconia. A sharp indenter was used to produce chips in flat and anatomically correct glass-infiltrated zirconia crown materials, and critical loads were measured as a function of distance from the specimen edge (flat) or side wall (crown). Control data were obtained on zirconia specimens without infiltration and on crowns veneered with porcelains. The results confirmed that the resistance to chipping in graded zirconia is more than 4 times higher than that of porcelain-veneered zirconia and is at least as high as that of non-veneered zirconia. PMID:22232142

  17. Materials design of ceramic-based layer structures for crowns.

    PubMed

    Lawn, B R; Deng, Y; Lloyd, I K; Janal, M N; Rekow, E D; Thompson, V P

    2002-06-01

    Radial cracking has been identified as the primary mode of failure in all-ceramic crowns. This study investigates the hypothesis that critical loads for radial cracking in crown-like layers vary explicitly as the square of ceramic layer thickness. Experimental data from tests with spherical indenters on model flat laminates of selected dental ceramics bonded to clear polycarbonate bases (simulating crown/dentin structures) are presented. Damage initiation events are video-recorded in situ during applied loading, and critical loads are measured. The results demonstrate an increase in the resistance to radial cracking for zirconia relative to alumina and for alumina relative to porcelain. The study provides simple a priori predictions of failure in prospective ceramic/substrate bilayers and ranks ceramic materials for best clinical performance. PMID:12097438

  18. Crown-formation time of a fossil hominid premolar tooth.

    PubMed

    Beynon, A D; Dean, M C

    1987-01-01

    Studies using surface or internal enamel growth indicators in hominids have suggested that crown-formation times were shorter than those in modern man. The crown-formation time in a robust australopithecine premolar tooth was calculated by counting enamel cross-striations, which correspond to daily increments of formation, on a replica of the fractured internal enamel surface of cuspal enamel using scanning electron microscopy. Cervical enamel completion time was estimated using other growth indicators including striae, and using measured and calculated cross-striation repeat intervals, giving a completion time of approx. 2.4 yr. This is much shorter than reported premolar crown formation times in modern man. These findings support the concept of an abbreviated period of dental development, with implications on the duration of the growth period in early hominids. PMID:3130039

  19. Vortex dynamics in jets from inclined nozzles

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Longmire, E. K.

    1997-03-01

    Experimental tests were performed on round jets exiting inclined nozzles at a Reynolds number of 9000. Both natural jets and jets forced with single frequencies corresponding to StD=0.25, 0.5, 0.75, and 1.0 were examined. In the natural case, the nozzle incline caused a mild increase in the radial spreading in the plane of azimuthal symmetry. The forcing amplified the asymmetric radial spreading by altering the vortex structure. In general, the inclined vortex rings rolled up at an angle slightly smaller than the nozzle incline angle. As the rings moved downstream, they migrated away from the jet centerline and their incline angle increased. Vortex rings generated at StD=0.5 did not pair because that Strouhal number was near the "preferred" mode. For nozzles with slight inclines, forcing at larger Strouhal numbers led to pairing near x/D=2 in order to achieve the "preferred" mode. For nozzles with larger inclines, the vortex cores broke down before pairing could occur. Forcing at a lower Strouhal number (StD=0.25) yielded ring formation at StD=0.5 and subsequent pairing. Increasing the incline angle moved the pairing location closer to the nozzle lip. Also, the pairing process was found to depend on the nozzle incline angle.

  20. On inclination resonances in Artificial Satellite Theory

    NASA Astrophysics Data System (ADS)

    Lara, Martin

    2015-05-01

    The frozen-perigee behavior of elliptic orbits at the critical inclination is usually displayed after an averaging procedure. However, this singularity in Artificial Satellite Theory manifests also in the presence of short-period effects. Indeed, a closed form expression relating orbital inclination and the ratio anomalistic draconitic frequencies is derived for the main problem, which demonstrates that the critical inclination results from commensurability between the periods with which the radial and polar variables evolve in the instantaneous plane of motion. This relation also shows that the critical inclination value is slightly modified by the degree of oblateness of the attracting body, as well as by the orbit's size and shape.

  1. Synchrotron radiation computed laminography using an inclined detector.

    PubMed

    Zhang, Jie; Li, Gang; Yi, Qiru; Chen, Yu; Gao, Zhenhua; Jiang, Xiaoming

    2015-01-01

    Synchrotron radiation computed laminography (SR-CL) has been in use in three-dimensional non-destructive imaging of flat objects for several years. A new set-up is proposed based on the traditional SR-CL method but with the detector inclined at the same angle as the sample inclination to collect projections. The results of computer simulations and real-sample experiments demonstrate that reconstructions acquired using an inclined detector are of better quality compared with those acquired using ordinary detecting methods, especially for the situation of few projections and small difference of attenuation ratio of the sample. This method could be applied to obtain high-quality images of weak-contrast samples with short measurement time and mild radiation damage. PMID:25537599

  2. Inclination flattening and the geocentric axial dipole hypothesis [rapid communication

    NASA Astrophysics Data System (ADS)

    Tauxe, Lisa

    2005-05-01

    model. The method can be tested using sediments deposited in a known field. Application of the elongation/inclination correction method to two magnetostratigraphic data sets from red beds in Asia and Pakistan brings the inclinations into agreement with those predicted from modern GPS measurements and from global paleomagnetic data. There appears to be no compelling reason at this time to abandon the geocentric dipole hypothesis, which has provided such an excellent working model for so long.

  3. [Long-term clinical results with Procera AllCeram full-ceramic crowns].

    PubMed

    Galindo, Martha L; Hagmann, Edgar; Marinello, Carlo P; Zitzmann, Nicola U

    2006-01-01

    The aim of this prospective clinical study was to investigate the long-term survival rate of Procera AllCeram full-ceramic crowns, which were fabricated with aluminiumoxide cores. In 50 patients, 155 Procera crowns with a conventional or reduced core (porcelain collar) were placed on natural abutment teeth. 78% of this group (39 patients with 135 crowns) were examined between May and August 2005 according to the modified USPHS-Criteria. These crowns had been in place for a period of one to 92 months (mean 55 months). Almost half of the crowns were located in the molar region, while 28% were premolars and 24% anterior crowns. Due to one crown fracture the cumulative survival rate was 99% after five and seven years. The clinical success was achieved irrespective of the tooth position, tooth vitality, the preparation margin and the cementum medium used (composite resin or glasionomer cement). In addition, survival was neither influenced by the core design with reduced or conventional margin nor by the core thickness, which measured regularly 0.6 mm in the majority of the specimens. Based on the present findings, it can be concluded that Procera AllCeram is a predictable technique for metal-free, esthetic full-ceramic crowns in the anterior and posterior region. PMID:16989114

  4. Transient natural convection in heated inclined tubes

    NASA Astrophysics Data System (ADS)

    McEligot, Donald M.; Denbow, David A.; Murphy, Hugh D.

    1990-05-01

    To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length-to-diameter (L/D) ratio of 36 at angles of 0, 20, and 35 degrees from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Results were primarily qualitative but were useful in providing insight into the phenomena occurring. Steady-state temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. Transient measurements of the temperature distribution were obtained during cooling from a higher temperature without a heat source to calibrate the heat losses. With the electrical heat source, temporal data were taken during heating to examine the approach to steady state. Quasi-steady flow conditions were approached rapidly, but the overall time constant of the apparatus was of the order of one-third of a day. Predictions with the three-dimensional TEMPEST code were first tested by comparison with simple conduction analyses. Comparison with actual data showed good agreement of the predicted temperature levels for the maximum inclination, 35 degrees, and slightly poorer agreement for the other limit, a vertical tube. Trends of temperature level and Nusselt number with heating rate or Rayleigh number were reasonable, but the predicted variation of the end Nusselt number versus inclination was in the opposite direction from the experiment.

  5. Transient natural convection in heated inclined tubes

    SciTech Connect

    McEligot, D.M. . Oceanic Div.); Denbow, D.A. ); Murphy, H.D. )

    1990-05-01

    To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length-to-diameter (L/D) ratio of 36 at angles of 0{degree}, 20{degree}, and 35{degree} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Results were primarily qualitative but were useful in providing insight into the phenomena occurring. Steady-state temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. transient measurements of the temperature distribution were obtained during cooling from a higher temperature without a heat source to calibrate the heat losses. With the electrical heat source, temporal data were taken during heating to examine the approach to steady state. Quasi-steady flow conditions were approached rapidly, but the overall time constant of the apparatus was of the order of one-third of a day. Predictions with the three-dimensional TEMPEST code were first tested by comparison with simple conduction analyses. Comparison with actual data showed good agreement of the predicted temperature levels for the maximum inclination, 35{degree}, and slightly poorer agreement for the other limit, a vertical tube. Trends of temperature level and Nusselt number with heating rate or Rayleigh number were reasonable, but the predicted variation of the end Nusselt number versus inclination was in the opposite direction from the experiment. 75 refs., 20 figs., 8 tabs.

  6. Marginal accuracy of temporary composite crowns.

    PubMed

    Tjan, A H; Tjan, A H; Grant, B E

    1987-10-01

    An in vitro study was conducted to quantitatively compare the marginal adaptation of temporary crowns made from Protemp material with those made from Scutan, Provisional, and Trim materials. A direct technique was used to make temporary restorations on prepared teeth with an impression as a matrix. Protem, Trim, and Provisional materials produced temporary crowns of comparable accuracy. Crowns made from Scutan material had open margins. PMID:2959770

  7. Intrinsic affinities of alkali cations for 15-crown-5 and 18-crown-6: Bond dissociation energies of gas-phase M{sup +}-crown ether complexes

    SciTech Connect

    More, M.B.; Ray, D.; Armentrout, P.B.

    1999-01-20

    Bond dissociation energies (BDEs) of M{sup +}[c-(C{sub 2}H{sub 4}O){sub 5}] and M{sup +}[c-(C{sub 2}H{sub 4}O){sub 6}] for M = Na, K, Rb, and Cs are reported. The BDEs are determined experimentally by analysis of the thresholds for collision-induced dissociation of the cation-crown ether complexes by xenon measured by using guided ion beam mass spectrometry. In all cases, the primary and lowest energy dissociation channel observed experimentally in endothermic loss of the ligand molecule. The cross section thresholds are interpreted to yield 0 and 298 K BDEs after accounting for the effects of multiple ion-molecule collisions, internal energy of the complexes, and unimolecular decay rates. For both 18-crown-6 and 15-crown-5, the BDEs decrease monotonically with increasing cation size. These results indicate that the intrinsic affinity of c-(C{sub 2}H{sub 4}O){sub 5} and c-(C{sub 2}H{sub 4}O){sub 6} for M{sup +} is determined principally by the charge density of the cation not by the ratio of the ionic radius to the cavity size. The BDEs reported here are in fair agreement with recent ab initio calculations at the MP2 level with 6-31+G* basis sets. The experimental values are systematically smaller than the computed values by 8 {+-} 2 kJ/mol per metal-oxygen interaction. The existence of less strongly bound isomers in the experimental apparatus for Rb{sup +}(15-crown-5) and Cs{sup +}(15-crown-5) appears likely, but their absence for Na{sup +} and K{sup +} complexes indicates interesting metal-dependent dynamics to the formation of such isomers.

  8. Slipping and Rolling on an Inclined Plane

    ERIC Educational Resources Information Center

    Aghamohammadi, Cina; Aghamohammadi, Amir

    2011-01-01

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ([mu]). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is…

  9. On crack growth in molar teeth from contact on the inclined occlusal surface.

    PubMed

    Chai, Herzl

    2015-04-01

    Extracted human molar teeth are indented by hard balls laid at the central fossa, sectioned, and their interior examined for damage. Contact on the fissured enamel coat generally occurs on three distinct spots. The main forms of damage are radial cracks growing from the DEJ to the occlusal surface and median radial and cylindrical cracks growing from a contact spot to the DEJ. For large balls failure by edge chipping near a cusp apex may occur. The median cracks tend to run unstably to the DEJ upon reaching the middle part of the enamel coat. The corresponding load, PFM, and the load needed to initiate radial cracks at the DEJ, PFR, are taken to signal crown failure. The mean values of PFM and PFR are on the order of 1000N. A conical bilayer model defined by thickness d, inclination angle θ, failure stress σF and toughness KC of the enamel coat is developed to assess crown failure. The analytical predictions for PFR and PFM agree well with the tests. The results indicate that enamel thickness is so designed as to ensure that PFR and PFM just exceed the maximum bite force under normal conditions while the choice of θ seems to reflect a compromise between needs to resist crown failure and break hard food particles. Both PFR and PFM are greatly reduced with reducing d, which points to the danger posed by tooth wear. The analytical expressions for PFR and PFM may also apply to other multi-cusp mammalian or prosthetic molar crowns. Cone cracking, suppressed in the anisotropic tooth enamel, may be an important failure mode in prosthetic crowns. PMID:25621848

  10. Effects of crown retrieval on implants and the surrounding bone: a finite element analysis

    PubMed Central

    Unal, Server Mutluay; Yurekli, Emel; Güven, Sedat

    2016-01-01

    PURPOSE The aim of this study was to observe stress concentration in the implant, the surrounding bone, and other components under the pull-out force during the crown removal. MATERIALS AND METHODS Two 3-dimensional models of implant-supported conventional metal ceramic crowns were digitally constructed. One model was designed as a vertically placed implant (3.7 mm × 10 mm) with a straight abutment, and the other model was designed as a 30-degree inclined implant (3.7 mm × 10 mm) with an angled abutment. A pull-out force of 40 N was applied to the crown. The stress values were calculated within the dental implant, the abutment, the abutment screw, and the surrounding bone. RESULTS The highest stress concentration was observed at the coronal portion of the straight implant (9.29 MPa). The stress concentrations at the cortical bone were lower than at the implants, and maximum stress concentration in bone structure was 1.73 MPa. At the abutment screws, the stress concentration levels were similiar (3.09 MPa and 3.44 MPa), but the localizations were different. The stress at the angled abutment was higher than the stress at the straight abutment. CONCLUSION The pull-out force, applied during a crown removal, did not show an evident effect in bone structure. The higher stress concentrations were mostly observed at the implant and the abutment collar. In addition, the abutment screw, which is the weakest part of an implant system, also showed stress concentrations. Implant angulation affected the stress concentration levels and localizations. CLINICAL IMPLICATIONS These results will help clinicians understand the mechanical behavior of cement-retained implant-supported crowns during crown retrieval. PMID:27141257

  11. The effect of zirconia framework design on the failure of all-ceramic crown under static loading

    PubMed Central

    Taenguthai, Pakamard

    2015-01-01

    PURPOSE This in vitro study aimed to compare the failure load and failure characteristics of two different zirconia framework designs of premolar crowns when subjected to static loading. MATERIALS AND METHODS Two types of zirconia frameworks, conventional 0.5 mm even thickness framework design (EV) and 0.8 mm cutback of full contour crown anatomy design (CB), were made for 10 samples each. The veneer porcelain was added on under polycarbonate shell crown made by vacuum of full contour crown to obtain the same total thickness of the experiment crowns. The crowns were cemented onto the Cobalt-Chromium die. The dies were tilted 45 degrees from the vertical plane to obtain the shear force to the cusp when loading. All crowns were loaded at the lingual incline of the buccal cusp until fracture using a universal testing machine with cross-head speed 0.5 mm/min. The load to fracture values (N) was recorded and statistically analyzed by independent sample t-test. RESULTS The mean and standard deviations of the failure load were 1,170.1 ± 90.9 N for EV design and 1,450.4 ± 175.7 N for CB design. A significant difference in the compressive failure load was found (P<.05). For the failure characteristic, the EV design was found only cohesive failures within veneering porcelain, while the CB design found more failures through the zirconia framework (8 from 10 samples). CONCLUSION There was a significant difference in the failure load between two designs, and the design of the framework influences failure characteristic of zirconia crown. PMID:25932313

  12. Pipe weld crown removal device

    SciTech Connect

    Sword, C.K.; Sette, P.J.

    1992-11-24

    A device is provided for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of the weld, a plurality of grinding wheels, supported by the cage assembly for grinding down the crown of the weld, and a plurality of support shafts, each extending longitudinally along the joined pipe sections, parallel thereto, for individually mounting respective grinding wheels. Each end of the support shafts is mounted for rotation in a bearing assembly housed within a radially directed opening in a corresponding one of the cage rings so as to provide radial movement of the associated shaft, and thus of the associated grinding wheel, towards and away from the weld. A first drive sprocket provides rotation of the cage assembly around the pipe sections while a second drive unit, driven by a common motor, provides rotation of the grinding wheels. 2 figs.

  13. Pipe weld crown removal device

    SciTech Connect

    Sword, C.K.; Sette, P.J.

    1991-12-31

    This invention is comprised of a device that provides for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of the weld, a plurality of grinding wheels, supported by the cage assembly for grinding down the crown of the weld, and a plurality of support shafts, each extending longitudinally along the joined pipe sections, parallel thereto, for individually mounting respective grinding wheels. Each end of the support shafts is mounted for rotation in a bearing assembly housed within a radially directed opening in a corresponding one of the cage rings so as to provide radial movement of the associated shaft, and thus of the associated grinding wheel, towards and away from the weld. A first drive sprocket provides rotation of the cage assembly around the pipe sections while a second drive unit, driven by a common motor, provides rotation of the grinding wheels.

  14. Pipe weld crown removal device

    DOEpatents

    Sword, Charles K.; Sette, Primo J.

    1992-01-01

    A device is provided for grinding down the crown of a pipe weld joining aligned pipe sections so that the weld is substantially flush with the pipe sections joined by the weld. The device includes a cage assembly comprising a pair of spaced cage rings adapted to be mounted for rotation on the respective pipe sections on opposite sides of the weld, a plurality of grinding wheels, supported by the cage assembly for grinding down the crown of the weld, and a plurality of support shafts, each extending longitudinally along the joined pipe sections, parallel thereto, for individually mounting respective grinding wheels. Each end of the support shafts is mounted for rotation in a bearing assembly housed within a radially directed opening in a corresponding one of the cage rings so as to provide radial movement of the associated shaft, and thus of the associated grinding wheel, towards and away from the weld. A first drive sprocket provides rotation of the cage assembly around the pipe sections while a second drive unit, driven by a common motor, provides rotation of the grinding wheels.

  15. A method for determining adequate resistance form of complete cast crown preparations.

    PubMed

    Weed, R M; Baez, R J

    1984-09-01

    A diagram with various degrees of occlusal convergence, which takes into consideration the length and diameter of complete crown preparations, was designed as a guide to assist the dentist to obtain adequate resistance form. To test the validity of the diagram, five groups of complete cast crown stainless steel dies were prepared (3.5 mm long, occlusal convergence 10, 13, 16, 19, and 22 degrees). Gold copings were cast for each of the 50 preparations. Displacement force was applied to the casting perpendicularly to a simulated 30-degree cuspal incline until the casting was displaced. Castings were deformed at margins except for the 22-degree group. Castings from this group were displaced without deformation, and it was concluded that there was a lack of adequate resistance form as predicted by the diagram. The hypothesis that the diagram could be used to predict adequate or inadequate resistance form was confirmed by this study. PMID:6384470

  16. Sclerotinia stem and crown rot of chickpea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White mold of chickpea is caused by three soil borne fungi Sclerotinia sclerotiorum, S. minor and S. trifoliorum, causing either stem rot and crown rot. Stem infection, usually above ground and initiated by ascospores through carpogenic germination of scleroia produces stem rot, whereas crown infe...

  17. 'Inclined abstainers': a problem for predicting health-related behaviour.

    PubMed

    Orbell, S; Sheeran, P

    1998-06-01

    A longitudinal test of the association between motivation to undertake a precautionary health action and subsequent behaviour was conducted on women's uptake of the cervical screening test. A sample of never-screened women (N = 166) completed measures derived from protection-motivation theory (PMT; Rogers, 1983). One year later, screening uptake was reliably determined from medical records. While regression analyses demonstrated that PMT variables predicted both motivation to undergo cervical screening and screening uptake, there was, nonetheless, a good deal of inconsistency between protection motivation and screening behaviour. Fifty-seven per cent of those who indicated they were willing to undergo the test did not do so within a one-year period. Discriminant analysis was therefore used to test the ability of cognitions specified by PMT to distinguish four patterns of association between motivation and behaviour: inclined actors, inclined abstainers, disinclined actors and disinclined abstainers. While PMT variables could successfully classify the four groups, it was not possible to derive a reliable discriminant function which distinguished between inclined actors and inclined abstainers. The results suggest that PMT provides a useful account of choice motivation but does not address the psychological processes by which intention is translated into action. Recent calls for the development of a social psychology of volition are discussed in the light of these findings. PMID:9639861

  18. Slip Potential for Commonly Used Inclined Grated Metal Walkways

    PubMed Central

    Pollard, Jonisha P.; Heberger, John R.; Dempsey, Patrick G.

    2016-01-01

    Background No specific guidelines or regulations are provided by the Mine Safety and Health Administration for the use of inclined grated metal walkways in mining plants. Mining and other companies may be using walkway materials that do not provide sufficient friction, contributing to slip and fall injuries. Purpose The purpose of this study was to determine if there are significant differences in the required friction for different grated metal walkways during walking in diverse conditions. Methods The normalized coefficients of friction were measured for 12 participants while walking up and down an instrumented walkway with different inclinations (0°, 5°, 10°, 15°, and 20°) and with and without the presence of a contaminant (glycerol). Self-reported slip events were recorded and the required coefficients of friction were calculated considering only the anterior/posterior components of the shear forces. Additionally, the available coefficients of friction for these walkway materials were measured at the 0° orientation using a tribometer, with and without the presence of the contaminant, using a boot heel as well as Neolite as the test feet. Results The number of slips increased when the inclination angle reached 10° and above. Of all materials tested, the diamond weave grating was found to have the best performance at all inclines and when contaminated or dry. A high number of slips occurred for the perforated grating and serrated bar grating at 20° when contaminated. Conclusions Results of this study suggest that the diamond weave grating provides significantly better friction compared to serrated bar and perforated gratings, especially at inclines greater than 10°. PMID:26779388

  19. Enamel wear caused by monolithic zirconia crowns after 6 months of clinical use.

    PubMed

    Stober, T; Bermejo, J L; Rammelsberg, P; Schmitter, M

    2014-04-01

    The purpose of this study was to evaluate enamel wear caused by monolithic zirconia crowns and to compare this with enamel wear caused by contralateral natural antagonists. Twenty monolithic zirconia crowns were placed in 20 patients requiring full molar crowns. For measurement of wear, impressions of both jaws were made at baseline after crown cementation and at 6-month follow-up. Mean and maximum wear of the occlusal contact areas of the crowns, of their natural antagonists and of the two contralateral natural antagonists were measured by the use of plaster replicas and 3D laser scanning methods. Wear differences were investigated by the use of two-sided paired Student's t-tests and by linear regression analysis. Mean vertical loss (maximum vertical loss in parentheses) was 10 (43) μm for the zirconia crowns, 33 (112) μm for the opposing enamel, 10 (58) μm for the contralateral teeth and 10 (46) μm for the contralateral antagonists. Both mean and maximum enamel wear were significantly different between the antagonists of the zirconia crowns and the contralateral antagonists. Gender and activity of the masseter muscle at night (bruxism) were identified as possible confounders which significantly affected wear. Under clinical conditions, monolithic zirconia crowns seem to be associated with more wear of opposed enamel than are natural teeth. With regard to wear behaviour, clinical application of monolithic zirconia crowns is justifiable because the amount of antagonistic enamel wear after 6 months is comparable with, or even lower than, that caused by other ceramic materials in previous studies. PMID:24447258

  20. 23. INCLINED END POST / VERTICAL / DIAGONAL / PORTAL ...

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

    23. INCLINED END POST / VERTICAL / DIAGONAL / PORTAL BRACING DETAIL. VIEW TO SOUTHEAST. - Abraham Lincoln Memorial Bridge, Spanning Missouri River on Highway 30 between Nebraska & Iowa, Blair, Washington County, NE

  1. The solid angle through the inclined rectangle

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We want to determine the solid angle through the inclined rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux(radiant flux or radiant power) is shown.

  2. Dewetting films with inclined contact lines

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Li, Lei; Lu, Xi-Yun

    2015-02-01

    A partially wetting plate withdrawn from a liquid reservoir causes the deposition of a liquid film that is characterized by inclined contact lines. It has been experimentally indicated that the normal component of the contact-line velocity relative to the plate remains constant and is independent of the inclination angles, a fact that has never theoretically been justified. We demonstrate, in the framework of lubrication theory, that the speed-angle independence is only approximate and the normal velocity actually exhibits a weak decrease with the inclination angle of the contact line. This correlation is attributed to the variation of the effective separation of microscopic and macroscopic length scales. In addition, the inclination of the contact line results in a tangential flux of the liquid, which is confined in the vicinity of the contact line. Simple scaling relations are provided for both the normal velocity and the tangential flux.

  3. Capillary Penetration into Inclined Circular Glass Tubes.

    PubMed

    Trabi, Christophe L; Ouali, F Fouzia; McHale, Glen; Javed, Haadi; Morris, Robert H; Newton, Michael I

    2016-02-01

    The spontaneous penetration of a wetting liquid into a vertical tube against the force of gravity and the imbibition of the same liquid into a horizontal tube (or channel) are both driven by capillary forces and described by the same fundamental equations. However, there have been few experimental studies of the transition from one orientation to the other. We report systematic measurements of capillary penetration of polydimethylsiloxane oils of viscosities 9.6, 19.2, and 48.0 mPa·s into glass capillary tubes. We first report the effect of tube radii R between 140 and 675 μm on the dynamics of spontaneous imbibition. We show that the data can be fitted using the exact numerical solution to the governing equations and that these are similar to fits using the analytical viscogravitational approximation. However, larger diameter tubes show a rate of penetration slower than expected using an equilibrium contact angle and the known value of liquid viscosity. To account for the slowness, an increase in viscosity by a factor (η/ρ)(scaling) is needed. We show full agreement with theory requires the ratio R/κ(-1) ∼ 0.1 or less, where κ(-1) is the capillary length. In addition, we propose an experimental method that enables the determination of the dynamic contact angle during imbibition, which gives values that agree with the literature values. We then report measurements of dynamic penetration into the tubes of R = 190 and 650 μm for a range of inclination angles to the horizontal, φ, from 5 to 90°. We show that capillary penetration can still be fitted using the viscogravitational solution, rather than the Bosanquet solution which describes imbibition without gravity, even for inclination angles as low as 10°. Moreover, at these low angles, the effect of the tube radius is found to diminish and this appears to relate to an effective capillary length, κ(-1)(φ) = (γ(LV)/ρg sin φ)(1/2). PMID:26738739

  4. How do the substrate reaction forces acting on a gecko's limbs respond to inclines?

    NASA Astrophysics Data System (ADS)

    Wang, Zhouyi; Dai, Zhendong; Li, Wei; Ji, Aihong; Wang, Wenbao

    2015-02-01

    Locomotion is an essential character of animals, and excellent moving ability results from the delicate sensing of the substrate reaction forces (SRF) acting on body and modulating the behavior to adapt the motion requirement. The inclined substrates present in habitats pose a number of functional challenges to locomotion. In order to effectively overcome these challenges, climbing geckos execute complex and accurate movements that involve both the front and hind limbs. Few studies have examined gecko's SRF on steeper inclines of greater than 90°. To reveal how the SRFs acting on the front and hind limbs respond to angle incline changes, we obtained detailed measurements of the three-dimensional SRFs acting on the individual limbs of the tokay gecko while it climbed on an inclined angle of 0-180°. The fore-aft forces acting on the front and hind limbs show opposite trends on inverted inclines of greater than 120°, indicating propulsion mechanism changes in response to inclines. When the incline angles change, the forces exerted in the normal and fore-aft directions by gecko's front and hind limbs are reassigned to take full advantage of limbs' different roles in overcoming resistance and in propelling locomotion. This also ensures that weight acts in the angle range between the forces generated by the front and hind limbs. The change in the distribution of SRF with a change in the incline angle is directly linked to the favorable trade-off between locomotive maneuverability and stability.

  5. How do the substrate reaction forces acting on a gecko's limbs respond to inclines?

    PubMed

    Wang, Zhouyi; Dai, Zhendong; Li, Wei; Ji, Aihong; Wang, Wenbao

    2015-02-01

    Locomotion is an essential character of animals, and excellent moving ability results from the delicate sensing of the substrate reaction forces (SRF) acting on body and modulating the behavior to adapt the motion requirement. The inclined substrates present in habitats pose a number of functional challenges to locomotion. In order to effectively overcome these challenges, climbing geckos execute complex and accurate movements that involve both the front and hind limbs. Few studies have examined gecko's SRF on steeper inclines of greater than 90°. To reveal how the SRFs acting on the front and hind limbs respond to angle incline changes, we obtained detailed measurements of the three-dimensional SRFs acting on the individual limbs of the tokay gecko while it climbed on an inclined angle of 0-180°. The fore-aft forces acting on the front and hind limbs show opposite trends on inverted inclines of greater than 120°, indicating propulsion mechanism changes in response to inclines. When the incline angles change, the forces exerted in the normal and fore-aft directions by gecko's front and hind limbs are reassigned to take full advantage of limbs' different roles in overcoming resistance and in propelling locomotion. This also ensures that weight acts in the angle range between the forces generated by the front and hind limbs. The change in the distribution of SRF with a change in the incline angle is directly linked to the favorable trade-off between locomotive maneuverability and stability. PMID:25645733

  6. Stair ascent and descent at different inclinations.

    PubMed

    Riener, Robert; Rabuffetti, Marco; Frigo, Carlo

    2002-02-01

    The aim of this study was to investigate the biomechanics and motor co-ordination in humans during stair climbing at different inclinations. Ten normal subjects ascended and descended a five-step staircase at three different inclinations (24 degrees, 30 degrees, 42 degrees ). Three steps were instrumented with force sensors and provided 6 dof ground reactions. Kinematics was analysed by a camera-based optoelectronic system. An inverse dynamics approach was applied to compute joint moments and powers. The different kinematic and kinetic patterns of stair ascent and descent were analysed and compared to level walking patterns. Temporal gait cycle parameters and ground reactions were not significantly affected by staircase inclination. Joint angles and moments showed a relatively low but significant dependency on the inclination. A large influence was observed in joint powers. This can be related to the varying amount of potential energy that has to be produced (during ascent) or absorbed (during descent) by the muscles. The kinematics and kinetics of staircase walking differ considerably from level walking. Interestingly, no definite signs could be found indicating that there is an adaptation or shift in the motor patterns when moving from level to stair walking. This can be clearly seen in the foot placement: compared to level walking, the forefoot strikes the ground first--independent from climbing direction and inclination. This and further findings suggest that there is a certain inclination angle or angular range where subjects do switch between a level walking and a stair walking gait pattern. PMID:11809579

  7. Crown condition dynamics of oak in southern Sweden 1988-1999.

    PubMed

    Drobyshev, Igor; Anderson, Stefan; Sonesson, Kerstin

    2007-11-01

    Crown defoliation of oak (Quercus robur and Q. petraea) was analysed in 808 trees during three forest condition surveys (1988, 1993, and 1999) in the southern Sweden. From 1988 to 1999 crown defoliation increased by more than 20%. Changes in crown defoliation were related to the pH in the upper 20-30 cm of the mineral soils, which was closely connected to other measures of soil fertility (cation exchange capacity, CEC and C/N ratio). Trees growing on soils with a high pH (> or =4.00, in BaCl2 filtrate), high CEC and low C/N ratio had significantly lower crown defoliation than trees growing on more acid soils (pH <4.00), indicating that less favourable soil conditions may further enhance oak decline. Age did not differentiate trees with respect to crown defoliation, indicating that decline in crown condition was not due to an age-related increase in crown transparency. Considering only trees younger than 100 years, a significant interaction was observed between changes in crown defoliation and soil pH. Trees younger than 100 years old growing on more acidic soils had a greater increase in crown transparency than trees on more basic soils between 1988 and 1999. Trees > or =100 years old had significantly higher defoliation on more acidic than on more basic soils, however defoliation dynamics of these trees over 1988-99 was not related to soil acidity. Two biotic agents (insect and fungal leaf infections) evaluated in this study did not prove to be important drivers of defoliation dynamics. PMID:17294275

  8. THE PHOTOMETRIC AND KINEMATIC STRUCTURE OF FACE-ON DISK GALAXIES. III. KINEMATIC INCLINATIONS FROM H{alpha} VELOCITY FIELDS

    SciTech Connect

    Andersen, David R.; Bershady, Matthew A. E-mail: mab@astro.wisc.edu

    2013-05-01

    Using the integral field unit DensePak on the WIYN 3.5 m telescope we have obtained H{alpha} velocity fields of 39 nearly face-on disks at echelle resolutions. High-quality, uniform kinematic data and a new modeling technique enabled us to derive accurate and precise kinematic inclinations with mean i{sub kin} = 23 Degree-Sign for 90% of these galaxies. Modeling the kinematic data as single, inclined disks in circular rotation improves upon the traditional tilted-ring method. We measure kinematic inclinations with a precision in sin i of 25% at 20 Degree-Sign and 6% at 30 Degree-Sign . Kinematic inclinations are consistent with photometric and inverse Tully-Fisher inclinations when the sample is culled of galaxies with kinematic asymmetries, for which we give two specific prescriptions. Kinematic inclinations can therefore be used in statistical ''face-on'' Tully-Fisher studies. A weighted combination of multiple, independent inclination measurements yield the most precise and accurate inclination. Combining inverse Tully-Fisher inclinations with kinematic inclinations yields joint probability inclinations with a precision in sin i of 10% at 15 Degree-Sign and 5% at 30 Degree-Sign . This level of precision makes accurate mass decompositions of galaxies possible even at low inclination. We find scaling relations between rotation speed and disk-scale length identical to results from more inclined samples. We also observe the trend of more steeply rising rotation curves with increased rotation speed and light concentration. This trend appears to be uncorrelated with disk surface brightness.

  9. Wear of double crown systems - electroplated vs. casted female part

    PubMed Central

    BAYER, Stefan; KRAUS, Dominik; KEILIG, Ludger; GÖLZ, Lina; STARK, Helmut; ENKLING, Norbert

    2012-01-01

    Objectives The wear of telescopic crowns is a common problem often reducing the patient's satisfaction with the denture and resulting in a renewal of the denture. The study aims to compare the wear behavior of conical crowns using electroplated copings (group E) with standard telescopic crowns with cast female parts (group C). Material and Methods 10 conical crowns were milled for each group of a cast gold alloy. The specimen of group E had a conicity of 2º. The cast secondary crowns of group C had a 0º design. The electroplated coping was established by direct electroforming. An apparatus accomplishing 10,000 wear cycles performed the wear test. The retentive forces and the correlating distance during insertion and separation were measured. The wear test was separated in a start phase, an initial wear phase and the long term wear period. The retention force value and the force-distance integral of the first 0.33 mm of each cycle were calculated. Results The retentive forces were significantly higher for group E and the integrals were significantly lower for this group except the integral at cycle 10,000. The changes of retention force and integral did not differ significantly between both groups in all phases. The change of the integrals as well as the integral at the particular cycles showed higher interquartile distances for group C. Conclusions Within the limitations of this study the tested conical crowns showed clinically acceptable retentive properties. The values reached a range comparable to retentive elements tested in recent literature. The values of group C showed higher ranges. The force measured for group E was significantly higher than for group C but the integrals showed an opposite tendency. The results indicate that an exclusive analysis of the force is not sufficient as the integral is not equivalent to the force although it describes the retentive property of the system in a better way than the force over a distance is described. Both systems

  10. Induction of Crown Gall on Carrot Slices.

    ERIC Educational Resources Information Center

    Babich, H.; Fox, K. D.

    1998-01-01

    Argues that the transfer of plasmid from a bacterium to a plant cell has received little attention. Presents an experiment for studying this type of genetic transformation using the causative agent of crown gall, a malignant plant tumor. (DDR)

  11. Moments of inclination error distribution computer program

    NASA Technical Reports Server (NTRS)

    Myler, T. R.

    1981-01-01

    A FORTRAN coded computer program is described which calculates orbital inclination error statistics using a closed-form solution. This solution uses a data base of trajectory errors from actual flights to predict the orbital inclination error statistics. The Scott flight history data base consists of orbit insertion errors in the trajectory parameters - altitude, velocity, flight path angle, flight azimuth, latitude and longitude. The methods used to generate the error statistics are of general interest since they have other applications. Program theory, user instructions, output definitions, subroutine descriptions and detailed FORTRAN coding information are included.

  12. ARTICULATOR-RELATED REGISTRATION AND ANALYSIS OF SAGITTAL CONDYLAR INCLINATION.

    PubMed

    Cimić, Samir; Simunković, Sonja Kraljević; Suncana Simonić Kocijan; Matijević, Jurica; Dulcić, Niksa; Catić, Amir

    2015-12-01

    The purpose of this investigation was to study sagittal condylar inclination values within a uniform sample (Angle class I occlusion) using 'articulator-related registration' and Camper's plane as a reference plane. The study was performed on a sample of 58 Angle class I subjects (mean age 25.1, SD 3.1). Measurements were performed with an ultrasonic jaw tracking device with six degrees of freedom. After a paraocclusal tray was fixed in the mouth, each subject had to make three protrusive movements and three right and left laterotrusive movements. From protrusive movements the software of the device automatically calculated the left and the right sagittal condylar inclination values used for setting of the articulator. The mean sagittal condylar inclinationvalue was 41.0° (SD 10.5) for the right joint and 40.7° (SD 9.8) for the left joint. The maximum value was 65.0° for the right and 68.6° for the left joint, and the minimum value was 13.7° for the right and 21.7° for the left joint. The results of this study suggested the average articulator setting for sagittal condylar inclination for fully dentate adult subjects to be 40° in relation to Camper's plane. This is especially important for the articulators that are set up in relation to Camper's plane. PMID:27017716

  13. ASSEMBLY OF PROTOPLANETARY DISKS AND INCLINATIONS OF CIRCUMBINARY PLANETS

    SciTech Connect

    Foucart, Francois; Lai, Dong

    2013-02-10

    The Kepler satellite has discovered a number of transiting planets around close binary stars. These circumbinary systems have highly aligned planetary and binary orbits. In this paper, we explore how the mutual inclination between the planetary and binary orbits may reflect the physical conditions of the assembly of protoplanetary disks and the interaction between protostellar binaries and circumbinary disks. Given the turbulent nature of star-forming molecular clouds, it is possible that the gas falling onto the outer region of a circumbinary disk and the central protostellar binary have different axes of rotation. Thus, the newly assembled circumbinary disk can be misaligned with respect to the binary. However, the gravitational torque from the binary produces a warp and twist in the disk, and the back-reaction torque tends to align the disk and the binary orbital plane. We present a new, analytic calculation of this alignment torque and show that the binary-disk inclination angle can be reduced appreciably after the binary accretes a few percent of its mass from the disk. Our calculation suggests that in the absence of other disturbances, circumbinary disks and planets around close (sub-AU) stellar binaries, for which mass accretion onto the proto-binary is very likely to have occurred, are expected to be highly aligned with the binary orbits, while disks and planets around wide binaries can be misaligned. Measurements of the mutual inclinations of circumbinary planetary systems can provide a clue to the birth environments of such systems.

  14. Effect of Luting Cement Space on the Strain Response of Gold Crowns Under Static Compressive Loading.

    PubMed

    Asbia, S; Ibbetson, R; Reuben, B

    2015-03-01

    The aim the work was to investigate the effect of varying degrees of luting cement thickness on the strain of the cemented gold alloy crowns under compression. Five dies with their corresponding crowns were fabricated using a lost wax technique. Three gold crowns for each die were fabricated under the control of specific die spacer layers to provide a space of 40 µm (10 layers of die-spacer thickness) and 80 µm (20 layers of die-spacer thickness). The crowns were subsequently cemented using zinc phosphate cement. The crowns were subjected to gradual static compressive loading between 10N to 250N (Newton) and the strain measured simultaneously. The results were statistically analysed using Independent t-test for the different die-spacer thickness at the 95% confidence interval (p = 0.05). It was found that a significant relationship in the three thicknesses. It was concluded that the absence of die-spacer significantly reduced strain response, whereas a very little change in the strain recorded as the die spacer layers has increased. Clinically, decreasing the number of die-spacer layers is advantageous as it provides a lower strain response under static compressive loading that would improve the longevity of the cemented full crowns inside the patient's mouth. PMID:26415332

  15. In vitro study of fracture strength of provisional crown materials

    PubMed Central

    Sayin, Gulsum; Kara, Ozlem

    2015-01-01

    PURPOSE The purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns. MATERIALS AND METHODS A master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at 37℃ for 24 hours, and then they were thermocycled (TC, 5000×, 5-55℃) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (α=.05). RESULTS Fmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01). CONCLUSION Composite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CAD-CAM technique offers more advantages than the direct technique. PMID:25722834

  16. Effect of the shades of background substructures on the overall color of zirconia-based all-ceramic crowns

    PubMed Central

    Tulapornchai, Chantana; Mamani, Jatuphol; Kamchatphai, Wannaporn; Thongpun, Noparat

    2013-01-01

    PURPOSE The objective of this study was to determine the effect of the color of a background substructure on the overall color of a zirconia-based all-ceramic crown. MATERIALS AND METHODS Twenty one posterior zirconia crowns were made for twenty subjects. Seven premolar crowns and six molar crowns were cemented onto abutments with metal post and core in the first and second group. In the third group, eight molar crowns were cemented onto abutments with a prefabricated post and composite core build-up. The color measurements of all-ceramic crowns were made before try-in, before and after cementation. A repeated measure ANOVA was used for a statistical analysis of a color change of all-ceramic crowns at α=.05. Twenty four zirconia specimens, with different core thicknesses (0.4-1 mm) were also prepared to obtain the contrast ratio of zirconia materials after veneering. RESULTS L*, a*, and b* values of all-ceramic crowns cemented either on a metal cast post and core or on a prefabricated post did not show significant changes (P>.05). However, the slight color changes of zirconia crowns were detected and represented by ΔE*ab values, ranging from 1.2 to 3.1. The contrast ratios of zirconia specimens were 0.92-0.95 after veneering. CONCLUSION No significant differences were observed between the L*, a*, and b* values of zirconia crowns cemented either on a metal cast post and core or a prefabricated post and composite core. However, the color of a background substructure could affect the overall color of posterior zirconia restorations with clinically recommended core thickness according to ΔE*ab values. PMID:24049574

  17. Crown Ethers in Nonaqueous Electrolytes for Lithium/Air Batteries

    SciTech Connect

    Xu, Wu; Xiao, Jie; Wang, Deyu; Zhang, Jian; Zhang, Jiguang

    2010-02-04

    The effects of three crown ethers, 12-crown-4, 15-crown-5, and 18-crown-6, as additives and co-solvents in non-aqueous electrolytes on the cell performance of primary Li/air batteries operated in a dry air environment were investigated. Crown ethers have large effects on the discharge performance of non-aqueous electrolytes in Li/air batteries. A small amount (normally less than 10% by weight or volume in electrolytes) of 12-Crown-4 and 15-crown-5 reduces the battery performance and a minimum discharge capacity appears at the crown ether content of ca. 5% in the electrolytes. However, when the content increases to about 15%, both crown ethers improve the capacity of Li/air cells by about 28% and 16%, respectively. 15-Crown-5 based electrolytes even show a maximum discharge capacity in the crown ether content range from 10% to 15%. On the other hand, the increase of 18-crown-6 amount in the electrolytes continuously lowers of the cell performance. The different battery performances of these three crown ethers in electrolytes are explained by the combined effects from the electrolytes’ contact angle, oxygen solubility, viscosity, ionic conductivity, and the stability of complexes formed between crown ether molecules and lithium ions.

  18. 46 CFR 28.535 - Inclining test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... section, each vessel for which the lightweight displacement and centers of gravity must be determined in... of the vessel which was inclined and the location of the longitudinal center of gravity differs less... characteristics can be made and the precise location of the position of the vessel's vertical center of gravity...

  19. 46 CFR 28.535 - Inclining test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... section, each vessel for which the lightweight displacement and centers of gravity must be determined in... undocumented weight difference between the two vessels is less than 3 percent of the lightweight displacement... test, or the inclining test may be dispensed with, if an accurate estimate of the vessel's...

  20. Particle Sliding on a Rough Incline

    ERIC Educational Resources Information Center

    Zurcher, Ulrich

    2007-01-01

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

  1. Penning trap with an inclined magnetic field.

    PubMed

    Yaremko, Yurij; Przybylska, Maria; Maciejewski, Andrzej J

    2016-08-01

    A modified Penning trap with a spatially uniform magnetic field B inclined with respect to the axis of rotational symmetry of the electrodes is considered. The inclination angle can be arbitrary. Canonical transformation of phase variables transforming the Hamiltonian of the considered system into a sum of three uncoupled harmonic oscillators is found. We determine the region of stability in space of two parameters controlling the dynamics: the trapping parameter κ and the squared sine of the inclination angle ϑ0. If the angle ϑ0 is smaller than 54°, a charge occupies a finite spatial volume within the processing chamber. A rigid hierarchy of trapping frequencies is broken if B is inclined at the critical angle: the magnetron frequency reaches the modified cyclotron frequency while the axial frequency exceeds them. Apart from this resonance, we reveal the family of resonant curves in the region of stability. In the relativistic regime, the system is not linear. We show that it is not integrable in the Liouville sense. The averaging over the fast variable allows to reduce the system to two degrees of freedom. An analysis of the Poincaré cross-sections of the averaged systems shows the regions of effective stability of the trap. PMID:27586614

  2. Analysis of inclined growth of silicon sheet

    NASA Technical Reports Server (NTRS)

    Brown, R. A.

    1984-01-01

    A general-purpose finite element program was developed for analysis of silicon sheet growth in inclined configurations. This program will be used to study parametric sensitivity of various growth geometries with respect to thermal control and growth rate, dopant segregation, thermal stress and interface morphology and instability.

  3. Crown cover chart for oak savannas. Forest Service technical brief

    SciTech Connect

    Law, J.R.; Johnson, P.S.; Houf, G.

    1994-07-01

    Although oak savannas have been defined in many ways, they are characterized by scattered trees, largely comprised of oaks, and a sparse ground layer rich in grasses and forbs. The crown cover chart can be used to estimate the crown cover of trees as a percent of total area. Potential applications of the chart include monitoring changes in savanna crown cover, determining needed reductions in crown cover, and defining the savanna state. in restoring savannas that have grown into closed canopy stands, one can use the chart to estimate initial crown cover before restoration work is begun and again after crown cover has been reduced.

  4. A combined periodontal - prosthetic treatment approach to manage unusual gingival visibility in resting lip position and inversely inclined upper anterior teeth: a case report with discussion.

    PubMed

    Biniraj, K R; Janardhanan, Mahija; Sunil, M M; Sagir, Mohammed; Hariprasad, A; Paul, Tony P; Emmatty, Rishi

    2015-03-01

    Excessive gingival visibility during smile is a common esthetic complaint in dentistry, but excessive gingival visibility in resting lip position is relatively uncommon condition. Several exclusive radical to conservative surgical treatment or its combination with orthodontic therapy to treat this condition are within the reach of every patient nowadays. A case report of an excessive gingival visibility because of altered passive eruption along with inversely inclined maxillary anterior teeth is presented here. A relatively simple treatment approach combining periodontal and restorative therapy is used here to achieve the desirable aesthetic results. The gingival exposure resulting from altered passive eruption was completely managed by a gingivectomy, but the inclined appearance of teeth was still an aesthetic complaint. After complete healing of gingivectomy surgery, appropriately designed crowns were given to rectify the inversely inclined appearance. A complete rehabilitation of patient's smile could be achieved, the case was followed up for 3 years and the condition was found satisfactory. PMID:25878482

  5. Effects of inclination and vorticity on interfacial flow dynamics in horizontal and inclined pipes

    NASA Astrophysics Data System (ADS)

    Kiara, Areti; Hendrickson, Kelli; Liu, Yuming

    2015-11-01

    The transport of oil and gas in long horizontal pipelines can be significantly affected by the development of violent roll waves and slugs, but the mechanics causing such transitions have not been well understood. To enable the improvement of the prediction of flow transition criteria in long pipelines we perform theoretical analysis and direct numerical simulations of multiphase pipe flows to quantify the roles of inclination and vorticity in the flow dynamics. We find that backflow or flooding may occur even in the absence of disturbances due to inclination effects and obtain criteria on the maximum pipe length for steady flows. We identify and compare the effects of inclination and vorticity on the stability of interfacial wave disturbances. We discuss the mechanisms of non-linear energy transfer between stable and unstable wave disturbances and present results from direct numerical simulations for the predictions of spectrum evolutions for broad-banded interfacial disturbances in inclined pipes.

  6. Magnetic fabric and inclination shallowing studies: depositional and post-depositional processes in hematite- and magnetite-bearing rocks

    NASA Astrophysics Data System (ADS)

    Bilardello, D.; Kodama, K. P.

    2009-12-01

    Magnetic anisotropy-based inclinations corrections of both hematite and magnetite-bearing sedimentary rocks indicate latitudinal variations of inclination shallowing. Rocks formed at mid latitudes suffer from more shallowing than those formed closer to the equator, consistent with the tan Im= f * tan If relationship, where Im is the measured inclination and If is the field inclination during deposition. Shallowing of the paleomagnetic vectors can be expressed in terms of the flattening factor f, a function of the rock’s magnetic fabric and the individual particle anisotropy, the a factor. Estimation of the f factor enables performing simplified inclination corrections. f factors derived from anisotropy-based inclination corrections were combined with f factors derived from corrections that use models of geomagnetic field secular variation for hematite and magnetite bearing rocks. Magnetite data indicate a smaller range of f factors, leading to smaller ranges of inclination shallowing. Using the reported range of f factors enables more precise estimations of inclination corrections. Hematite data, on the other hand, show a broader range of f factors, which makes estimating inclination shallowing and correcting for it more difficult. However, because hematite has magneto-crystalline anisotropy, the value of a doesn’t have much variation, thus requiring a precise measure of the magnetic fabric only. Hematite fabrics were measured for an inclination shallowing study of red beds from the Maritime Provinces of Canada (Shepody Fm), using a high field anisotropy of isothermal remanence technique (hf-AIR). The technique allows to fully saturate hematite’s remanence without the need to demagnetize the samples between the different positions required to measure the anisotropy tensor, eliminating the risk of thermo-chemical alteration. The technique makes it possible for typical paleomagnetic laboratories to measure the remanence anisotropy of high coercivity hematite

  7. Deriving stellar inclination of slow rotators using stellar activity signal

    NASA Astrophysics Data System (ADS)

    Dumusque, Xavier

    2015-01-01

    Stellar inclination is an important parameter for many astrophysical studies. In the context of exoplanets, this allows us to derive the true obliquity of a system if the projected stellar spin-planetary orbit angle can measured via the Rossiter-Mclaughlin effect. Although different techniques allow us to estimate stellar inclination for fast rotators, it becomes much more difficult when stars are rotating slower than 2-2.5 km.s-1. By using the new activity simulation SOAP 2.0 that can reproduce the photometric and spectroscopic variations induced by stellar activity, we are able to fit the activity variation of solar-type stars and derive their inclination. The case of the equator-on star HD189733 will be presented, as well as the case of Alpha Centauri B, which present an inclination of 45+9-19 degrees, implying that the earth-mass orbiting planet is not transiting if aligned with its host star. Other exemples will also demonstrate the power of the technique, that can infer a stellar inclination, even for slow rotators like Alpha Centauri B, that present a projected rotational velocity smaller than 1.15 km.s-1. In addition, the SOAP 2.0 simulation can be used to correct for the effect of activity when one major active region is dominating the RV signal. This could enhance the detection of small mass exoplanets orbiting slightly active stars.This project is funded by ETAEARTH (European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n. 313014), a transnational collaboration between European countries and the US (the Swiss Space Office, the Harvard Origin of Life Initiative, the Scottish Universities Physics Alliance, the University of Geneva, the Smithsonian Astrophysical Observatory, the Italian National Astrophysical Institute, the University of St. Andrews, Queens University Belfast, and the University of Edinburgh) setup to optimize the synergy between space-and ground-based data whose scientific potential for the characterization of

  8. 9. VIEW OF CROWN POINT LOOKING NORTH. VISTA HOUSE, UPPER ...

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

    9. VIEW OF CROWN POINT LOOKING NORTH. VISTA HOUSE, UPPER RETAINING WALL, FLAG POLE AND PARKING LOT IN VIEW. - Historic Columbia River Highway, Crown Point, East of Corbett, Troutdale, Multnomah County, OR

  9. Castable glass ceramic crowns and their reaction to endodontic therapy.

    PubMed

    Cohen, B D; Wallace, J A

    1991-07-01

    The purpose of this investigation was to determine how castable glass (Dicor) crowns would react to both cold testing and endodontic access intervention. Full crown preparations were made on six extracted maxillary teeth. The teeth were then forwarded to Dentsply International, York, Pa. Six castable glass crowns were fabricated to fit these teeth and returned to us. Subsequently the teeth were dried and the crowns were cemented. Scanning electron micrographs of the cemented crowns were made, and endodontic access openings were drilled. The teeth were also cold tested with standard methods. The teeth were then again subjected to scanning electron microscopy to determine any changes the crowns might have undergone. One crown cracked around the gingival collar as scanning electron microscopy was performed. The other crowns did not exhibit any problems such as cracking or crazing from either the access openings or the cold testing. PMID:1891229

  10. 11. DETAIL VIEW LOOKING EAST OF MASONRY RAILING AT CROWN ...

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

    11. DETAIL VIEW LOOKING EAST OF MASONRY RAILING AT CROWN POINT. ASHLAR EXAMPLE ON LEFT. RANDOM RUBBLE ON RIGHT. BEACON ROCK IN DISTANCE. - Historic Columbia River Highway, Crown Point, East of Corbett, Troutdale, Multnomah County, OR

  11. 10. LOWER STATION, FIRST FLOOR, INCLINE PLANE TRCK LOOKING SOUTH ...

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

    10. LOWER STATION, FIRST FLOOR, INCLINE PLANE TRCK LOOKING SOUTH SOUTHEAST, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  12. 1. VIEW WEST SOUTHWEST, UPPER STATION. INCLINE PLANE TRACK AND ...

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

    1. VIEW WEST SOUTHWEST, UPPER STATION. INCLINE PLANE TRACK AND LOWER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  13. 8. LOWER STATION, FIRST FLOOR, EAST SIDE ACCESS TO INCLINE ...

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

    8. LOWER STATION, FIRST FLOOR, EAST SIDE ACCESS TO INCLINE PLANE CARS, LOOKING NORTH NORTHEAST. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  14. 4. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER ...

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

    4. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  15. 19. UPPER STATION, FIRST FLOOR, OPERATOR'S CABIN, DOORS TO INCLINE ...

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

    19. UPPER STATION, FIRST FLOOR, OPERATOR'S CABIN, DOORS TO INCLINE PLANE CARS, LOOKING WEST. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  16. 5. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER ...

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

    5. VIEW SOUTHWEST, LOWER STATION FRONT, INCLINE PLANE TRACK, UPPER STATION. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  17. 5. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM TOP OF ...

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

    5. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM TOP OF ABUTMENT, FILL CONFIGURATION - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  18. 6. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM MIDSLOPE VICINITY, ...

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

    6. VIEW WEST, PERSPECTIVE UP INCLINED PLANE FROM MID-SLOPE VICINITY, CUT CONFIGURATION - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  19. 2. VIEW SOUTH, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON ...

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

    2. VIEW SOUTH, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON WEST SIDE OF PA ROUTE 56 - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  20. 3. VIEW NORTHWEST, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON ...

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

    3. VIEW NORTHWEST, PERSPECTIVE OF ABUTMENT AND INCLINED PLANE ON WEST SIDE OF PA ROUTE 56 - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  1. A new inclination instability in planetary systems

    NASA Astrophysics Data System (ADS)

    Madigan, Ann-Marie

    2015-08-01

    I describe a new instability in Keplerian disks of massive particles on eccentric orbits. Gravitational torques between the orbits align their angles of pericenter and drive exponential growth in orbital inclination. This instability implies specific ratios for Kepler elements of the orbits, similar to what is seen in the inner Oort Cloud of our solar system. I also discuss implications for extra-solar planetary systems and for nuclear star clusters in the centers of galaxies.

  2. A jumping cylinder on an inclined plane

    NASA Astrophysics Data System (ADS)

    Gómez, R. W.; Hernández-Gómez, J. J.; Marquina, V.

    2012-09-01

    The problem of a cylinder of mass m and radius r, with its centre of mass out of the cylinder’s axis, rolling on an inclined plane that makes an angle α with respect to the horizontal, is analysed. The equation of motion is partially solved to obtain the site where the cylinder loses contact with the inclined plane (jumps). Several simplifications are made: the analysed system consists of an homogeneous disc with a one-dimensional straight line mass parallel to the disc axis at a distance y < r of the centre of the cylinder. To compare our results with experimental data, we use a styrofoam cylinder to which a long brass rod is embedded parallel to the disc axis at a distance y < r from it, so the centre of mass lies at a distance d from the centre of the cylinder. Then the disc rolls without slipping on a long wooden ramp inclined at 15°, 30° and 45° with respect to the horizontal. To determine the jumping site, the movements are recorded with a high-speed video camera (Casio EX ZR100) at 240 and 480 frames per second. The experimental results agree well with the theoretical predictions.

  3. A jumping cylinder in an incline

    NASA Astrophysics Data System (ADS)

    Gomez, Raul W.; Hernandez, Jorge; Marquina, Vivianne

    2012-02-01

    The problem of a cylinder of mass m and radius r, with its center of mass out of the cylinder axis, rolling in an incline that makes an angle α respect to the horizontal is analyzed. The equation of motion is solved to obtain the site where the cylinder loses contact with the incline (jumps). Several simplifications are made: the analyzed system consists of an homogeneous disc with a one dimensional straight line of mass parallel to the disc axis at a distance d < r of the center of the cylinder. To compare our results with experimental data, we use a Styrofoam cylinder of radius r = 10.0 ± 0.05 cm, high h = 5.55 ± 0.05 cm and a mass m1 = 24.45 ± 0.05 g, to which a 9.50 ± 0.01 mm diameter and 5.10 ± 0.001 cm long brass road of mass m2 = 30.75 ± 0.05 g was imbibed parallel to the disc axis at a distance of 5.40 ± 0.05 cm from it. Then the disc rolls on a 3.20 m long wooden ramp inclined at 30 and 45 respect to the horizontal. To determine the jumping site, the movements were recorded with a high-speed video camera (Casio EX ZR100) at 400 frames per second. The experimental results agree well with the theoretical predictions.

  4. HIGH-INCLINATION ATENS ARE INDEED RARE

    SciTech Connect

    Greenstreet, S.; Gladman, B.

    2013-04-10

    A recent publication by the Near-Earth Object (NEOWISE) team (Mainzer et al.) using data from the Wide-field Infrared Survey Explorer compared the spacecraft's detected near-Earth asteroid subpopulation orbital element distributions to those expected from the Bottke et al. NEO orbital model. They found a discrepency between the detected and expected Aten inclination distribution. We show that the more recent NEO orbital distribution model by Greenstreet et al., when biased using the NEOWISE detection biases, gives a better match to the NEOWISE detections for the Aten (a < 1.0 AU, Q > 0.983 AU) population in semimajor axis (a), eccentricity (e), and inclination (i) than the Bottke et al. model. A Kolmogorov-Smirnov test gives the probability of drawing the NEOWISE detections from the biased Bottke et al. model as not rejectable (at >99% confidence) for the Aten semimajor axis distribution, but is rejectable at such a high level of confidence for the Aten eccentricity and inclination distributions. For all three orbital element distributions, the biased Greenstreet et al. model provides an acceptable match to the NEOWISE Aten detections. The deficiency in the previous model is likely due to the numerical integration's accuracy having broken down in the high-speed regime for planetary encounters near the Sun, an effect which the newer model does not suffer, and thus likely is the model of preference for perihelia q < 1.0 AU.

  5. Earth Collision with High Inclination Asteroids

    NASA Astrophysics Data System (ADS)

    Solovaya, N. A.; Pittich, E. M.

    2000-01-01

    The orbital evolution of fictitious high inclination main belt asteroids with movement corresponding to the conditions of the Tisserand invariant for C = C(Ll) in the restricted three body problem has been investigated. The obtained results showed that the bodies with inclinations within 40-80 deg and 100-140 deg and eccentricities within 0-0.4 are dynamically stable at least during the 200,000 years investigated period, and periodically change their inclinations, eccentricities and perihelion distances. In some time, they can reach the vicinity of the Sun and during their orbital evolution they cross the Earth orbits many times. The bodies belong to the potential candidates dangerous for the Earth in that they may bring about catastrophic events on its surface. The discoveries of some tents retrograde sungrazers with LASCO coronographs of the SOHO spacecraft and MMC and SOLWIN space equipments lead to the idea that bodies with the studied orbital parameters exist, whereby majority of their revolution around the Sun occur in the space outside the Mars orbit.

  6. Drop impact on inclined superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Choi, Wonjae; Leclear, Sani; Leclear, Johnathon; Abhijeet, .; Park, Kyoo-Chul

    We report an empirical study and dimensional analysis on the impact patterns of water drops on inclined superhydrophobic surfaces. While the classic Weber number determines the spreading and recoiling dynamics of a water drop on a horizontal / smooth surface, for a superhydrophobic surface, the dynamics depends on two distinct Weber numbers, each calculated using the length scale of the drop or of the pores on the surface. Impact on an inclined superhydrophobic surface is even more complicated, as the velocity that determines the Weber number is not necessarily the absolute speed of the drop but the velocity components normal and tangential to the surface. We define six different Weber numbers, using three different velocities (absolute, normal and tangential velocities) and two different length scales (size of the drop and of the texture). We investigate the impact patterns on inclined superhydrophobic surfaces with three different types of surface texture: (i) posts, (ii) ridges aligned with and (iii) ridges perpendicular to the impact direction. Results suggest that all six Weber numbers matter, but affect different parts of the impact dynamics, ranging from the Cassie-Wenzel transition, maximum spreading, to anisotropic deformation. We acknowledge financial support from the Office of Naval Research (ONR) through Contract 3002453812.

  7. Simulations of Seasonal and Latitudinal Variations in Leaf Inclination Angle Distribution: Implications for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Huemmrich, Karl F.

    2013-01-01

    The leaf inclination angle distribution (LAD) is an important characteristic of vegetation canopy structure affecting light interception within the canopy. However, LADs are difficult and time consuming to measure. To examine possible global patterns of LAD and their implications in remote sensing, a model was developed to predict leaf angles within canopies. Canopies were simulated using the SAIL radiative transfer model combined with a simple photosynthesis model. This model calculated leaf inclination angles for horizontal layers of leaves within the canopy by choosing the leaf inclination angle that maximized production over a day in each layer. LADs were calculated for five latitude bands for spring and summer solar declinations. Three distinct LAD types emerged: tropical, boreal, and an intermediate temperate distribution. In tropical LAD, the upper layers have a leaf angle around 35 with the lower layers having horizontal inclination angles. While the boreal LAD has vertical leaf inclination angles throughout the canopy. The latitude bands where each LAD type occurred changed with the seasons. The different LADs affected the fraction of absorbed photosynthetically active radiation (fAPAR) and Normalized Difference Vegetation Index (NDVI) with similar relationships between fAPAR and leaf area index (LAI), but different relationships between NDVI and LAI for the different LAD types. These differences resulted in significantly different relationships between NDVI and fAPAR for each LAD type. Since leaf inclination angles affect light interception, variations in LAD also affect the estimation of leaf area based on transmittance of light or lidar returns.

  8. The effects of forward and backward walking according to treadmill inclination in children with cerebral palsy

    PubMed Central

    Kim, Won-hyo; Kim, Won-bok; Yun, Chang-kyo

    2016-01-01

    [Purpose] This study investigated the effects of forward and backward walking using different treadmill incline positions on lower muscle activity in children with cerebral palsy, to provide baseline data for gait training intensity. [Subjects and Methods] Nineteen subjects with cerebral palsy walked forward and backward at a self-selected pace on a treadmill with inclines of 0%, 5%, 10%, and 15%. Activation of the rectus femoris, biceps femoris, tibialisanterior, and lateral gastrocnemius was measured using surface electromyography during the stance phase. [Results] As treadmill incline increased during forward walking, muscle activation of the paralyzed lower limbs did not significantly change. However, as treadmill incline increased during backward walking, rectus femoris activation significantly increased and a significant difference was found between treadmill inclines of 0% and 10%. A comparison of backward and forward walking showed a significant difference in rectus femoris activation at treadmill inclines of 0%, 5%, and 10%. Activation of the tibialis anterior was only significantly higher for backward walking at the 10% gradient. [Conclusion] Backward walking may strengthen the rectus femoris and tibialis anterior in walking training for cerebral palsy. Gradient adjustment of the treadmill can be used to select the intensity of walking training. PMID:27313373

  9. Vortex-induced vibrations of a flexibly-mounted inclined cylinder

    NASA Astrophysics Data System (ADS)

    Jain, Anil; Modarres-Sadeghi, Yahya

    2013-11-01

    The majority of studies on vortex-induced vibrations of a flexibly-mounted rigid cylinder are for the cases where the flow direction is perpendicular to the long axis of the structure. However, in many engineering applications, such as cable stays in bridges and mooring lines of floating offshore wind turbines, the flow direction may not be perpendicular to the structure. To understand the vortex shedding behind a fixed inclined cylinder, the Independence Principle (IP) has been used. The IP assumes that an inclined cylinder behaves similarly to a normal-incidence case, if only the component of the free stream velocity normal to the cylinder axis is considered. The IP neglects the effect of the axial component of the flow, which seems reasonable for small angles of inclination, but not for large angles. In the present study, a series of experiments have been conducted on a flexibly-mounted rigid cylinder placed inclined to the oncoming flow with various angles of inclination (0°<θ<75°) in a range of Reynolds numbers from 500 to 4000 to investigate how the angle of inclination affects VIV. A rigid cylinder was mounted on springs, and air bearings were used to reduce the structural damping of the system. The system was placed in the test-section of a recirculating water tunnel and the crossflow displacements were measured at each flow velocity. Even at high angles of inclination, large-amplitude oscillations were observed. As the angle of inclination was increased, the lock-in range (the range of reduced flow velocities for which the cylinder oscillates with a large amplitude) started at a higher reduced velocity. When only the normal component of the oncoming flow was considered, the onset of lock-in was observed to be at the same normalized flow velocity for all angles of inclination except for 75°. However, the width of the lock-in region, its pattern, the maximum amplitude of oscillations and its corresponding normalized reduced velocity were not following

  10. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  11. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  12. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  13. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  14. 47 CFR 25.280 - Inclined orbit operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Inclined orbit operations. 25.280 Section 25... COMMUNICATIONS Technical Operations § 25.280 Inclined orbit operations. (a) Satellite operators may commence operation in inclined orbit mode without obtaining prior Commission authorization provided that...

  15. 4. VIEW EAST, PERSPECTIVE DOWN INCLINED PLANE FROM TOP OF ...

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

    4. VIEW EAST, PERSPECTIVE DOWN INCLINED PLANE FROM TOP OF ABUTMENT TO CONEMAUGH RIVER AND AREA OF LOWER INCLINE - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  16. Precession of a Spinning Ball Rolling down an Inclined Plane

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    A routine problem in an introductory physics course considers a rectangular block at rest on a plane inclined at angle a to the horizontal. In order for the block not to slide down the incline, the coefficient of sliding friction, µ, must be at least tan a. The situation is similar for the case of a ball rolling down an inclined plane. In order…

  17. Growth rates of great egret, snowy egret and black-crowned night-heron chicks

    USGS Publications Warehouse

    Custer, T.W.; Peterson, D.W., Jr.

    1991-01-01

    Growth rates of Great Erget (Casmerodius albus), Snowy Erget (Egretta thula), and Black-crowned Night-Heron (Nycticorax nycticorax) chicks to 18 days-of-age were estimated from repeated measurements of chicks in broods of three young. Weight gain (g/day) or increase in length (mm/day) of forearm, tarsus, or culmen did not between Black-crowned Night-Heron chicks at a colony in Rhode Island and a colony in Texas (USA). In Black-crowned night-Herons and Great Egrets, the last chick (C-chick) to hatch had lower growth rates than the first (A-) or second (B-) hatched chick. Black-crowned Night-Heron and Great Egret A-chicks gained weight faster than Snowy Egret A-chicks; however growth rates of the forearm, tarsus, or culmen each were not different among the three species. Equations based on the growth rate of culmen, forearm, or tarsus for repeatedly measured A-chicks estimated age of Great Egret, Snowy Egret, and Black-crowned Night-Heron chicks collected elsewhere to within two days of known age.

  18. Tooth wear against ceramic crowns in posterior region: a systematic literature review

    PubMed Central

    Hmaidouch, Rim; Weigl, Paul

    2013-01-01

    The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against ceramic crowns in posterior region. The selected studies were analyzed in regard to type of crowns, natural antagonist, measuring protocol and outcome. From a yield of 1 000 titles, 43 articles were selected for full-text analysis; finally, no in vitro and only five in vivo studies met the inclusion criteria. As there is heterogeneity in design, used measuring method, ceramics and analysis-form, a meta-analysis was not possible. Results of these studies are very controversial which makes a scientifically valid comparison impossible. This review indicated that some all-ceramic crowns are as wear friendly as metal-ceramic crowns. Up to now, it has been impossible to associate tooth wear with any specific causal agent. The role of ceramic surface treatment that might be responsible for the changing in rate of tooth wear seems undetermined as yet through clinical trials. The literature reveals that studies on this topic are subject to a substantial amount of bias. Therefore, additional clinical studies, properly designed to diminish bias, are warranted. PMID:24136675

  19. 28. Photocopy of Crown Roller Mill illustration; originally published in ...

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

    28. Photocopy of Crown Roller Mill illustration; originally published in The Crown Roller Mill, Northwestern Miller 9 (May 21, 1880): 321; SHOWING WEST SIDE, LOOKING EAST - Crown Roller Mill, 105 Fifth Avenue, South, West Side Milling District, Minneapolis, Hennepin County, MN

  20. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  1. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  2. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  3. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  4. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such...

  5. Root-Crown Ratio in Permanent Dentition Using Panoramic Radiography in a Selected Iranian Population

    PubMed Central

    Haghanifar, Sina; Moudi, Ehsan; Abbasi, Shirin; Bijani, Ali; Poorsattar Bejeh Mir, Arash; Ghasemi, Nafiseh

    2014-01-01

    Statement of the Problem: Determining the crown-root ratio is crucial in many dental clinical decisions. There are no reliable data presented for Iranian population. Purpose: The aim of this study was to assess the root-crown ratio of permanent teeth with regards to the relationship of gender and jaw type using panoramic radiographs. The reliability of method was also assessed. Materials and Method: The crown and root lengths of teeth were measured by a digital caliper on panoramic radiographs of 185 individuals except for the third molars. A total of 1994 teeth was studied and 50.8% of the teeth belonged to males and 49.2% belonged to females. The modified Lind method was applied. Results: The highest mean root-crown ratios in both arches of both genders were obtained in the second premolars, followed by the first premolars and canines. In both genders, the lowest root-crown ratios were found in the maxillary central incisors. In male patients, the mean root-crown ratio was higher (p= 0.003) than that of females. Using Bland-Altman analysis, a non-significant difference of 0.006 (95% CI: -0.012-0.024) and 0.0002 (95% CI: -0.011-0.011) were found for intra-observer and inter-observer agreement, respectively. Conclusion: Assessment of the root-crown ratio in permanent dentition could be performed on panoramic radiographs with acceptable reproducibility in an Iranian Population. Considering observed differences, our findings suggest that for the accurate assessment, this ratio must be calculated for male and female patients and also for the upper and lower jaws, separately. PMID:25469356

  6. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate.

    PubMed

    Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

    2016-01-01

    The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

  7. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

    PubMed Central

    Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

    2016-01-01

    The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

  8. Three-dimensional, transient natural convection in inclined wellbores

    SciTech Connect

    McEligot, D.M. . Oceanic Div.); Denbow, D.A. ); Murphy, H.D. )

    1990-01-01

    The occurrence of natural conduction in a wellbore can affect geothermal gradient measurements and heat flow estimates. In the Hot Dry Rock geothermal concept, the wellbores are purposely inclined in the deep regions to enhance heat production. To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length to diameter (L/D) ratio of 36 at angles of 0{degrees}, 20{degrees}, and 35{degrees} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. Comparison with measurements showed good agreement of the predicted temperature levels for the maximum inclination and slightly poorer agreement for the other limit, a vertical tube. 50 refs., 9 figs.

  9. Tree Crown Mapping in Managed Woodlands (Parklands) of Semi-Arid West Africa Using WorldView-2 Imagery and Geographic Object Based Image Analysis

    PubMed Central

    Karlson, Martin; Reese, Heather; Ostwald, Madelene

    2014-01-01

    Detailed information on tree cover structure is critical for research and monitoring programs targeting African woodlands, including agroforestry parklands. High spatial resolution satellite imagery represents a potentially effective alternative to field-based surveys, but requires the development of accurate methods to automate information extraction. This study presents a method for tree crown mapping based on Geographic Object Based Image Analysis (GEOBIA) that use spectral and geometric information to detect and delineate individual tree crowns and crown clusters. The method was implemented on a WorldView-2 image acquired over the parklands of Saponé, Burkina Faso, and rigorously evaluated against field reference data. The overall detection rate was 85.4% for individual tree crowns and crown clusters, with lower accuracies in areas with high tree density and dense understory vegetation. The overall delineation error (expressed as the difference between area of delineated object and crown area measured in the field) was 45.6% for individual tree crowns and 61.5% for crown clusters. Delineation accuracies were higher for medium (35–100 m2) and large (≥100 m2) trees compared to small (<35 m2) trees. The results indicate potential of GEOBIA and WorldView-2 imagery for tree crown mapping in parkland landscapes and similar woodland areas. PMID:25460815

  10. Tree crown mapping in managed woodlands (parklands) of semi-arid West Africa using WorldView-2 imagery and geographic object based image analysis.

    PubMed

    Karlson, Martin; Reese, Heather; Ostwald, Madelene

    2014-01-01

    Detailed information on tree cover structure is critical for research and monitoring programs targeting African woodlands, including agroforestry parklands. High spatial resolution satellite imagery represents a potentially effective alternative to field-based surveys, but requires the development of accurate methods to automate information extraction. This study presents a method for tree crown mapping based on Geographic Object Based Image Analysis (GEOBIA) that use spectral and geometric information to detect and delineate individual tree crowns and crown clusters. The method was implemented on a WorldView-2 image acquired over the parklands of Saponé, Burkina Faso, and rigorously evaluated against field reference data. The overall detection rate was 85.4% for individual tree crowns and crown clusters, with lower accuracies in areas with high tree density and dense understory vegetation. The overall delineation error (expressed as the difference between area of delineated object and crown area measured in the field) was 45.6% for individual tree crowns and 61.5% for crown clusters. Delineation accuracies were higher for medium (35-100 m(2)) and large (≥100 m(2)) trees compared to small (<35 m(2)) trees. The results indicate potential of GEOBIA and WorldView-2 imagery for tree crown mapping in parkland landscapes and similar woodland areas. PMID:25460815

  11. Cementing porcelain-fused-to-metal crowns.

    PubMed

    Vadachkoria, D

    2009-12-01

    The clinical success of fixed prosthodontic restorations can be complex and involve multifaceted procedures. Preparation design, oral hygiene/micro flora, mechanical forces, and restorative materials are only a few of the factors which contribute to overall success. One key factor to success is choosing the proper cement. Popular use of cements for PFM crowns has shifted from zinc phosphate and glass ionomer cements to resin-reinforced glass ionomer, or RRGI, cements. This change has been rapid and profound. Dental cements have always been less than ideal materials, but this is shift to the relatively new RRGI category justified. Resin-reinforced glass ionomer (RRGI) cements appear to be better than zinc phosphate and glass ionomer cements when placing porcelain-to-metal crowns. RRGI cements, such as RelyX Luting, Fuji Plus and Vitremer Luting Cement, satisfy more of the ideal characteristics of PFM cementation than any other previous cement. Expansion of all three cements has not caused any apparent problems with the cements when used with PFM or metal crowns, but these cements, however, should be avoided when cementing all-ceramic crowns. PMID:20090144

  12. "Crown Ether" Synthesis: An Organic Laboratory Experiment.

    ERIC Educational Resources Information Center

    Field, Kurt W.; And Others

    1979-01-01

    This experiment is designed to acquaint the student with a macromolecular synthesis of a crown ether type compound. The starting materials are readily available and the product, a cyclic polyether, belongs to a class of compounds that has aroused the interest of chemist and biologist alike. (Author/BB)

  13. 21 CFR 872.3330 - Preformed crown.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... greater gold and metals of the platinum group intended to be affixed temporarily to a tooth after removal of, or breakage of, the natural crown (that portion of the tooth that normally protrudes above the...) tooth until the adult tooth erupts. (b) Classification. Class I (general controls). The device is...

  14. 21 CFR 872.3330 - Preformed crown.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... greater gold and metals of the platinum group intended to be affixed temporarily to a tooth after removal of, or breakage of, the natural crown (that portion of the tooth that normally protrudes above the...) tooth until the adult tooth erupts. (b) Classification. Class I (general controls). The device is...

  15. 21 CFR 872.3330 - Preformed crown.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... greater gold and metals of the platinum group intended to be affixed temporarily to a tooth after removal of, or breakage of, the natural crown (that portion of the tooth that normally protrudes above the...) tooth until the adult tooth erupts. (b) Classification. Class I (general controls). The device is...

  16. 21 CFR 872.3330 - Preformed crown.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... greater gold and metals of the platinum group intended to be affixed temporarily to a tooth after removal of, or breakage of, the natural crown (that portion of the tooth that normally protrudes above the...) tooth until the adult tooth erupts. (b) Classification. Class I (general controls). The device is...

  17. 21 CFR 872.3330 - Preformed crown.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... greater gold and metals of the platinum group intended to be affixed temporarily to a tooth after removal of, or breakage of, the natural crown (that portion of the tooth that normally protrudes above the...) tooth until the adult tooth erupts. (b) Classification. Class I (general controls). The device is...

  18. Aspergillosis in a red-crowned crane

    USGS Publications Warehouse

    Stroud, R.K.; Duncan, R.M.

    1983-01-01

    An unusual form of pulmonary aspergillosis in a red-crowned crane (Grus japonensis) is described in this report. The major lesion is unique because it closely resembles a lesion referred to as an aspergilloma. An aspergilloma is a single large granulomatous lesion that resembles a tumor and is caused by fungi of the genus Aspergillus.

  19. Sexual dimorphism in crown units of mandibular deciduous and permanent molars in Australian Aborigines.

    PubMed

    Kondo, S; Townsend, G C

    2004-01-01

    Sexual differences in the crown units of mandibular molars were investigated in Australian Aborigines. The first and second deciduous molars (dm1 and dm2), and first to third permanent molars (M1, M2 and M3) were measured on dental casts using a sliding caliper. Measurements of tooth crowns included overall mesiodistal and buccolingual diameters, as well as the mesiodistal and buccolingual diameters of the trigonid and talonid. Percentage dimorphism values were greater in the talonid dimensions than the trigonid, indicating that sex differences tend to be larger in the later-developing crown units. Sex differences in mesiodistal diameters increased from dm1 to M2 but decreased for M3, the tooth that showed the least dimorphism of all the molars. This result seems to be due to the marked variability in size of the M3 between individuals. PMID:15553268

  20. [Retention of crowns as affected by film thickness of zinc phosphate cement and taper angle of crowns (author's transl)].

    PubMed

    Otani, H; Goto, T

    1979-10-01

    Dependence of the retention of crowns at their axial wall on the film thickness of zinc phosphate cement and the taper angle was investigated. Stainless steel dies, composed of a preparation and an occlusally perforated crown the taper angle of which was 2.9, 5.7, 8.5 and 11.3 degrees respectively (Fig. 1, (a) and (b)), were cemented within three min. after the start of mix with a Shofu Micro Cement having a powder-liquid ratio of 1.5 g/0.5 cc. The thickness of the cement layer at the axial wall was regulated to a given value between 9 and 55 mu through the use of a discrepancy measurer. A Shimazu Autograph tensile test machine was employed to measure 48-hr retention (kg/cm2). The retention of the crowns was strongly dependent on the cement film thickness and the taper angle when the film thickness was below a critical value (15 mu in this experiment), but not when the film thickness was above this value (Fig. 3). This may be explained by the term of mechanical interlocking of either of the unreacted powder grains and the matrix phase in the luting cement, as schematically drawn in Fig. 6. The same findings were more evidently appeared on the semilogarythmic diagram in Fig. 4. In this diagram, the critical value was shown as intersection of two straight lines which could be drawn through all the measurements for four taper angles, using the least squares. PMID:295065

  1. a Modified Method for Image Triangulation Using Inclined Angles

    NASA Astrophysics Data System (ADS)

    Alsadik, Bashar

    2016-06-01

    The ongoing technical improvements in photogrammetry, Geomatics, computer vision (CV), and robotics offer new possibilities for many applications requiring efficient acquisition of three-dimensional data. Image orientation is one of these important techniques in many applications like mapping, precise measurements, 3D modeling and navigation. Image orientation comprises three main techniques of resection, intersection (triangulation) and relative orientation, which are conventionally solved by collinearity equations or by using projection and fundamental matrices. However, different problems still exist in the state - of -the -art of image orientation because of the nonlinearity and the sensitivity to proper initialization and spatial distribution of the points. In this research, a modified method is presented to solve the triangulation problem using inclined angles derived from the measured image coordinates and based on spherical trigonometry rules and vector geometry. The developed procedure shows promising results compared to collinearity approach and to converge to the global minimum even when starting from far approximations. This is based on the strong geometric constraint offered by the inclined angles that are enclosed between the object points and the camera stations. Numerical evaluations with perspective and panoramic images are presented and compared with the conventional solution of collinearity equations. The results show the efficiency of the developed model and the convergence of the solution to global minimum even with improper starting values.

  2. Stress and Reliability Analysis of a Metal-Ceramic Dental Crown

    NASA Technical Reports Server (NTRS)

    Anusavice, Kenneth J; Sokolowski, Todd M.; Hojjatie, Barry; Nemeth, Noel N.

    1996-01-01

    Interaction of mechanical and thermal stresses with the flaws and microcracks within the ceramic region of metal-ceramic dental crowns can result in catastrophic or delayed failure of these restorations. The objective of this study was to determine the combined influence of induced functional stresses and pre-existing flaws and microcracks on the time-dependent probability of failure of a metal-ceramic molar crown. A three-dimensional finite element model of a porcelain fused-to-metal (PFM) molar crown was developed using the ANSYS finite element program. The crown consisted of a body porcelain, opaque porcelain, and a metal substrate. The model had a 300 Newton load applied perpendicular to one cusp, a load of 30ON applied at 30 degrees from the perpendicular load case, directed toward the center, and a 600 Newton vertical load. Ceramic specimens were subjected to a biaxial flexure test and the load-to-failure of each specimen was measured. The results of the finite element stress analysis and the flexure tests were incorporated in the NASA developed CARES/LIFE program to determine the Weibull and fatigue parameters and time-dependent fracture reliability of the PFM crown. CARES/LIFE calculates the time-dependent reliability of monolithic ceramic components subjected to thermomechanical and/Or proof test loading. This program is an extension of the CARES (Ceramics Analysis and Reliability Evaluation of Structures) computer program.

  3. Experimental investigation of turbulent flow in a channel with the backward-facing inclined step

    NASA Astrophysics Data System (ADS)

    Příhoda, Jaromír; Kotek, Michal; Uruba, Václav; Kopecký, Václav; Hladík, Ondřej

    2012-04-01

    The work deals with the experimental investigation of turbulent flow in a closed channel with the backward-facing inclined step. Experiments were carried by means of the PIV optical measuring method in the channel of the rectangular cross-section in the inlet part and with inclined steps of the constant height H mm and various inclination angles for a wide range of the Reynolds number. The attention was paid especially to the separation region behind the step and to the relaxation of the shear layer after the reattachment in the outlet part of the channel. The dependence of the length of the separation region on the Reynolds number was obtained for various step angles. Optical measurements were completed by the measurement of static pressure distribution in the inlet and outlet part of the channel to estimate energy losses.

  4. Cerec anterior crowns: restorative options with monolithic ceramic materials.

    PubMed

    Reich, Sven; Fiedlar, Kurt

    2013-01-01

    The aim of this article is to discuss the different types of monolithic ceramic crowns that can be placed on anterior teeth with existing shoulder preparations. Anterior crowns were indicated for the teeth 12 to 22 in the present case. The patient, a 65-year-old male, had received all-ceramic crowns 20 years earlier, which had started to develop cracks and palatal fractures over the last few years. The patient's teeth were prepared and four sets of crowns were fabricated using different monolithic ceramic materials: IPS e.max CAD, Cerec Blocs C In, VITABLOCS Real Life, and ENAMIC. Both shade characterization and crystallization firing were performed on the monolithic lithium disilicate glass ceramic crowns. The silicate ceramic crowns received glaze firing alone. The crowns made of hybrid ceramic (ENAMIC) were treated with a polymer sealant. PMID:24555406

  5. Electrically assisted drop sliding on inclined planes

    NASA Astrophysics Data System (ADS)

    't Mannetje, D. J. C. M.; Murade, C. U.; van den Ende, D.; Mugele, F.

    2011-01-01

    We demonstrate that electrowetting using alternating current (ac) voltage can be used to overcome pinning of small drops due to omnipresent heterogeneities on solid surfaces. By balancing contact angle hysteresis with gravity on inclined planes, we find that the critical electrowetting number for mobilizing drops is consistent with the voltage-dependent reduction in contact angle hysteresis in ac electrowetting. Moreover, the terminal velocity of sliding drops under ac electrowetting is found to increase linearly with the electrowetting number. Based on this effect, we present a prototype of a wiper-free windscreen.

  6. Internal Extinction in Spiral Galaxies. Inclination Dependence

    NASA Astrophysics Data System (ADS)

    Magris, G. C.; Bruzual, G. A.

    1987-05-01

    . Kent (1986) finds that the surface brightness profiles (r) of spiral galaxies have a weak dependence, if any, on the inclination e with respect to the line of sight. This author also finds a correlation between the MIL ratio and the inclination of a galaxy. The lack of dependence of (r) in , = cos 8 indicates that the disk of these galaxies is optically thick ( .>l), due to the presence of dust grains. For an optically thick system o(r) a + 2.5 log . The cosecant law : 1.086 (Holmberg, 1975) does not explain the observed behaviour of a(r) with . 8ru'ual, Magris and Calvet (1986) solved the radiative transfer equation for a mixture of stars and dispersive dust grains distributed homogeneously in a plane parallel configuration, taking into account the wavelenght dependence of the albedo and , as well as the redistribution in angle of photons scattered by dust grains. The transfer equation is solved for the dimensionless intensity ?( , ) I( , )/I*, where 1* is the intensity emerging from the dust free configuration. The solution, CA -2.5 log (r..=0, ) , includes the correction to the galaxy magnitude due to the excess number 0+ stellar sources along the line o+ sigth (cc -i) with respect to the =I case (face on galaxy). For optically thick systems, does not depend on . The luminosity of a disk galaxy observed with inclination ,q 1 given in our model by L cc , from which log(M/L) = const + (.4 8.N( )'. with G.N . ) = -2.5 log( ). The constant is determined from the mass- luminosity. ratio of a dust free system. In terms of the correction (3(N) we can explain Kent's observations with values of between .3 and 4. These values are consistent with the observation of . -independent surface brightness profiles mentioned above. From this analysis we conclude that the correction terms of Bruzual, Magris and Calvet (1986), which take into account the dispersive properties of interstellar dust, can explain the behaviour of ar) and MIL with galaxy inclination. These correction

  7. The speed of an inclined ruck

    PubMed Central

    Balmforth, N. J.; Craster, R. V.; Hewitt, I. J.

    2015-01-01

    Steady rucks in an elastic beam can roll at constant speed down an inclined plane. We examine the dynamics of these travelling-wave structures and argue that their speed can be dictated by a combination of the physical conditions arising in the vicinity of the ‘contact points’ where the beam is peeled off the underlying plane and stuck back down. We provide three detailed models for the contact dynamics: viscoelastic fracture, a thermodynamic model for bond formation and detachment and adhesion mediated by a thin liquid film. The results are compared with experiments. PMID:25568622

  8. [Assessment of the amount of palladium-silver alloy used for cast posts and veneer crowns].

    PubMed

    Catović, A; Baucić, I

    1988-01-01

    Average amounts of palladium-silver alloy were assessed in a sample of 966 veneer crowns and 667 casted posts. The mean weight values of the samples under study were compared in relation to particular types of anterior teeth. The specimens cast in Auropal SE were weight by the precise balance, Tehtnica, type 6215. Results were analyzed by weight according to the type of the sample under study, and classified according to age, and to the anterior teeth of the upper and lower jaws. On an average, the heaviest posts and veneer crowns were measured on upper canines, whereas the lighest were those on lower incisors. A cast post was found to be by about 40% heavier than a veneer crown on the same tooth. PMID:3076349

  9. Crown Features Extraction from Low Altitude AVIRIS Data

    NASA Astrophysics Data System (ADS)

    Ogunjemiyo, S. O.; Roberts, D.; Ustin, S.

    2005-12-01

    Automated tree recognition and crown delineations are computer-assisted procedures for identifying individual trees and segmenting their crown boundaries on digital imagery. The success of the procedures is dependent on the quality of the image data and the physiognomy of the stand as evidence by previous studies, which have all used data with spatial resolution less than 1 m and average crown diameter to pixel size ratio greater than 4. In this study we explored the prospect of identifying individual tree species and extracting crown features from low altitude AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data with spatial resolution of 4 m. The test site is a Douglas-fir and Western hemlock dominated old-growth conifer forest in the Pacific Northwest with average crown diameter of 12 m, which translates to a crown diameter pixel ratio less than 4 m; the lowest value ever used in similar studies. The analysis was carried out using AVIRIS reflectance imagery in the NIR band centered at 885 nm wavelength. The analysis required spatial filtering of the reflectance imagery followed by application of a tree identification algorithm based on maximum filter technique. For every identified tree location a crown polygon was delineated by applying crown segmentation algorithm. Each polygon boundary was characterized by a loop connecting pixels that were geometrically determined to define the crown boundary. Crown features were extracted based on the area covered by the polygons, and they include crown diameters, average distance between crowns, species spectral, pixel brightness at the identified tree locations, average brightness of pixels enclosed by the crown boundary and within crown variation in pixel brightness. Comparison of the results with ground reference data showed a high correlation between the two datasets and highlights the potential of low altitude AVIRIS data to provide the means to improve forest management and practices and estimates of critical

  10. Skin conductance, Marlowe-Crowne defensiveness, and dental anxiety.

    PubMed

    Benjamins, C; Schuurs, A H; Hoogstraten, J

    1994-08-01

    The present study assesses the relationship between self-reported dental anxiety (Dental Anxiety Inventory, Dental Anxiety Scale, and Duration of Psychophysiological Fear Reactions), electrodermal activity (skin-conductance level and frequency of spontaneous responses), and Marlowe-Crowne defensiveness. All measurements were made twice. The first session was scheduled immediately before a semi-annual dental check-up (stress condition), and baseline measurements were made two months later without the prospect of a dental appointment. Subjects were male dental patients who regularly attended a university dental clinic and a clinic for Special Dental Care. The main findings were that the low anxious-high defensive-scoring (Marlowe-Crowne Denial subscale) university patients showed significantly higher skin-conductance levels and frequency of nonspecific fluctuations than the low anxious-low defensive-scoring subjects. Besides, the conductance values of the low anxious-high defensive-scoring subjects resembled those of the high anxious-low defensive-scoring patients of the clinic for Special Dental Care, the baseline frequency of nonspecific fluctuations excepted. PMID:7808902

  11. [Evaluation of cervical gaps in complete metal crowns cast in alternative silver-tin alloys. Relationship to investing techniques].

    PubMed

    Vecchio, G M; Pretti, E; Vaz, R R; Zaniquelli, O

    1990-01-01

    The purpose of this study was to evaluate cervical mistifing of casting full metal crowns according to investment techniques using commercial available alloys made from silver stannum. Fifteen metal full crowns were obtained through stainless steel die with full crowns preparation, included into three groups as follows: conventional technique, vacuum technique and pressure technique. Readings of cervical disagreement were made through a comparing microscope increased 45 x and each crown was measured in 4 different regions (vestibular, lingual mesial and distal). This way it was verified which of the techniques proposed would balance the casting shrinkage for the silver-stannum alloy used. From the results obtained we conclude that the best cercical adaptation was the one got through pressure technique. PMID:2135769

  12. Nonlocal modeling of granular flows down inclines.

    PubMed

    Kamrin, Ken; Henann, David L

    2015-01-01

    Flows of granular media down a rough inclined plane demonstrate a number of nonlocal phenomena. We apply the recently proposed nonlocal granular fluidity model to this geometry and find that the model captures many of these effects. Utilizing the model's dynamical form, we obtain a formula for the critical stopping height of a layer of grains on an inclined surface. Using an existing parameter calibration for glass beads, the theoretical result compares quantitatively to existing experimental data for glass beads. This provides a stringent test of the model, whose previous validations focused on driven steady-flow problems. For layers thicker than the stopping height, the theoretical flow profiles display a thickness-dependent shape whose features are in agreement with previous discrete particle simulations. We also address the issue of the Froude number of the flows, which has been shown experimentally to collapse as a function of the ratio of layer thickness to stopping height. While the collapse is not obvious, two explanations emerge leading to a revisiting of the history of inertial rheology, which the nonlocal model references for its homogeneous flow response. PMID:25376561

  13. Tenebrio beetles use magnetic inclination compass

    NASA Astrophysics Data System (ADS)

    Vácha, Martin; Drštková, Dana; Půžová, Tereza

    2008-08-01

    Animals that guide directions of their locomotion or their migration routes by the lines of the geomagnetic field use either polarity or inclination compasses to determine the field polarity (the north or south direction). Distinguishing the two compass types is a guideline for estimation of the molecular principle of reception and has been achieved for a number of animal groups, with the exception of insects. A standard diagnostic method to distinguish a compass type is based on reversing the vertical component of the geomagnetic field, which leads to the opposite reactions of animals with two different compass types. In the present study, adults of the mealworm beetle Tenebrio molitor were tested by means of a two-step laboratory test of magnetoreception. Beetles that were initially trained to memorize the magnetic position of the light source preferred, during the subsequent test, this same direction, pursuant geomagnetic cues only. In the following step, the vertical component was reversed between the training and the test. The beetles significantly turned their preferred direction by 180°. Our results brought until then unknown original findings that insects, represented here by the T. molitor species, use—in contrast to another previously researched Arthropod, spiny lobster—the inclination compass.

  14. Distribution of solar irradiance on inclined surfaces caused by moving clouds

    NASA Astrophysics Data System (ADS)

    Tomson, Teolan

    2016-05-01

    The distribution of solar irradiance in shadows of discrete (broken) clouds differs from the distribution calculated for inclined surfaces on the basis of traditional transposition models and changes fast. This phenomenon is studied in this paper. For calculations of dynamic distributions of irradiance on inclined surfaces, a formal point source of direct radiation near the real position of the sun is defined as the source of the "imaginable radiation." This notion is used to create a one-dimensional (1D) simulation model, which allows the fast-changing distribution of irradiance to be calculated. In general, the coincidence of calculated and measured irradiance on inclined surfaces is good. The paper also shows how the current value of the diffuse component of solar radiation can be derived from measurements of total radiation in four differently tilted planes.

  15. Comparative analysis of trunk muscle activities in climbing of during upright climbing at different inclination angles

    PubMed Central

    Park, Byung-Joon; Kim, Joong-Hwi; Kim, Jang-Hwan; Choi, Byeong-Ho

    2015-01-01

    [Purpose] This study was performed to provide evidence for the therapeutic exercise approach through a compative analysis of muscle activities according to climbing wall inclination. [Subjects and Methods] Twentyfour healthy adult subjects without climbing experience performed static exercises at a therapeutic climbing at with various inclination angles (0°, 10°, 20°), and the activities of the trunk muscles (rectus abdominis, obliquus externus abdominis, obliquus internus abdominis, erector spinae) were measured using surface electromyography (EMG) for 7 seconds. [Results] Significant differences were found between the inclination angles of 10° and 0°, as well as 20° in the rectus abdominis, obliquus internus abdominis, right obliquus externus abdominis, and right erector spinae. [Conclusion] Based on measurements of trunk muscle activity in a static climbing standing position at different angles, significant changes in muscle activity appear to be induced at 10 degrees. Therefore, the results appear to provide clinically relevant evidence. PMID:26644661

  16. Recovering Grain-Boundary Inclination Parameters through Oblique Double Sectioning

    NASA Astrophysics Data System (ADS)

    Homer, E. R.; Adams, B. L.; Wagoner, R. H.

    2007-07-01

    A method for the retrieval of grain-boundary inclination parameters of the grain-boundary character distribution (GBCD) by oblique double sectioning (ODS) is proposed. In this hybrid approach, grain-boundary inclination parameters are directly measured by double sectioning, while a statistically reliable sampling of the microstructure is achieved by oblique sectioning. The solution to the fundamental equations is posed in a manner similar to the recovery of the orientation distributions from sets of incomplete pole figures, using classical Fourier representations of the distribution functions. The ODS is validated by and compared to the L A /S V stereology through simulations and experimental implementation in a sample of 439 stainless steel. Simulations show that the grain-boundary normal distributions recovered by ODS and stereology are comparable, giving errors on the order of 10-2. Experimental implementation of ODS and the L A /S V stereology in alloy 439 stainless steel demonstrate additional practical limitations of the ODS methodology when applied to materials of large or uneven grain size.

  17. An experimental study on jets issuing from elliptic inclined nozzles

    NASA Astrophysics Data System (ADS)

    New, T. H.

    2009-06-01

    This paper reports on an experimental flow visualisation and digital particle image velocimetry investigation on forced jets exhausting from aspect ratio equal to three elliptic nozzles with exits inclined at 30° and 60°. Flow images show that shear layer instabilities and subsequent vortex roll-ups are formed parallel to the inclined nozzle exits at 30° incline and that rapid re-orientation of the vortex roll-ups occurs at 60° incline. Flow observations also show that strong axis-switching occurs in a non-inclined elliptic nozzle. However, 30° and 60° elliptic inclined nozzles produce significant distortions to and suppression of the axis-switching behaviour, respectively. As a result, flow stresses and turbulent kinetic energy distributions become increasingly asymmetric. Their coherency and magnitudes along the shorter nozzle lengths also vary significantly. This can be attributed to the dissimilar formations of vortex roll-ups and rib structures, as well as unequal mutual interactions between them as the incline-angle increases. Lastly, results also show that unlike circular inclined nozzles, elliptic inclined nozzles do not produce serpentine-shaped jet columns nor lead to significant lateral jet-spread at large incline-angles.

  18. Stabilizing distressed glass furnace melter crowns

    SciTech Connect

    1997-08-01

    Before the advent of pump casting, hot patching a melter or regenerator crown was extremely time and labor intensive. During these installations, known to many as the bucket brigade, the slurry was mixed on floor level and hauled in 50--65 lb batches up to 100 ft to the top of the crown. Today, in a single shift, a crew of seven can accomplish what took two days and a crew of {approximately}25 in the past. The first application of pump-casting zircon patch occurred on the AZS crown of an insulation-wool-glass furnace. For this application, 23 in. of insulating firebrick had to be removed to gain access to the fused AZS surface. The zircon patch was applied by pumping the mix from floor level up {approximately}60 ft to the crown by means of a concrete pump. Postmortems were performed on samples from two of the gas-fired TV-panel-glass furnaces. These postmortems were performed to determine if alterations occurred on the hot face of exposed zircon patch and, if so, how much alteration did occur. There was no destructive alteration because of alkali penetration into the patch. In fact, only trace amounts of lead, barium and strontium were detected, no further than 1 in. from the hot face. There was slight loss of P{sub 2}O{sub 5} on the hot face because of migration of phosphate toward the cold face, but it did not decrease the integrity of the patch. The dissociation of zircon was <3% baddelyite detected, all within an in. of the hot face.

  19. Aza crown ether compounds as anion receptors

    DOEpatents

    Lee, Hung Sui; Yang, Xiao-Oing; McBreen, James

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI.sup.+ ion in alkali metal batteries.

  20. Aza crown ether compounds as anion receptors

    DOEpatents

    Lee, H.S.; Yang, X.O.; McBreen, J.

    1998-08-04

    A family of aza-ether based compounds including linear, multi-branched and aza-crown ethers is provided. When added to non-aqueous battery electrolytes, the new family of aza-ether based compounds acts as neutral receptors to complex the anion moiety of the electrolyte salt thereby increasing the conductivity and the transference number of LI{sup +} ion in alkali metal batteries. 3 figs.

  1. Is stomatal conductance optimized over both time and space in plant crowns? A field test in grapevine (Vitis vinifera).

    PubMed

    Buckley, Thomas N; Martorell, Sebastia; Diaz-Espejo, Antonio; Tomàs, Magdalena; Medrano, Hipólito

    2014-12-01

    Crown carbon gain is maximized for a given total water loss if stomatal conductance (gs ) varies such that the marginal carbon product of water (∂A/∂E) remains invariant both over time and among leaves in a plant crown, provided the curvature of assimilation rate (A) versus transpiration rate (E) is negative. We tested this prediction across distinct crown positions in situ for the first time by parameterizing a biophysical model across 14 positions in four grapevine crowns (Vitis vinifera), computing optimal patterns of gs and E over a day and comparing these to the observed patterns. Observed water use was higher than optimal for leaves in the crown interior, but lower than optimal in most other positions. Crown carbon gain was 18% lower under measured gs than under optimal gs . Positive curvature occurred in 39.6% of cases due to low boundary layer conductance (gbw ), and optimal gs was zero in 11% of cases because ∂A/∂E was below the target value at all gs . Some conclusions changed if we assumed infinite gbw , but optimal and measured E still diverged systematically in time and space. We conclude that the theory's spatial dimension and assumption of positive curvature require further experimental testing. PMID:24689930

  2. Fracture strength of ceramic monolithic crown systems of different thickness.

    PubMed

    Nordahl, Niklas; Vult von Steyern, Per; Larsson, Christel

    2015-09-01

    The objective of this study was to evaluate fracture strength of high-translucent (HTZ) and low-translucent (LTZ) zirconia and glass-ceramic (LDS) crowns. HTZ and LTZ crowns were made with thicknesses of; 0.3 mm, 0.5 mm, 0.7 mm, 1.0 mm, and 1.5 mm; and LDS crowns of 1.0 mm and 1.5 mm thicknesses. Each group consisted of 10 crowns. All crowns underwent artificial aging before loading until fracture. Mean fracture strengths varied from 450 N to 3,248 N in the LTZ group, 438 N to 3,487 N in the HTZ group, and 1,030 N to 1,431 N in the LDS group. The load at fracture of HTZ and LTZ crowns was equal. The load at fracture of yttria-stabilized tetragonal zirconia polycrystals crowns was significantly greater than LDS crowns (P = 0.000). Two types of fractures were recorded; complete and partial crack-like fracture. The crack type fracture occurred most frequently in all groups except in the thicker LTZ groups (1.0 mm and 1.5 mm). According to this study, there is no difference in strength between crowns made of high-translucent or low-translucent zirconia. At equal thickness, the strength of zirconia crowns was significantly greater than that of lithium-disilicate glass-ceramic. PMID:26369491

  3. Archimedes and the Golden Crown

    ERIC Educational Resources Information Center

    Thompson, Frank

    2008-01-01

    Archimedes (287-212 BC) is well known for his explanation of buoyancy, and in particular for his "eureka" moment. This experiment uses his density measurement method to find the purity of gold, and additional confirmation of the findings are given by x-ray fluorescence. (Contains 4 figures and 1 table.)

  4. Research on work roll thermal crown in cold rolling mill

    NASA Astrophysics Data System (ADS)

    Song, Lei; Shen, Mingang; Chen, Xuebo; Wang, Junsheng

    2013-05-01

    The factors which have influence on the work roll thermal crown in cold strip rolling are discussed. The heat transferring in three directions (radial axis and circumference) were considered for calculating the work roll thermal deformation. Therefore, it is a three dimensions unstable system for the work roll temperature calculation. The plastic deformation work and friction heat are calculated by the divided element and digital integration method. The simplified calculation model is built for the heat transferring along work roll. There are four zones for work roll heat transferring: roll gap zone air cooling zone emulsion zone rolls contact zone. The heat transferring between the zones is decided by the temperature difference. The inter temperature field and thermal deformation of work roll can be calculated by two-dimension finite difference method. The work roll temperature and thermal crown of actual application cold rolling mill are analyzed by the model. By the comparison between calculated values and measured values, the work roll thermal calculation model can meet the accuracy requirement of on-line control.

  5. The characterization of the hole-contour and plume ejection in the laser drilling with various inclination angles

    NASA Astrophysics Data System (ADS)

    Yao, Kuan-Chung; Lin, Jehnming

    2013-06-01

    The contours of the drilling-hole for the laser drilling at various inclination angles were investigated in this study. A simple model was proposed to estimate the drilling-hole shape and it was verified with experiments in pulsed laser drilling process. The contour dimensions of the drilling hole are significantly affected by laser power and inclination angle, and there is a good agreement between the simulation and measurement. Furthermore the laser induced plume on the graphite substrate heated by a Nd-YAG pulsed laser at various inclination angles was visualized experimentally. It can be found that the plume ejection is mainly normal to the substrate surface without the shielding gas.

  6. Comparison of trace element concentrations in grey heron and black-crowned night heron chicks.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2015-01-01

    Cadmium (Cd), lead (Pb), manganese (Mn), zinc (Zn), and iron (Fe) concentrations were measured in the prey and liver of grey heron (Ardea cinerea) and black-crowned night heron (Nycticorax nycticorax) chicks (24-26 days after hatching) at the Pyeongtaek colony, Korea in 2001 (n = 10, respectively) and 2008 (n = 11 and n = 10). Cadmium and Pb concentrations in livers of grey heron (Cd geomean 0.06, Pb 3.90 μg/g dw) and black-crowned night heron (Cd 0.20, Pb 4.24 μg/g dw) chicks were increased with diet concentrations of grey heron (Cd 0.18, Pb 1.76 μg/g dw) and black-crowned night heron (Cd 0.20, Pb 3.96 μg/g dw) chicks. Cadmium and Pb concentrations in prey items of grey heron and black-crowned night heron chicks were a good predictor of chick liver concentrations. Cadmium concentrations in livers of both heron species collected at the Pyeongtaek heronry were relatively low and within the background level (<3 μg/g dw) for birds. Five of 20 (25.0%) grey heron and 4 of 18 (22.2%) black-crowned night heron chicks were higher than the background level for lead (>6 μg/g dw). Prey Cd and Pb concentrations were within the range of other heron and egret studies. Manganese, Zn, and Fe concentrations in grey heron and black-crowned night heron chicks were within the background or normal physiological levels reported earlier in other birds including herons and egrets. PMID:25410946

  7. Critical inclination for absolute/convective instability transition in inverted falling films

    NASA Astrophysics Data System (ADS)

    Scheid, Benoit; Kofman, Nicolas; Rohlfs, Wilko

    2016-04-01

    Liquid films flowing down the underside of inclined plates are subject to the interaction between the hydrodynamic and the Rayleigh-Taylor (R-T) instabilities causing a patterned and wavy topology at the free surface. The R-T instability results from the denser liquid film being located above a less dense ambient gas, and deforming into an array of droplets, which eventually drip if no saturation mechanism arises. Such saturation mechanism can actually be provided by a fluid motion along the inclined plate. Using a weighted integral boundary layer model, this study examines the critical inclination angle, measured from the vertical, that separates regimes of absolute and convective instability. If the instability is of absolute type, growing perturbations stay localized in space potentially leading to dripping. If the instability is of convective type, growing perturbations move downwards the inclined plate, forming waves and eventually, but not necessarily, droplets. Remarkably, there is a minimum value of the critical angle below which a regime of absolute instability cannot exist. This minimum angle decreases with viscosity: it is about 85° for water, about 70° for silicon oil 20 times more viscous than water, and reaches a limiting value for liquid with a viscosity larger than about 1000 times the one of water. It results that for any fluid, absolute dripping can only exist for inclination angle (taken from the vertical) larger than 57.4°.

  8. Unsteady granular flows down an inclined plane.

    PubMed

    Parez, Stanislav; Aharonov, Einat; Toussaint, Renaud

    2016-04-01

    The continuum description of granular flows is still a challenge despite their importance in many geophysical and industrial applications. We extend previous works, which have explored steady flow properties, by focusing on unsteady flows accelerating or decelerating down an inclined plane in the simple shear configuration. We solve the flow kinematics analytically, including predictions of evolving velocity and stress profiles and the duration of the transient stage. The solution shows why and how granular materials reach steady flow on slopes steeper than the angle of repose and how they decelerate on shallower slopes. The model might facilitate development of natural hazard assessment and may be modified in the future to explore unsteady granular flows in different configurations. PMID:27176375

  9. Unsteady granular flows down an inclined plane

    NASA Astrophysics Data System (ADS)

    Parez, Stanislav; Aharonov, Einat; Toussaint, Renaud

    2016-04-01

    The continuum description of granular flows is still a challenge despite their importance in many geophysical and industrial applications. We extend previous works, which have explored steady flow properties, by focusing on unsteady flows accelerating or decelerating down an inclined plane in the simple shear configuration. We solve the flow kinematics analytically, including predictions of evolving velocity and stress profiles and the duration of the transient stage. The solution shows why and how granular materials reach steady flow on slopes steeper than the angle of repose and how they decelerate on shallower slopes. The model might facilitate development of natural hazard assessment and may be modified in the future to explore unsteady granular flows in different configurations.

  10. [Gdansk combined crown with occlusal rest. 1. Clinical and laboratory preparation of combined crown with occlusal rest on the basis of cast crown].

    PubMed

    Tejchman, H; Czerwińska, W

    1990-01-01

    The combined crown used since many years in the Prosthetic Laboratory, Institute of Stomatology, Medical Academy in Gdańsk contains an occlusal rest basis of a cast crown (the metal part is of a gold alloy or chromium-nickel steel, with veneer of acrylateor Colorstat) provides, owing to a special preparation of the abutment tooth and laboratory procedure, full stabilization of the crown, protection of parodontium and good maintenance of the veneer which plays a cosmetic role in this type of crown. The combined crowns with occlusal rest are particularly suitable for supporting bridgeworks. They may be applied onto devitalized or live teeth since they require less extensive grinding of teeth. PMID:2103019

  11. Enhanced photovoltaic performance of an inclined nanowire array solar cell.

    PubMed

    Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

    2015-11-30

    An innovative solar cell based on inclined p-i-n nanowire array is designed and analyzed. The results show that the inclined geometry can sufficiently increase the conversion efficiency of solar cells by enhancing the absorption of light in the active region. By tuning the nanowire array density, nanowire diameter, nanowire length, as well as the proportion of intrinsic region of the inclined nanowire solar cell, a remarkable efficiency in excess of 16% can be obtained in GaAs. Similar results have been obtained in InP and Si nanowire solar cells, demonstrating the universality of the performance enhancement of inclined nanowire arrays. PMID:26698807

  12. Detection of very inclined showers with the Auger Observatory

    SciTech Connect

    Nellen, Lukas; /Mexico U., ICN

    2005-07-01

    The Pierre Auger Observatory can detect air showers with high efficiency at large zenith angles with both the fluorescence and surface detectors. Since half the available solid angle corresponds to zeniths between 60 and 90 degrees, a large number of inclined events can be expected and are indeed observed. In this paper, we characterize the inclined air showers detected by the Observatory and we present the aperture for inclined showers and an outlook of the results that can be obtained in future studies of the inclined data set.

  13. Fiber optic inclination detector system having a weighted sphere with reference points

    DOEpatents

    Cwalinski, Jeffrey P.

    1995-01-01

    A fiber optic inclination detector system for determining the angular displacement of an object from a reference surface includes a simple mechanical transducer which requires a minimum number of parts and no electrical components. The system employs a single light beam which is split into two light beams and provided to the transducer. Each light beam is amplitude modulated upon reflecting off the transducer to detect inclination. The power values associated with each of the reflected light beams are converted by a pair of photodetectors into voltage signals, and a microprocessor manipulates the voltage signals to provide a measure of the angular displacement between the object and the reference surface.

  14. Alveolar bone thickness around maxillary central incisors of different inclination assessed with cone-beam computed tomography

    PubMed Central

    Liu, Fang; Sun, Hong-jing; Lv, Pin; Cao, Yu-ming; Yu, Mo; Yue, Yang

    2015-01-01

    Objective To assess the labial and lingual alveolar bone thickness in adults with maxillary central incisors of different inclination by cone-beam computed tomography (CBCT). Methods Ninety maxillary central incisors from 45 patients were divided into three groups based on the maxillary central incisors to palatal plane angle; lingual-inclined, normal, and labial-inclined. Reformatted CBCT images were used to measure the labial and lingual alveolar bone thickness (ABT) at intervals corresponding to every 1/10 of the root length. The sum of labial ABT and lingual ABT at the level of the root apex was used to calculate the total ABT (TABT). The number of teeth exhibiting alveolar fenestration and dehiscence in each group was also tallied. One-way analysis of variance and Tukey's honestly significant difference test were applied for statistical analysis. Results The labial ABT and TABT values at the root apex in the lingual-inclined group were significantly lower than in the other groups (p < 0.05). Lingual and labial ABT values were very low at the cervical level in the lingual-inclined and normal groups. There was a higher prevalence of alveolar fenestration in the lingual-inclined group. Conclusions Lingual-inclined maxillary central incisors have less bone support at the level of the root apex and a greater frequency of alveolar bone defects than normal maxillary central incisors. The bone plate at the marginal level is also very thin. PMID:26445719

  15. Dietary exposure of the red-crowned crane (Grus japonensis) to total and methyl mercury in Zhalong Wetland, northeastern China.

    PubMed

    Luo, Jinming; Ye, Yajie; Wang, Yongjie

    2014-06-01

    To determine the dietary exposure of the migratory red-crowned crane to mercury (Hg), this study analyzed the concentrations of total mercury (T-Hg) and methyl mercury (MeHg) in its prey, i.e., reeds and three aquatic animal families (Perccottus glenni Dybowski, Cybister japonicus Sharp, and Viviparidae) in northeastern China. Results indicated that the Hg concentration in Zhalong Wetland was elevated through the food chain, and the prey of the red-crowned crane contained measurable levels of T-Hg and MeHg. In prey tissues, MeHg was the main form of the Hg element and accounted for 61% of total Hg concentration in Viviparidae, 58% in C. japonicus Sharp, and 85% in P. glenni Dybowski. The highest T-Hg and MeHg concentrations ranged from 1.66 to 3.89 ppm and from 1.12 to 2.67 ppm, respectively, and they were detected in the feathers of the red-crowned cranes. The lowest T-Hg concentration was determined in the excretions of wild red-crowned cranes at 0.21 ppm; furthermore, the content of MeHg was below the detection limit. In Zhalong Wetland, the level of dietary exposure of the population of red-crowned cranes to Hg is below the threshold of Hg toxicity. Moreover, eggshells are suitable indicators of Hg risk levels to the red-crowned crane. PMID:24793423

  16. Zirconia crowns - the new standard for single-visit dentistry?

    PubMed

    Wiedhahn, Klaus; Fritzsche, Günter; Wiedhahn, Claudine; Schenk, Olaf

    2016-01-01

    Zirconia crowns combine the advantages of metal restorations, such as minimally invasive tooth preparation and ease of cementation, with those of full ceramic crowns, such as low thermal conductivity and tooth color. With the introduction of a high-speed sintering procedure, it is possible to produce and cement zirconia crowns and small monolithic bridges in a Cerec Single Visit procedure. This new procedure is compared to established chairside methods. PMID:27027100

  17. An Overview of Preformed Metal Crowns. Part 1: Conventional Technique.

    PubMed

    Rogers, Helen J; Batley, Haris A; Deery, Chris

    2015-12-01

    This article details the clinical techniques for conventional preformed metal crown placement. It aims to increase the readers' awareness of the clinical advantages of preformed metal crowns and the indications for their use. The second part will discuss the Hall Technique. CPD/Clinical Relevance: This two-part article aims to guide the reader through the conventional and alternative techniques available for placement of a preformed metal crown whilst providing an update of the evidence for each. PMID:26855999

  18. Differences in articular-eminence inclination between medieval and contemporary human populations.

    PubMed

    Kranjčić, Josip; Vojvodić, Denis; Žabarović, Domagoj; Vodanović, Marin; Komar, Daniel; Mehulić, Ketij

    2012-08-01

    The articular-eminence inclination is an important element in the biomechanics of the temporomandibular joint and the entire masticatory system; however, very little is known about this inclination in archaeological human populations. Therefore, the aim of this study was to determine the values of, in addition to the differences between, the articular-eminence inclination in medieval and contemporary human populations. The study was carried out on two dry skull groups. The first group consisted of 14 dry skulls from the medieval culture group Bijelo Brdo (BB) of East Croatia, and the other consisted of 137 recent dry skulls from the osteologic collection of the Institute of Anatomy (IA) in Zagreb. All BB skulls were dentulous, whereas the IA skulls were divided into dentulous and edentulous groups. The articular-eminence inclination was measured in relation to the Frankfurt horizontal plane on digital images of the skull's two lateral views using AutoCAD computer software. The mean value of the articular-eminence inclination in the BB sample group (49.57°) was lower, with a statistical significance (p<0.01), than those of the IA dentulous (61.56°), the IA edentulous (62.54°), and all the combined IA (61.99°) specimens. Because the values of the articular-eminence inclination can vary a lot with reference to the number of specimens and the different methods used for measuring, the obtained values yield only orientational information. Further investigations including a larger number of medieval specimens are needed to confirm the results obtained from this study. PMID:22721644

  19. Detecting and correcting for paleomagnetic inclination shallowing of sedimentary rocks: A review

    NASA Astrophysics Data System (ADS)

    Li, Yong-Xiang; Kodama, Kenneth

    2016-02-01

    Magnetic anisotropy and the elongation/inclination (E-I) approaches have been increasingly employed as two important means for detecting and correcting the paleomagnetic inclination shallowing in sedimentary rocks that was first recognized sixty years ago. Both approaches are based on certain assumptions, and thus have advantages and intrinsic limitations in investigating shallow inclinations in sedimentary rocks. The E-I approach is relatively easy to use, but it needs a large dataset to adequately sample paleomagnetic directions due to paleosecular variation of the geomagnetic field. Also, slow sediment accumulation rates and local tectonics could lead to under- or over-corrections using the E-I approach. For the magnetic anisotropy technique, labor-intensive, sophisticated laboratory rock magnetic experiments are required in order to accurately determine both bulk magnetic anisotropy of remanence-carrying grains and magnetic anisotropy of an individual particle, i.e., "a" factor, of samples. Our review shows that, despite the intensive laboratory work necessary for applying anisotropy-based inclination corrections, it is worth investing the effort. In addition, the joint use of magnetic susceptibility and remanence anisotropy measurements as well as detailed rock magnetic measurements for determining the particle anisotropy "a" factor have the advantage of retrieving direct evidence of inclination shallowing and correcting for it with high confidence. We caution against use of either of the two approaches without full appreciation of the underlying assumptions and intrinsic limitations of each technique. The use and comparison of both techniques could provide the most robust inclination shallowing correction for sedimentary rocks.

  20. Dense inclined flows: Theory and experiments. Final report

    SciTech Connect

    Jenkins, J.T.; Louge, M.Y.

    1995-12-01

    Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum ad energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that focuses on such flows. the effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. A goal of the project is to provide a sound theoretical and experimental base for a better understanding of the behavior and properties of multiphase flow and solid transport.

  1. Inclination Dependence of Estimated Galaxy Masses and Star Formation Rates

    NASA Astrophysics Data System (ADS)

    Hernandez, Betsy; Maller, Ariyeh; McKernan, Barry; Ford, Saavik

    2016-01-01

    We examine the inclination dependence of inferred star formation rates and galaxy mass estimates in the Sloan Digital Sky Survey by combining the disk/bulge de-convolved catalog of Simard et al 2011 with stellar mass estimates catalog of Mendel et al 2014 and star formation rates measured from spectra by Brinchmann et al 2004. We know that optical star formation indicators are reddened by dust, but calculated star formation rates and stellar mass estimates should account for this. However, we find that face-on galaxies have a higher calculated average star formation rates than edge-on galaxies. We also find edge-on galaxies have ,on average, slightly smaller but similar estimated masses to face-on galaxies, suggesting that there are issues with the applied dust corrections for both models.

  2. Reliability of magnetic inclination angle determinations for pulsars

    NASA Technical Reports Server (NTRS)

    Miller, M. C.; Hamilton, Russell J.

    1993-01-01

    We compare the recent estimates of the inclination angle alpha between the rotation and magnetic axes of 56 pulsars made by both Lyne and Manchester (1988) and Rankin (1990). Their results agree reasonably well when alpha is less than about 40 deg; however, there is no correlation between the two estimates of alpha if either estimate exceeds 40 deg. The correlation is better for pulsars with beams having more complicated core structure. Nevertheless, the differences between the two sets of estimates are large enough that use of these estimates to investigate pulsar physics is questionable. We discuss the method for determining alpha based on the Radhakrishnan and Cooke (1969) single-vector model, emphasizing its sensitivity to measurement errors. This method complements the approaches of Rankin and Lyne and Manchester and is preferable when accurate polarization data are available.

  3. Quantitative characterization of clumping in Scots pine crowns

    PubMed Central

    Stenberg, Pauline; Mõttus, Matti; Rautiainen, Miina; Sievänen, Risto

    2014-01-01

    Background and Aims Proper characterization of the clumped structure of forests is needed for calculation of the absorbed radiation and photosynthetic production by a canopy. This study examined the dependency of crown-level clumping on tree size and growth conditions in Scots pine (Pinus sylvestris), and determined the ability of statistical canopy radiation models to quantify the degree of self-shading within crowns as a result of the clumping effect. Methods Twelve 3-D Scots pine trees were generated using an application of the LIGNUM model, and the crown-level clumping as quantified by the crown silhouette to total needle area ratio (STARcrown) was calculated. The results were compared with those produced by the stochastic approach of modelling tree crowns as geometric shapes filled with a random medium. Key Results Crown clumping was independent of tree height, needle area and growth conditions. The results supported the capability of the stochastic approach in characterizing clumping in crowns given that the outer shell of the tree crown is well represented. Conclusions Variation in the whole-stand clumping index is induced by differences in the spatial pattern of trees as a function of, for example, stand age rather than by changes in the degree of self-shading within individual crowns as they grow bigger. PMID:24431344

  4. Evaluation of the marginal and internal gap of metal-ceramic crown fabricated with a selective laser sintering technology: two- and three-dimensional replica techniques

    PubMed Central

    Kim, Ki-Baek; Kim, Jae-Hong; Kim, Woong-Chul; Kim, Hae-Young

    2013-01-01

    PURPOSE One of the most important factors in evaluating the quality of fixed dental prostheses (FDPs) is their gap. The purpose of this study was to compare the marginal and internal gap of two different metal-ceramic crowns, casting and selective laser sintering (SLS), before and after porcelain firing. Furthermore, this study evaluated whether metal-ceramic crowns made using the SLS have the same clinical acceptability as crowns made by the traditional casting. MATERIALS AND METHODS The 10 study models were produced using stone. The 20 specimens were produced using the casting and the SLS methods; 10 samples were made in each group. After the core gap measurements, 10 metal-ceramic crowns in each group were finished using the conventional technique of firing porcelain. The gap of the metal-ceramic crowns was measured. The marginal and internal gaps were measured by two-dimensional and three-dimensional replica techniques, respectively. The Wilcoxon signed-rank test, the Wilcoxon rank-sum test and nonparametric ANCOVA were used for statistical analysis (α=.05). RESULTS In both groups, the gap increased after completion of the metal-ceramic crown compared to the core. In all measured areas, the gap of the metal cores and metal-ceramic crowns produced by the SLS was greater than that of the metal cores and metal-ceramic crowns produced using the casting. Statistically significant differences were found between cast and SLS (metal cores and metal-ceramic crown). CONCLUSION Although the gap of the FDPs produced by the SLS was greater than that of the FDPs produced by the conventional casting in all measured areas, none exceeded the clinically acceptable range. PMID:23755345

  5. Comparison of Primary Molar Crown Dimensions with Stainless Steel Crowns in a Sample of Iranian Children

    PubMed Central

    Afshar, Hossein; Kamali Sabeti, Arghavan; Shahrabi, Mahdi

    2015-01-01

    Background and aims. Due to anatomic variation in tooth anatomy between populations, this study compared the buccolingual (BL) and mesiodistal (MD) dimensions of primary molars with those of stainless steel crowns (SSCs) in anIranian population. Materials and methods. Impressions were taken from both dental arches of children, and casts were poured. Teeth with caries, restoration, hypoplasia or other dental anomalies were excluded. 216 primary molars were selected and divided into 4 groups of 54 each (maxillary and mandibular first and second primary molars). MD/BL dimensions were measured using a digital caliper with 0.01 mm precision on casts and SCCs (3M brand). Data were assessed using paired t-test, post hoc test and ANOVA. P < 0.05 was considered statistically significant. Results. The MD dimension of the lower first molar SSC and the BL dimension of the lower second molar SSC had the least difference with the corresponding values of the respective teeth. The MD dimension of the upper second molar SSC and the BL dimension of the upper first molar SSC had the greatest difference with the corresponding values in the respective teeth. Comparison of the two different brands of SSCs for the upper first molar revealed that both types had significant differences with the teeth in terms of both MD (P = 0.0) and BL (P = 0.0) dimensions. Conclusion. In the studied population, best adaptation was seen in second lower molars and the least adaptationswere seen in first and second upper molars. PMID:26236433

  6. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  7. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  8. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  9. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  10. 46 CFR 111.01-19 - Inclination of the vessel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Inclination of the vessel. 111.01-19 Section 111.01-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS General § 111.01-19 Inclination of the vessel. (a) All electrical equipment must...

  11. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  12. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  13. Generation of highly inclined protoplanetary discs through single stellar flybys

    NASA Astrophysics Data System (ADS)

    Xiang-Gruess, M.

    2016-01-01

    We study the three-dimensional evolution of a viscous protoplanetary disc which is perturbed by a passing star on a parabolic orbit. The aim is to test whether a single stellar flyby is capable to excite significant disc inclinations which would favour the formation of so-called misaligned planets. We use smoothed particle hydrodynamics to study inclination, disc mass and angular momentum changes of the disc for passing stars with different masses. We explore different orbital configurations for the perturber's orbit to find the parameter spaces which allow significant disc inclination generation. Prograde inclined parabolic orbits are most destructive leading to significant disc mass and angular momentum loss. In the remaining disc, the final disc inclination is only below 20°. This is due to the removal of disc particles which have experienced the strongest perturbing effects. Retrograde inclined parabolic orbits are less destructive and can generate disc inclinations up to 60°. The final disc orientation is determined by the precession of the disc angular momentum vector about the perturber's orbital angular momentum vector and by disc orbital inclination changes. We propose a sequence of stellar flybys for the generation of misalignment angles above 60°. The results taken together show that stellar flybys are promising and realistic for the explanation of misaligned Hot Jupiters with misalignment angles up to 60°.

  14. 40. CONSTRUCTION OF GALLERY NO. 3, SHOWING INCLINED PLANE USED ...

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

    40. CONSTRUCTION OF GALLERY NO. 3, SHOWING INCLINED PLANE USED TO TRANSPORT MATERIALS, ALSO SPOIL FROM TUNNEL INTERIOR. POWDER HOUSE AND TOOL SHED VISIBLE TO RIGHT OF BASE INCLINE - Zion-Mount Carmel Highway, Tunnel, Two miles east of Zion Canyon Scenic Drive, Springdale, Washington County, UT

  15. 3. Inclined Plane 10, 1970. Track bed at left. View ...

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

    3. Inclined Plane 10, 1970. Track bed at left. View some what similar to that of NJ-30-2. Stone track bed is visible under cable system of NJ-30-2. - Morris Canal, Inclined Plane 10 West, Phillipsburg, Warren County, NJ

  16. 7. VIEW WEST, PERSPECTIVE VIEW OF TOP OF INCLINED PLANE ...

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

    7. VIEW WEST, PERSPECTIVE VIEW OF TOP OF INCLINED PLANE AND EAST FACE OF CUT STONE TOWER - Laurel Hill Quarry, Incline Plane, Both sides of State Route 56, 2.4 miles East of State Route 711, Seward, Westmoreland County, PA

  17. Gaining Momentum: Re-Creating Galileo's Inclined Plane.

    ERIC Educational Resources Information Center

    Albrecht, Bob; Firedrake, George

    1998-01-01

    Provides an excerpt of Galileo's description of his inclined plane experiment. Describes the replication of Galileo's inclined plane experiment by students at Rice University (Texas) using an Internet site called the Galileo Project; then describes the authors' replication of the Project. (AEF)

  18. A New Dynamics Cart on an Inclined Plane.

    ERIC Educational Resources Information Center

    Theodorsson, Pall

    1995-01-01

    Presents an experiment to study the acceleration of a cart moving up and down an inclined plane. Demonstrates how multitiming and the study of the movement in both directions allows the determination of the component of gravitational force along an inclined plane without any assumptions about friction. (JRH)

  19. Operational Experiences in Planning and Reconstructing Aqua Inclination Maneuvers

    NASA Technical Reports Server (NTRS)

    Rand, David; Reilly, Jacqueline; Schiff, Conrad

    2004-01-01

    As the lead satellite in NASA's growing Earth Observing System (EOS) PM constellation, it is increasingly critical that Aqua maintain its various orbit requirements. The two of interest for this paper are maintaining an orbit inclination that provides for a consistent mean local time and a semi-major Axis (SMA) that allows for ground track repeatability. Maneuvers to adjust the orbit inclination involve several flight dynamics constraints and complexities which make planning such maneuvers challenging. In particular, coupling between the orbital and attitude degrees of freedom lead to changes in SMA when changes in inclination are effected. A long term mission mean local time trend analysis was performed in order to determine the size and placement of the required inclination maneuvers. Following this analysis, detailed modeling of each burn and its Various segments was performed to determine its effects on the immediate orbit state. Data gathered from an inclination slew test of the spacecraft and first inclination maneuver uncovered discrepancies in the modeling method that were investigated and resolved. The new modeling techniques were applied and validated during the second spacecraft inclination maneuver. These improvements should position Aqua to successfully complete a series of inclination maneuvers in the fall of 2004. The following paper presents the events and results related

  20. 46 CFR 58.01-40 - Machinery, angles of inclination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery, angles of inclination. 58.01-40 Section 58.01... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-40 Machinery, angles of inclination. (a) Propulsion machinery and all auxiliary machinery essential to the propulsion and safety of the vessel must...

  1. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  2. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  3. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  4. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  5. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  6. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  7. 30 CFR 56.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Inclined conveyors: backstops or brakes. 56.14113 Section 56.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to prevent...

  8. 30 CFR 57.14113 - Inclined conveyors: backstops or brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Inclined conveyors: backstops or brakes. 57.14113 Section 57.14113 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR...: backstops or brakes. Backstops or brakes shall be installed on drive units of inclined conveyors to...

  9. [Adhesive strengths of cast crowns with various types of cements].

    PubMed

    Utz, K H; Grüner, M; Büscher, M

    1990-12-01

    In an in vitro study the adhesive strength of sand-blasted castings (gold alloy) was tested on human teeth prepared and finished in different ways. For cementation we used two glass ionomer and one phosphate cement. On the surfaces treated with carbide finishing instruments the force required for separating the crown from the tooth was about 1.9 N/mm2 for Ketac-cem, about 2 N/mm2 for Fuji Ionomer, and about 1.8 N/mm2 for Harvard (a zinc oxide phosphate cement). Compared with this, the values obtained for dentin surfaces pretreated with fine diamonds (red ring) were 1.5 N/mm2 for Ketac-cem, 1.6 N/mm2 for Fuji Ionomer, and 1.9 N/mm2 for Harvard. The measured differences between the various types of cement were statistically not significant. PMID:2135267

  10. Rainforest air-conditioning: the moderating influence of epiphytes on the microclimate in tropical tree crowns

    NASA Astrophysics Data System (ADS)

    Stuntz, Sabine; Simon, Ulrich; Zotz, Gerhard

    2002-05-01

    Epiphytes are often assumed to influence the microclimatic conditions of the tree crowns that they inhabit. In order to quantify this notion, we measured the parameters "temperature" (of the substrate surface and the boundary layer of air above it), "evaporative drying rate" and "evapotranspiration" at various locations within tree crowns with differing epiphyte assemblages. The host tree species was Annona glabra, which was either populated by one of three epiphyte species ( Dimerandra emarginata, Tillandsia fasciculata, or Vriesea sanguinolenta) or was epiphyte-free. We found that during the hottest and driest time of day, microsites in the immediate proximity of epiphytes had significantly lower temperatures than epiphyte-bare locations within the same tree crown, even though the latter were also shaded by host tree foliage or branches. Moreover, water loss through evaporative drying at microsites adjacent to epiphytes was almost 20% lower than at exposed microsites. We also found that, over the course of several weeks, the evapotranspiration in tree crowns bearing epiphytes was significantly lower than in trees without epiphytes. Although the influence of epiphytes on temperature extremes and evaporation rates is relatively subtle, their mitigating effect could be of importance for small animals like arthropods inhabiting an environment as harsh and extreme as the tropical forest canopy.

  11. Functional implications of variation in tooth spacing and crown size in pinnipedimorpha (mammalia: carnivora).

    PubMed

    Churchill, Morgan; Clementz, Mark T

    2015-05-01

    Pinnipeds (seals, sea lions, and walruses) show variation in tooth morphology that relates to ecology. However, crown size and spacing are two aspects of morphology that have not been quantified in prior studies. We measured these characters for nearly all extant pinnipeds and three fossil taxa and then determined the principal sources of variation in tooth size and spacing using principal components (PCAs) and hierarchical cluster analysis (HCA). PCA and HCA showed that species sorted into three groups: taxa with small crowns and large diastemata, taxa with large crowns and small diastemata, and taxa that fell between these two extremes. We then performed discriminant function analysis (DFA) to determine if tooth morphology correlated with foraging strategy or diet. DFA results indicated weak correlation with diet, and stronger correlation with prey capture strategies. Tooth size and spacing were most strongly correlated with the importance of teeth in prey acquisition, with tooth size decreasing and tooth spacing increasing as teeth become less necessary in capturing food items. Taxa which relied on teeth for filtering prey from the water column or processing larger or tougher food items generally had larger crowns and smaller tooth spacing then taxa which swallowed prey whole. We found the fossil taxa Desmatophoca and Enaliarctos were most similar in tooth morphology to extant otariids, suggesting that both taxa were generalist feeders. This study established the relationship between tooth size and feeding behavior, and provides a new tool to explore the paleoecology of fossil pinnipeds and other aquatic tetrapods. PMID:25367223

  12. Retention of gold alloy crowns cemented with traditional and resin cements.

    PubMed

    Pinzón, Lilliam M; Frey, Gary N; Winkler, Mark M; Tate, William H; Burgess, John O; Powers, John M

    2009-01-01

    The aim of this study was to measure in vitro retention of cast gold crowns cemented with traditional and resin cements. Forty-eight human molars were prepared on a lathe to produce complete crown preparations with a consistent taper and split into six groups, eight crowns in each group. Crowns were cast in a high-gold alloy and then cemented. After 24 hours, the retention force (N) was recorded and mean values were analyzed by one-way analysis of variance and the Fisher post-hoc least significant difference (PLSD) multiple comparisons test (a = .05). Failure sites were examined under 3100 magnification and recorded. Mean values (SD) for each group in increasing order of retention force were: Harvard Cement: 43 N (27), TempoCem: 59 N (16), PermaCem Dual: 130 N (42), RelyX Luting Cement: 279 N (26), Contax and PermaCem Dual: 286 N (38), and TempoCem with Contax and PermaCem Dual: 340 N (14). The Fisher PLSD interval (P = .05) for comparing cements was 29 N. Zinc-phosphate cement and provisional resin cements had the lowest retention forces. Resin cement with a bonding agent and the hybrid-ionomer cement had similar retention forces. Resin cement with a bonding agent applied after use of a provisional resin cement had a significantly higher retention force than the other cements tested. PMID:19639070

  13. Micro-CT evaluation of the marginal fit of CAD/CAM all ceramic crowns

    NASA Astrophysics Data System (ADS)

    Brenes, Christian

    Objectives: Evaluate the marginal fit of CAD/CAM all ceramic crowns made from lithium disilicate and zirconia using two different fabrication protocols (model and model-less). METHODS: Forty anterior all ceramic restorations (20 lithium disilicate, 20 zirconia) were fabricated using a CEREC Bluecam scanner. Two different fabrication methods were used: a full digital approach and a printed model. Completed crowns were cemented and marginal gap was evaluated using Micro-CT. Each specimen was analyzed in sagittal and trans-axial orientations, allowing a 360° evaluation of the vertical and horizontal fit. RESULTS: Vertical measurements in the lingual, distal and mesial views had and estimated marginal gap from 101.9 to 133.9 microns for E-max crowns and 126.4 to 165.4 microns for zirconia. No significant differences were found between model and model-less techniques. CONCLUSION: Lithium disilicate restorations exhibited a more accurate and consistent marginal adaptation when compared to zirconia crowns. No statistically significant differences were observed when comparing model or model-less approaches.

  14. UNBIASED INCLINATION DISTRIBUTIONS FOR OBJECTS IN THE KUIPER BELT

    SciTech Connect

    Gulbis, A. A. S.; Elliot, J. L.; Adams, E. R.; Benecchi, S. D.; Buie, M. W.; Trilling, D. E.; Wasserman, L. H. E-mail: jle@mit.ed E-mail: lhw@lowell.ed E-mail: buie@boulder.swri.ed

    2010-08-15

    Using data from the Deep Ecliptic Survey (DES), we investigate the inclination distributions of objects in the Kuiper Belt. We present a derivation for observational bias removal and use this procedure to generate unbiased inclination distributions for Kuiper Belt objects (KBOs) of different DES dynamical classes, with respect to the Kuiper Belt plane. Consistent with previous results, we find that the inclination distribution for all DES KBOs is well fit by the sum of two Gaussians, or a Gaussian plus a generalized Lorentzian, multiplied by sin i. Approximately 80% of KBOs are in the high-inclination grouping. We find that Classical object inclinations are well fit by sin i multiplied by the sum of two Gaussians, with roughly even distribution between Gaussians of widths 2.0{sup +0.6}{sub -0.5}{sup 0} and 8.1{sup +2.6}{sub -2.1}{sup 0}. Objects in different resonances exhibit different inclination distributions. The inclinations of Scattered objects are best matched by sin i multiplied by a single Gaussian that is centered at 19.1{sup +3.9}{sub -3.6}{sup 0} with a width of 6.9{sup +4.1}{sub -2.7}{sup 0}. Centaur inclinations peak just below 20{sup 0}, with one exceptionally high-inclination object near 80{sup 0}. The currently observed inclination distribution of the Centaurs is not dissimilar to that of the Scattered Extended KBOs and Jupiter-family comets, but is significantly different from the Classical and Resonant KBOs. While the sample sizes of some dynamical classes are still small, these results should begin to serve as a critical diagnostic for models of solar system evolution.

  15. Machining accuracy of crowns by CAD/CAM system using TCP/IP: influence of restorative material and scanning condition.

    PubMed

    Tomita, Sachiko; Shin-ya, Akiyoshi; Gomi, Harunori; Shin-ya, Akikazu; Yokoyama, Daiichiro

    2007-07-01

    The purpose of this study was to determine the optimal condition for fabricating accurate crowns efficiently using an internet-based CAD/CAM system. The influences of three different CAD/CAM restorative materials (titanium, porcelain, and composite resin) and three different step-over scanning distances (0.01 mm, 0.11 mm, and 0.21 mm) were evaluated, and their interactive effects were carefully examined. Several points on the inner and outer surfaces of machined crowns - as well as height - were measured. These measurements were then compared with the original models, from which machining accuracy was obtained. At all measuring points, the inner surface of all crowns was machined larger than the die model, whereas the cervical area of porcelain crown was machined smaller than the crown model. Results of this study revealed that a step-over distance of 0.11 mm was an optimal scanning condition, taking into consideration the interactive effects of scanning time required, data volume, and machining accuracy. PMID:17886460

  16. Extracting the inclination angle of nerve fibers within the human brain with 3D-PLI independent of system properties

    NASA Astrophysics Data System (ADS)

    Reckfort, Julia; Wiese, Hendrik; Dohmen, Melanie; Grässel, David; Pietrzyk, Uwe; Zilles, Karl; Amunts, Katrin; Axer, Markus

    2013-09-01

    The neuroimaging technique 3D-polarized light imaging (3D-PLI) has opened up new avenues to study the complex nerve fiber architecture of the human brain at sub-millimeter spatial resolution. This polarimetry technique is applicable to histological sections of postmortem brains utilizing the birefringence of nerve fibers caused by the regular arrangement of lipids and proteins in the myelin sheaths surrounding axons. 3D-PLI provides a three-dimensional description of the anatomical wiring scheme defined by the in-section direction angle and the out-of-section inclination angle. To date, 3D-PLI is the only available method that allows bridging the microscopic and the macroscopic description of the fiber architecture of the human brain. Here we introduce a new approach to retrieve the inclination angle of the fibers independently of the properties of the used polarimeters. This is relevant because the image resolution and the signal transmission inuence the measured birefringent signal (retardation) significantly. The image resolution was determined using the USAF- 1951 testchart applying the Rayleigh criterion. The signal transmission was measured by elliptical polarizers applying the Michelson contrast and histological slices of the optic tract of a postmortem brain. Based on these results, a modified retardation-inclination transfer function was proposed to extract the fiber inclination. The comparison of the actual and the inclination angles calculated with the theoretically proposed and the modified transfer function revealed a significant improvement in the extraction of the fiber inclinations.

  17. Development and characterization of an inclined quad-vortex range hood.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Lee, Ji-Heng

    2013-11-01

    In order to increase containment efficiency and reduce energy consumption, an inclined quad-vortex range hood (IQV range hood) was developed and tested by experimental methods. The flow structure was observed by a laser-assisted flow visualization technique and laser Doppler velocimetry (LDV). Leakage characteristics were measured by the tracer gas (sulfur hexafluoride) detection method. By arranging a narrow suction slot on the bottom face of the hood and two side plates hanging under lateral faces of the hood, a flow field featuring four backwards-inclined vortical flow structures was formed at suction velocities of larger than about 10 m s(-1) (suction flow rate 7.2 m(3) min(-1)). Oil mists were coherently contained in the vortical flow structures without observable dispersion out of the vortices; they rose up spirally with inclination towards the rear wall and were inducted into the suction slot. The backwards inclination of the oil-mist-containing vortical flow structures, caused by the backwards offset arrangement of the suction slot and the Coanda effect, benefited from the reduction in pollutant leakage induced by the influence of a mannequin's presence. Experimental results using the tracer gas concentration detection method showed a close correlation with the results from the flow visualization and LDV measurements. Under both occupied and unoccupied conditions, in which the mannequin was either present or not present, the IQV range hood provided low SF6 leakage concentration levels. PMID:23831934

  18. Evaluation of wild Juglans species for crown gall resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paradox, the most widely used rootstock in CA walnut production, is highly susceptible to the causal agent of crown gall (CG) Agrobacterium tumefaciens. The bacterial pathogen induces the formation of large tumors around the crown of the tree resulting in a reduction in both vigor and yield. If left...

  19. Management of Rhizoctonia root and crown rot of subarbeet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root and crown rot is caused by the fungus Rhizoctonia solani and is one of the most severe soil-borne diseases of sugarbeet in Minnesota and North Dakota. Rhizoctonia root and crown rot may reduce yield significantly, and diseased beets may cause problems in storage piles. Fields with...

  20. Estimating canine tooth crown height in early Australopithecus.

    PubMed

    Plavcan, J Michael; Ward, Carol V; Paulus, Faydre L

    2009-07-01

    Canine tooth size reduction and the associated reduction in canine dimorphism is a basal hominin character that also provides important evidence for models of behavioral evolution. Two specimens of Australopithecus anamensis (KNM-KP 29287 and KNM-KP 29283) that do not preserve the canine crown, but do preserve the root or alveolus, appear to suggest that canine size variation and canine dimorphism in this species may have been greater than in other hominins. We evaluate canine root and crown dimensions in a series of extant hominoids, and estimate canine crown height in Australopithecus afarensis and A. anamensis. Our results demonstrate that it is possible to generate estimates of canine crown height from basal canine crown and root dimensions with a moderate degree of accuracy. Estimates of maxillary canine crown size for A. anamensis are slightly larger than those of A. afarensis, and are approximately the same size as canines of modern female chimpanzees. Estimated mandibular canine crown height is very similar in the two species. Variation within the A. anamensis sample of estimated canine crown heights is similar to that of modern humans, suggesting a low degree of sexual dimorphism. Inclusion of estimates for KNM-KP 29287 and KNM-KP 29283 does not substantially increase either the estimate of overall canine size or variation for A. anamensis. PMID:19482334

  1. Using 15-crown-5, 18-crown-6 and dicyclohexano-18-crown-6 for Am, Ce, Eu and Cm extraction from acid solutions

    SciTech Connect

    Romanovski, V.V.; Proyaev, V.V.; Wester, D.W.

    1994-08-01

    The extraction from nitric acid of Am, Eu, Ce, Cm(III) tracers by 15-crown-5 (15C5), 18-crown-6 (18C6), dicyclohexano-18-crown-6 (DCH18C6) as well as mixtures of crown ethers and chlorinated cobalt dicarbollide (ChCoD) in nitrobenzene solutions has been investigated. It was revealed that 18C6 is selective for Ce, Am and Cm compared with Eu. The addition of 18C6 to a solution of ChCoD allows Am and Cm to be separated from lanthanides by using this extractant more efficiently. The separation factors of Ce, Am, Cm and Eu are increased as a function of the ionic strength of the aqueous phase for extraction by mixtures of 18C6 and ChCoD and of DCH18C6 and ChCoD.

  2. Oscillations of relative inclination angles in compact extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Adams, Fred C.

    2016-01-01

    The Kepler mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the inferred orbits. A large fraction of the observational sample contains limited multiplicity, begging the question whether there is a true diversity of multitransiting systems, or if some systems merely possess high mutual inclinations, allowing them to appear as single-transiting systems in a transit-based survey. This paper begins an exploration of the effectiveness of dynamical mechanisms in exciting orbital inclination within exoplanetary systems of this class. For these tightly packed systems, we determine that the orbital inclination angles are not spread out appreciably through self-excitation. In contrast, the two Kepler multiplanet systems with additional non-transiting planets are susceptible to oscillations of their inclination angles, which means their currently observed configurations could be due to planet-planet interactions alone. We also provide constraints and predictions for the expected transit duration variations for each planet. In these multiplanet compact Kepler systems, oscillations of their inclination angles are remarkably hard to excite; as a result, they tend to remain continually mutually transiting (CMT-stable). We study this issue further by augmenting the planet masses and determining the enhancement factor required for oscillations to move the systems out of transit. The oscillations of inclination found here inform the recently suggested dichotomy in the sample of Solar systems observed by Kepler.

  3. Size Distribution of Main-Belt Asteroids with High Inclination

    NASA Astrophysics Data System (ADS)

    Terai, Tsuyoshi; Itoh, Yoichi

    2011-04-01

    We investigated the size distribution of high-inclination main-belt asteroids (MBAs) so as to explore asteroid collisional evolution under hypervelocity collisions of around 10 km s-1. We performed a wide-field survey for high-inclination sub-km MBAs using the 8.2-m Subaru Telescope with the Subaru Prime Focus Camera (Suprime-Cam). Suprime-Cam archival data were also used. A total of 616 MBA candidates were detected in an area of 9.0 deg² with a limiting magnitude of 24.0 mag in the SDSS r filter. Most of the candidate diameters were estimated to be smaller than 1 km. We found a scarcity of sub-km MBAs with high inclination. Cumulative size distributions (CSDs) were constructed using Subaru data and published asteroid catalogs. The power-law indexes of the CSDs were 2.17±0.02 for low-inclination (<15°) MBAs and 2.02±0.03 for high-inclination (>15°) MBAs in the 0.7-50 km diameter range. The high-inclination MBAs had a shallower CSD. We also found that the CSD of S-like MBAs had a small slope with high inclination, whereas the slope did not vary with the inclination in the C-like group. The most probable cause of the shallow CSD of the high-inclination S-like MBAs is the large power-law index in the diameter-impact strength curve in hypervelocity collisions. The collisional evolution of MBAs may have advanced with oligopolistic survival during the dynamical excitation phase in the final stage of planet formation.

  4. Effects of Added Salts on Surface Tension and Aggregation of Crown Ether Surfactants.

    PubMed

    Suzuki, Maki; Fujio, Katsuhiko

    2016-01-01

    Two crown ether surfactants, dodecanoyloxymethyl- (C11Φ6) and octanoyloxymethyl-18-crown-6 (C7Φ6), were synthesized and the surface tension dependence on surfactant concentration of their aqueous solutions was measured both in the absence and presence of alkali chlorides to confirm the critical micelle concentration (CMC) is highest for the added cation that have an ionic diameter comparable to the hole size of the crown ether ring and that several break points on the surface tension vs. concentration curves occur for these crown ether surfactants. For C11Φ6 and C7Φ6, in the absence of salt, the surface tension vs. concentration curves had two break points. Using the solubilization of a water-insoluble dye as an indicator, we found that the break point at the higher concentration (m0) for C7Φ6 was due to micelle formation. Two break points were also observed for the aqueous solution of C11Φ6 in the presence of NaCl, KCl, RbCl, and CsCl salts at concentrations of 0.22 mol kg(-1) and for C7Φ6 with 0.22 mol kg(-1) KCl added. The CMC (m0) was found to be the highest for solutions containing K(+) salts because K(+) has an ionic diameter comparable to the hole size of 18-crown-6 ring. Furthermore, the CMC decreased as the ionic diameters of the added cations deviated from the hole size. The molecular areas at two break points, estimated by the Gibbs adsorption isotherm, except for that at the break point at mI of C7Φ6, were very small for an adsorbed monolayer. Further investigation is required to elucidate the reason for the break point at mI. PMID:26666275

  5. The interaction between ketamine and some crown ethers in common organic solvents studied by NMR: The effect of donating atoms and ligand structure

    NASA Astrophysics Data System (ADS)

    Chekin, Fereshteh; Bordbar, Maryam; Fathollahi, Yaghoub; Alizadeh, Naader

    2006-02-01

    1H NMR spectroscopy was used to investigate the stoichiometry and stability of the drug ketamine cation complexes with some crown ethers, such as 15-crown-5 (15C5), aza-15-crown-5 (A15C5), 18-crown-6 (18C6), aza-18-crown-6 (A18C6), diaza-18-crown-6 (DA18C6), dibenzyl-diaza-18-crown-6 (DBzDA18C6) and cryptant [2,2,2] (C222) in acetonitrile (AN), dimethylsulfoxide (DMSO) and methanol (MeOH) at 27 °C. In order to evaluate the formation constants of the ketamine cation complexes, the CH 3 protons chemical shift (on the nitrogen atom of ketamine) was measured as function of ligand/ketamine mole ratio. The formation constant of resulting complexes were calculated by the computer fitting of chemical shift versus mole ratio data to appropriate equations. A significant chemical shift variation was not observed for 15C5 and 18C6. The stoichiometry of the mono aza and diaza ligands are 1:1 and 1:2 (ligand/ketamine), respectively. In all of the solvents studied, DA18C6 formed more stable complexes than other ligands. The solvent effect on the stability of these complexes is discussed.

  6. Maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width groups

    PubMed Central

    Shahid, Fazal; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli

    2015-01-01

    Objective: To investigate the maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width (intercanine, interpremolar, and intermolar) groups. Materials and Methods: The calculated sample size was 128 subjects. The crown width/height, arch length, arch perimeter, and arch width of the maxilla and mandible were obtained via digital calliper (Mitutoyo, Japan). A total of 4325 variables were measured. The sex differences in the crown width and height were evaluated. Analysis of variance was applied to evaluate the differences between arch length, arch perimeter, and arch width groups. Results: Males had significantly larger mean values for crown width and height than females (P ≤ 0.05) for maxillary and mandibular arches, both. There were no significant differences observed for the crown width/height ratio in various arch length, arch perimeter, and arch width (intercanine, interpremolar, and intermolar) groups (P ≤ 0.05) in maxilla and mandible, both. Conclusions: Our results indicate sexual disparities in the crown width and height. Crown width and height has no significant relation to various arch length, arch perimeter, and arch width groups of maxilla and mandible. Thus, it may be helpful for orthodontic and prosthodontic case investigations and comprehensive management. PMID:26929686

  7. Crowns and other extra-coronal restorations: try-in and cementation of crowns.

    PubMed

    Wassell, R W; Barker, D; Steele, J G

    2002-07-13

    Having successfully negotiated the planning, preparation, impression and prescription of your crown, the cementation stage represents the culmination of all your efforts. This stage is not difficult, but a successful outcome needs as much care as the preceding stages. Once a restoration is cemented there is no scope for modification or repeat You have to get it right first time. Decemented crowns often have thick layers of residual cement suggesting problems with either initial seating or cement handling. When the fate of restorations costing hundreds of pounds depends on correct proportioning of cements and the quality of the mix, the value of a well-trained and experienced dental nurse is easy to see. Both dentist and nurse need a working knowledge of the materials they are handling. PMID:12171196

  8. Simple Model of a Rolling Water-Filled Bottle on an Inclined Ramp

    NASA Astrophysics Data System (ADS)

    Lin, Shihao; Hu, Naiwen; Yao, Tianchen; Chu, Charles; Babb, Simona; Cohen, Jenna; Sangiovanni, Giana; Watt, Summer; Weisman, Danielle; Klep, James; Walecki, Wojciech J.; Walecki, Eve S.; Walecki, Peter S.

    2015-12-01

    We investigate a water-filled bottle rolling down an incline and ask the following question: is a rolling bottle better described by a model ignoring all internal motion where the bottle is approximated by a material point sliding down an incline, or is it better described by a rigid solid cylinder rolling down the incline without skidding? The measurements presented here represent a special case of similar experiments described by K.A. Jackson et al. (see Ref. 1 and references within). There exists also a report by Kagan describing the motion of soda cans rolling on an incline. In our case we investigate motion of the fully filled bottle. We demonstrate that within accuracy of our experiment the motion of the bottle can be described by a simple "frictionless water" model. The analysis of the dynamics of the bodies sliding and rolling on a ramp is a standard component of introductory physics classes, and a required component of the Advanced Placement (AP) Physics curriculum.

  9. Lattice-Boltzmann Simulations of Flows Over Backward-Facing Inclined Steps

    NASA Astrophysics Data System (ADS)

    Kotapati, Rupesh B.; Shock, Richard; Chen, Hudong

    2014-01-01

    The lattice-Boltzmann method (LBM) is used in conjunction with a very large-eddy simulation (VLES) turbulence modeling approach to compute separated flows over backward-facing steps at different wall inclination angles. The Reynolds number ReH based on the step height H and center-line velocity at the channel inlet ucl is 64 000. The expansion ratio of the outlet section to the inlet section of the channel is 1.48. Wall inclination angles α considered include 10°, 15°, 20°, 25°, 30° and 90°. The computed flow fields for different inclination angles of the step are assessed against the laser Doppler anemometry (LDA) measurements of Makiola [B. Makiola, Ph.D. Thesis, University of Karlsruhe (1992); B. Ruck and B. Makiola, Flow separation over the step with inclined walls, in Near-Wall Turbulent Flows, eds. R. M. C. So, C. G. Speziale and B. E. Launder (Elsevier, 1993), p. 999.]. In addition to validating the lattice-Boltzmann solution with the experiments, this study also investigates the effects of three dimensionality, the proximity of the inlet to the step, and the grid resolution on the quality of the predictions.

  10. Experimental Study of the Richtmyer-Meshkov Instability on a Coupled Multimode and Inclined Interface Perturbation

    NASA Astrophysics Data System (ADS)

    Reilly, David; Creel, Skylar; McFarland, Jacob; Mitruka, Jatin; McDonald, Christopher; Ranjan, Devesh

    2013-11-01

    The inclined shock tube in the Texas A&M Shock Tube and Advanced Mixing Laboratory was used to study the effect of small amplitude, long wavelength multimode perturbations imposed on the inclined interface initial condition of the Richtmyer-Meshkov instability. The inclined interface is essentially a long wavelength, extremely large amplitude perturbation. Images of the shocked flow-field were captured with the angle of the shock tube with respect to the horizontal at 60° (η/ λ = √{ 3}/6). The modal content of the initial conditions was determined by taking the Fourier decomposition of the interface. This work is a proof of concept for creating a coupled multimode and inclined interface. Work that is currently underway will investigate the effect of these initial conditions on intermediate and late-time mixing as well as the transition to turbulence before reshock by using qualitative comparisons of Mie scattering images, mixing width measurements, and circulation from Particle Image Velocimetry (PIV). This research was funded by the Air Force Office of Scientific Research Young Investigator Research Program (AFOSR-YIP) grant.

  11. Is Mandibular Fossa Morphology and Articular Eminence Inclination Associated with Temporomandibular Dysfunction?

    PubMed Central

    Paknahad, Maryam; Shahidi, Shoaleh; Akhlaghian, Marzieh; Abolvardi, Masoud

    2016-01-01

    Statement of the Problem Finding a significant relationship between temporomandibular joint (TMJ) morphology and the incidence of temporomandibular dysfunction (TMD) may help early prediction and prevention of these problems. Purpose The purpose of the present study was to determine the morphology of mandibular fossa and the articular eminence inclination in patients with TMD and in control group using cone beam computed tomography (CBCT). Materials and Method The CBCT data of bilateral TMJs of 40 patients with TMD and 23 symptom-free cases were evaluated. The articular eminence inclination, as well as the glenoid fossa depth and width of the mandibular fossa were measured. The paired t-test was used to compare these values between two groups. Results The articular eminence inclination and glenoid fossa width and depth were significantly higher in patients with TMD than in the control group (p < 0.05). Conclusion The articular eminence inclination was steeper in patients with TMD than in the control group. Glenoid fossa width and depth were higher in patients with TMD than that in the control group. This information may shed light on the relationship between TMJ morphology and the incidence of TMD. PMID:27284559

  12. Alcohol Craving in Patients Diagnosed with a Severe Mental Illness and Alcohol Use Disorder: Bi-Directional Relationships between Approach and Avoidance Inclinations and Drinking

    PubMed Central

    Schlauch, Robert C.; Levitt, Ash; Bradizza, Clara M.; Stasiewicz, Paul R.; Lucke, Joseph F.; Maisto, Stephen A.; Zhuo, Yue; Connors, Gerard J.

    2014-01-01

    Objective The current study was undertaken to better understand the craving-drinking relationship among individuals dually diagnosed with a severe mental illness (SMI) and an alcohol use disorder (AUD). Using an ambivalence conceptualization of craving (Breiner et al., 1999), we investigated the bi-directional relationships between desires and behavioral intentions to use (approach inclinations) and not use (avoidance inclinations) alcohol and drinking outcomes in patients diagnosed with a SMI-AUD. Method Patients (N = 278) seeking outpatient dual diagnosis treatment from a community mental health center were followed longitudinally over the course of 6 months. Assessments at baseline, 2-month, 4-month, and 6-month intervals included approach and avoidance inclinations, alcohol urges, readiness to change, and drinking outcomes. Results Time-lagged multilevel growth curve modeling found that avoidance inclinations moderated the effect of approach inclinations on subsequent drinking outcomes differentially over time. Specifically, avoidance inclinations attenuated the effect of approach on subsequent heavier drinking levels, and high avoidance/low approach demonstrated significant decreases on levels of drinking over time. Results also indicated that number of drinks consumed and heavy drinking days predicted subsequent approach inclinations differentially over time, such that lower levels of drinking predicted decreases in approach inclinations. Decreases in drinking also predicted higher subsequent avoidance inclinations, which were maintained over time. Conclusions These findings highlight the complexity of subjective craving responses and the importance of measuring both approach and avoidance inclinations. Among those diagnosed with SMI-AUDs, treatment strategies that increase avoidance inclinations may increase abstinence rates in this difficult-to-treat population. PMID:23895085

  13. Comparison of Plantar Pressure Distribution between Different Speed and Incline During Treadmill Jogging

    PubMed Central

    Ho, I-Ju; Hou, Yi-You; Yang, Chich-Haung; Wu, Wen-Lan; Chen, Sheng-Kai; Guo, Lan-Yuen

    2010-01-01

    The aim of this study was to examine the effect of changes in speed and incline slope on plantar pressure distribution of the foot during treadmill jogging. Plantar pressure parameters were measured with the Pedar-X system in twenty healthy girls (mean age of 20.7 years, mean height of 1.60m, and a mean weight of 53.35kg). Because variations in walking speed or slope can significantly change the magnitude of plantar pressure, comparisons of plantar pressure distribution between the two independent protocols during treadmill jogging were considered in this study. First, the subjects ran at the same speed of 2 m·s-1 with different incline slopes of 0%, 5%, 10%, and 15%. Second, they ran on the same slope of 0% with different speeds of 1.5 m·s-1, 2.0 m·s-1, and 2.5 m·s-1. The peak pressure of the eight plantar surface areas, apart from the medial forefoot and the hallux, significantly increased (p < 0.05) with an increase of 33% of peak pressure from 1.5 m·s-1 to 2.5 m·s-1 (speed) at heel region. In contrast, the peak pressures at the heel, medial fore-foot, toe and hallux decreased significantly (p < 0. 05) with increasing incline slope. At the heel, peak pressure reduced by 27% from 0% to 15% incline, however, pressure at the lateral midfoot region increased as following. Different speeds and incline slopes during jogging were associated with changes in plantar pressures. By systematic investigation of foot kinematics and plantar pressure during jogging with varying incline slope and speed, the results of this study provided further insight into foot biomechanics during jogging. Key points The study aimed to compare the plantar pressure distribution of the foot between different incline and speed during treadmill jogging by using plantar insole measurement system. With the increase of speed, apart from the hallux and medical forefoot, the peak pressure of all regions was raised significantly. As the slope increased, there was reduced peak pressure of the heel

  14. Earliest known crown-group salamanders.

    PubMed

    Gao, Ke-Qin; Shubin, Neil H

    2003-03-27

    Salamanders are a model system for studying the rates and patterns of the evolution of new anatomical structures. Recent discoveries of abundant Late Jurassic and Early Cretaceous salamanders are helping to address these issues. Here we report the discovery of well-preserved Middle Jurassic salamanders from China, which constitutes the earliest known record of crown-group urodeles (living salamanders and their closest relatives). The new specimens are from the volcanic deposits of the Jiulongshan Formation (Bathonian), Inner Mongolia, China, and represent basal members of the Cryptobranchidae, a family that includes the endangered Asian giant salamander (Andrias) and the North American hellbender (Cryptobranchus). These fossils document a Mesozoic record of the Cryptobranchidae, predating the previous record of the group by some 100 million years. This discovery provides evidence to support the hypothesis that the divergence of the Cryptobranchidae from the Hynobiidae had taken place in Asia before the Middle Jurassic period. PMID:12660782

  15. Clinical outcome of double crown-retained implant overdentures with zirconia primary crowns

    PubMed Central

    Buergers, Ralf; Ziebolz, Dirk; Roediger, Matthias

    2015-01-01

    PURPOSE This retrospective study aims at the evaluation of implant-supported overdentures (IODs) supported by ceramo-galvanic double crowns (CGDCs: zirconia primary crowns + galvano-formed secondary crown). MATERIALS AND METHODS In a private practice, 14 patients were restored with 18 IODs (mandible: 11, maxilla: 7) retained by CGDCs on 4 - 8 implants and annually evaluated for technical and/or biological failures/complications. RESULTS One of the 86 inserted implants failed during the healing period (cumulative survival rate (CSR) implants: 98.8%). During the prosthetic functional period (mean: 5.9 ± 2.2 years), 1 implant demonstrated an abutment fracture (CSR-abutments: 98.2%), and one case of peri-implantitis was detected. All IODs remained in function (CSR-denture: 100%). A total of 15 technical complications required interventions to maintain function (technical complication rate: 0.178 treatments/patients/year). CONCLUSION Considering the small sample size, the use of CGDCs for the attachment of IODs is possible without an increased risk of technical complications. However, for a final evaluation, results from a larger cohort are required. PMID:26330981

  16. In Situ Quantification of Experimental Ice Accretion on Tree Crowns Using Terrestrial Laser Scanning

    PubMed Central

    Nock, Charles A.; Greene, David; Delagrange, Sylvain; Follett, Matt; Fournier, Richard; Messier, Christian

    2013-01-01

    In the eastern hardwood forests of North America ice storms are an important disturbance event. Ice storms strongly influence community dynamics as well as urban infrastructure via catastrophic branch failure; further, the severity and frequency of ice storms are likely to increase with climate change. However, despite a long-standing interest into the effects of freezing rain on forests, the process of ice accretion and thus ice loading on branches remains poorly understood. This is because a number of challenges have prevented in situ measurements of ice on branches, including: 1) accessing and measuring branches in tall canopies, 2) limitations to travel during and immediately after events, and 3) the unpredictability of ice storms. Here, utilizing a novel combination of outdoor experimental icing, manual measurements and terrestrial laser scanning (TLS), we perform the first in situ measurements of ice accretion on branches at differing heights in a tree crown and with increasing duration of exposure. We found that TLS can reproduce both branch and iced branch diameters with high fidelity, but some TLS instruments do not detect ice. Contrary to the expectations of ice accretion models, radial accretion varied sharply within tree crowns. Initially, radial ice accretion was similar throughout the crown, but after 6.5 hours of irrigation (second scanning) radial ice accretion was much greater on upper branches than on lower (∼factor of 3). The slope of the change in radial ice accretion along branches increased with duration of exposure and was significantly greater at the second scanning compared to the first. We conclude that outdoor icing experiments coupled with the use of TLS provide a robust basis for evaluation of models of ice accretion and breakage in tree crowns, facilitating estimation of the limiting breaking stress of branches by accurate measurements of ice loads. PMID:23741409

  17. In situ quantification of experimental ice accretion on tree crowns using terrestrial laser scanning.

    PubMed

    Nock, Charles A; Greene, David; Delagrange, Sylvain; Follett, Matt; Fournier, Richard; Messier, Christian

    2013-01-01

    In the eastern hardwood forests of North America ice storms are an important disturbance event. Ice storms strongly influence community dynamics as well as urban infrastructure via catastrophic branch failure; further, the severity and frequency of ice storms are likely to increase with climate change. However, despite a long-standing interest into the effects of freezing rain on forests, the process of ice accretion and thus ice loading on branches remains poorly understood. This is because a number of challenges have prevented in situ measurements of ice on branches, including: 1) accessing and measuring branches in tall canopies, 2) limitations to travel during and immediately after events, and 3) the unpredictability of ice storms. Here, utilizing a novel combination of outdoor experimental icing, manual measurements and terrestrial laser scanning (TLS), we perform the first in situ measurements of ice accretion on branches at differing heights in a tree crown and with increasing duration of exposure. We found that TLS can reproduce both branch and iced branch diameters with high fidelity, but some TLS instruments do not detect ice. Contrary to the expectations of ice accretion models, radial accretion varied sharply within tree crowns. Initially, radial ice accretion was similar throughout the crown, but after 6.5 hours of irrigation (second scanning) radial ice accretion was much greater on upper branches than on lower (∼factor of 3). The slope of the change in radial ice accretion along branches increased with duration of exposure and was significantly greater at the second scanning compared to the first. We conclude that outdoor icing experiments coupled with the use of TLS provide a robust basis for evaluation of models of ice accretion and breakage in tree crowns, facilitating estimation of the limiting breaking stress of branches by accurate measurements of ice loads. PMID:23741409

  18. Characterizing the influence of surface roughness and inclination on 3D vision sensor performance

    NASA Astrophysics Data System (ADS)

    Hodgson, John R.; Kinnell, Peter; Justham, Laura; Jackson, Michael R.

    2015-12-01

    This paper reports a methodology to evaluate the performance of 3D scanners, focusing on the influence of surface roughness and inclination on the number of acquired data points and measurement noise. Point clouds were captured of samples mounted on a robotic pan-tilt stage using an Ensenso active stereo 3D scanner. The samples have isotropic texture and range in surface roughness (Ra) from 0.09 to 0.46 μm. By extracting the point cloud quality indicators, point density and standard deviation, at a multitude of inclinations, maps of scanner performance are created. These maps highlight the performance envelopes of the sensor, the aim being to predict and compare scanner performance on real-world surfaces, rather than idealistic artifacts. The results highlight the need to characterize 3D vision sensors by their measurement limits as well as best-case performance, determined either by theoretical calculation or measurements in ideal circumstances.

  19. Survival rates of porcelain molar crowns-an update.

    PubMed

    Kassem, Amr Shebl; Atta, Osama; El-Mowafy, Omar

    2010-01-01

    The aim of this study was to identify recent studies that dealt with the clinical performance of porcelain molar crowns and to explore the possibility of grouping the findings from similar studies together to draw overall conclusions. A MEDLINE literature search was conducted in early 2009 covering the preceding 12 years. Seventeen studies were indentified. However, only seven met the specific inclusion criteria and were analyzed. Among seven studies, five European countries were covered. Five studies reported on Procera AllCeram molar crowns while one reported on In-Ceram Alumina and Spinell crowns and another on CEREC crowns. For comparison, one additional study that reported on premolar crowns was included. In the five Procera AllCeram studies, 235 molar crowns were evaluated for 5 or more years, of which 24 failed. When the results of the five studies on the performance of Procera AllCeram molar crowns were considered collectively, an overall failure rate of 10.2% was found at 5 or more years. Int J Prosthodont 2010;23:60-62. PMID:20234895

  20. 8. DETAIL VIEW OF INCLINED OUTLET GATE WHEEL, LOOKING EAST ...

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

    8. DETAIL VIEW OF INCLINED OUTLET GATE WHEEL, LOOKING EAST - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  1. 7. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING ...

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

    7. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING NORTH - High Mountain Dams in Upalco Unit, Kidney Lake Dam, Ashley National Forest, 4.7 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  2. 12. DETAIL VIEW OF NORTHEAST CORNER, SHOWING HIP VERTICAL, INCLINED ...

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

    12. DETAIL VIEW OF NORTHEAST CORNER, SHOWING HIP VERTICAL, INCLINED END POST, AND UPPER CHORD - Kennan-Jump River Bridge, Spanning South fork of Jump River on County Highway "N", Kennan, Price County, WI

  3. 22. INCLINED END POST / DECK / GUARDRAIL DETAIL OF ...

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

    22. INCLINED END POST / DECK / GUARDRAIL DETAIL OF THROUGH TRUSSES. VIEW TO SOUTHEAST. - Abraham Lincoln Memorial Bridge, Spanning Missouri River on Highway 30 between Nebraska & Iowa, Blair, Washington County, NE

  4. 5. DETAIL OF NORTHWEST END OF TRUSS, SHOWING INCLINED POST, ...

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

    5. DETAIL OF NORTHWEST END OF TRUSS, SHOWING INCLINED POST, TOP CHORD AND DIAGONAL BRACING. - North Branch Quantico Creek Bridge, Prince William Forest Park, on NPS Route 406 spanning north branch of Quantico Creek, Dumfries, Prince William County, VA

  5. 20. VIEW LOOKING SOUTHWEST OF NORTH PONY TRUSS; SHOWING INCLINED ...

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

    20. VIEW LOOKING SOUTHWEST OF NORTH PONY TRUSS; SHOWING INCLINED END POST, HIP VERTICAL, VERTICAL POSTS, DIAGONALS, AND COUNTER BRACING - Boyleston Bridge, Spanning Skunk River, Lowell, Henry County, IA

  6. 26. UPPER STATION, LOWER FLOOR, BULL WHEEL. Monongahela Incline ...

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

    26. UPPER STATION, LOWER FLOOR, BULL WHEEL. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  7. 6. VIEW NORTH, LOWER STATION EAST SIDE. Monongahela Incline ...

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

    6. VIEW NORTH, LOWER STATION EAST SIDE. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  8. Students as Researchers: An Inclined-Plane Activity.

    ERIC Educational Resources Information Center

    Edwards, Thomas G.

    1995-01-01

    Describes an inquiry activity in which students explore the variables that influence the amount of time it takes a ball to roll down an inclined plane. Relates features of the activity to recommendations in the NCTM Standards. (MKR)

  9. Mission analysis data for inclined geosynchronous orbits, part 1

    NASA Technical Reports Server (NTRS)

    Graf, O. F., Jr.; Wang, K. C.

    1980-01-01

    Data needed for preliminary design of inclined geosynchronous missions are provided. The inertial and Earth fixed coordinate systems are described, as well as orbit parameters and elements. The complete family of geosynchronous orbits is discussed. It is shown that circular inclined geosynchronous orbits comprise only one set in this family. The major orbit perturbation and their separate effects on the geosynchronous orbit are discussed. Detailed information on the orbit perturbation of inclined circular geosynchronous orbits is given, with emphasis on time history data of certain orbital elements. Orbit maintenance delta velocity (V) requirements to counteract the major orbit perturbations are determined in order to provide order of magnitude estimates and to show the effects of orbit inclination on delta V. Some of the considerations in mission design for a multisatellite system, such as a halo orbit constellation, are discussed.

  10. 5. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    5. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE, (12' DIAMETER HARDESTY MODEL 112 CIRCULAR GATE), LOOKING NORTHEAST - High Mountain Dams in Bonneville Unit, Island Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  11. 4. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING ...

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

    4. VIEW OF INCLINED OUTLET GATE WHEEL AND STEM, LOOKING NORTHWEST - High Mountain Dams in Upalco Unit, Brown Duck Lake Dam, Ashley National Forest, 4.4 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  12. 7. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    7. VIEW OF INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (15' HARDESTY MODEL 115 GATE), LOOKING NORTHWEST - High Mountain Dams in Bonneville Unit, Marjorie Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  13. 5. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    5. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (28' WIDE HARDESTY CAST IRON SLIDE HEADGATE), LOOKING NORTHEAST - High Mountain Dams in Bonneville Unit, Duck Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  14. 4. VIEW OF INCLINED OUTLET GATE, STEM, STEM GUIDE AND ...

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

    4. VIEW OF INCLINED OUTLET GATE, STEM, STEM GUIDE AND WHEEL (10' HARDESTY VERTICAL LIFT GATE), LOOKING NORTHWEST - High Mountain Dams in Bonneville Unit, Pot Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  15. 6. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM ...

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

    6. VIEW SHOWING INCLINED OUTLET GATE WHEEL, STEM AND STEM GUIDE (18' HARDESTY GATE), LOOKING SOUTHEAST - High Mountain Dams in Bonneville Unit, Long Lake Dam, Wasatch National Forest, Kamas, Summit County, UT

  16. 58. VIEW OF CABLE INCLINE, LOCATED ON THE HILLSIDE BELOW ...

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

    58. VIEW OF CABLE INCLINE, LOCATED ON THE HILLSIDE BELOW THE FOREBAY (NORTHWEST OF FOREBAY), Print No. 156, August 1903 - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

  17. 1. EXTERIORANGLED AND INCLINED TO AUTOMATIC PLOTTING AND ORTHOPRINTING LIMITS ...

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

    1. EXTERIOR--ANGLED AND INCLINED TO AUTOMATIC PLOTTING AND ORTHOPRINTING LIMITS Copy photograph of photogrammetric plate LC-HABS-GS05-T-4950-101L. - Lemon Building, 1729 New York Avenue, Northwest, Washington, District of Columbia, DC

  18. The Asymmetrical "Sticking" Behavior of Two Balls on an Incline.

    ERIC Educational Resources Information Center

    Mallinckrodt, A. John

    1999-01-01

    Offers a relatively simple analysis of the asymmetrical "sticking" and rolling behavior of two balls, one steel and one rubber, on an incline. Describes an Interactive Physics (TM) simulation designed to study the problem and gives rough experimental results. (WRM)

  19. 7. DETAIL VIEW OF ROCKER ARM, SHOWING POCKETS, LUGS, INCLINED ...

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

    7. DETAIL VIEW OF ROCKER ARM, SHOWING POCKETS, LUGS, INCLINED STOPPING BLOCK AT SHOREWARD END OF TRACK GIRDER - Seddon Island Scherzer Rolling Lift Bridge, Spanning Garrison Channel from Tampa to Seddon Island, Tampa, Hillsborough County, FL

  20. Detail of inside of inclined end post, with portal cross ...

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

    Detail of inside of inclined end post, with portal cross bar member. - Phoenix Iron Company, French Creek Bridge, Spanning French Creek between Gay Street & Main Street, Phoenixville, Chester County, PA

  1. Safety Case Notations: Alternatives for the Non-Graphically Inclined?

    NASA Technical Reports Server (NTRS)

    Holloway, C. M.

    2008-01-01

    This working paper presents preliminary ideas of five possible text-based notations for representing safety cases, which may be easier for non-graphically inclined people to use and understand than the currently popular graphics-based representations.

  2. Estimating forest crown area removed by selection cutting: a linked regression-GIS approach based on stump diameters

    USGS Publications Warehouse

    Anderson, S.C.; Kupfer, J.A.; Wilson, R.R.; Cooper, R.J.

    2000-01-01

    The purpose of this research was to develop a model that could be used to provide a spatial representation of uneven-aged silvicultural treatments on forest crown area. We began by developing species-specific linear regression equations relating tree DBH to crown area for eight bottomland tree species at White River National Wildlife Refuge, Arkansas, USA. The relationships were highly significant for all species, with coefficients of determination (r(2)) ranging from 0.37 for Ulmus crassifolia to nearly 0.80 for Quercus nuttalliii and Taxodium distichum. We next located and measured the diameters of more than 4000 stumps from a single tree-group selection timber harvest. Stump locations were recorded with respect to an established gl id point system and entered into a Geographic Information System (ARC/INFO). The area occupied by the crown of each logged individual was then estimated by using the stump dimensions (adjusted to DBHs) and the regression equations relating tree DBH to crown area. Our model projected that the selection cuts removed roughly 300 m(2) of basal area from the logged sites resulting in the loss of approximate to 55 000 m(2) of crown area. The model developed in this research represents a tool that can be used in conjunction with remote sensing applications to assist in forest inventory and management, as well as to estimate the impacts of selective timber harvest on wildlife.

  3. On the Emmenthal distribution of highly inclined asteroids

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Machuca, J. F.

    2011-12-01

    Highly inclined asteroids are objects with sin (i) > 0.3. Among highly inclined asteroids, we can distinguish between objects with inclinations smaller than that of the centre of the ν6= g - g6 secular resonance and objects at higher inclinations. Using the current mechanisms of dynamical mobility, it is not easy to increase the values of an asteroid with an initial small inclination to values higher than that of the centre of the ν6 resonance. The presence of highly inclined objects might therefore be related to the early phases of the Solar system. It has been observed that several dynamically stable regions are characterized by a very low number density of objects, unlike low-inclined bodies that tend to occupy all the dynamically viable regions. The distribution of asteroids at a high inclination in the domain of proper elements in dynamically stable regions resembles an Emmenthal cheese, with regions of low number density close to highly populated areas. While this phenomenon has been observed qualitatively in the past, no quantitative study has yet been carried out on the extent and long-term stability of these regions. In this paper, we identify two dynamically stable regions characterized by very low values of number density and permanence times of 100 Myr or more when the Yarkovsky force is considered. We show that the low number density of objects in these areas cannot be produced as a statistical fluctuation of any simple one-dimensional statistical distribution, such as the Poissonian, uniform and Gaussian distributions, or of a tri-dimensional distribution, such as the tri-variate normal distribution. The presence of unoccupied dynamically stable regions could indicate that the primordial asteroidal population might not have reached all available zones at high-i. This sets constraints on the scenarios for the early phases of the history of our Solar system.

  4. Unique case of a geminated supernumerary tooth with trifid crown

    PubMed Central

    Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi

    2012-01-01

    Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper. PMID:23071971

  5. An Explanation for the High Inclinations of Amalthea and Thebe

    NASA Astrophysics Data System (ADS)

    Proctor, Amanda; Hamilton, Douglas; Rauch, Kevin

    2002-04-01

    We propose that the anomalously large inclinations of the inner moons Amalthea (I=0.33^circ) and Thebe (I=1.09^circ) result from kicks imparted by Io's strong resonances as those resonances scan across the location of the moons. Both the eccentricities and inclinations of the moons are excited during resonant passages. But while the eccentricities decay rapidly due to the large satellite tides raised by the planet, the inclinations are basically preserved since they decay slowly due to the tiny planetary tides raised by the satellite. Through analysis of our numerical simulations we were able to limit Io's formation distance from Jupiter to between 4.02 and 4.92 Jovian Radii. Io's 3:1 resonances can impart an inclination of ~ 0.3^circ to Amalthea, while the 4:2 resonance gives too large a kick. We find that either the 4:2 resonance acting alone, or in combination with the 5:3 and the 6:4, causes Thebe's inclination to rise to about 1 degree. Our theory naturally explains the high inclinations of these two small satellites.

  6. Spreading dynamics of droplet on an inclined surface

    NASA Astrophysics Data System (ADS)

    Shen, Chaoqun; Yu, Cheng; Chen, Yongping

    2016-06-01

    A three-dimensional unsteady theoretical model of droplet spreading process on an inclined surface is developed and numerically analyzed to investigate the droplet spreading dynamics via the lattice Boltzmann simulation. The contact line motion and morphology evolution for the droplet spreading on an inclined surface, which are, respectively, represented by the advancing/receding spreading factor and droplet wetted length, are evaluated and analyzed. The effects of surface wettability and inclination on the droplet spreading behaviors are examined. The results indicate that, dominated by gravity and capillarity, the droplet experiences a complex asymmetric deformation and sliding motion after the droplet comes into contact with the inclined surfaces. The droplet firstly deforms near the solid surface and mainly exhibits a radial expansion flow in the start-up stage. An evident sliding-down motion along the inclination is observed in the middle stage. And the surface-tension-driven retraction occurs during the retract stage. Increases in inclination angle and equilibrium contact angle lead to a faster droplet motion and a smaller wetted area. In addition, increases in equilibrium contact angle lead to a shorter duration time of the middle stage and an earlier entry into the retract stage.

  7. Development and characterization of an inclined air-curtain (IAC) fume hood.

    PubMed

    Huang, Rong Fung; Chen, Jia-Kun; Tang, Kun-Chi

    2015-06-01

    An inclined air-curtain (IAC) fume hood was developed and characterized using the laser-assisted smoke flow visualization technique and tracer-gas (sulphur hexafluoride) concentration detection method. The IAC fume hood features four innovative design elements: (i) an elongated suction slot installed at the hood roof with an offset towards the rear wall, (ii) an elongated up-blowing planar jet issued from the work surface near the hood inlet, (iii) two deflection plates installed at the left and right side walls, and (iv) a boundary-layer separation controller installed at the sash bottom. Baffles employed in conventional hoods were not used. The suction slot and the up-blowing planar jet formed a rearward-inclined push-pull air curtain. The deflection plates worked with the inclined air curtain to induce four rearward-inclined counter-rotating 'tornados.' The fumes generated in the hood were isolated behind the rearward-inclined air curtain, entrained by the low pressure within the vortical flows, moved up spirally, and finally exhausted through the suction slot. The risk of containment leakage due to the large recirculation vortex that usually exists behind the sash of conventional hoods was reduced by the boundary-layer separation controller. The results of the tracer-gas concentration detection method based on the EN-14175 method showed that the flow field created by the geometric configurations of the IAC hood presented characteristics of low leakage and high resistance to dynamic disturbances at low face velocities. The leakage levels measured by the static, sash movement, and walk-by tests were negligible at a face velocity of 0.26 m s(-1). PMID:25690760

  8. Patterns of crown damage within a large wildfire in the Klamath-Siskiyou bioregion

    NASA Astrophysics Data System (ADS)

    Thompson, Jonathan R.

    The 2002 Biscuit Fire burned through more than 200,000 ha of mixed-conifer/evergreen hardwood forests in southwestern Oregon and northwestern California. In chapter two, I focused on a region that had burned previously by the 1987 Silver Fire then was subject, in part, to salvage-logging and conifer planting before being reburned by the Biscuit Fire. I used the Landsat-based differenced normalized burn ratio (dNBR) to quantify severity in both fires and took a hypothesis-testing approach to answering two questions: First, was severity in the Biscuit Fire associated with severity in the Silver Fire in unmanaged areas? And second, did areas that were salvaged-logged and planted with conifers after the Silver Fire burn more or less severely in the Biscuit Fire than comparable unmanaged areas? I found that areas that burned severely in 1987 tended to re-burn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. In addition, areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that post-fire logging and planting did not reduce future fire severity as had been suggested by some. In chapter three, I again focused on the twice-burned landscape, but this time I used a temporal sequence of digital aerial photography plots (6.25 ha) to measure changes in shrub-stratum, hardwood, and conifer cover. I estimated the strength and nature of relationships between crown damage and several fuel, topographical, weather, and management variables. Median crown damage, including damage to the shrub-stratum, on unmanaged plots was 63% after the Biscuit Fire and was most strongly related to damage in the Silver Fire. Plots that burned severely in the Silver Fire and had succeeded to a mix of shrubs and tree regeneration experienced high levels of Biscuit Fire damage

  9. Modeling intra-crown and intra-canopy interactions in red maple: assessment of light transfer on carbon dioxide and water vapor exchange.

    PubMed

    Bauerle, William L; Bowden, Joseph D; McLeod, Michael F; Toler, Joe E

    2004-05-01

    Daily and seasonal net photosynthesis (Anet), transpiration (E), absorbed photosynthetically active radiation (Qa) and light-use efficiency (epsilonc) in a red maple container nursery were simulated with MAESTRA, a three-dimensional canopy model. Effects of canopy heterogeneity were simulated by imposing changes in crown spacing. The light transfer sub-model, a distribution model of incident, direct, diffuse and scattered radiation within MAESTRA, was validated against field measurements of light interception on an intra-crown scale. In the container nursery, we found that a fiber-optic-based method of integrating photosynthetically active radiation (Q) was more suitable for crown-layer light transfer measurements and adjustments than either orthogonal line or individual quantum sensor measurements. The model underestimated intercepted Q by 9.3, 18 and 11.1% for crown layers 1, 2 and 3, respectively; however, there were linear relationships between model estimates and observations made with each of the three measurement methods. We used the validated and parameterized light transfer model to assess intra-crown and intra-canopy light transfer on a layer, crown and canopy basis, and investigated effects of tree size ratio and tree spacing interactions on Anet, E, Qa and epsilonc in the container nursery. Heterogeneous crown and canopy photosynthesis were predicted to exceed values for a uniform canopy under space-limiting conditions. Tree size ratio had large effects on Anet, E, Qa and epsilonc when light to lower-canopy layers was limited by inadequate space between crowns. Increasing Qa at lower-crown layers had the largest impact on whole-crown and whole-canopy Anet, E, Qa and epsilonc. Increases in canopy productivity led to increased water use. Simulations of heterogeneous stands with adequate soil water indicated that light absorption is maximized under space-limiting conditions as a canopy crown moves toward heterogeneity. Nursery and plantation productivity

  10. Tree crown structural characterization: A study using terrestrial laser scanning and three-dimensional radiative transfer modeling

    NASA Astrophysics Data System (ADS)

    Moorthy, Inian

    Spectroscopic observational data for vegetated environments, have been coupled with 3D physically-based radiative transfer models for retrievals of biochemical and biophysical indicators of vegetation health and condition. With the recent introduction of Terrestrial Laser Scanning (TLS) units, there now exists a means of rapidly measuring intricate structural details of vegetation canopies, which can also serve as input into 3D radiative transfer models. In this investigation, Intelligent Laser Ranging and Imaging System (ILRIS-3D) data was acquired of individual tree crowns in laboratory, and field-based experiments. The ILRIS-3D uses the Time-Of-Flight (TOF) principle to measure the distances of objects based on the time interval between laser pulse exitance and return, upon reflection from an object. At the laboratory-level, this exploratory study demonstrated and validated innovative approaches for retrieving crown-level estimates of Leaf Area Index (LAI) (r2 = 0.98, rmse = 0.26m2/m2), a critical biophysical parameter for vegetation monitoring and modeling. These methods were implemented and expanded in field experiments conducted in olive (Olea europaea L.) orchards in Cordoba, Spain, where ILRIS-3D observations for 24 structurally-variable trees were made. Robust methodologies were developed to characterize diagnostic architectural parameters, such as tree height (r2 = 0.97, rmse = 0.21m), crown width (r 2 = 0.98, rmse = 0.12m), crown height (r2 = 0.81, rmse = 0.11m), crown volume (r2 = 0.99, rmse = 2.6m3), and LAI (r2 = 0.76, rmse = 0.27m2/ m2). These parameters were subsequently used as direct inputs into the Forest LIGHT (FLIGHT) 3D ray tracing model for characterization of the spectral behavior of the olive crowns. Comparisons between FLIGHT-simulated spectra and measured data showed small differences in the visible (< 3%) and near infrared (< 10%) spectral ranges. These differences between model simulations and measurements were significantly correlated

  11. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    SciTech Connect

    Aab, Alexander; et al.

    2014-08-08

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.

  12. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    SciTech Connect

    Collaboration: Pierre Auger Collaboration

    2014-08-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.

  13. Fully Automated Gis-Based Individual Tree Crown Delineation Based on Curvature Values from a LIDAR Derived Canopy Height Model in a Coniferous Plantation

    NASA Astrophysics Data System (ADS)

    Argamosa, R. J. L.; Paringit, E. C.; Quinton, K. R.; Tandoc, F. A. M.; Faelga, R. A. G.; Ibañez, C. A. G.; Posilero, M. A. V.; Zaragosa, G. P.

    2016-06-01

    The generation of high resolution canopy height model (CHM) from LiDAR makes it possible to delineate individual tree crown by means of a fully-automated method using the CHM's curvature through its slope. The local maxima are obtained by taking the maximum raster value in a 3 m x 3 m cell. These values are assumed as tree tops and therefore considered as individual trees. Based on the assumptions, thiessen polygons were generated to serve as buffers for the canopy extent. The negative profile curvature is then measured from the slope of the CHM. The results show that the aggregated points from a negative profile curvature raster provide the most realistic crown shape. The absence of field data regarding tree crown dimensions require accurate visual assessment after the appended delineated tree crown polygon was superimposed to the hill shaded CHM.

  14. Effects of coronal substrates and water storage on the microhardness of a resin cement used for luting ceramic crowns

    PubMed Central

    de MENDONÇA, Luana Menezes; PEGORARO, Luiz Fernando; LANZA, Marcos Daniel Septímio; PEGORARO, Thiago Amadei; de CARVALHO, Ricardo Marins

    2014-01-01

    Composite resin and metallic posts are the materials most employed for reconstruction of teeth presenting partial or total destruction of crowns. Resin-based cements have been widely used for cementation of ceramic crowns. The success of cementation depends on the achievement of adequate cement curing. Objectives To evaluate the microhardness of Variolink® II (Ivoclar Vivadent, Schaan, Liechtenstein), used for cementing ceramic crowns onto three different coronal substrate preparations (dentin, metal, and composite resin), after 7 days and 3 months of water storage. The evaluation was performed along the cement line in the cervical, medium and occlusal thirds on the buccal and lingual aspects, and on the occlusal surface. Material and Methods Thirty molars were distributed in three groups (N=10) according to the type of coronal substrate: Group D- the prepared surfaces were kept in dentin; Groups M (metal) and R (resin)- the crowns were sectioned at the level of the cementoenamel junction and restored with metallic cast posts or resin build-up cores, respectively. The crowns were fabricated in ceramic IPS e.max® Press (Ivoclar Vivadent, Schaan, Liechtenstein) and luted with Variolink II. After 7 days of water storage, 5 specimens of each group were sectioned in buccolingual direction for microhardness measurements. The other specimens (N=5) were kept stored in deionized water at 37ºC for three months, followed by sectioning and microhardness measurements. Results Data were first analyzed by three-way ANOVA that did not reveal significant differences between thirds and occlusal surface (p=0.231). Two-way ANOVA showed significant effect of substrates (p<0.001) and the Tukey test revealed that microhardness was significantly lower when crowns were cemented on resin cores and tested after 7 days of water storage (p=0.007). Conclusion The type of material employed for coronal reconstruction of preparations for prosthetic purposes may influence the cement properties

  15. Studies of granular flow down an inclined chute

    SciTech Connect

    Hanes, D.M.

    1992-01-01

    A preliminary series of experiments were run in order to examine the effects sidewalls have on the steady-state mass flow rate of granular material in a rectangular, inclined chute. These experiments also serve to assess the problems associated with the initial operation of the granular flow apparatus. Presumably, the friction between the sidewalls and the flowing material will slow the flow rate of that material. The relative effect of the sidewalls should decrease with increasing width for a given flow entrance condition. For instance, when the width of the chute is at a minimum (one grain diameter), the sidewalls will have a maximum frictional effect. And as the width approaches infinity, the sidewalls will have a minimum frictional effect. It is desired to know at what chute widths the sidewall effects will reasonably approach this minimum, if this condition can even be approached with the existing apparatus. The relationship between chute width and flow rate will be important to know during more involved experiments which will follow this initial investigation. These experiments will include the measurement of localized grain density, local velocity and individual grain dynamics (rotation and translation) and collisions. The secondary objective, to observe and correct problems with the system, is a more general and qualitative goal.

  16. Development of coated conductors by inclined substrate deposition

    NASA Astrophysics Data System (ADS)

    Balachandran, U.; Ma, B.; Li, M.; Fisher, B. L.; Koritala, R. E.; Miller, D. J.; Dorris, S. E.

    2003-10-01

    Inclined substrate deposition (ISD) offers the potential for rapid production of high-quality biaxially textured buffer layers suitable for YBa 2Cu 3O 7- δ (YBCO)-coated conductors. We have grown biaxially textured magnesium oxide (MgO) films on Hastelloy C276 (HC) substrates by ISD at deposition rates of 20-100 Å/s. Scanning electron microscopy of the ISD MgO films showed columnar grain structures with a roof-tile-shaped surface. X-ray pole figure analysis revealed that the c-axis of the ISD MgO films is titled at an angle ≈32° from the substrate normal. A small full-width at half maximum of ≈9° was observed for the φ-scan of MgO films. YBCO films were grown on ISD MgO buffered HC substrates by pulsed laser deposition and were determined to be biaxially aligned with the c-axis parallel to the substrate normal. The orientation relationship between the ISD template and the top YBCO film was investigated by X-ray pole figure analysis and transmission electron microscopy. A transport critical current density of Jc=5.5×10 5 A/cm 2 at 77 K in self-field was measured on a YBCO film that was 0.46-μm thick, 4-mm wide, 10-mm long.

  17. 6. BRIDGE LOOKING SOUTH FROM CROWN POINT STATE PARK SHOWING ...

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

    6. BRIDGE LOOKING SOUTH FROM CROWN POINT STATE PARK SHOWING SURROUNDING DEVELOPMENT FROM CONSTRUCTION OF DAM - Columbia River Bridge at Grand Coulee Dam, Spanning Columbia River at State Route 155, Coulee Dam, Okanogan County, WA

  18. Estimation of crown closure from AVIRIS data using regression analysis

    NASA Technical Reports Server (NTRS)

    Staenz, K.; Williams, D. J.; Truchon, M.; Fritz, R.

    1993-01-01

    Crown closure is one of the input parameters used for forest growth and yield modelling. Preliminary work by Staenz et al. indicates that imaging spectrometer data acquired with sensors such as the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) have some potential for estimating crown closure on a stand level. The objectives of this paper are: (1) to establish a relationship between AVIRIS data and the crown closure derived from aerial photography of a forested test site within the Interior Douglas Fir biogeoclimatic zone in British Columbia, Canada; (2) to investigate the impact of atmospheric effects and the forest background on the correlation between AVIRIS data and crown closure estimates; and (3) to improve this relationship using multiple regression analysis.

  19. Influence of porcelain veneering on the marginal fit of Digident and Lava CAD/CAM zirconia ceramic crowns

    PubMed Central

    Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2010-01-01

    PURPOSE Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS The means and standard deviations of the marginal fit were 61.52 ± 2.88 µm for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and 83.15 ± 3.51 µm after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of 62.22 ± 1.78 µm before porcelain veneering and 82.03 ± 1.85 µm after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically

  20. The effect of thermal barrier coated piston crown on engine characteristics

    SciTech Connect

    Chan, S.H.; Khor, K.A.

    2000-02-01

    While there have been numerous research papers in recent years describing the theoretical benefits obtained from the use of ceramic components in reciprocating engines, the amount of literature that describes practical results is very limited. Although successes have been reported and ceramic components are now in service in production engines, mainly for reduced in-cylinder heat rejection, many researchers have experienced failures or a drop in engine performance. This article presents the work completed on a low heat rejection engine. Extensive experiments were conducted on a three-cylinder SI Daihatsu engine with piston crowns coated with a layer of ceramic, which consisted of yttria-stabilized zirconia (YSZ). Measurement and comparison of engine performance, in particular fuel consumption, were made before and after the application of YSZ coatings deposited onto the piston crowns. The details of the cylinder pressures during the combustion process were also investigated.

  1. Scattered radiation from dental metallic crowns in head and neck radiotherapy.

    PubMed

    Shimozato, T; Igarashi, Y; Itoh, Y; Yamamoto, N; Okudaira, K; Tabushi, K; Obata, Y; Komori, M; Naganawa, S; Ueda, M

    2011-09-01

    We aimed to estimate the scattered radiation from dental metallic crowns during head and neck radiotherapy by irradiating a jaw phantom with external photon beams. The phantom was composed of a dental metallic plate and hydroxyapatite embedded in polymethyl methacrylate. We used radiochromic film measurement and Monte Carlo simulation to calculate the radiation dose and dose distribution inside the phantom. To estimate dose variations in scattered radiation under different clinical situations, we altered the incident energy, field size, plate thickness, plate depth and plate material. The simulation results indicated that the dose at the incident side of the metallic dental plate was approximately 140% of that without the plate. The differences between dose distributions calculated with the radiation treatment-planning system (TPS) algorithms and the data simulation, except around the dental metallic plate, were 3% for a 4 MV photon beam. Therefore, we should carefully consider the dose distribution around dental metallic crowns determined by a TPS. PMID:21813962

  2. Some observations on vortex-ring collisions upon inclined surfaces

    NASA Astrophysics Data System (ADS)

    New, T. H.; Shi, Shengxian; Zang, B.

    2016-06-01

    This paper reports upon a laser-induced fluorescence visualization and time-resolved particle image velocimetry study to resolve the detailed dynamics associated with Re = 2000 and 4000 circular vortex rings colliding with 30°-75° inclined surfaces. Two-dimensional visualization results show that larger inclination angles lead to increasingly rapid size reduction in the primary vortex-ring core closer to the surface, faster formation of the secondary vortex-ring core, and subsequent ingestion by the former. In contrast, primary vortex-ring core further away from the surface becomes physically larger and incoherent more rapidly, with slower formation and entrainment of the secondary vortex-ring core. Interestingly, a vortex dipole and small vortex-ring-like structure are produced for the largest inclination angle of 75°, possibly due to vortex disconnection and reconnection processes. Results taken along the non-inclined plane show significant bulging of the primary vortex-ring cores when the inclination angle increases from 30° onwards. More importantly, additional vortex cores are observed to entwine with the primary vortex-ring core and provide strong direct evidence for the bi-helical vortex line flow mechanism put forward by Lim (Exp Fluids 7:453-463, 1989). Lastly, the behaviour of the primary and secondary vortex-ring cores further away from the surface is highly sensitive towards the state of the bi-helical lines compressed at that region. Strong compression driven by circumferential flows due to large inclination angles may explain the unique flow structures and behaviour observed for 75° inclination angle here.

  3. Surgical crown lengthening: a periodontal and restorative interdisciplinary approach.

    PubMed

    Parwani, Simran R; Parwani, Rajkumar N

    2014-01-01

    Surgical crown lengthening helps to provide an adequate retention form for proper tooth preparation, thus enabling dentists to create esthetically pleasing and healthy restorations. Long-term stability requires accurate diagnosis and development of a comprehensive treatment plan in each case. This sequence of events stresses the importance of communication between the restorative dentist and the periodontist. This article presents 2 cases that involve surgical crown lengthening (including mucoperiosteal flap and ostectomy) for the restoration of teeth. PMID:25369395

  4. Failure Probability of Three Designs of Zirconia Crowns.

    PubMed

    Ramos, Gabriela Freitas; Monteiro, Evelyn Barbosa; Bottino, Marco Antonio; Zhang, Yu; Marques de Melo, Renata

    2015-01-01

    This study used a two-parameter Weibull analysis for evaluation of the lifespan of fully or partially porcelain-/glaze-veneered zirconia crowns after fatigue test. A sample of 60 first molars were selected and prepared for full-coverage crowns with three different designs (n = 20): traditional (crowns with zirconia framework covered with feldspathic porcelain), modified (crowns partially covered with veneering porcelain), and monolithic (full-contour zirconia crowns). All specimens were treated with a glaze layer. Specimens were subjected to mechanical cycling (100 N, 3 Hz) with a piston with a hemispherical tip (Ø = 6 mm) until the specimens failed or up to 2 × 10⁶ cycles. Every 500,000 cycles, the fatigue tests were interrupted and stereomicroscopy (10×) was used to inspect the specimens for damage. The authors performed Weibull analysis of interval data to calculate the number of failures in each interval. The types and numbers of failures according to the groups were: cracking (13 traditional, 6 modified) and chipping (4 traditional) of the feldspathic porcelain, followed by delamination (1 traditional) at the veneer/core interface and debonding (2 monolithic) at the cementation interface. Weibull parameters (β, scale; η, shape), with a two-sided confidence interval of 95%, were: traditional-1.25 and 0.9 × 10⁶ cycles; modified-0.58 and 11.7 × 10⁶ cycles; and monolithic-1.05 and 16.5 × 10⁶ cycles. Traditional crowns showed greater susceptibility to fatigue, the modified group presented higher propensity to early failures, and the monolithic group showed no susceptibility to fatigue. The modified and monolithic groups presented the highest number of crowns with no failures after the fatigue test. The three crown designs presented significantly different behaviors under fatigue. The modified and monolithic groups presented less probability of failure after 2 × 10⁶ cycles. PMID:26509988

  5. Failure probability of three designs of zirconia crowns

    PubMed Central

    Ramos, G. Freitas; Monteiro, E. Barbosa Carmona; Bottino, M.A.; Zhang, Y.; de Melo, R. Marques

    2015-01-01

    Objectives This study utilized a 2-parameter Weibull analysis for evaluation of lifetime of fully or partially porcelain-/glaze-veneered zirconia crowns after fatigue test. Methods Sixty first molars were selected and prepared for full-coverage crowns with three different designs(n = 20): Traditional –crowns with zirconia framework covered with feldspathic porcelain; Modified– crowns partially covered with veneering porcelain; and Monolithic–full-contour zirconia crowns. All specimens were treated with a glaze layer. Specimens were subjected to mechanical cycling (100N, 3Hz) with a piston with hemispherical tip (Ø=6 mm) until the specimens failed or up to 2×106 cycles. Every 500,000 cycles intervals, the fatigue tests were interrupted, and stereomicroscopy (10 X) was used to inspect the specimens for damage. We performed Weibull analysis of interval data to calculate the number of failures in each interval. Results The types and number of failures according to the groups were: cracking (Traditional-13, Modified-6) and chipping (Traditional-4) of the feldspathic porcelain, followed by delamination (Traditional-1) at the veneer/core interface and debonding (Monollithic-2) at the cementation interface. Weibull parameters (beta, scale; and eta, shape), with a two-sided confidence interval of 95%, were: Traditional – 1.25 and 0.9 × 106cycles; Modified– 0.58 and 11.7 × 106 cycles; and Monolithic – 1.05 and 16.5 × 106 cycles. Traditional crowns showed greater susceptibility to fatigue, the Modified group presented higher propensity to early failures, and the Monolithic group showed no susceptibility to fatigue. The Modified and Monolithic groups presented the highest number of crowns with no failures after the fatigue test. Conclusions The three crown designs presented significantly different behaviors under fatigue. The Modified and the Monolithic groups presented less probability to failure after 2×106cycles. PMID:26509988

  6. Analysis of the dental morphology of Plio-Pleistocene hominids. III. Mandibular premolar crowns.

    PubMed Central

    Wood, B A; Uytterschaut, H

    1987-01-01

    Accurate measurements were made of the overall size of both the crown and its components of 91 mandibular premolar teeth of early hominids. The shape of the crown outline and the fissure pattern, and the expression of four morphological traits, were also recorded. Non-dental criteria were used to allocate the specimens into four major taxonomic categories (EAFROB, EAFHOM, SAFROB and SAFGRA), approximating to the hypodigms of, respectively, A. boisei, H. habilis and Homo sp., A. robustus and A. africanus. Those specimens that could not be so allocated were regarded as 'unknown'. Intertaxonomic overall size differences were established for both the P3 and P4, with the latter showing little overlap in crown size between the three taxonomic categories usually associated with East African sites (i.e. EAFROB, EAFHOM and SAFGRA). Crown shape is a better discriminator between taxonomic groups for P3 than for P4, with the P3s of EAFHOM showing less buccolingual expansion than the other taxonomic categories. Cusp number, the location of the lingual cusp and the expression of the median longitudinal fissure, show systematic variation between the main taxonomic categories, with the 'robust' taxa being distinguished by additional distal cusps, and a more deeply incised median longitudinal fissure, and EAFHOM being peculiar in having a distally situated lingual cusp. Marginal grooves show more overlap in their incidence and expression between taxonomic categories. Both the 'robust' australopithecine taxonomic categories have relatively large talonids, apparently at the expense of the size of the buccal cusp. The relative talonid enlargement was greater for P3 than for P4, a conclusion which is at variance with previous published assessments. Investigation of the allometric relationships between relative talonid size and overall crown size in the pooled 'non-robust' taxonomic categories did not suggest that talonid enlargement was a simple consequence of a larger-size crown. The

  7. Analysis of the dental morphology of Plio-Pleistocene hominids. III. Mandibular premolar crowns.

    PubMed

    Wood, B A; Uytterschaut, H

    1987-10-01

    Accurate measurements were made of the overall size of both the crown and its components of 91 mandibular premolar teeth of early hominids. The shape of the crown outline and the fissure pattern, and the expression of four morphological traits, were also recorded. Non-dental criteria were used to allocate the specimens into four major taxonomic categories (EAFROB, EAFHOM, SAFROB and SAFGRA), approximating to the hypodigms of, respectively, A. boisei, H. habilis and Homo sp., A. robustus and A. africanus. Those specimens that could not be so allocated were regarded as 'unknown'. Intertaxonomic overall size differences were established for both the P3 and P4, with the latter showing little overlap in crown size between the three taxonomic categories usually associated with East African sites (i.e. EAFROB, EAFHOM and SAFGRA). Crown shape is a better discriminator between taxonomic groups for P3 than for P4, with the P3s of EAFHOM showing less buccolingual expansion than the other taxonomic categories. Cusp number, the location of the lingual cusp and the expression of the median longitudinal fissure, show systematic variation between the main taxonomic categories, with the 'robust' taxa being distinguished by additional distal cusps, and a more deeply incised median longitudinal fissure, and EAFHOM being peculiar in having a distally situated lingual cusp. Marginal grooves show more overlap in their incidence and expression between taxonomic categories. Both the 'robust' australopithecine taxonomic categories have relatively large talonids, apparently at the expense of the size of the buccal cusp. The relative talonid enlargement was greater for P3 than for P4, a conclusion which is at variance with previous published assessments. Investigation of the allometric relationships between relative talonid size and overall crown size in the pooled 'non-robust' taxonomic categories did not suggest that talonid enlargement was a simple consequence of a larger-size crown. The

  8. The effect of investment type on the fit of cast titanium crowns.

    PubMed

    Mori, T; Jean-Louis, M; Yabugami, M; Togaya, T

    1994-12-01

    In order to determine the best laboratory procedure for titanium crown casting, a set of thermal expansion measurements and casting experiments were carried out using a casting machine (argon arc, pressure difference type) and three different investments, two conventional SiO2 based investments and a new Al2O3/MgO based investment. The thermal expansion measurements involved a cycle of heating and cooling. The relatively low mould temperatures recommended (200 degrees C) or chosen (350 degrees C) for the conventional investments provided zero or negative mould expansion for the compensation of metal shrinkage. Crowns made from these investments exhibited heavy reaction with the mould, and the common cleaning method of sand blasting appeared to be essential. This cleaning process, however, was not adequate for the assessment of casting accuracy as the short sand blasting time (15 s) rapidly altered the fit of the crowns. The metal reacted little with the new investment and the best compensation (0.15 mm discrepancy) for the metal shrinkage, as assessed 'as cast', was achieved when the investment was heated to 950 degrees C and then cooled to the recommended mould temperature (600 degrees C). PMID:7832681

  9. Effect of Vertical Misfit on Screw Joint Stability of Implant-Supported Crowns

    NASA Astrophysics Data System (ADS)

    Assunção, Wirley Gonçalves; Delben, Juliana Aparecida; Tabata, Lucas Fernando; Barão, Valentim Adelino Ricardo; Gomes, Érica Alves

    2011-08-01

    The passive fit between prosthesis and implant is a relevant factor for screw joint stability and treatment success. The aim of this study was to evaluate the influence of vertical misfit in abutment-implant interface on preload maintenance of retention screw of implant-supported crowns. The crowns were fabricated with different abutments and veneering materials and divided into 5 groups ( n = 12): Gold UCLA abutments cast in gold alloy veneered with ceramic (Group I) and resin (Group II), UCLA abutments cast in titanium veneered with ceramic (Group III) and resin (Group IV), and zirconia abutments with ceramic veneering (Group V). The crowns were attached to implants by gold retention screws with 35-N cm insertion torque. Specimens were submitted to mechanical cycling up to 106 cycles. Measurements of detorque and vertical misfit in abutment-implant interface were performed before and after mechanical cycling. ANOVA revealed statistically significant difference ( P < 0.05) among groups for vertical misfit measured before and after mechanical cycling. The abutments cast in titanium exhibited the highest misfit values. Pearson correlation test did not demonstrate significant correlation ( P > 0.05) between vertical misfit and detorque value. It was concluded that vertical misfit did not influence torque maintenance and the abutments cast in titanium exhibited the highest misfit values.

  10. Validation of Scores on the Marlowe-Crowne Social Desirability Scale and the Balanced Inventory of Desirable Responding

    ERIC Educational Resources Information Center

    Leite, Walter L.; Beretvas, S. Natasha

    2005-01-01

    The Marlowe-Crowne Social Desirability Scale (MCSDS), the most commonly used social desirability bias (SDB) assessment, conceptualizes SDB as an individual's need for approval. The Balanced Inventory of Desirable Responding (BIDR) measures SDB as two separate constructs: impression management and self-deception. Scores on SDB scales are commonly…

  11. Large area mapping of southwestern forest crown cover, canopy height, and biomass using the NASA Multiangle Imaging Spectro-Radiometer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid canopy reflectance model inversion experiment was performed using multiangle reflectance data from the NASA Multi-angle Imaging Spectro-Radiometer (MISR) on the Earth Observing System Terra satellite, with the goal of obtaining measures of forest fractional crown cover, mean canopy height, a...

  12. Accuracy Assessment of Crown Delineation Methods for the Individual Trees Using LIDAR Data

    NASA Astrophysics Data System (ADS)

    Chang, K. T.; Lin, C.; Lin, Y. C.; Liu, J. K.

    2016-06-01

    Forest canopy density and height are used as variables in a number of environmental applications, including the estimation of biomass, forest extent and condition, and biodiversity. The airborne Light Detection and Ranging (LiDAR) is very useful to estimate forest canopy parameters according to the generated canopy height models (CHMs). The purpose of this work is to introduce an algorithm to delineate crown parameters, e.g. tree height and crown radii based on the generated rasterized CHMs. And accuracy assessment for the extraction of volumetric parameters of a single tree is also performed via manual measurement using corresponding aerial photo pairs. A LiDAR dataset of a golf course acquired by Leica ALS70-HP is used in this study. Two algorithms, i.e. a traditional one with the subtraction of a digital elevation model (DEM) from a digital surface model (DSM), and a pit-free approach are conducted to generate the CHMs firstly. Then two algorithms, a multilevel morphological active-contour (MMAC) and a variable window filter (VWF), are implemented and used in this study for individual tree delineation. Finally, experimental results of two automatic estimation methods for individual trees can be evaluated with manually measured stand-level parameters, i.e. tree height and crown diameter. The resulting CHM generated by a simple subtraction is full of empty pixels (called "pits") that will give vital impact on subsequent analysis for individual tree delineation. The experimental results indicated that if more individual trees can be extracted, tree crown shape will became more completely in the CHM data after the pit-free process.

  13. Composite fuselage crown panel manufacturing technology

    NASA Technical Reports Server (NTRS)

    Willden, Kurtis; Metschan, S.; Grant, C.; Brown, T.

    1992-01-01

    Commercial fuselage structures contain significant challenges in attempting to save manufacturing costs with advanced composite technology. Assembly issues, material costs, and fabrication of elements with complex geometry are each expected to drive the cost of composite fuselage structures. Boeing's efforts under the NASA ACT program have pursued key technologies for low-cost, large crown panel fabrication. An intricate bond panel design and manufacturing concepts were selected based on the efforts of the Design Build Team (DBT). The manufacturing processes selected for the intricate bond design include multiple large panel fabrication with the Advanced Tow Placement (ATP) process, innovative cure tooling concepts, resin transfer molding of long fuselage frames, and utilization of low-cost material forms. The process optimization for final design/manufacturing configuration included factory simulations and hardware demonstrations. These efforts and other optimization tasks were instrumental in reducing cost by 18 percent and weight by 45 percent relative to an aluminum baseline. The qualitative and quantitative results of the manufacturing demonstrations were used to assess manufacturing risks and technology readiness.

  14. The energetic characterization of pineapple crown leaves.

    PubMed

    Braga, R M; Queiroga, T S; Calixto, G Q; Almeida, H N; Melo, D M A; Melo, M A F; Freitas, J C O; Curbelo, F D S

    2015-12-01

    Energetic characterization of biomass allows for assessing its energy potential for application in different conversion processes into energy. The objective of this study is to physicochemically characterize pineapple crown leaves (PC) for their application in energy conversion processes. PC was characterized according to ASTM E871-82, E1755-01, and E873-82 for determination of moisture, ash, and volatile matter, respectively; the fixed carbon was calculated by difference. Higher heating value was determined by ASTM E711-87 and ash chemical composition was determined by XRF. The thermogravimetric and FTIR analyses were performed to evaluate the thermal decomposition and identify the main functional groups of biomass. PC has potential for application in thermochemical processes, showing high volatile matter (89.5%), bulk density (420.8 kg/m(3)), and higher heating value (18.9 MJ/kg). The results show its energy potential justifying application of this agricultural waste into energy conversion processes, implementing sustainability in the production, and reducing the environmental liabilities caused by its disposal. PMID:26233737

  15. Cost studies for commercial fuselage crown designs

    NASA Technical Reports Server (NTRS)

    Walker, T. H.; Smith, P. J.; Truslove, G.; Willden, K. S.; Metschan, S. L.; Pfahl, C. L.

    1991-01-01

    Studies were conducted to evaluate the cost and weight potential of advanced composite design concepts in the crown region of a commercial transport. Two designs from each of three design families were developed using an integrated design-build team. A range of design concepts and manufacturing processes were included to allow isolation and comparison of cost centers. Detailed manufacturing/assembly plans were developed as the basis for cost estimates. Each of the six designs was found to have advantages over the 1995 aluminum benchmark in cost and weight trade studies. Large quadrant panels and cobonded frames were found to save significant assembly labor costs. Comparisons of high- and intermediate-performance fiber systems were made for skin and stringer applications. Advanced tow placement was found to be an efficient process for skin lay up. Further analysis revealed attractive processes for stringers and frames. Optimized designs were informally developed for each design family, combining the most attractive concepts and processes within that family. A single optimized design was selected as the most promising, and the potential for further optimization was estimated. Technical issues and barriers were identified.

  16. The vibration of inclined backrests: perception and discomfort of vibration applied parallel to the back in the z-axis of the body.

    PubMed

    Basri, Bazil; Griffin, Michael J

    2011-12-01

    This study determined how backrest inclination and the frequency of vibration influence the perception and discomfort of vibration applied parallel to the back (vertical vibration when sitting upright, horizontal vibration when recumbent). Subjects experienced backrest vibration at frequencies in the range 2.5 to 25 Hz at vibration magnitudes up to 24 dB above threshold. Absolute thresholds, equivalent comfort contours, and the principal locations for feeling vibration were determined with four backrest inclinations: 0° (upright), 30°, 60° and 90° (recumbent). With all backrest inclinations, acceleration thresholds and equivalent comfort contours were similar and increased with increasing frequency at 6 dB per octave (i.e. velocity constant). It is concluded that backrest inclination has little effect on the frequency dependence of thresholds and equivalent comfort contours for vibration applied along the back, and that the W (d) frequency weighting in current standards is appropriate for evaluating z-axis vibration of the back at all backrest inclinations. STATEMENT OF RELEVANCE: To minimise the vibration discomfort of seated people, it is necessary to understand how discomfort varies with backrest inclination. It is concluded that the vibration on backrests can be measured using a pad between the backrest and the back, so that it reclines with the backrest, and the measured vibration evaluated without correcting for the backrest inclination. PMID:22103729

  17. TRANSIT PROBABILITIES FOR STARS WITH STELLAR INCLINATION CONSTRAINTS

    SciTech Connect

    Beatty, Thomas G.; Seager, Sara

    2010-04-01

    The probability that an exoplanet transits its host star is high for planets in close orbits, but drops off rapidly for increasing semimajor axes. This makes transit surveys for planets with large semimajor axes orbiting bright stars impractical, since one would need to continuously observe hundreds of stars that are spread out over the entire sky. One way to make such a survey tractable is to constrain the inclination of the stellar rotation axes in advance, and thereby enhance the transit probabilities. We derive transit probabilities for stars with stellar inclination constraints, considering a reasonable range of planetary system inclinations. We find that stellar inclination constraints can improve the transit probability by almost an order of magnitude for habitable-zone planets. When applied to an ensemble of stars, such constraints dramatically lower the number of stars that need to be observed in a targeted transit survey. We also consider multiplanet systems where only one planet has an identified transit and derive the transit probabilities for the second planet assuming a range of mutual planetary inclinations.

  18. Evolution of magnetic field inclination in a forming penumbra

    NASA Astrophysics Data System (ADS)

    Jurčák, Jan; Bello González, Nazaret; Schlichenmaier, Rolf; Rezaei, Reza

    2014-12-01

    As a sunspot penumbra forms, the magnetic field vector at the outer boundary of the protospot undergoes a transformation. We study the changes of the magnetic field vector at this boundary as a penumbral segment forms. We analyze a set of spectropolarimetric maps covering 2 hr during the formation of a sunspot in NOAA 11024. The data were recorded with the GFPI instrument attached to the German VTT. We observe a stationary umbra/quiet Sun boundary, where the magnetic field becomes more horizontal with time. The magnetic field inclination increases by 5°, reaching a maximum value of about 59°. The maximum inclination coincides with the onset of filament formation. In time, the penumbra filaments become longer and the penumbral bright grains protrude into the umbra, where the magnetic field is stronger and more vertical. Consequently, we observe a decrease in the magnetic field inclination at the boundary as the penumbra grows. In summary, in order to initiate the formation of the penumbra, the magnetic field at the umbral (protospot) boundary becomes more inclined. As the penumbra grows, the umbra/penumbra boundary migrates inwards, and at this boundary the magnetic field turns more vertical again, while it remains inclined in the outer penumbra.

  19. Thickness of immediate dentin sealing materials and its effect on the fracture load of a reinforced all-ceramic crown

    PubMed Central

    Spohr, Ana Maria; Borges, Gilberto Antonio; Platt, Jeffrey A.

    2013-01-01

    Objectives: The objective of this study is to evaluate, in vitro, the thickness of immediate dentin sealing (IDS) materials on full crown preparations and its effect on the fracture load of a reinforced all-ceramic crown. Materials and Methods: Sixty premolars received full crown preparation and were divided into the following groups according to the IDS technique: G1-control; G2-Clearfil SE Bond; and G3-Clearfil SE Bond and Protect Liner F. After the impressions were taken, the preparations were temporized with acrylic resin crowns. IPS empress 2 restorations were fabricated and later cemented on the preparations with Panavia F. 10 specimens from each group were submitted to fracture load testing. The other 10 specimens were sectioned buccolingually before the thicknesses of Panavia F, Clearfil SE Bond and Protect Liner F were measured in 10 different positions using a microscope. Results: According to analysis of variance and Tukey's test, the fracture load of Group 3 (1300 N) was significantly higher than that of Group 1 (1001 N) (P < 0.01). Group 2 (1189 N) was not significantly different from Groups 1 and 3. The higher thickness of Clearfil SE Bond was obtained in the concave part of the preparation. Protect Liner F presented a more uniform range of values at different positions. The thickness of Panavia F was higher in the occlusal portion of the preparation. Conclusions: The film thickness formed by the IDS materials is influenced by the position under the crown, suggesting its potential to increase the fracture load of the IPS empress 2 ceramic crowns. PMID:24932124

  20. Total skin electron beam therapy using an inclinable couch on motorized table and a compensating filter

    SciTech Connect

    Fuse, H.; Suzuki, K.; Shida, K.; Takahashi, H.; Kobayashi, D.; Seki, M.; Mori, Y.; Sakae, T.; Isobe, T.; Okumura, T.; Sakurai, H.

    2014-06-15

    Total skin electron beam is a specialized technique that involves irradiating the entire skin from the skin surface to only a few millimetres in depth. In the Stanford technique, the patient is in a standing position and six different directional positions are used during treatment. Our technique uses large electron beams in six directions with an inclinable couch on motorized table and a compensating filter was also used to spread the electron beam and move its intensity peak. Dose uniformity measurements were performed using Gafchromic films which indicated that the surface dose was 2.04 ± 0.05 Gy. This technique can ensure the dose reproducibility because the patient is fixed in place using an inclinable couch on a motorized table.

  1. Diffuse ultraviolet erythemal irradiance on inclined planes: a comparison of experimental and modeled data.

    PubMed

    Utrillas, María P; Marín, María J; Esteve, Anna R; Estellés, Victor; Tena, Fernando; Cañada, Javier; Martínez-Lozano, José A

    2009-01-01

    Values of measured and modeled diffuse UV erythemal irradiance (UVER) for all sky conditions are compared on planes inclined at 40 degrees and oriented north, south, east and west. The models used for simulating diffuse UVER are of the geometric-type, mainly the Isotropic, Klucher, Hay, Muneer, Reindl and Schauberger models. To analyze the precision of the models, some statistical estimators were used such as root mean square deviation, mean absolute deviation and mean bias deviation. It was seen that all the analyzed models reproduce adequately the diffuse UVER on the south-facing plane, with greater discrepancies for the other inclined planes. When the models are applied to cloud-free conditions, the errors obtained are higher because the anisotropy of the sky dome acquires more importance and the models do not provide the estimation of diffuse UVER accurately. PMID:19496991

  2. Role of Edge Inclination in an Optical Microdisk Resonator for Label-Free Sensing

    PubMed Central

    Gandolfi, Davide; Ramiro-Manzano, Fernando; Rebollo, Francisco Javier Aparicio; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

    2015-01-01

    In this paper, we report on the measurement and modeling of enhanced optical refractometric sensors based on whispering gallery modes. The devices under test are optical microresonators made of silicon nitride on silicon oxide, which differ in their sidewall inclination angle. In our approach, these microresonators are vertically coupled to a buried waveguide with the aim of creating integrated and cost-effective devices. Device modeling shows that the optimization of the device is a delicate balance of the resonance quality factor and evanescent field overlap with the surrounding environment to analyze. By numerical simulations, we show that the microdisk thickness is critical to yield a high figure of merit for the sensor and that edge inclination should be kept as high as possible. We also show that bulk-sensing figures of merit as high as 1600 RIU−1 (refractive index unit) are feasible. PMID:25730483

  3. Role of edge inclination in an optical microdisk resonator for label-free sensing.

    PubMed

    Gandolfi, Davide; Ramiro-Manzano, Fernando; Rebollo, Francisco Javier Aparicio; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

    2015-01-01

    In this paper, we report on the measurement and modeling of enhanced optical refractometric sensors based on whispering gallery modes. The devices under test are optical microresonators made of silicon nitride on silicon oxide, which differ in their sidewall inclination angle. In our approach, these microresonators are vertically coupled to a buried waveguide with the aim of creating integrated and cost-effective devices. Device modeling shows that the optimization of the device is a delicate balance of the resonance quality factor and evanescent field overlap with the surrounding environment to analyze. By numerical simulations, we show that the microdisk thickness is critical to yield a high figure of merit for the sensor and that edge inclination should be kept as high as possible. We also show that bulk-sensing figures of merit as high as 1600 RIU(-1) (refractive index unit) are feasible. PMID:25730483

  4. The microscopic structure of mono-disperse granular heaps and sediments of particles on inclined surfaces.

    PubMed

    Topic, Nikola; Schaller, Fabian M; Schröder-Turk, Gerd E; Pöschel, Thorsten

    2016-04-01

    Granular heaps of particles created by deposition of mono-disperse particles raining from an extended source of finite size are characterized by a non-homogeneous field of density. It was speculated that this inhomogeneity is due to the transient shape of the sediment during the process of construction of the heap, thus reflecting the history of the creation of the heap. By comparison of structural characteristics of the heap with sediments created on top of inclined planes exploiting the method of Minkowski tensors, we provide further evidence to support this hypothesis. Moreover, for the case of sediments generated by homogeneous rain on surfaces, we provide relationships between the inclination of the surface and the Minkowski measures characterizing the isotropy of local particle environments. PMID:26892630

  5. An experimental investigation of the motion of long bubbles in inclined tubes

    SciTech Connect

    Bendiksen, K.H.

    1984-08-01

    The relative motion of single long air bubbles suspended in a constant liquid flow in inclined tubes has been studied experimentally. Specially designed instrumentation, based on the difference in refractive properties of air and liquid with respect to infrared light, has been constructed and applied to measure bubble propagation rates. A series of experiments were performed to determine the effect of tube inclination on bubble motion with liquid Reynolds and Froude numbers, and tube diameter as the most important parameters. Particular aspects of the flow are described theoretically, and model predictions were found to compare well with observations. A correlation of bubble and average liquid velocities, based on a least squares fit to the data is suggested. Comparisons with other relevant models and data are also presented.

  6. Crown depth as a result of evolutionary games: decreasing solar angle should lead to shallower, not deeper crowns.

    PubMed

    Vermeulen, Peter Johannes

    2014-06-01

    There is a general notion in the literature that, with increasing latitude, trees have deeper crowns as a result of a lower solar elevation angle. However, these predictions are based on models that did not include the effects of competition for light between individuals. Here, I argue that there should be selection for trees to increase the height of the crown base, as this decreases shading by neighbouring trees, leading to an evolutionarily stable strategy (ESS). Because the level of between-tree shading increases with decreasing solar angle, the predicted ESS will shift to higher crown base height. This argument is supported by a simulation model to check for the effects of crown shape and the change of light intensity that occurs with changing solar angle on model outcomes. So, the lower solar angle at higher latitudes would tend to select for shallower, and not deeper, crowns. This casts doubt on the common belief that a decreasing solar angle increases crown depth. More importantly, it shows that different assumptions about what should be optimized can lead to different predictions, not just for absolute trait values, but for the direction of selection itself. PMID:24548219

  7. Enantiomeric recognition of organic ammonium salts by chiral crown ethers based on the pyridino-18-crown-6 structure

    SciTech Connect

    Davidson, R.B.; Bradshaw, J.S.; Jones, B.A.; Dalley, N.K.; Christensen, J.J.; Izatt, R.M.

    1984-01-27

    Enantiomeric recognition by several chiral dimethyl-substituted macrocycles of the pyridino-18-crown-6 type for chiral organic ammonium salts has been studied by titration calorimetry in CH/sub 3/OH, temperature-dependent /sup 1/H NMR spectroscopy in CD/sub 2/CL/sub 2/, and selective crystallization. Results from the three procedures are consistent in demonstrating either host-guest recognition or nonrecognition in the systems investigated. Futhermore, enaniomeric recognition by one chiral host for a pair of chiral guests is correlated with X-ray crystallographic data for the same system. The chiral dimethyl-substituted ligands used in the study include three dimethyl diester pyridino-18-crown-6 ligands, dimethyl thiono diester pyridino-18-crown-6, and dimethyl-pyridino-18-crown-6 ligands. All of these ligands exhibited chiral recognition. Dimethylpyridino-18-crown-6 in complexation with (R)- and (S)-(..cap alpha..-(1-naphthyl)ethyl)ammonium perchlorate exhibited the largest ratio of ..delta..G/sub c/+ yet observed by the /sup 1/H NMR technique. A diphenyl-substituted diester pyridino-18-crown-6 where the phenyl substituents are in less rigid portion of the macrocycle failed to show chiral recognition.

  8. The Association between Lower Incisal Inclination and Morphology of the Supporting Alveolar Bone — A Cone-Beam CT Study

    PubMed Central

    Yu, Quan; Pan, Xiao-gang; Ji, Guo-ping; Shen, Gang

    2009-01-01

    Aim To investigate the relationship between the positioning of the lower central incisor and physical morphology of the surrounding alveolar bone. Methodology Thirty-eight patients (18 males, 20 females), with mean age of 13.4 years, were included in this study. As part of orthodontic treatment planning the patients were required to take dental Cone-beam CT (CBCT) covering the region of lower incisors, the surrounding alveolar bone and the mandibular symphysis. The cephalometric parameters were designed and measured to indicate the inclination of lower central incisor and physical morphology of the adjacent alveolar bone. Computer-aided descriptive statistical analysis was performed using SPSS 15.0 software package for Windows. A correlation analysis and a linear regression analysis between the incisor inclination and the alveolar bone morphology were performed. Results Significant positive correlations were found between the lower central incisor inclination and the morphological contour of the alveolar bone (P <0.05). The lower central incisor root apex was closer to the lingual alveolar crest when it was buccally inclined. Conclusion The morphology of the alveolar bone may be affected by incisal inclination. PMID:20690425

  9. On the inclination and habitability of the HD 10180 system

    SciTech Connect

    Kane, Stephen R.; Gelino, Dawn M.

    2014-09-10

    There are numerous multi-planet systems that have now been detected via a variety of techniques. These systems exhibit a range of both planetary properties and orbital configurations. For those systems without detected planetary transits, a significant unknown factor is the orbital inclination. This produces an uncertainty in the mass of the planets and their related properties, such as atmospheric scale height. Here we investigate the HD 10180 system, which was discovered using the radial velocity technique. We provide a new orbital solution for the system which allows for eccentric orbits for all planets. We show how the inclination of the system affects the mass/radius properties of the planets and how the detection of phase signatures may resolve the inclination ambiguity. We finally evaluate the Habitable Zone properties of the system and show that the g planet spends 100% of an eccentric orbit within the Habitable Zone.

  10. Interplay between geometry and temperature for inclined Casimir plates

    SciTech Connect

    Weber, Alexej; Gies, Holger

    2009-09-15

    We provide further evidence for the nontrivial interplay between geometry and temperature in the Casimir effect. We investigate the temperature dependence of the Casimir force between an inclined semi-infinite plate above an infinite plate in D dimensions using the worldline formalism. Whereas the high-temperature behavior is always found to be linear in T in accordance with dimensional-reduction arguments, different power-law behaviors at small temperatures emerge. Unlike the case of infinite parallel plates, which shows the well-known T{sup D} behavior of the force, we find a T{sup D-1} behavior for inclined plates, and a {approx}T{sup D-0.3} behavior for the edge effect in the limit where the plates become parallel. The strongest temperature dependence {approx}T{sup D-2} occurs for the Casimir torque of inclined plates. Numerical as well as analytical worldline results are presented.

  11. Low velocity impact of inclined CSM composite laminates

    SciTech Connect

    Arnold, W.S.; Madjidi, S.; Marshall, I.H.; Robb, M.D.

    1993-12-31

    The damage tolerance of composite laminates subject to low velocity impact is an important aspect of current design philosophies required to ensure the integrity of primary load bearing structures. To the authors knowledge, no work published in the open literature has addressed the damage tolerance of composites subject to impacts at non-perpendicular inclinations, which in practical situations is the most common form of impact. This paper describes an experimental study, devised to assess the influence of inclined impact on the residual strength characteristics of CSM laminates. Preliminary experimental results and comparisons with previous work on flat plate impact tests are presented. The influence of the degree of inclination and impact energy are correlated with the laminates damage area and residual tensile properties.

  12. Comparison of the Effect of Dentin Bonding, Dentin Sealing Agents on the Microleakage of Provisional Crowns Fabricated with Direct and Indirect Technique-An Invitro Study

    PubMed Central

    Muthukumar, B; Kumar, M Vasantha

    2015-01-01

    showed the least amount of microleakage when compared with group A and group C. Group C (Dental Varnish) specimen showed comparatively more amount of microleakage than that of group B. Group A (control group) specimens showed the maximum amount of microleakage. Conclusion The application of a single layer of Dental varnish appears to be of no significant benefit when compared to crowns cemented with the application of Dentin bonding agent on the tooth surface. The application of a single layer of Dentin bonding agent (Solobond M) and temporary crowns fabricated with direct technique may be of some benefit for crown preparations as an interim measure prior to the luting of final crown. PMID:26266219

  13. Crown ether-modified electrodes for the simultaneous stripping voltammetric determination of Cd(II), Pb(II) and Cu(II).

    PubMed

    Serrano, Núria; González-Calabuig, Andreu; del Valle, Manel

    2015-06-01

    This work describes the immobilization of 4-carboxybenzo-18-crown-6 (CB-18-crown-6) and 4-carboxybenzo-15-crown-5 (CB-15-crown-5) assisted by lysine on aryl diazonium salt monolayers anchored to the surface of graphite-epoxy composite electrodes (GEC), and their use for the simultaneous determination of Cd(II), Pb(II) and Cu(II) by differential pulse anodic stripping voltammetry (DPASV). These modified electrodes display a good repeatability and reproducibility with detection and quantification limits at levels of µg L(-1) (ppb), confirming their suitability for the determination of Cd(II), Pb(II) and Cu(II) ions in environmental samples. The overlapped nature of the multimetal stripping measurements was resolved by employing the two-sensor array CB-15-crown-5-GEC and CB-18-crown-6-GEC, since the metal complex selectivity exhibited by the considered ligands could add some discrimination power. For the processing of the voltammograms, Discrete Wavelet Transform and Causal Index were selected as preprocessing tools for data compression coupled with an artificial neural network for the modeling of the obtained responses, allowing the resolution of mixtures of these metals with good prediction of their concentrations (correlation with expected values for an external test subset better than 0.942). PMID:25863381

  14. Does crown/implant ratio influence the survival and marginal bone level of short single implants in the mandibular molar? A preliminary investigation consisting of 12 patients.

    PubMed

    Ghariani, L; Segaan, L; Rayyan, M M; Galli, S; Jimbo, R; Ibrahim, A

    2016-02-01

    Crown/implant (C/I) ratio has been proven to not affect the survival of the implants; however, it is also a fact that no evidence exists with regard to the use of single short implants in the mandibular molar. The aim of this study was to determine whether the crown/implant ratios of single implant-supported fixed restorations on implants of 6-8 mm in the mandibular molar have an impact on the implant survival and marginal bone maintenance. Twelve short dental implants (6-8 mm) were installed and restored with single crowns, loaded after 3 months of healing. The restorations were divided according to crown-to-implant ratio into two groups: Group 1: C/I < 2.0 and Group 2: C/I ≧ 2.0. Alveolar bone loss was measured using CBCT scan, taken at the implant placement and after 12 months follow-up from loading. Reduced implant/crown ratio shown no statistic significant differences on implant survival and the alveolar bone level compared with recommended implant/crown ratio. Within the limitation of this study, it can be concluded that reduced C/I ratio could be used as a substitute for recommended C/I ratio in severely mandibular atrophic residual alveolar ridges. PMID:26333185

  15. Characterization of the Migration of Hop Volatiles into Different Crown Cork Liner Polymers and Can Coatings.

    PubMed

    Wietstock, Philip C; Glattfelder, Richard; Garbe, Leif-Alexander; Methner, Frank-Jürgen

    2016-04-01

    Absorption of hop volatiles by crown cork liner polymers and can coatings was investigated in beer during storage. All hop volatiles measured were prone to migrate into the closures, and the absorption kinetics was demonstrated to fit Fick's second law of diffusion well for a plane sheet. The extent and rate of diffusion were significantly dissimilar and were greatly dependent upon the nature of the volatile. Diffusion coefficients ranged from 1.32 × 10(-5) cm(2)/day (limonene) to 0.26 × 10(-5) cm(2)/day (α-humulene). The maximum amounts absorbed into the material at equilibrium were in the following order: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With the application of low-density polyethylene (LDPE) liners with oxygen-scavenging functionality, oxygen-barrier liners made up from high-density polyethylene (HDPE) or liner polymers from a different manufacturer had no significant effect on the composition of hop volatiles in beers after prolonged storage of 55 days; however, significantly higher amounts of myrcene and limonene were found in the oxygen-barrier-type crown cork, while all other closures behaved similarly. Can coatings were demonstrated to absorb hop volatiles in a similar pattern as crown corks but to a lesser extent. Consequently, significantly higher percentages of myrcene were found in the beers. PMID:26996287

  16. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors

    PubMed Central

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz; Riahi, Siavash

    2008-01-01

    Ionophore incorporated PVC membrane sensors are well-established analytical tools routinely used for the selective and direct measurement of a wide variety of different ions in complex biological and environmental samples. Potentiometric sensors have some outstanding advantages including simple design and operation, wide linear dynamic range, relatively fast response and rational selectivity. The vital component of such plasticized PVC members is the ionophore involved, defining the selectivity of the electrodes' complex formation. Molecular recognition causes the formation of many different supramolecules. Different types of supramolecules, like calixarenes, cyclodextrins and podands, have been used as a sensing material in the construction of ion selective sensors. Schiff's bases and crown ethers, which feature prominently in supramolecular chemistry, can be used as sensing materials in the construction of potentiometric ion selective electrodes. Up to now, more than 200 potentiometric membrane sensors for cations and anions based on Schiff's bases and crown ethers have been reported. In this review cation binding and anion complexes will be described. Liquid membrane sensors based on Schiff's bases and crown ethers will then be discussed.

  17. Numerical simulation of the casting process of titanium tooth crowns and bridges.

    PubMed

    Wu, M; Augthun, M; Wagner, I; Sahm, P R; Spiekermann, H

    2001-06-01

    The objectives of this paper were to simulate the casting process of titanium tooth crowns and bridges; to predict and control porosity defect. A casting simulation software, MAGMASOFT, was used. The geometry of the crowns with fine details of the occlusal surface were digitized by means of laser measuring technique, then converted and read in the simulation software. Both mold filling and solidification were simulated, the shrinkage porosity was predicted by a "feeding criterion", and the gas pore sensitivity was studied based on the mold filling and solidification simulations. Two types of dental prostheses (a single-crown casting and a three-unit-bridge) with various sprue designs were numerically "poured", and only one optimal design for each prosthesis was recommended for real casting trial. With the numerically optimized design, real titanium dental prostheses (five replicas for each) were made on a centrifugal casting machine. All the castings endured radiographic examination, and no porosity was detected in the cast prostheses. It indicates that the numerical simulation is an efficient tool for dental casting design and porosity control. PMID:15348262

  18. Large ontogenetic declines in intra-crown leaf area index in two temperate deciduous tree species.

    PubMed

    Nock, C A; Caspersen, J P; Thomas, S C

    2008-03-01

    The widespread occurrence of age-related changes in leaf morphology and allocation suggests that the leaf area index of individual trees (intra-crown LAI) may decline late in ontogeny. We used direct, within-canopy measurements to quantify the LAI of canopy trees with exposed crowns of two temperate deciduous species. Intra-crown LAI declined from approximately 7 to 4 in Acer saccharum, and from approximately 9.5 to 6.5 in Betula alleghaniensis, as tree size increased (from 15 to 72 cm diameter at breast height [dbh]). For A. saccharum, age (which varied from 30 to 160 years) was a significantly better predictor of LAI decline than dbh. We also modeled the effect of ontogenetic declines in LAI on understory light availability and found that light transmission increases significantly as canopy trees grow and mature. Our results thus suggest that gradual declines in LAI with tree age may play an important and overlooked role in contributing to the heterogeneity of sub-canopy light regimes in mature forests. PMID:18459337

  19. Impact of surface treatment of different reinforced glass-ceramic anterior crowns on load bearing capacity.

    PubMed

    Emslander, Angela; Reise, Michael; Eichberger, Marlis; Uhrenbacher, Julia; Edelhoff, Daniel; Stawarczyk, Bogna

    2015-01-01

    This study investigated the influence of different surface treatments on fracture load (FL) of canine crowns fabricated from two different pressable lithium-disilicate ceramics: A (HS10PC, estetic ceram, n=180) and B (IPS e.max Press, IvoclarVivadent, n=120). The standardized specimens were divided into groups of six different surface treatments and two glazing temperatures. A-group specimens were additionally assigned two glazing pastes with various thermal expansion coefficients (TEC). FL was measured and TECs were determined. Data were analyzed using three/one-way ANOVA followed by post-hoc Scheffe's test. B showed comparable or higher FL than A (B: 503-876 N; A: 375-734 N). Lithium-disilicate crowns show higher FL when not grinded but only polished or glazed. Glazing pastes affected FL depending on their TECs, firing temperature and crown treatment. TEC of A and B was 10 ppm/K, glazing pastes for A presented TECs of 7.5 ppm/K and 10 ppm/K and for B of 9 ppm/K. PMID:26438982

  20. Gap comparison between single crown and three-unit bridge zirconia substructures

    PubMed Central

    Charoenchitt, Masnisa; Asvanund, Chanavut

    2014-01-01

    PURPOSE To compare marginal and internal gaps of zirconia substructure of single crowns with those of three-unit fixed dental prostheses. MATERIALS AND METHODS Standardized Co-Cr alloy simulated second premolar and second molar abutments were fabricated and subsequently duplicated into type-III dental stone for working casts. After that, all zirconia substructures were made using Lava™ system. Marginal and internal gaps were measured in 2 planes (mesial-distal plane and buccal-palatal plane) at 5 locations: marginal opening (MO), chamfer area (CA), axial wall (AW), cusp tip (CT) and mid-occlusal (OA) using Replica technique. RESULTS There were significant differences between gaps at all locations. The mean ± SD of marginal gap in premolar was 43.6 ± 0.4 µm and 46.5 ± 0.5 µm for single crown and 3-unit bridge substructure respectively. For molar substructure the mean ± SD of marginal gap was 48.5 ± 0.4 µm and 52.6 ± 0.4 µm for single crown and 3-unit bridge respectively. The largest gaps were found at the occlusal area, which was 150.5 ± 0.5 µm and 154.5 ± 0.4 µm for single and 3-unit bridge premolar substructures respectively and 146.5 ± 0.4 µm and 211.5 ± 0.4 µm for single and 3-unit bridge molar substructure respectively. CONCLUSION Independent-samples t-test showed significant differences of gap in zirconia substructure between single crowns and three-unit bridge (P<.001). Therefore, the span length has the effect on the fit of zirconia substructure that is fabricated using CAD/CAM technique especially at the occlusal area. PMID:25177467

  1. A graph-based segmentation algorithm for tree crown extraction using airborne LiDAR data

    NASA Astrophysics Data System (ADS)

    Strîmbu, Victor F.; Strîmbu, Bogdan M.

    2015-06-01

    This work proposes a segmentation method that isolates individual tree crowns using airborne LiDAR data. The proposed approach captures the topological structure of the forest in hierarchical data structures, quantifies topological relationships of tree crown components in a weighted graph, and finally partitions the graph to separate individual tree crowns. This novel bottom-up segmentation strategy is based on several quantifiable cohesion criteria that act as a measure of belief on weather two crown components belong to the same tree. An added flexibility is provided by a set of weights that balance the contribution of each criterion, thus effectively allowing the algorithm to adjust to different forest structures. The LiDAR data used for testing was acquired in Louisiana, inside the Clear Creek Wildlife management area with a RIEGL LMS-Q680i airborne laser scanner. Three 1 ha forest areas of different conditions and increasing complexity were segmented and assessed in terms of an accuracy index (AI) accounting for both omission and commission. The three areas were segmented under optimum parameterization with an AI of 98.98%, 92.25% and 74.75% respectively, revealing the excellent potential of the algorithm. When segmentation parameters are optimized locally using plot references the AI drops to 98.23%, 89.24%, and 68.04% on average with plot sizes of 1000 m2 and 97.68%, 87.78% and 61.1% on average with plot sizes of 500 m2. More than introducing a segmentation algorithm, this paper proposes a powerful framework featuring flexibility to support a series of segmentation methods including some of those recurring in the tree segmentation literature. The segmentation method may extend its applications to any data of topological nature or data that has a topological equivalent.

  2. Transit Timing Variations for Inclined and Retrograde Exoplanetary Systems

    NASA Astrophysics Data System (ADS)

    Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

    2010-03-01

    We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0° < i < 170°, only reducing in amplitude for i>170°. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45°, becoming approximately constant for 45° < i < 135°, and then declining for i>135°. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0° to 180°, whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135° < i <= 180°), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

  3. Excitation of the orbital inclination of Iapetus during planetary encounters

    SciTech Connect

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio; Walsh, Kevin J.

    2014-09-01

    Saturn's moon, Iapetus, has an orbit in a transition region where the Laplace surface is bending from the equator to the orbital plane of Saturn. The orbital inclination of Iapetus to the local Laplace plane is ≅ 8°, which is unexpected because the inclination should be ≅ 0 if Iapetus formed from a circumplanetary disk on the Laplace surface. It thus appears that some process has pumped up Iapetus's inclination while leaving its eccentricity near zero (e ≅ 0.03 at present). Here, we examined the possibility that Iapetus's inclination was excited during the early solar system instability when encounters between Saturn and ice giants occurred. We found that the dynamical effects of planetary encounters on Iapetus's orbit sensitively depend on the distance of the few closest encounters. In 4 out of 10 instability cases studied here, the orbital perturbations were too large to be plausible. In one case, Iapetus's orbit was practically unaffected. In the remaining five cases, the perturbations of Iapetus's inclination were adequate to explain its present value. In three of these cases, however, Iapetus's eccentricity was excited to >0.1-0.25, and it is not clear whether it could have been damped to its present value (≅ 0.03) by a subsequent process (e.g., tides and dynamical friction from captured irregular satellites do not seem to be strong enough). Our results therefore imply that only 2 out of 10 instability cases (∼20%) can excite Iapetus's inclination to its current value (∼30% of trials lead to >5°) while leaving its orbital eccentricity low.

  4. Laser all-ceramic crown removal and pulpal temperature--a laboratory proof-of-principle study.

    PubMed

    Rechmann, P; Buu, N C H; Rechmann, B M T; Finzen, F C

    2015-11-01

    The objective of this proof-of-principle laboratory pilot study was to evaluate the temperature increase in the pulp chamber in a worst case scenario during Er:YAG laser debonding of all-ceramic crowns. Twenty extracted molars were prepared to receive all-ceramic IPS E.max CAD full contour crowns. The crowns were bonded to the teeth with Ivoclar Multilink Automix. Times for laser debonding and temperature rise in the pulp chamber using micro-thermocouples were measured. The Er:YAG was used with 560 mJ/pulse. The irradiation was applied at a distance of 5 mm from the crown surface. Additional air-water spray for cooling was utilized. Each all-ceramic crown was successfully laser debonded with an average debonding time of 135 ± 35 s. No crown fractured, and no damage to the underlying dentin was detected. The bonding cement deteriorated, but no carbonization at the dentin/cement interface occurred. The temperature rise in the pulp chamber averaged 5.4° ± 2.2 °C. During 8 out of the 20 crown removals, the temperature rise exceeded 5.5 °C, lasting 5 to 43 s (average 18.8 ± 11.6 s). A temperature rise of 11.5 °C occurred only once, while seven times the temperature rise was limited to 6.8 ± 0.5 °C. Temperature rises above 5.5 °C occurred only when the laser was applied from one side and additional cooling from the side opposite the irradiation. Er:YAG laser energy can successfully be used to efficiently debond all-ceramic crowns from natural teeth. Temperature rises exceeding 5.5 °C only occur when an additional air/water cooling from a dental syringe is inaccurately directed. To avoid possible thermal damage and to allow further heat diffusion, clinically temperature-reduced water might be applied. PMID:25782432

  5. Open-grown crown radius of eleven bottomland hardwood species: Prediction and use in assessing stocking

    SciTech Connect

    Goelz, J.C.G.

    1996-08-01

    Equations were prepared to predict crown radius for eleven species of open-grown bottomland hardwood trees. Crown radius was predicted as a function of diameter at breast height (dbh) and as a function of dbh, total height, and crown ratio. Equations were prepared for individual species and species groups. Pecan has the largest crowns over a broad range of dbh. Eastern cottonwood has the smallest crowns for most levels of dbh. Sweetgum has relatively small crowns for trees of small dbh, but crown radius is comparable to most species at the largest dbh. The crown radius predictions may be used to calculate crown competition factor. B-lines of stocking may be calculated that represent a stand of one species as well as a mixed-species stand of any particular species proportion.

  6. 3D statistical failure analysis of monolithic dental ceramic crowns.

    PubMed

    Nasrin, Sadia; Katsube, Noriko; Seghi, Robert R; Rokhlin, Stanislav I

    2016-07-01

    For adhesively retained ceramic crown of various types, it has been clinically observed that the most catastrophic failures initiate from the cement interface as a result of radial crack formation as opposed to Hertzian contact stresses originating on the occlusal surface. In this work, a 3D failure prognosis model is developed for interface initiated failures of monolithic ceramic crowns. The surface flaw distribution parameters determined by biaxial flexural tests on ceramic plates and point-to-point variations of multi-axial stress state at the intaglio surface are obtained by finite element stress analysis. They are combined on the basis of fracture mechanics based statistical failure probability model to predict failure probability of a monolithic crown subjected to single-cycle indentation load. The proposed method is verified by prior 2D axisymmetric model and experimental data. Under conditions where the crowns are completely bonded to the tooth substrate, both high flexural stress and high interfacial shear stress are shown to occur in the wall region where the crown thickness is relatively thin while high interfacial normal tensile stress distribution is observed at the margin region. Significant impact of reduced cement modulus on these stress states is shown. While the analyses are limited to single-cycle load-to-failure tests, high interfacial normal tensile stress or high interfacial shear stress may contribute to degradation of the cement bond between ceramic and dentin. In addition, the crown failure probability is shown to be controlled by high flexural stress concentrations over a small area, and the proposed method might be of some value to detect initial crown design errors. PMID:27215334

  7. Walking on inclines: energetics of locomotion in the ant Camponotus.

    PubMed

    Lipp, Alexandra; Wolf, Harald; Lehmann, Fritz-Olaf

    2005-02-01

    To assess energetic costs during rest and locomotion in a small insect, we measured metabolic rate in freely moving ants Camponotus sp. (average body mass 11.9 mg). The animals ran in a straight respirometric chamber in which locomotor speed and CO2 release were monitored simultaneously using flow-through respirometry and conventional video analysis. In resting intact ants, standard metabolic rate was on average 0.32 ml CO2 g(-1) body mass h(-1). During walking, the ants breathed continuously and metabolic rate increased between 4.3 times (level walking at 0-5 mm s(-1)) and 6.9 times (30 degrees ascent at 85-95 mm s(-1)) over resting rates. Metabolic rate increased linearly with increasing walking speed but superficially leveled off beyond speeds of about 70 mm s(-1). Walking on incline (uphill) or decline slopes (downhill) of up to 60 degrees had only a small effect on energy consumption compared to level walking. During slope walking, total metabolic rate averaged over all running speeds ranged from a minimum of 1.55+/-0.4 (horizontal running) to a maximum of 1.89+/-0.7 ml CO2 h(-1) g(-1) body mass (30 degrees downhill). The mean cost of transport in Camponotus was approximately 130 J g(-1) km(-1). The metabolic requirements in the comparatively small insect Camponotus for walking were mostly in the range expected from data obtained from other insects and small poikilotherms, and from allometric scaling laws. PMID:15695763

  8. Gingival health in relation to clinical crown length: a case report

    PubMed Central

    2009-01-01

    Introduction Gingival margin position in relation to synthetic crowns and crown length could be etiological factors in gingival health. Case presentation A 27-year-old male presented with necrotizing ulcerative gingivitis with short clinical crowns suggestive of altered passive eruption. Three years after the initial diagnosis, he presented with crowns on the maxillary incisors. There were short clinical crowns and marked gingival inflammation. Conclusion Placement of the crown margin could be an etiological factor in gingival inflammation. Therefore, should the margin be subgingival, equigingival or supragingival? PMID:20062553

  9. Gingival health in relation to clinical crown length: a case report

    PubMed Central

    2009-01-01

    Introduction Gingival margin position in relation to synthetic crowns and crown length could be etiological factors in gingival health. Case presentation A 27-year-old male presented with necrotizing ulcerative gingivitis with short clinical crowns suggestive of altered passive eruption. Three years after the initial diagnosis, he presented with crowns on the maxillary incisors. There were short clinical crowns and marked gingival inflammation. Conclusion Placement of the crown margin could be an etiological factor in gingival inflammation. Therefore, should the margin be subgingival, equigingival or supragingival? PMID:20184687

  10. Predictors of sprint start speed: the effects of resistive ground-based vs. inclined treadmill training.

    PubMed

    Myer, Gregory D; Ford, Kevin R; Brent, Jensen L; Divine, Jon G; Hewett, Timothy E

    2007-08-01

    There is currently no consensus with regard to the most effective method to train for improved acceleration, or with regard to which kinematic variable provides the greatest opportunity for improvement in this important performance characteristic. The purpose of this study was to determine the effects of resistive ground-based speed training and incline treadmill speed training on speed-related kinematic measures and sprint start speed. The hypothesis tested was that incline treadmill training would improve sprint start time, while the ground-based resistive training would not. Corollary hypotheses were that treadmill training would increase stride frequency and ground-based training would not affect kinematics during the sprint start. Thirty-one high school female soccer players (15.7 +/- 0.5 years) were assigned to either treadmill (n = 17) or ground-based (n = 14) training groups and trained 2 times a week for 6 weeks. The treadmill group utilized incline speed training on a treadmill, while the ground-based group utilized partner band resistance ground-based techniques. Three-dimensional motion analysis was used (4.5 m mark) before and after training to quantify kinematics during the fastest of 3 recorded sprint starts (9.1 m). Both groups decreased average sprint start time from 1.75 +/- 0.12 to 1.68 +/- 0.08 seconds (p < 0.001). Training increased stride frequency (p = 0.030) but not stride length. After training, total vertical pelvic displacement and stride length predicted 62% of the variance in sprint start time for the resistive ground-based group, while stride length and stride frequency accounted for 67% prediction of the variance in sprint start time for the treadmill group. The results of this study indicate that both incline treadmill and resistive ground-based training are effective at improving sprint start speed, although they potentially do so through differing mechanisms. PMID:17685716

  11. Experimental investigation of inclined liquid water jet flow onto vertically located superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kibar, Ali; Karabay, Hasan; Yiğit, K. Süleyman; Ucar, Ikrime O.; Erbil, H. Yıldırım

    2010-11-01

    In this study, the behaviour of an inclined water jet, which is impinged onto hydrophobic and superhydrophobic surfaces, has been investigated experimentally. Water jet was impinged with different inclination angles (15°-45°) onto five different hydrophobic surfaces made of rough polymer, which were held vertically. The water contact angles on these surfaces were measured as 102°, 112°, 123°, 145° and 167° showing that the last surface was superhydrophobic. Two different nozzles with 1.75 and 4 mm in diameters were used to create the water jet. Water jet velocity was within the range of 0.5-5 m/s, thus the Weber number varied from 5 to 650 and Reynolds number from 500 to 8,000 during the experiments. Hydrophobic surfaces reflected the liquid jet depending on the surface contact angle, jet inclination angle and the Weber number. The variation of the reflection angle with the Weber number showed a maximum value for a constant jet angle. The maximum value of the reflection angle was nearly equal to half of the jet angle. It was determined that the viscous drag decreases as the contact angle of the hydrophobic surface increases. The drag force on the wall is reduced dramatically with superhydrophobic surfaces. The amount of reduction of the average shear stress on the wall was about 40%, when the contact angle of the surface was increased from 145° to 167°. The area of the spreading water layer decreased as the contact angle of the surface increased and as the jet inclination angle, Weber number and Reynolds number decreased.

  12. Biology and control of the raspberry crown borer (Lepidoptera: Sesiidae).

    PubMed

    McKern, Jacquelyn A; Johnson, Donn T; Lewis, Barbara A

    2007-04-01

    This study explored the biology of raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), in Arkansas and the optimum timing for insecticide and nematode applications. The duration of P. marginata's life cycle was observed to be 1 yr in Arkansas. Insecticide trials revealed that bifenthrin, chlorpyrifos, imidacloprid, metaflumizone, and metofluthrin efficacy were comparable with that of azinphosmethyl, the only labeled insecticide for P. marginata in brambles until 2005. Applications on 23 October 2003 for plots treated with bifenthrin, chlorpyrifos, and azinphosmethyl resulted in >88% reduction in larvae per crown. Applications on 3 November 2004 of metaflumizone, metofluthrin, and bifenthrin resulted in >89% reduction in larvae per crown. Applications on 7 April 2005 for metofluthrin, imidacloprid, bifenthrin, metaflumizone, and benzoylphenyl urea resulted in >64% reduction in the number of larvae per crown. Applications on 6 May 2004 did not reduce larval numbers. The optimum timing for treatments was found to be between October and early April, before the larvae tunneled into the crowns of plants. Applying bifenthrin with as little as 468 liters water/ha (50 gal/acre) was found to be as effective against larvae as higher volumes of spray. Nematode applications were less successful than insecticides. Nematode applications of Steinernemafeltiae, Steinernema carpocapsae, and Heterorhabditis bacteriophora reduced larvae counts per plant by 46, 53, and 33%, respectively. PMID:17461064

  13. Effect of cements on fracture resistance of monolithic zirconia crowns

    PubMed Central

    Nakamura, Keisuke; Mouhat, Mathieu; Nergård, John Magnus; Lægreid, Solveig Jenssen; Kanno, Taro; Milleding, Percy; Örtengren, Ulf

    2016-01-01

    Abstract Objectives The present study investigated the effect of cements on fracture resistance of monolithic zirconia crowns in relation to their compressive strength. Materials and methods Four different cements were tested: zinc phosphate cement (ZPC), glass-ionomer cement (GIC), self-adhesive resin-based cement (SRC) and resin-based cement (RC). RC was used in both dual cure mode (RC-D) and chemical cure mode (RC-C). First, the compressive strength of each cement was tested according to a standard (ISO 9917-1:2004). Second, load-to-failure test was performed to analyze the crown fracture resistance. CAD/CAM-produced monolithic zirconia crowns with a minimal thickness of 0.5 mm were prepared and cemented to dies with each cement. The crown–die samples were loaded until fracture. Results The compressive strength of SRC, RC-D and RC-C was significantly higher than those of ZPC and GIC (p < 0.05). However, there was no significant difference in the fracture load of the crown between the groups. Conclusion The values achieved in the load-to-failure test suggest that monolithic zirconia crowns with a minimal thickness of 0.5 mm may have good resistance against fracture regardless of types of cements. PMID:27335900

  14. Digital modeling technology for full dental crown tooth preparation.

    PubMed

    Dai, Ning; Zhong, Yicheng; Liu, Hao; Yuan, Fusong; Sun, Yuchun

    2016-04-01

    A dental defect is one of the most common oral diseases, and it often requires a full crown restoration. In this clinical operation, the dentist must manually prepare the affected tooth for the full crown so that it has a convergence angle between 4° and 10°, no undercuts, and uniform and even shoulder widths and depths using a high speed diamond bur in the patient׳s mouth within one hour, which is a difficult task that requires visual-manual operation. The quality of the tooth preparation has an important effect on the success rate of the subsequent prosthodontic treatment. This study involved research into digital modeling technology for full dental crown tooth preparation. First, the margin line of the tooth preparation was designed using a semi-automatic interactive process. Second, the inserting direction was automatically computed. Then, the characteristic parameters and the constraints on the tooth preparation were defined for the model. Next, the shoulder and axial surface of the tooth preparation were formed using parametric modeling. Finally, the implicit surface of a radial basis function was used to construct the tooth preparation׳s occlusal surface. The experimental results verified that the method of digital modeling for full crown preparation proposed in this study can quickly and accurately implement personalized designs of various parameters, such as the shoulder width and the convergence angle; it provides a digital design tool for full crown preparation. PMID:26945598

  15. Orthodontic band retention on primary molar stainless steel crowns.

    PubMed

    Beemer, R L; Ferracane, J L; Howard, H E

    1993-01-01

    The retention of orthodontic bands cemented on primary molar stainless steel crowns (SSC) was studied in vitro. Unitek maxillary and mandibular 1st and 2nd primary molar SSC were fitted with one of four commonly used orthodontic bands (Unitek regular, Unitek narrow, Rocky Mountain, or custom bands made from SSC) using glass ionomer cement. The cemented samples were tested for their resistance to dislodgment on the Instron Universal Testing Machine (Instron Engineering Corp., Canton, MA) in tensile mode. Alpha level for statistical significance was set at alpha = 0.05. Unitek regular bands cemented on the 2nd molar crowns and Unitek narrow bands cemented on the 1st molar crown samples had equivalent or superior resistance to dislodgment compared with the other bands in the study. When the inside of the band and the outside band-bearing surfaces of selected crowns were lightly scored with a diamond bur prior to cementation, samples exhibited significantly superior retention. Subgroup means increased from 107 to 330%, compared to the values obtained in their preroughened state. The mean values obtained using the roughened band/crown interface technique (range 52.9 +/- 7.6 to 73.6 +/- 8.4 lbs) compared favorably with retention values from the literature for orthodontic bands cemented on permanent molar and premolar teeth. PMID:8153003

  16. Effect of an inclined magnetic field on peristaltic flow of Williamson fluid in an inclined channel with convective conditions

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Bibi, Shahida; Rafiq, M.; Alsaedi, A.; Abbasi, F. M.

    2016-03-01

    This paper deals with the influence of inclined magnetic field on peristaltic flow of an incompressible Williamson fluid in an inclined channel with heat and mass transfer. Convective conditions of heat and mass transfer are employed. Viscous dissipation and Joule heating are taken into consideration. Mathematical modeling also includes Soret and Dufour effects. Channel walls have compliant properties. Analysis has been carried out through long wavelength and low Reynolds number approach. Resulting problems are solved for small Weissenberg number. Impacts of variables reflecting the salient features of wall properties, Biot numbers and Soret and Dufour on the velocity, temperature, concentration and heat transfer coefficient are pointed out. Trapping phenomenon is also analyzed.

  17. Highly Inclined Jets in Cross Flow

    NASA Technical Reports Server (NTRS)

    Milanovic, I. M.; Zaman, K. B. M. Q.

    2003-01-01

    Results from an experimental investigation of flow field generated by pitched and yawed jets discharging from a flat plate into a cross-flow are presented. The circular jet was pitched at alpha = 20deg and 45deg and yawed between Beta = 0deg and 90deg in increments of 15deg. The measurements were performed with two ×-wires providing all three components of velocity and turbulent stresses. These data were obtained at downstream locations of x = 3, 5, 10 and 20, where the distance x, normalized by the jet diameter, is measured from the center of the orifice. Data for all configurations were acquired at a momentum-flux ratio J = 8. Additionally, for selected angles and locations, surveys were conducted for J = 1.5, 4, and 20. As expected, the jet penetration is found to be higher at larger alpha. With increasing beta the jet spreads more. The rate of reduction of peak streamwise vorticity, ? max, with the downstream distance is significantly less at higher Beta but is found to be practically independent of alpha. Thus, at the farthest measurement station x = 20, ?xmax is about five times larger for Beta = 75deg compared to the levels at Beta = 0deg. Streamwise velocity within the jet-vortex structure is found to depend on the parameter J. At J = 1.5 and 4, 'wake-like' velocity profiles are observed. In comparison, a 'jet-like' overshoot is present at higher J. Distributions of turbulent stresses for various cases are documented. Peak normal stresses are found to occur within the core of the streamwise vortices. With yaw, at lower values of J, high turbulence is also observed in the boundary layer underneath the jet-vortex structure

  18. 11. VIEW SOUTHEAST, DETAIL OF INCLINED END POST, SHOWING CASTIRON ...

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

    11. VIEW SOUTHEAST, DETAIL OF INCLINED END POST, SHOWING CAST-IRON WEDGE SET INTO LOWER CHORD; FLOOR-BEAM HANGER BLOCKS TO LEFT - Meeting House Bridge, Spanning Boston & Maine Railroad 0.1 mile east of Biddleford Road, Arundel, York County, ME

  19. 1. SAND DRAINING & DRYING BUILDING (RIGHT), COVERED INCLINE CONVEYOR ...

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

    1. SAND DRAINING & DRYING BUILDING (RIGHT), COVERED INCLINE CONVEYOR (LOWER RIGHT) THAT EXTENDS TO THE SAND-SORTING BUILDING, AND REMAINS OF ORIGINAL (1917) WASHING, DRAINING & DRYING BUILDING (LEFT), VIEW LOOKING WEST FROM TOP OF SAND-SORTING BUILDING - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  20. Students' Entrepreneurial Inclination at a Malaysian Polytechnic: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Yasin, Ahmad Yasruddin Md; Mahmood, Nik Abdul Aziz Nik; Jaafar, Nik Azyyati Nik

    2011-01-01

    This paper reports preliminary results of an ongoing project to examine students' inclination towards entrepreneurship at a Malaysian polytechnic. The study used a self-administered questionnaire to explore the influence of entrepreneurial intent, perceived behavioral control, self-efficacy, perceived barriers, perceived support factors and…

  1. North portal and deck view, from north, showing inclined endposts, ...

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

    North portal and deck view, from north, showing inclined endposts, Pratt through trusses, north portal strut, overhead bracing, pipe rails and posts, and concrete deck with bituminous wearing surface - Castle Garden Bridge, Township Route 343 over Bennetts Branch of Sinnemahoning Creek, Driftwood, Cameron County, PA

  2. South portal and deck view from south, showing inclined endposts, ...

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

    South portal and deck view from south, showing inclined endposts, Pratt through trusses, south portal strut, overhead bracing, pipe rails and posts, and concrete deck with bituminous wearing surface - Castle Garden Bridge, Township Route 343 over Bennetts Branch of Sinnemahoning Creek, Driftwood, Cameron County, PA

  3. Inclined Planes and Motion Detectors: A Study of Acceleration.

    ERIC Educational Resources Information Center

    Tracy, Dyanne M.

    2001-01-01

    Presents an activity in which students work in cooperative groups and roll balls down inclined planes, collect data with the help of an electronic motion detector, and represent data with a graphing calculator to explore concepts such as mass, gravity, velocity, and acceleration. (Contains 12 references.) (Author/ASK)

  4. Reconstruction of Galileo Galilei's Experiment: The Inclined Plane

    ERIC Educational Resources Information Center

    Straulino, S.

    2008-01-01

    In the "Third Day" of the "Discourses and Mathematical Demonstrations Concerning Two New Sciences" Galileo Galilei describes the famous experiment of the inclined plane and uses it to bring an experimental confirmation to the laws of uniformly accelerated motion. We describe a reconstruction of the experiment and how the results can be used for…

  5. 85. INCLINED PLANE 7 EAST. FLUME AND STONE POWER HOUSE ...

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

    85. INCLINED PLANE 7 EAST. FLUME AND STONE POWER HOUSE ARE ON RIGHT SIDE OF PHOTOGRAPH. NOTE THE CABLE LEAVING THE POWER HOUSE. THIS CABLE IS ATTATCHED TO A DRUM ON THE INSIDE THE POWER HOUSE WHICH IS TURNED BY MEANS OF A WATER POWERED TURBINE. - Morris Canal, Phillipsburg, Warren County, NJ

  6. Motion on an Inclined Plane and the Nature of Science

    ERIC Educational Resources Information Center

    Pendrill, Ann-Marie; Ekström, Peter; Hansson, Lena; Mars, Patrik; Ouattara, Lassana; Ryan, Ulrika

    2014-01-01

    Friction is an important phenomenon in everyday life. All children are familiar with playground slides, which may thus be a good starting point for investigating friction. Motion on an inclined plane is a standard physics example. This paper presents an investigation of friction by a group of 11-year olds. How did they plan their investigations?…

  7. Spatio-temporal patterns in inclined layer convection

    NASA Astrophysics Data System (ADS)

    Subramanian, Priya; Brausch, Oliver; Daniels, Karen E.; Bodenschatz, Eberhard; Schneider, Tobias M.; Pesch, Werner

    2016-05-01

    This paper reports on a theoretical analysis of the rich variety of spatio-temporal patterns observed recently in inclined layer convection at medium Prandtl number when varying the inclination angle $\\gamma$ and the Rayleigh number $R$. The present numerical investigation of the inclined layer convection system is based on the standard Oberbeck-Boussinesq equations. The patterns are shown to originate from a complicated competition of buoyancy-driven and shear-flow driven pattern forming mechanisms. The former are expressed as \\rm{longitudinal} convection rolls with their axes oriented parallel to the incline, the latter as perpendicular \\rm{transverse} rolls. Along with conventional methods to study roll patterns and their stability, we employ direct numerical simulations in large spatial domains, comparable with the experimental ones. As a result, we determine the phase diagram of the characteristic complex 3D convection patterns above onset of convection in the $\\gamma-R$ plane, and find that it compares very well with the experiments. In particular we demonstrate that interactions of specific Fourier modes, characterized by a resonant interaction of their wavevectors in the layer plane, are key to understanding the pattern morphologies.

  8. Crystal Structure and Vibrational Spectra of N,N{sup '}-Di(2,4-Dinitrophenyl)diaza-18-Crown-6 and N,N{sup '}-Di(tetrafluoropyridyl)diaza-18-Crown-6

    SciTech Connect

    Minacheva, L.Kh.; Ivanova, I.S.; Pyatova, E.N.; Sergienko, V.S.; Tsivadze, A.Yu.; Artamkina, G.A.; Beletskaya, I.P.

    2004-11-01

    Two new diaza-18-crown-6 derivatives, namely, N,N{sup '}-di(2,4-dinitrophenyl)diaza-18-crown-6 (I) and N,N{sup '}-di(tetrafluoropyridyl)diaza-18-crown-6 (II), are studied using X-ray diffraction. The vibrational spectra of these compounds are measured and analyzed. Crystals I are monoclinic, a = 9.746(2) A, b = 12.117(4) A, c = 11.378(6) A, {beta} = 98.90(3) deg., V = 1327.5(4) A{sup 3}, Z = 2, space group P2{sub 1}/c, and R = 0.055 for 1013 reflections with I > 2{sigma}(I). Crystals II are orthorhombic, a = 8.225(4) A, b = 11.816(4) A, c = 24.626(5) A, V = 2393.3(9) A{sup 3}, Z = 4, space group Pbca, and R = 0.035 for 451 reflections with I > 2{sigma}(I) . Molecules I and II have a centrosymmetric structure and different conformations. It is demonstrated that the shape and size of the cavity and the conformation of the macrocycle depend substantially on the structure of the substituents at the nitrogen atoms of diaza-18-crown-6.

  9. Stability of stratified two-phase flows in inclined channels

    NASA Astrophysics Data System (ADS)

    Barmak, I.; Gelfgat, A. Yu.; Ullmann, A.; Brauner, N.

    2016-08-01

    Linear stability of the stratified gas-liquid and liquid-liquid plane-parallel flows in the inclined channels is studied with respect to all wavenumber perturbations. The main objective is to predict the parameter regions in which the stable stratified configuration in inclined channels exists. Up to three distinct base states with different holdups exist in the inclined flows, so that the stability analysis has to be carried out for each branch separately. Special attention is paid to the multiple solution regions to reveal the feasibility of the non-unique stable stratified configurations in inclined channels. The stability boundaries of each branch of the steady state solutions are presented on the flow pattern map and are accompanied by the critical wavenumbers and the spatial profiles of the most unstable perturbations. Instabilities of different nature are visualized by the streamlines of the neutrally stable perturbed flows, consisting of the critical perturbation superimposed on the base flow. The present analysis confirms the existence of two stable stratified flow configurations in a region of low flow rates in the countercurrent liquid-liquid flows. These configurations become unstable with respect to the shear mode of instability. It was revealed that in slightly upward inclined flows the lower and middle solutions for the holdup are stable in the part of the triple solution region, while the upper solution is always unstable. In the case of downward flows, in the triple solution region, none of the solutions are stable with respect to the short-wave perturbations. These flows are stable only in the single solution region at low flow rates of the heavy phase, and the long-wave perturbations are the most unstable ones.

  10. [Study on the compatibility of slip casting aluminous ceramic crowns

    PubMed

    Wan, Q B; Xue, M; You, L; Du, C S; Chao, Y L

    1997-03-01

    One of the key factors for a good slip casting aluminous ceramic crown is good compatibility between its core material and the veneering porcelain.The chemical and thermal compatibility of two slip casting aluminous ceramic crown systems(In-Ceram and GI-I) were investigated by means of SEM and EDAX,thermal shock tests were also performed to evaluate the crazing resistance.The results showed: the crazing resistance of In-Ceram was 158 degrees centigrade,and that of GI-I was degrees centigrade;there existed tightly bonded interfaces between the slip casting aluminous ceramic cores and the veneering porcelains in both of the two systems,where ion transferences were found.The results also suggested good compatibility of the two slip casting aluminous ceramic crown systems. PMID:15159959

  11. Effect of the Crystallization Process on the Marginal and Internal Gaps of Lithium Disilicate CAD/CAM Crowns

    PubMed Central

    Kim, Jae-Hong; Oh, Seunghan; Uhm, Soo-Hyuk

    2016-01-01

    The aim of this study is to quantify the effect of the crystallization process on lithium disilicate ceramic crowns fabricated using a computer-aided design/computer-aided manufacturing (CAD/CAM) system and to determine whether the effect of crystallization is clinically acceptable by comparing values of fit before and after the crystallization process. The mandibular right first molar was selected as the abutment for the experiments. Fifteen working models were prepared. Lithium disilicate crowns appropriate for each abutment were prepared using a commercial CAD/CAM system. Gaps in the marginal area and 4 internal areas of each crown were measured twice—before and after crystallization—using the silicone replica technique. The mean values of fit before and after crystallization were analyzed using a paired t-test to examine whether the conversion that occurred during crystallization affected marginal and internal gaps (α = 0.05). Gaps increased in the marginal area and decreased in the internal areas after crystallization. There were statistically significant differences in all of the investigated areas (P < 0.05). None of the values for marginal and internal fit of lithium disilicate CAD/CAM crowns after crystallization exceeded 120 μm, which is the clinically acceptable threshold. PMID:27123453

  12. Effect of the Crystallization Process on the Marginal and Internal Gaps of Lithium Disilicate CAD/CAM Crowns.

    PubMed

    Kim, Jae-Hong; Oh, Seunghan; Uhm, Soo-Hyuk

    2016-01-01

    The aim of this study is to quantify the effect of the crystallization process on lithium disilicate ceramic crowns fabricated using a computer-aided design/computer-aided manufacturing (CAD/CAM) system and to determine whether the effect of crystallization is clinically acceptable by comparing values of fit before and after the crystallization process. The mandibular right first molar was selected as the abutment for the experiments. Fifteen working models were prepared. Lithium disilicate crowns appropriate for each abutment were prepared using a commercial CAD/CAM system. Gaps in the marginal area and 4 internal areas of each crown were measured twice-before and after crystallization-using the silicone replica technique. The mean values of fit before and after crystallization were analyzed using a paired t-test to examine whether the conversion that occurred during crystallization affected marginal and internal gaps (α = 0.05). Gaps increased in the marginal area and decreased in the internal areas after crystallization. There were statistically significant differences in all of the investigated areas (P < 0.05). None of the values for marginal and internal fit of lithium disilicate CAD/CAM crowns after crystallization exceeded 120 μm, which is the clinically acceptable threshold. PMID:27123453

  13. Closing a gap in tropical forest biomass estimation: accounting for crown mass variation in pantropical allometries

    NASA Astrophysics Data System (ADS)

    Ploton, P.; Barbier, N.; Momo, S. T.; Réjou-Méchain, M.; Boyemba Bosela, F.; Chuyong, G.; Dauby, G.; Droissart, V.; Fayolle, A.; Goodman, R. C.; Henry, M.; Kamdem, N. G.; Katembo Mukirania, J.; Kenfack, D.; Libalah, M.; Ngomanda, A.; Rossi, V.; Sonké, B.; Texier, N.; Thomas, D.; Zebaze, D.; Couteron, P.; Berger, U.; Pélissier, R.

    2015-12-01

    Accurately monitoring tropical forest carbon stocks is an outstanding challenge. Allometric models that consider tree diameter, height and wood density as predictors are currently used in most tropical forest carbon studies. In particular, a pantropical biomass model has been widely used for approximately a decade, and its most recent version will certainly constitute a reference in the coming years. However, this reference model shows a systematic bias for the largest trees. Because large trees are key drivers of forest carbon stocks and dynamics, understanding the origin and the consequences of this bias is of utmost concern. In this study, we compiled a unique tree mass dataset on 673 trees measured in five tropical countries (101 trees > 100 cm in diameter) and an original dataset of 130 forest plots (1 ha) from central Africa to quantify the error of biomass allometric models at the individual and plot levels when explicitly accounting or not accounting for crown mass variations. We first showed that the proportion of crown to total tree aboveground biomass is highly variable among trees, ranging from 3 to 88 %. This proportion was constant on average for trees < 10 Mg (mean of 34 %) but, above this threshold, increased sharply with tree mass and exceeded 50 % on average for trees ≥ 45 Mg. This increase coincided with a progressive deviation between the pantropical biomass model estimations and actual tree mass. Accounting for a crown mass proxy in a newly developed model consistently removed the bias observed for large trees (> 1 Mg) and reduced the range of plot-level error from -23-16 to 0-10 %. The disproportionally higher allocation of large trees to crown mass may thus explain the bias observed recently in the reference pantropical model. This bias leads to far-from-negligible, but often overlooked, systematic errors at the plot level and may be easily corrected by accounting for a crown mass proxy for the largest trees in a stand, thus suggesting that

  14. Uniform versus Asymmetric Shading Mediates Crown Recession in Conifers

    PubMed Central

    Schoonmaker, Amanda L.; Lieffers, Victor J.; Landhäusser, Simon M.

    2014-01-01

    In this study we explore the impact of asymmetrical vs. uniform crown shading on the mortality and growth of upper and lower branches within tree crowns, for two conifer species: shade intolerant lodgepole pine (Pinus contorta) and shade tolerant white spruce (Picea glauca). We also explore xylem hydraulics, foliar nutrition, and carbohydrate status as drivers for growth and expansion of the lower and upper branches in various types of shading. This study was conducted over a two-year period across 10 regenerating forest sites dominated by lodgepole pine and white spruce, in the lower foothills of Alberta, Canada. Trees were assigned to one of four shading treatments: (1), complete uniform shading of the entire tree, (2) light asymmetric shading where the lower 1/4–1/3 of the tree crown was shaded, (3) heavy asymmetric shading as in (2) except with greater light reduction and (4) control in which no artificial shading occurred and most of the entire crown was exposed to full light. Asymmetrical shading of only the lower crown had a larger negative impact on the bud expansion and growth than did uniform shading, and the effect was stronger in pine relative to spruce. In addition, lower branches in pine also had lower carbon reserves, and reduced xylem-area specific conductivity compared to spruce. For both species, but particularly the pine, the needles of lower branches tended to store less C than upper branches in the asymmetric shade, which could suggest a movement of reserves away from the lower branches. The implications of these findings correspond with the inherent shade tolerance and self-pruning behavior of these conifers and supports a carbon based mechanism for branch mortality – mediated by an asymmetry in light exposure of the crown. PMID:25136823

  15. Detection, quantification and modelling of small-scale lateral translocation of throughfall in tree crowns of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.)

    NASA Astrophysics Data System (ADS)

    Frischbier, Nico; Wagner, Sven

    2015-03-01

    The redistribution of precipitation in forests depends on the amount of above-canopy precipitation and is characterised by high small-scale variability. Although higher and lower values of net forest precipitation at small scales are typically averaged at larger spatial scales, the small-scale variability of throughfall needs to be understood because subordinate ecological processes in the forest ecosystem, e.g., regeneration of tree species, often take place at the same small scale. High stemflow amounts and canopy driplines at the crown edge of particular tree species can only be explained by lateral flow processes within tree crowns. This study tests the hypothesis that lateral water translocation within the crown can be determined from simultaneous records of precipitation at defined measurement points below and above the canopy by taking single-tree characteristics such as species and crown width into account. Spatially explicit simultaneous measurements of gross precipitation (above-canopy reference) and throughfall were conducted repeatedly at 175 measurements points in a mixed European beech-Norway spruce stand for a total of 26 individual rain events. Subsequent analysis with a new regression approach resulted in an estimated average canopy storage capacity of 3.5 mm and 5.8 mm for beech (leaf-bearing period) and spruce stands, respectively. Values of calculated lateral flow showed considerable variability between individual measurement points. The highest discharge amounts were observed at positions below the inner beech crowns during the leaf-bearing period. For an exemplary rainfall event with a gross precipitation of 25 mm, the predicted discharge ranged from 5 mm underneath the inner beech crown to about zero near the crown edge. A comparison with the measured values indicated that the predicted amount of lateral flow, which could be translated into stemflow for single beech trees, was realistic. However, for the same rainfall event, lateral flow in

  16. Museum security and the Thomas Crown Affair.

    SciTech Connect

    Michaud, E. C.

    2010-01-01

    Over the years, I've daydreamed about stealing a Vermeer, a Picasso, or Rembrandt. It tickles me, as much as watching the reboot of The Thomas Crown Affair. Why is it, do you suppose, so much fun to think about stealing a world renowned piece off the wall of a major metropolitan museum? Is it the romantic thoughts of getting away with it, walking past infrared detectors, and pressure sensors ala Indiana Jones with the sack of sand to remove the idol without triggering the security system? Is it the idea of snatching items with such fantastic prices, where the romance of possessing an item of such value is less intoxicating than selling it to a private collector for it to never be seen again? I suspect others share my daydreams as they watch theater or hear of a brazen daylight heist at museums around the world, or from private collections. Though when reality sets in, the mind of the security professional kicks in. How could one do it, why would one do it, what should you do once it's done? The main issue a thief confronts when acquiring unique goods is how to process or fence them. They become very difficult to sell because they are one-of-a-kind, easy to identify, and could lead to the people involved with the theft. The whole issue of museum security takes up an ironic twist when one considers the secretive British street artist 'Banksy'. Banksy has made a name for himself by brazenly putting up interesting pieces of art in broad daylight (though many critics don't consider his work to be art) on building walls, rooftops, or even museums. I bring him up for a interesting take on what may become a trend in museum security. In March of 2005, Banksy snuck a piece of his called 'Vandalized Oil Painting' into the Brooklyn Museum's Great Historical Painting Wing, plus 3 other pieces into major museums in New York. Within several days, 2 paintings had been torn down, but 2 stayed up much longer. In his home country of the UK, a unauthorized piece he created and placed

  17. Warped Disks and Inclined Rings around Galaxies

    NASA Astrophysics Data System (ADS)

    Casertano, Stefano; Sackett, Penny D.; Briggs, Franklin H.

    2006-11-01

    Preface; Acknowledgements; Workshop participants; Group photograph; 1. The intergalactic HI supply F. Briggs; 2. Neutral gas infall into NGC 628 J. Kamphuis and F. Briggs; 3. VLA HI observations of the radio galaxy Centaurus A J. M. van der Hulst, J. H. van Gorkom, A. D. Haschick and A. D. Tubbs; 4. A geometric model for the dust-band of Centaurus A R. A. Nicholson, K. Taylor and J. Bland; 5. The circumgalactic ring of gas in Leo S. E. Schneider; 6. Using gas kinematics to measure M/L in elliptical galaxies T. de Zeeuw; 7. Velocity fields of disks in triaxial potentials P. J. Teuben; 8. Modeling the atomic gas in NGC 4278 J. F. Lees; 9. A few statistics from the catalog of polar-ring galaxies B. C. Whitmore; 10. Dynamics of polar rings L. S. Sparke; 11. Mergers and the structure of disk galaxies L. Hernquist; 12. Formation of polar rings H.-W. Rix and N. Katz; 13. Gas-dynamical models of settling disks D. Christodoulou and J. E. Tohline; 14. Evolutionary processes affecting galactic accretion disks T. Steiman-Cameron; 15. Particle simulations of polar rings T. Quinn; 16. A bending instability in prolate stellar systems D. Merritt; 17. The Milky Way: lopsided or barred? K. Kuijken; 18. Merger origin of starburst galaxies L. Hernquist; 19. Warped and flaring HI disks A. Bosma; 20. Behaviour of warps in extended disks F. Briggs and J. Kamphuis; 21. Observational constraints for the explanation of warps E. Battaner, E. Florido, M.-L. Sanchez-Saavedra and M. Prieto; 22. Warps in S0s: observations versus theories G. Galletta; 23. Warps and bulges J. Pitesky; 24. Time evolution of galactic warps P. Hofner and L. S. Sparke; 25. Are warps normal modes? S. Casertano; 26. Disk warping in a slewing potential E. C. Ostriker; 27. Concluding discussion Moderator: K. C. Freeman; Name index; Object index; Subject index.

  18. Warped Disks and Inclined Rings around Galaxies

    NASA Astrophysics Data System (ADS)

    Casertano, Stefano; Sackett, Penny D.; Briggs, Franklin H.

    1991-05-01

    Preface; Acknowledgements; Workshop participants; Group photograph; 1. The intergalactic HI supply F. Briggs; 2. Neutral gas infall into NGC 628 J. Kamphuis and F. Briggs; 3. VLA HI observations of the radio galaxy Centaurus A J. M. van der Hulst, J. H. van Gorkom, A. D. Haschick and A. D. Tubbs; 4. A geometric model for the dust-band of Centaurus A R. A. Nicholson, K. Taylor and J. Bland; 5. The circumgalactic ring of gas in Leo S. E. Schneider; 6. Using gas kinematics to measure M/L in elliptical galaxies T. de Zeeuw; 7. Velocity fields of disks in triaxial potentials P. J. Teuben; 8. Modeling the atomic gas in NGC 4278 J. F. Lees; 9. A few statistics from the catalog of polar-ring galaxies B. C. Whitmore; 10. Dynamics of polar rings L. S. Sparke; 11. Mergers and the structure of disk galaxies L. Hernquist; 12. Formation of polar rings H.-W. Rix and N. Katz; 13. Gas-dynamical models of settling disks D. Christodoulou and J. E. Tohline; 14. Evolutionary processes affecting galactic accretion disks T. Steiman-Cameron; 15. Particle simulations of polar rings T. Quinn; 16. A bending instability in prolate stellar systems D. Merritt; 17. The Milky Way: lopsided or barred? K. Kuijken; 18. Merger origin of starburst galaxies L. Hernquist; 19. Warped and flaring HI disks A. Bosma; 20. Behaviour of warps in extended disks F. Briggs and J. Kamphuis; 21. Observational constraints for the explanation of warps E. Battaner, E. Florido, M.-L. Sanchez-Saavedra and M. Prieto; 22. Warps in S0s: observations versus theories G. Galletta; 23. Warps and bulges J. Pitesky; 24. Time evolution of galactic warps P. Hofner and L. S. Sparke; 25. Are warps normal modes? S. Casertano; 26. Disk warping in a slewing potential E. C. Ostriker; 27. Concluding discussion Moderator: K. C. Freeman; Name index; Object index; Subject index.

  19. An episode of steep geomagnetic inclination 120,000 years ago.

    PubMed

    Verosub, K L

    1983-07-22

    The mean inclinations of three sections of 120,000-year-old fine-grained sediments from northern California range from 62 degrees to 66 degrees . These inclinations are significantly steeper than the inclination of the geocentric axial dipole at this site. Because these sediments have probably recorded an actual episode of steep inclination lasting several thousand years, they provide new insights into the significance of mean inclinations shallower than the geocentric axial dipole. Such inclinations are characteristic of fine-grained sediments younger than 35,000 years. The results raise questions about the time-averaged geomagnetic field and about the determination of plate motions from paleomagnetic data. PMID:17798888

  20. Supramolecular polymers constructed by crown ether-based molecular recognition.

    PubMed

    Zheng, Bo; Wang, Feng; Dong, Shengyi; Huang, Feihe

    2012-03-01

    Supramolecular polymers, polymeric systems beyond the molecule, have attracted more and more attention from scientists due to their applications in various fields, including stimuli-responsive materials, healable materials, and drug delivery. Due to their good selectivity and convenient enviro-responsiveness, crown ether-based molecular recognition motifs have been actively employed to fabricate supramolecular polymers with interesting properties and novel applications in recent years. In this tutorial review, we classify supramolecular polymers based on their differences in topology and cover recent advances in the marriage between crown ether-based molecular recognition and polymer science. PMID:22012256

  1. Dental enamel growth, perikymata and hypoplasia in ancient tooth crowns.

    PubMed Central

    Hillson, S W

    1992-01-01

    This paper describes the hypoplastic defects commonly seen on the surface of ancient human tooth crowns, excavated from archaeological sites, and presents a new method for estimating the ages at which these defects were initiated during life. The method is based upon examination of microscopic incremental structures on the enamel surface and it is possible also to apply it to reconstruction of the sequence and timing of dental crown development. The method of examination is non-destructive and allows full use to be made of the large numbers of complete, unworn dentitions which are found amongst archaeological remains. Images Figure 1. Figure 4. PMID:1404194

  2. Macromolecular leakage benath full cast crowns. Part II: The diffusion of lipopolysaccharide and dextran.

    PubMed

    Coleman, A J

    1996-01-01

    Fifteen extracted molars were prepared for crowns. Crowns with access ports (one facial, one lingual) were cast in gold. Teeth and crowns luted with provisional cement with filters inserted into the ports were immersed in a solution of labeled macromolecules (FITC-dextran, TRITC-LPS) and evaluated for leakage. Filters were retrieved and analyzed by use of fluorescent microscopy. Leakage of LPS and dextran occurred as early as 2 weeks beneath crowns luted with a provisional cement (NoGenol). PMID:8850458

  3. Deontological and utilitarian inclinations in moral decision making: a process dissociation approach.

    PubMed

    Conway, Paul; Gawronski, Bertram

    2013-02-01

    Dual-process theories of moral judgment suggest that responses to moral dilemmas are guided by two moral principles: the principle of deontology states that the morality of an action depends on the intrinsic nature of the action (e.g., harming others is wrong regardless of its consequences); the principle of utilitarianism implies that the morality of an action is determined by its consequences (e.g., harming others is acceptable if it increases the well-being of a greater number of people). Despite the proposed independence of the moral inclinations reflecting these principles, previous work has relied on operationalizations in which stronger inclinations of one kind imply weaker inclinations of the other kind. The current research applied Jacoby's (1991) process dissociation procedure to independently quantify the strength of deontological and utilitarian inclinations within individuals. Study 1 confirmed the usefulness of process dissociation for capturing individual differences in deontological and utilitarian inclinations, revealing positive correlations of both inclinations to moral identity. Moreover, deontological inclinations were uniquely related to empathic concern, perspective-taking, and religiosity, whereas utilitarian inclinations were uniquely related to need for cognition. Study 2 demonstrated that cognitive load selectively reduced utilitarian inclinations, with deontological inclinations being unaffected. In Study 3, a manipulation designed to enhance empathy increased deontological inclinations, with utilitarian inclinations being unaffected. These findings provide evidence for the independent contributions of deontological and utilitarian inclinations to moral judgments, resolving many theoretical ambiguities implied by previous research. PMID:23276267

  4. Automated individual tree crown delineation from LIDAR data using morphological techniques

    NASA Astrophysics Data System (ADS)

    Jing, L.; Hu, B.; Li, H.; Li, J.; Noland, T.

    2014-03-01

    In current tree crown delineation from LiDAR data, treetops and 3D geometric shapes of tree crowns are frequently extracted from LiDAR-derived Crown Height Model (CHM) and used as references to localize and delineate crowns. However, it is difficult to detect deciduous treetops and delineate deciduous tree crowns. The 3D shape of a crown, which can be derived from CHM, may be taken as a half ellipsoid, and any horizontal slice of the ellipsoid contains the treetop and indicates not only the location but also the spatial extent of the crown. Based on such slices, a novel multi-scale method for individual tree crown delineation from CHM was proposed in this study. This method consists mainly of two steps: (1) morphologically open the CHM over the scale range of target tree crowns; and (2) take local maxima within each resulting opened CHM as the horizontal slices of target crowns at the corresponding scale level and integrate all the slices within the scale range together to represent the spatial distribution of target crowns. In an experiment on CHMs over two natural closed canopy forests in Ontario, Canada, the proposed method accurately delineated the majority of the tree crowns from closed canopy forests.

  5. Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

    PubMed Central

    Kwon, Taek-Ka; Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2013-01-01

    PURPOSE All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident. MATERIALS AND METHODS Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns. RESULTS The mean fracture strengths were as follows: 54.9 ± 15.6 N for the Lava CAD/CAM zirconia crowns and 87.0 ± 16.0 N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain. CONCLUSION The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain. PMID:23755332

  6. Evaluation of the marginal fit of full ceramic crowns by the microcomputed tomography (micro-CT) technique

    PubMed Central

    Demir, Necla; Ozturk, Atiye Nilgun; Malkoc, Meral Arslan

    2014-01-01

    Objective: To evaluate the marginal gap (MG) and absolute marginal discrepancy (MD) of full ceramic crowns with two finish line designs, shoulder and chamfer, using microcomputed tomography (micro-CT) before and after cementation. Materials and Methods: Sixty extracted human maxillary premolar teeth were divided into two groups based on the finish line design: Group I: 90° shoulder and Group II: 135° chamfer. The specimens were further grouped based on the type of full ceramic crown they received: Group A: Feldspathic Cerec inLab ceramic system, Group B: Cerec inLab aluminum oxide ceramic system and Group C: Lithium disilicate press ceramic system. Before cementation, five crowns from each group were scanned using micro-CT in two sections, sagittal and coronal, to determine the MG and MD values for four regions of the crown (sagittal buccal, sagittal lingual, coronal mesial and coronal distal). After cementation and thermal cycling, the scanning was repeated. Measurements were obtained from 10 points for each region, 80 points totally, to evaluate the MG and MD values. Files were processed using NRecon and CTAn software. Results were statistically analyzed using one- and two-way ANOVA and Tukey HSD tests (P = 0.05). Results: Full ceramic systems showed clinically acceptable marginal adaptation values. The Feldspathic Cerec inLab ceramic system generally presented the lowest variance, except in the MG values of the coronal mesial region. The MG and MD values of all ceramics increased significantly after cementation, except in the shoulder preparation design (sagittal buccal region) for MG and in the chamfer preparation design (sagittal lingual region) for MD values. Conclusions: Full-ceramic crowns showed clinically acceptable marginal adaptation values. The Feldspathic Cerec inLab ceramic system (Vitablocs Mark II) generally presented the lowest variance when compared with the other ceramics, except for the MG values on the mesial surface of the coronal section

  7. [Preparation of hard crown and bridge resin without PMMA powder (author's transl)].

    PubMed

    Nagata, K; Suzuki, S; Nakabayashi, N; Masuhara, E

    1979-01-01

    Elimination of PMMA powder to prepare better hard crown and bridge resin had been pointed out by the authors even though polyfunctional methacrylates were used. Application of hydrophobic coloidal silica instead of PMMA pearl with triethyleneglycol dimethacrylate and Bis-GMA was studied. Polyermization was carried out in the hot air stream at 120 degrees approximately 130 degrees C or in a pressure vessel at 4.5 kg/cm2 gauge, 100 degrees C. Mechanical properties, brinell hardness, compressive strength, an amount of water sorption, comparative average abrasion loss depth with those of PMMA, were measured. They were improved very much by this new system. PMID:221600

  8. Randomized, Controlled Clinical Trial of Bilayer Ceramic and Metal-Ceramic Crown Performance

    PubMed Central

    Esquivel-Upshaw, Josephine; Rose, William; Oliveira, Erica; Yang, Mark; Clark, Arthur E.; Anusavice, Kenneth

    2013-01-01

    Purpose Analyzing the clinical performance of restorative materials is important, as there is an expectation that these materials and procedures will restore teeth and do no harm. The objective of this research study was to characterize the clinical performance of metal-ceramic crowns, core ceramic crowns, and core ceramic/veneer ceramic crowns based on 11 clinical criteria. Materials and Methods An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study. The following three types of full crowns were fabricated: (1) metal-ceramic crown (MC) made from a Pd-Au-Ag-Sn-In alloy (Argedent 62) and a glass-ceramic veneer (IPS d.SIGN veneer); (2) non-veneered (glazed) lithium disilicate glass-ceramic crown (LDC) (IPS e.max Press core and e.max Ceram Glaze); and (3) veneered lithia disilicate glass-ceramic crown (LDC/V) with glass-ceramic veneer (IPS Empress 2 core and IPS Eris). Single-unit crowns were randomly assigned. Patients were recalled for each of 3 years and were evaluated by two calibrated clinicians. Thirty-six crowns were placed in 31 patients. A total of 12 crowns of each of the three crown types were studied. Eleven criteria were evaluated: tissue health, marginal integrity, secondary caries, proximal contact, anatomic contour, occlusion, surface texture, cracks/chips (fractures), color match, tooth sensitivity, and wear (of crowns and opposing enamel). Numerical rankings ranged from 1 to 4, with 4 being excellent, and 1 indicating a need for immediate replacement. Statistical analysis of the numerical rankings was performed using a Fisher’s exact test. Results There was no statistically significant difference between performance of the core ceramic crowns and the two veneered crowns at year 1 and year 2 (p > 0.05). All crowns were rated either as excellent or good for each of the clinical criteria; however, between years 2 and 3, gradual roughening of the occlusal surface occurred in some of the ceramic-ceramic crowns

  9. Kepler-108: A Mutually Inclined Giant Planet System

    NASA Astrophysics Data System (ADS)

    Mills, Sean M.; Fabrycky, Daniel

    2016-06-01

    The vast majority of well studied giant-planet systems, including the Solar System, are nearly coplanar which implies dissipation within a primordial gas disk. However, intrinsic instability may lead to planet-planet scattering, which often produces non-coplanar, eccentric orbits. Planet scattering theories have been developed to explain observed high eccentricity systems and possibly hot Jupiters; thus far their predictions for mutual inclination (I) have barely been tested. Here we characterize a highly mutually-inclined (I ~ 15-60 degrees), moderately eccentric (e > 0.1) giant planet system: Kepler-108. This system consists of two Saturn mass planets with periods of ~49 and ~190 days around a star with a wide (~300 AU) binary companion in an orbital configuration inconsistent with a purely disk migration origin.

  10. Control system for inclined impact-type surface seismic source

    SciTech Connect

    Karner, G.M.

    1987-07-28

    A system is described for controlling the azimuths and inclinations of the respective shooting paths of separate vehicle-transported surface seismic sources. Each source has an impact mass, means for propelling the mass along the shooting path to strike an earth contacting base plate, and means for adjusting each shooting path by rotation thereof about two mutually perpendicular gimbal axes oriented in predetermined relation to the heading of the associated vehicle. The system consists of: (a) means for determining each such vehicle heading; (b) means dependent upon each vehicle heading for calculating the angular positions of each shooting path with respect to the gimbal axes which align the shooting path with desired values of azimuth and inclination; and (c) means responsive to the calculation means for actuating each shooting path adjustment means to effect such alignment.

  11. 2006 U.S. oat crown rust race survey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crown rust severities and resulting yield losses were much lower in 2006 throughout much of the U.S. compared to 2005. Widespread drought conditions throughout the central plains limited disease development. A total of 102 and 27 isolates were collected from the spring and winter oat growing regions...

  12. Spatiotemporal characterization of Sclerotinia crown rot epidemics in pyrethrum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sclerotinia crown rot, caused by Sclerotinia minor and S. sclerotiorum is a disease of pyrethrum in Australia that may cause substantial decline in plant density. The spatiotemporal characteristics of the disease were quantified in 14 fields spread across three growing seasons. Fitting the binary ...

  13. Suppressors of oat crown rust resistance in interspecific oat crosses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Attempts to transfer disease resistance genes between related species may be hindered by suppression, or lack of expression, of the trait in the interspecific combination. In crosses of diploid oat Avena strigosa (Schreb.) accession CI6954SP with resistance to oat crown rust Puccinia coronata f. sp....

  14. Delineation of individual tree crowns for mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Wu, Rosen; Chen, Yiping; Wen, Chenglu; Wang, Cheng; Li, Jonathan

    2016-03-01

    The information of individual trees plays an important role in urban surveying and mapping. With the development of Light Detection and Ranging (LiDAR) technology, 3-Dimenisonal (3D) structure of trees can be generated in point clouds with high spatial resolution and accuracy. Individual tree segmentations are used to derive tree structural attributes such as tree height, crown diameter, stem position etc. In this study, a framework is proposed to take advantage of the detailed structures of tree crowns which are represented in the mobile laser scanning (MLS) data. This framework consists of five steps: (1) Automatically detect and remove ground points using RANSAC; (2) Compress all the above ground points to image grid with 3D knowledge reserved; (3) Simplify and remove unqualified grids; (4) Find tree peaks using a heuristic searching method; (5) Delineate the individual tree crowns by applying a modified watershed method. In an experiment on the point clouds on Xiamen Island, China, individual tree crowns from MLS point cloud data are successfully extracted.

  15. 14. Photograph of sheet 2 (general plan; section @ crown, ...

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

    14. Photograph of sheet 2 (general plan; section @ crown, plan, and elevation) of the Indiana State Highway Commission repair plans of 1969 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

  16. Identification of new sources of partial resistance to oat crown

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Control of oat crown rust (Puccinia coronata f.sp. avenae) has traditionally been achieved with the use of cultivars with race-specific seedling genes (Pc genes), but this resistance typically is only effective for 3-5 years once a cultivar becomes widely grown. Over 90 Pc genes have been described ...

  17. EVALUATION OF WILD JUGLANS SPECIES FOR CROWN GALL RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crown Gall disease of walnut is caused by the ubiquitous soil-borne bacterium, Agrobacterium tumefaciens which is able to transfer a specific piece of its own DNA into the genome of the plant host cell. The result of this genetic transformation is the autonomous undifferentiated massive growth of i...

  18. Restoration of decayed primary incisors using strip crowns.

    PubMed

    Pollard, M A; Curzon, J A; Fenlon, W L

    1991-05-01

    Caries of the primary incisors is a common problem that can be arrested if recognized early enough. However, the arrested decay is unsightly. Celluloid 'strip' crown forms, used with composite resin, now allow the restoration of even the most badly decayed primary incisors. The authors describe this quick and efficient technique. PMID:1884866

  19. Novel Ordered Crown Ether-Containing Polyimides for Ion Conduction

    NASA Technical Reports Server (NTRS)

    Irvin, Jennifer A.; Stasko, Daniel; Fallis, Stephen; Guenthner, Andrew J.; Webber, Cynthia; Blackwell, John; Chvalun, Sergei N.

    2003-01-01

    We report the synthesis and characterization of thermally-stable polyimides for use as battery and fuel cell electrolyte membranes. Dianhydrides used were 1,4,5,8- naphthalenetetracarboxylic dianhydride and/or 4,4'-(hexafluoroisopropylidene)diphthalic anhydride. Diamines used were anti-4,4-diaminodibenzo-l8-crown-6, 4,4'- diaminodibenzo-24-crown-8, 2,2-bis(4-aminophenyl)hexafluoropropane, and/or 2,5- diaminobenzenesulfonic acid. The polymers were characterized using electrochemical impedance spectroscopy (EIS), thermal analysis and X-ray diffraction. Polymers containing the hexafluoroisopropylidene (HFIP) group were soluble in common organic solvents, while polymers without the HFIP group were very poorly soluble. Sulfonation yields polymers that are sparingly soluble in aqueous base and/or methanol. Degree of sulfonation, determined by titration, was between one and three sulfonate groups per repeat unit. Proton conductivity was determined as a function of water content, with a maximum conductivity of l x 10(exp -2) per centimeter when fully hydrated. Crown ether-containing polymers exhibit a high degree of order that may be indicative of crown ether channel formation, which may facilitate Li(+) transport for use in battery membranes.

  20. Primate molar crown formation times and life history evolution revisited.

    PubMed

    Macho, G A

    2001-12-01

    Comparative studies have convincingly demonstrated that the pattern and timing of tooth emergence are highly correlated with life-history variables and brain size. Conversely, a firm relationship between molar formation time and life-history variables has not yet been established. It seems counterintuitive that one aspect of dental development should be correlated with life-history variables, whereas the other should not. In order to shed light on this apparent discrepancy this study analyzed all data on primate molar crown formations available in the published literature in relation to life-history variables, brain size, and female body mass. Crown formation times were found to be particularly highly correlated with both female body mass and brain size. Species that depart from the overall brain/body allometry by being relatively large-bodied, e.g., Gorilla gorilla and later Theropithecus oswaldi, also have shorter molar crown formation times than expected. The reverse is not found for species that depart from the overall brain/body allometry due to their larger brains, i.e., Homo sapiens. This finding is interpreted within an evolutionary and ecological framework. Specifically, by focusing on ecological commonalities, a scenario is proposed which may allow predictions to be made about the evolutionary history of other extinct primates also. If confirmed in future studies, crown formation time may again become a powerful tool in evolutionary enquiry. PMID:11748692

  1. Laser pediatric crowns performed without anesthesia: a contemporary technique.

    PubMed

    Jacboson, B; Berger, J; Kravitz, R; Patel, P

    2003-01-01

    Extensive caries resulting in the need for a stainless steel crown in primary teeth may now be prepared with the use of the WaterlaseTM YSGG Laser, (Biolase) hard and soft-tissue laser. The use of the laser eliminates the need for local anesthesia, thereby providing optimal patient comfort and compliance. PMID:14604135

  2. Evolution of the mandibular third premolar crown in early Australopithecus.

    PubMed

    Delezene, Lucas K; Kimbel, William H

    2011-06-01

    The Pliocene hominins Australopithecus anamensis and Australopithecus afarensis likely represent ancestor-descendent taxa--possibly an anagenetic lineage--and capture significant change in the morphology of the canine and mandibular third premolar (P(3)) crowns, dental elements that form the canine honing complex in nonhuman catarrhines. This study focuses on the P(3) crown, highlighting plesiomorphic features in A. anamensis. The A. afarensis P(3) crown, in contrast, is variable in its expression of apomorphic features that are characteristic of geologically younger hominins. Temporal variation characterizes each taxon as well. The A. anamensis P(3) from Allia Bay, Kenya expresses apomorphic character states, shared with A. afarensis, which are not seen in the older sample of A. anamensis P(3)s from Kanapoi, Kenya, while spatiotemporal differences in shape exist within the A. afarensis hypodigm. The accumulation of derived features in A. afarensis results in an increased level of P(3) molarisation. P(3) molarisation did not evolve concurrent with postcanine megadontia and neither did the appearance of derived aspects of P(3) occlusal form coincide with the loss of canine honing in hominins, which is apparent prior to the origin of the genus Australopithecus. A. afarensis P(3) variation reveals the independence of shape, size, and occlusal form. The evolution of the P(3) crown in early Australopithecus bridges the wide morphological gap that exists between geologically younger hominins on the one hand and extant apes and Ardipithecus on the other. PMID:21481921

  3. Film cooling from inclined cylindrical holes using large eddy simulations

    NASA Astrophysics Data System (ADS)

    Peet, Yulia V.

    2006-12-01

    The goal of the present study is to investigate numerically the physics of the flow, which occurs during the film cooling from inclined cylindrical holes, Film cooling is a technique used in gas turbine industry to reduce heat fluxes to the turbine blade surface. Large Eddy Simulation (LES) is performed modeling a realistic film cooling configuration, which consists of a large stagnation-type reservoir, feeding an array of discrete cooling holes (film holes) flowing into a flat plate turbulent boundary layer. Special computational methodology is developed for this problem, involving coupled simulations using multiple computational codes. A fully compressible LES code is used in the area above the flat plate, while a low Mach number LES code is employed in the plenum and film holes. The motivation for using different codes comes from the essential difference in the nature of the flow in these different regions. Flowfield is analyzed inside the plenum, film hole and a crossflow region. Flow inside the plenum is stagnating, except for the region close to the exit, where it accelerates rapidly to turn into the hole. The sharp radius of turning at the trailing edge of the plenum pipe connection causes the flow to separate from the downstream wall of the film hole. After coolant injection occurs, a complex flowfield is formed consisting of coherent vortical structures responsible for bringing hot crossflow fluid in contact with the walls of either the film hole or the blade, thus reducing cooling protection. Mean velocity and turbulent statistics are compared to experimental measurements, yielding good agreement for the mean flowfield and satisfactory agreement for the turbulence quantities. LES results are used to assess the applicability of basic assumptions of conventional eddy viscosity turbulence models used with Reynolds-averaged (RANS) approach, namely the isotropy of an eddy viscosity and thermal diffusivity. It is shown here that these assumptions do not hold

  4. Numerical Solution of Supersonic Laminar Flow Over an Inclined Body of Revolution

    NASA Technical Reports Server (NTRS)

    Hung, C. M.

    1980-01-01

    A mixed explicit-implicit scheme is used to solve the time-dependent thin-layer approximation of the Navier-Stokes equations for a supersonic laminar flow over an inclined body of revolution. Test cases for Mach 2.8 flow over a cylinder with 15-deg flare angle at angles of attack of 0,1, and 4 deg are calculated. Good agreement is obtained between the present computed results and experimental measurements of surface pressure. A pair of vortices on the leeward and a peak in the normal force distribution near the flared juncture are predicted; the role of circumferential communication is discussed.

  5. Numerical solution of supersonic laminar flow over an inclined body of revolution

    NASA Technical Reports Server (NTRS)

    Hung, C. M.

    1979-01-01

    A mixed explicit-implicit scheme is used to solve the time-dependent thin-layer approximation of the Navier-Stokes equations for a supersonic laminar flow over an inclined body of revolution. Test cases for Mach 2.8 flow over a cylinder with 15 deg flare angle at angles of attack of 0, 1, and 4 deg are calculated. Good agreement is obtained between the present computed results and experimental measurements of surface pressure. A pair of vortices on the leeward and a peak in the normal force distribution near the flared juncture are predicted; the role of circumferential communication is discussed.

  6. Drop impact and rebound dynamics on an inclined superhydrophobic surface.

    PubMed

    Yeong, Yong Han; Burton, James; Loth, Eric; Bayer, Ilker S

    2014-10-14

    Due to its potential in water-repelling applications, the impact and rebound dynamics of a water drop impinging perpendicular to a horizontal superhydrophobic surface have undergone extensive study. However, drops tend to strike a surface at an angle in applications. In such cases, the physics governing the effects of oblique impact are not well studied or understood. Therefore, the objective of this study was to conduct an experiment to investigate the impact and rebound dynamics of a drop at various liquid viscosities, in an isothermal environment, and on a nanocomposite superhydrophobic surface at normal and oblique impact conditions (tilted at 15°, 30°, 45°, and 60°). This study considered drops falling from various heights to create normal impact Weber numbers ranging from 6 to 110. In addition, drop viscosity was varied by decreasing the temperature for water drops and by utilizing water-glycerol mixtures, which have similar surface tension to water but higher viscosities. Results revealed that oblique and normal drop impact behaved similarly (in terms of maximum drop spread as well as rebound dynamics) at low normal Weber numbers. However, at higher Weber numbers, normal and oblique impact results diverged in terms of maximum spread, which could be related to asymmetry and more complex outcomes. These asymmetry effects became more pronounced as the inclination angle increased, to the point where they dominated the drop impact and rebound characteristics when the surface was inclined at 60°. The drop rebound characteristics on inclined surfaces could be classified into eight different outcomes driven primarily by normal Weber number and drop Ohnesorge numbers. However, it was found that these outcomes were also a function of the receding contact angle, whereby reduced receding angles yielded tail-like structures. Nevertheless, the contact times of the drops with the coating were found to be generally independent of surface inclination. PMID:25216298

  7. Inclined fluidized bed system for drying fine coal

    DOEpatents

    Cha, Chang Y.; Merriam, Norman W.; Boysen, John E.

    1992-02-11

    Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

  8. Graphs and matroids weighted in a bounded incline algebra.

    PubMed

    Lu, Ling-Xia; Zhang, Bei

    2014-01-01

    Firstly, for a graph weighted in a bounded incline algebra (or called a dioid), a longest path problem (LPP, for short) is presented, which can be considered the uniform approach to the famous shortest path problem, the widest path problem, and the most reliable path problem. The solutions for LPP and related algorithms are given. Secondly, for a matroid weighted in a linear matroid, the maximum independent set problem is studied. PMID:25126607

  9. Shock waves in Stokes flows down an inclined plate.

    PubMed

    Benilov, E S; Lapin, V N

    2011-06-01

    We consider a viscous flow on an inclined plate, such that the liquid's depth far upstream is larger than that far downstream, resulting in a "smoothed-shock wave" steadily propagating downstream. Our numerical simulations show that in a large section of the problem's parameter space all initial conditions overturn (i.e., the liquid's surface becomes vertical at some point) and thus no steady solution exists. The overturning can only be stopped by a sufficiently strong surface tension. PMID:21797491

  10. Trigonometric series representations of the orbital inclination function

    NASA Astrophysics Data System (ADS)

    El-Sayed Awad, M.

    1986-08-01

    New trigonometric representations of the orbital inclination function in multiples of cosines or sines are developed for all possible values of l, m, and p. The literal analytical expressions and the recurrence formulas which are satisfied by their coefficients are derived, and an efficient algorithm for the table formulation of the trigonometric series representations is presented. Numerical examples for the representations are demonstrated for the cases l = 2(1)4, m = 0(1)l, and p = 0(1)l.

  11. Sex Differences in Incline-Walking among Humans.

    PubMed

    Wall-Scheffler, Cara M

    2015-12-01

    Previous research has shown that people tend to walk around the speed that minimizes energy consumption when traveling a given distance. It has further been shown that men and women have different speeds that minimize energy and that women will choose slower speeds when the activity itself is a high-rate activity (e.g. carrying a load). Here we investigate what men and women will do when given a high rate walking activity, namely walking on an inclined surface. Fourteen people (nine men and five women) walked at four speeds on a level treadmill and four speeds on an inclined treadmill while their metabolic rate, kinematics and core temperature were monitored. Following the data collection, participants were asked to identify their ‘preferred’ walking speed at each of the conditions. Cost of transport (CoT) curves were calculated for each individual, and the delta between the preferred and the ‘optimal’ speeds were calculated. People chose to walk at slightly slower speeds on the level; there was minimal change in the cost to walk at these slower speeds. Women walked at absolutely slower speeds on the incline than men (P=0.06) and had significantly larger speed deltas (P=0.02), thus choosing to walk at slower rate speeds. Women also showed a significant relationship between the rate of activity and core temperature, whereas men did not. This is consistent with other research showing that women choose behavioral strategies to minimize body temperature changes. PMID:26901887

  12. a Study of Ricochet Phenomenon for Inclined Impact of Projectile

    NASA Astrophysics Data System (ADS)

    Jo, Jong-Hyun; Lee, Young-Shin

    In this study, the numerical simulation using AUTODYN-3D program was investigated for trajectory prediction for inclined impacts of projectiles. The penetration and perforation of polycarbonate(PC) plate by 7.62 mm projectile was investigated numerically. The characteristic structure of the projectile's trajectory in the PC plates was studied. Two combined failure criteria were used in the target plate, and the target plate was modeled with the properties of polycarbonate for simulating the ricochet phenomenon. The numerical analyses were used to study the effect of the angle of inclination on the trajectory and kinetic energy of the projectile. The dynamic deformation behaviors tests of PC were compared with numerical simulation results which can be used for predictive purpose. Ricochet phenomenon for angles of inclination of 0° ≤ θ ≤ 20° in the analysis. The projectile perforated the plate for θ > 30°, thus defined a failure envelope for numerical configuration. The numerical analyses was used to study the effect under the projectile impact velocity on the depth of penetration(DOP).

  13. Brief communication: Molar development and crown areas in early Australopithecus.

    PubMed

    Lacruz, Rodrigo S; Ramirez Rozzi, Fernando V; Wood, Bernard A; Bromage, Timothy G

    2012-08-01

    Recent studies suggest that the hypodigms representing the two earliest Australopithecus (Au. anamensis and Au. afarensis) form an ancestor-descendant lineage. Understanding the details of this possible transition is important comparative evidence for assessing the likelihood of other examples of ancestor-descendant lineages within the hominin clade. To this end we have analyzed crown and cusp base areas of high resolution replicas of the mandibular molars of Au. anamensis (Allia Bay and Kanapoi sites) and those of Au. afarensis (Hadar, Laetoli, and Maka). We found no statistically significant differences in crown areas between these hypodigms although the mean of M(1) crowns was smaller in Au. anamensis, being the smallest of any Australopithecus species sampled to date. Intraspecies comparison of the areas of mesial cusps for each molar type using Wilcoxon signed rank test showed no differences for Au. anamensis. Significant differences were found between the protoconid and metaconid of Au. afarensis M(2)s and M(3)s. Furthermore, the area formed by the posterior cusps as a whole relative to the anterior cusps showed significant differences in Au. afarensis M(1)s and in Au. anamensis M(2)s but no differences were noted for M(3)s of either taxon. Developmental information derived from microstructural details in enamel shows that M(1) crown formation in Au. anamensis is similar to Pan and shorter than in H. sapiens. Taken together, these data suggests that the overall trend in the Au. anamensis-Au. afarensis transition may have involved a moderate increase in M(1) crown areas with relative expansion of distal cusps. PMID:22623291

  14. Improved determination of dynamic balance using the centre of mass and centre of pressure inclination variables in a complete golf swing cycle.

    PubMed

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2016-01-01

    Golf requires proper dynamic balance to accurately control the club head through a harmonious coordination of each human segment and joint. In this study, we evaluated the ability for dynamic balance during a golf swing by using the centre of mass (COM)-centre of pressure (COP) inclination variables. Twelve professional, 13 amateur and 10 novice golfers participated in this study. Six infrared cameras, two force platforms and SB-Clinic software were used to measure the net COM and COP trajectories. In order to evaluate dynamic balance ability, the COM-COP inclination angle, COM-COP inclination angular velocity and normalised COM-COP inclination angular jerk were used. Professional golfer group revealed a smaller COM-COP inclination angle and angular velocity than novice golfer group in the lead/trail direction (P < 0.01). In the normalised COM-COP inclination angular jerk, the professional golfer group showed a lower value than the other two groups in all directions. Professional golfers tend to exhibit improved dynamic balance, and this can be attributed to the neuromusculoskeletal system that maintains balance with proper postural control. This study has the potential to allow for an evaluation of the dynamic balance mechanism and will provide useful basic information for swing training and prevention of golf injuries. PMID:26264189

  15. Simple Model of a Rolling Water-Filled Bottle on an Inclined Ramp

    ERIC Educational Resources Information Center

    Lin, Shihao; Hu, Naiwen; Yao, Tianchen; Chu, Charles; Babb, Simona; Cohen, Jenna; Sangiovanni, Giana; Watt, Summer; Weisman, Danielle; Klep, James; Walecki, Wojciech J.; Walecki, Eve S.; Walecki, Peter S.

    2015-01-01

    We investigate a water-filled bottle rolling down an incline and ask the following question: is a rolling bottle better described by a model ignoring all internal motion where the bottle is approximated by a material point sliding down an incline, or is it better described by a rigid solid cylinder rolling down the incline without skidding? The…

  16. Constraining the relative inclinations of the planets B and C of the millisecond pulsar PSR B1257+12

    NASA Astrophysics Data System (ADS)

    Iorio, Lorenzo

    2010-09-01

    We investigate on the relative inclination of the planets B and C orbiting the pulsar PSR B1257+12. First, we show that the third Kepler’s law does represent an adequate model for the orbital periods P of the planets, because other Newtonian and Einsteinian corrections are orders of magnitude smaller than the accuracy in measuring P B/C. Then, on the basis of available timing data, we determine the ratio sin i C/ sin i B = 0.92±0.05 of the orbital inclinations i B and i C independently of the pulsar’s mass M. It turns out that coplanarity of the orbits of B and C would imply a violation of the equivalence principle. Adopting a pulsar mass range 1 ≲ M ≲ 3, in solar masses (supported by present-day theoretical and observational bounds for pulsar’s masses), both face-on and edge-on orbital configurations for the orbits of the two planets are ruled out; the acceptable inclinations for B span the range 36 deg ≲ i B ≲ 66 deg, with a corresponding relative inclination range 6 deg ≲ ( i C - i B) ≲ 13 deg.

  17. Paleomagnetic inclination errors in sediments cored from a Gulf of Mexico salt dome - An indicator of ancient sea level

    SciTech Connect

    Sager, W.W.; Singleton, S.W. )

    1989-08-01

    A paleomagnetic study of piston-cored sediments was done in conjunction with a high-resolution seismic reflection study of a salt dome on the upper continental slope in the northern Gulf of Mexico. Seismic data showed that late Pleistocene sediment layers are exposed around the bank and tilted up to 8{degree} by the diapiric uplift. Cores were taken on the flanks of the bank to test the use of paleomagnetism in measuring the tectonic tilt of the sediments. After structural corrections, results from six cores agreed with the geocentric axial dipole inclination for the site, but four other cores displayed significantly shallowed inclinations. Moreover, several cores showed linear trends of inclination shallowing, increasing downcore. The anomalous results are from the summit of the bank and suggest a relation to subaerial exposure during a sea-level lowstand. The authors think that the shallow inclinations were caused by compaction, but that the linear trends resulted from rehydration of the sediments after exposure by erosion.

  18. Detailed statistical contact angle analyses; "slow moving" drops on inclining silicon-oxide surfaces.

    PubMed

    Schmitt, M; Groß, K; Grub, J; Heib, F

    2015-06-01

    Contact angle determination by sessile drop technique is essential to characterise surface properties in science and in industry. Different specific angles can be observed on every solid which are correlated with the advancing or the receding of the triple line. Different procedures and definitions for the determination of specific angles exist which are often not comprehensible or reproducible. Therefore one of the most important things in this area is to build standard, reproducible and valid methods for determining advancing/receding contact angles. This contribution introduces novel techniques to analyse dynamic contact angle measurements (sessile drop) in detail which are applicable for axisymmetric and non-axisymmetric drops. Not only the recently presented fit solution by sigmoid function and the independent analysis of the different parameters (inclination, contact angle, velocity of the triple point) but also the dependent analysis will be firstly explained in detail. These approaches lead to contact angle data and different access on specific contact angles which are independent from "user-skills" and subjectivity of the operator. As example the motion behaviour of droplets on flat silicon-oxide surfaces after different surface treatments is dynamically measured by sessile drop technique when inclining the sample plate. The triple points, the inclination angles, the downhill (advancing motion) and the uphill angles (receding motion) obtained by high-precision drop shape analysis are independently and dependently statistically analysed. Due to the small covered distance for the dependent analysis (<0.4mm) and the dominance of counted events with small velocity the measurements are less influenced by motion dynamics and the procedure can be called "slow moving" analysis. The presented procedures as performed are especially sensitive to the range which reaches from the static to the "slow moving" dynamic contact angle determination. They are characterised by

  19. MnBr₂/18-crown-6 coordination complexes showing high room temperature luminescence and quantum yield.

    PubMed

    Hausmann, David; Kuzmanoski, Ana; Feldmann, Claus

    2016-04-21

    The reaction of manganese(ii) bromide and the crown ether 18-crown-6 in the ionic liquid [(n-Bu)3MeN][N(Tf)2] under mild conditions (80-130 °C) resulted in the formation of three different coordination compounds: MnBr2(18-crown-6) (), Mn3Br6(18-crown-6)2 () and Mn3Br6(18-crown-6) (). In general, the local coordination and the crystal structure of all compounds are driven by the mismatch between the small radius of the Mn(2+) cation (83 pm) and the ring opening of 18-crown-6 as a chelating ligand (about 300 pm). This improper situation leads to different types of coordination and bonding. MnBr2(18-crown-6) represents a molecular compound with Mn(2+) coordinated by two bromine atoms and only five oxygen atoms of 18-crown-6. Mn3Br6(18-crown-6)2 falls into a [MnBr(18-crown-6)](+) cation - with Mn(2+) coordinated by six oxygen atoms and Br - and a [MnBr(18-crown-6)MnBr4](-) anion. In this anion, Mn(2+) is coordinated by five oxygen atoms of the crown ether as well as by two bromine atoms, one of them bridging to an isolated (MnBr4) tetrahedron. Mn3Br6(18-crown-6), finally, forms an infinite, non-charged [Mn2(18-crown-6)(MnBr6)] chain. Herein, 18-crown-6 is exocyclically coordinated by two Mn(2+) cations. All compounds show intense luminescence in the yellow to red spectral range and exhibit remarkable quantum yields of 70% (Mn3Br6(18-crown-6)) and 98% (Mn3Br6(18-crown-6)2). The excellent quantum yield of Mn3Br6(18-crown-6)2 and its differentiation from MnBr2(18-crown-6) and Mn3Br6(18-crown-6) can be directly correlated to the local coordination. PMID:26956783

  20. Method and apparatus for controlling an earthworking implement to preserve a crown on a road surface

    NASA Technical Reports Server (NTRS)

    Staub, Michael D. (Inventor); Alster, Louis G. (Inventor); Lundquist, Steve D. (Inventor)

    1999-01-01

    A method and apparatus for controlling an earthworking implement on an earthworking machine to preserve a crown on the surface of a road, including determining the position of the crown on the road surface, choosing a sloped grade on one side of the crown, positioning the earthworking implement on the sloped grade so that a first end of the earthworking implement is on the road surface. The processor determines a desired position of a second end of the earthworking implement so that the second end overlaps the crown and the earthworking implement does not cut the crown.

  1. 4-Methoxyanilinium Perrhenate 18-Crown-6: A New Ferroelectric with Order Originating in Swinglike Motion Slowing Down

    NASA Astrophysics Data System (ADS)

    Fu, Da-Wei; Cai, Hong-Ling; Li, Shen-Hui; Ye, Qiong; Zhou, Lei; Zhang, Wen; Zhang, Yi; Deng, Feng; Xiong, Ren-Gen

    2013-06-01

    A supramolecular adduct 4-methoxyanilinium perrhenate 18-crown-6 was synthesized, which undergoes a disorder-order structural phase transition at about 153 K (Tc) due to slowing down of a pendulumlike motion of the 4-methoxyanilinium group upon cooling. Ferroelectric hysteresis loop measurements give a spontaneous polarization of 1.2μC/cm2. Temperature-dependent solid-state nuclear magnetic resonance measurements reveal three kinds of molecular motions existing in the compound: pendulumlike swing of 4-methoxyanilinium cation, rotation of 18-crown-6 ring, and rotation of the methoxyl group. When the temperature decreases, the first two motions are frozen at about 153 K and the methoxyl group becomes rigid at around 126 K. The slowing down or freezing of pendulumlike motion of the cation triggered by temperature decreasing corresponds to the centrosymmetric-to-noncentrosymmetric arrangement of the compound, resulting in the formation of ferroelectricity.

  2. OsCAND1 is required for crown root emergence in rice.

    PubMed

    Wang, Xiao-Fei; He, Fen-Fang; Ma, Xiao-Xia; Mao, Chuan-Zao; Hodgman, Charlie; Lu, Chun-Gui; Wu, Ping

    2011-03-01

    Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant defective in crown root emergence designated as Oscand1 (named after the Arabidopsis homologous gene AtCAND1). The defect of visible crown root in the Oscand1 mutant is the result of cessation of the G2/M cell cycle transition in the crown root meristem. Map-based cloning revealed that OsCAND1 is a homolog of Arabidopsis CAND1. During crown root primordium development, the expression of OsCAND1 is confined to the root cap after the establishment of fundamental organization. The transgenic plants harboring DR5::GUS showed that auxin signaling in crown root tip is abnormal in the mutant. Exogenous auxin application can partially rescue the defect of crown root development in Oscand1. Taken together, these data show that OsCAND1 is involved in auxin signaling to maintain the G2/M cell cycle transition in crown root meristem and, consequently, the emergence of crown root. Our findings provide new information about the molecular regulation of the emergence of crown root in rice. PMID:20978084

  3. Biomonitoring environmental contamination with pipping black-crowned night heron embryos: Induction of cytochrome P450

    USGS Publications Warehouse

    Rattner, B.A.; Melancon, M.J.; Custer, T.W.; Hothem, R.L.; King, K.A.; LeCaptain, L.J.; Spann, J.W.; Woodin, Bruce R.; Stegeman, John J.

    1993-01-01

    Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins were measured in pipping black-crowned night heron (Nycticorax nycticorax) embryos collected from a reference site (next to the Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). In a laboratory study, artificially incubated night heron embryos from the reference site were treated with 3-methylcholanthrene (200 mu-g administered into the air cell 2 d before pipping) or phenobarbital (2 mg daily for 2 d before pipping). Compared to controls (untreated + vehicle-treated embryos), 3-methylcholanthrene induced a greater than five-fold increase in activities of several monooxygenases (arylhydrocarbon hydroxylase, AHH; benzyloxyresorufin-O-dealkylase, BROD; ethoxyresorufin-O-dealkylase, EROD; pentoxyresorufin-O-dealkylase, PROD) and a greater than 100-fold increase in the concentration of immunodetected cytochrome P450 1A (CYP1A). Phenobarbital treatment resulted in only a slight increase in BROD activity but induced proteins recognized by antibodies to cytochrome P450 2B (CYP2B) by 2,000-fold. In a field study, activities of AHH, BROD, EROD, and ethoxycoumarin-O-dealkylase (ECOD) were up to 85-fold higher in pipping black-crowned night herons collected from Cat Island compared to other sites. Hepatic CYP1A and CYP2B cross-reactive proteins were detected in significantly more individuals from Cat Island than from the reference site. Greatest burdens of total PCBs and p, p'-DDE were detected in embryos from Cat Island. Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins (AHH, BROD, EROD, ECOD, CYP1A, CYP2B) were significantly associated with total PCB burdens (r = 0.50-0.72). These data indicate that cytochrome P450 may be a useful biomarker of exposure to some PCB mixtures in black-crowned night heron embryos.

  4. Biomonitoring environmental contamination with pipping black-crowned night heron embryos: Induction of cytochrome P450

    USGS Publications Warehouse

    Rattner, B.A.; Melancon, M.J.; Custer, T.W.; Hothem, R.L.; King, K.A.; LeCaptain, L.J.; Spann, J.W.; Woodin, Bruce R.; Stegeman, John J.

    1993-01-01

    Cytochrome P450-associated monooxygenase activities and cytochrome P450 proteins were measured in pipping black-crowned night heron (Nycticorax nycticorax) embryos collected from a reference site (next to the Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). In a laboratory study, artificially incubated night heron embryos from the reference site were treated with 3-methylcholanthrene (200 mu g administered into the air cell 2 d before pipping) or phenobarbital (2 mg daily for 2 d before pipping). Compared to controls (untreated + vehicle-treated embryos), 3-methylcholanthrene induced a greater than fivefold increase in activities of several monooxygenases (arylhydrocarbon hydroxylase, AHH; benzyloxyresorufin-O-dealkylase, BROD; ethoxyresorufin-O-dealkylase, EROD; pentoxyresorufin-O- dealkylase, PROD) and a greater than 100-fold increase in the concentration of immunodetected cytochrome P450 1A (CYP1A). Phenobarbital treatment resulted in only a slight increase in BROD activity but induced proteins recognized by antibodies to cytochrome P450 2B (CYP2B) by 2,000-fold. In a field study, activities of AHH, BROD, EROD, and ethoxycoumarin-O-dealkylase (ECOD) were up to 85-fold higher in pipping black- crowned night herons collected from Cat Island compared to other sites. Hepatic CYP1A and CYP2B cross- reactive proteins were detected in significantly more individuals from Cat Island than from the reference site. Greatest burdens of total PCBs and p,p'-DDE were detected in embryos from Cat Island. Cytochrome P450- associated monooxygenase activities and cytochrome P450 proteins (AHH, BROD, EROD, ECOD, CYP1A, CYP2B) were significantly associated with total PCB burdens (r = 0.50-0.72). These data indicate that cytochrome P450 may be a useful biomarker of exposure to some PCB mixtures in black-crowned night heron embryos.

  5. Effects of crown development on leaf irradiance, leaf morphology and photosynthetic capacity in a peach tree.

    PubMed

    Walcroft, Adrian; Le Roux, Xavier; Diaz-Espejo, Antonio; Dones, Nicolas; Sinoquet, Hervé

    2002-09-01

    The three-dimensional (3-D) architecture of a peach tree (Prunus persica L. Batsch) growing in an orchard near Avignon, France, was digitized in April 1999 and again four weeks later in May 1999 to quantify increases in leaf area and crown volume as shoots developed. A 3-D model of radiation transfer was used to determine effects of changes in leaf area density and canopy volume on the spatial distribution of absorbed quantum irradiance (PAR(a)). Effects of changes in PAR(a) on leaf morphological and physiological properties were determined. Leaf mass per unit area (M(a)) and leaf nitrogen concentration per unit leaf area (N(a)) were both nonlinearly related to PAR(a), and there was a weak linear relationship between leaf nitrogen concentration per unit leaf mass (N(m)) and PAR(a). Photosynthetic capacity, defined as maximal rates of ribulose-1,5-bisphosphate carboxylase (Rubisco) carboxylation (V(cmax)) and electron transport (J(max)), was measured on leaf samples representing sunlit and shaded micro-environments at the same time that the tree crown was digitized. Both V(cmax) and J(max) were linearly related to N(a) during May, but not in April when the range of N(a) was low. Photosynthetic capacity per unit N(a) appeared to decline between April and May. Variability in leaf nitrogen partitioning between Rubisco carboxylation and electron transport was small, and the partitioning coefficients were unrelated to N(a). Spatial variability in photosynthetic capacity resulted from acclimation to varying PAR(a) as the crown developed, and acclimation was driven principally by changes in M(a) rather than the amount or partitioning of leaf nitrogen. PMID:12204849

  6. Internal fit of two all-ceramic systems and metal-ceramic crowns

    PubMed Central

    MARTINS, Leandro Moura; LORENZONI, Fabio Cesar; de MELO, Alcides Oliveira; da SILVA, Luciana Mendonça; de OLIVEIRA, José Luiz G.; de OLIVEIRA, Pedro Cesar Garcia; BONFANTE, Gerson

    2012-01-01

    Objectives The aim of this study was to investigate the internal fit (IF) of glass-infiltrated alumina (ICA - In-Ceram Alumina), yttria-stabilized tetragonal zirconia polycrystals (Y-TZP - IPS e.max ZirCAD), and metal-ceramic (MC - Ni-Cr alloy) crowns. Material and Methods Sixty standardized resin-tooth replicas of a maxillary first molar were produced for crown placement and divided into 3 groups (n=20 each) according to the core material used (metal, ICA or Y-TZP). The IF of the crowns was measured using the replica technique, which employs a light body polyvinyl siloxane impression material to simulate the cement layer thickness. The data were analyzed according to the surfaces obtained for the occlusal space (OS), axial space (AS) and total mean (TM) using two-way ANOVA with Tukey's multiple comparison test (p<0.05). Results No differences among the different areas were detected in the MC group. For the Y-TZP and ICA groups, AS was statistically lower than both OS and TM. No differences in AS were observed among the groups. However, OS and TM showed significantly higher values for ICA and Y-TZP groups than MC group. Comparisons of ICA and Y-TZP revealed that OS was significantly lower for Y-TZP group, whereas no differences were observed for TM. Conclusions The total mean achieved by all groups was within the range of clinical acceptability. However, the metal-ceramic group demonstrated significantly lower values than the all-ceramic groups, especially in OS. PMID:22666843

  7. Fracture resistance of computer-aided design/computer-aided manufacturing-generated composite resin-based molar crowns.

    PubMed

    Harada, Akio; Nakamura, Keisuke; Kanno, Taro; Inagaki, Ryoichi; Örtengren, Ulf; Niwano, Yoshimi; Sasaki, Keiichi; Egusa, Hiroshi

    2015-04-01

    The aim of this study was to investigate whether different fabrication processes, such as the computer-aided design/computer-aided manufacturing (CAD/CAM) system or the manual build-up technique, affect the fracture resistance of composite resin-based crowns. Lava Ultimate (LU), Estenia C&B (EC&B), and lithium disilicate glass-ceramic IPS e.max press (EMP) were used. Four types of molar crowns were fabricated: CAD/CAM-generated composite resin-based crowns (LU crowns); manually built-up monolayer composite resin-based crowns (EC&B-monolayer crowns); manually built-up layered composite resin-based crowns (EC&B-layered crowns); and EMP crowns. Each type of crown was cemented to dies and the fracture resistance was tested. EC&B-layered crowns showed significantly lower fracture resistance compared with LU and EMP crowns, although there was no significant difference in flexural strength or fracture toughness between LU and EC&B materials. Micro-computed tomography and fractographic analysis showed that decreased strength probably resulted from internal voids in the EC&B-layered crowns introduced by the layering process. There was no significant difference in fracture resistance among LU, EC&B-monolayer, and EMP crowns. Both types of composite resin-based crowns showed fracture loads of >2000 N, which is higher than the molar bite force. Therefore, CAD/CAM-generated crowns, without internal defects, may be applied to molar regions with sufficient fracture resistance. PMID:25683749

  8. Effect of dual task type on gait and dynamic stability during stair negotiation at different inclinations.

    PubMed

    Madehkhaksar, Forough; Egges, Arjan

    2016-01-01

    Stair gait is a common daily activity with great potential risk for falls. Stairs have varying inclinations and people may perform other tasks concurrently with stair gait. This study investigated dual-task interference in the context of complex gait tasks, such as stair gait at different inclinations, a topic about which little is understood. We examined how secondary cognitive and manual tasks interfere with stair gait when a person concurrently performed tasks at different levels of complexity. Gait kinematic data and secondary task performance measures were obtained from fifteen healthy young males while ascending and descending a four-step staircase at three inclinations (17.7°, 29.4°, and 41.5°) as well as level walking. They performed a cognitive task, 'backward digit recall', a manual task, 'carrying a cup of water' and a combination of the two tasks. Gait performance and dynamic stability were assessed by gait speed and whole body center of mass (COM) range of motion in the medial-lateral direction, respectively. No significant effect of the gait task on the cognitive task performance was observed. In contrast, stair walking adversely affected the performance of the manual task compared to level walking. Overall, more difficult postural and secondary tasks resulted in a decrease in gait speed and variation in COM displacement within normal range. Results suggest that COM displacement and gait alterations might be adopted to enhance the stability, and optimize the secondary task performance while walking under challenging circumstances. Our findings are useful for balance and gait evaluation, and for future falls prediction. PMID:26410477

  9. Buoyancy effects in steeply inclined air-water bubbly shear flow in a rectangular channel

    NASA Astrophysics Data System (ADS)

    Sanaullah, K.; Arshad, M.; Khan, A.; Chughtai, I. R.

    2015-07-01

    We report measurements of two-dimensional ( B/ D = 5) fully turbulent and developed duct flows (overall length/depth, L/ D = 60; D-based Reynolds number Re > 104) for inclinations to 30° from vertical at low voidages (< 5 % sectional average) representative of disperse regime using tap water bubbles (4-6 mm) and smaller bubbles (2 mm) stabilised in ionic solution. Pitot and static probe instrumentation, primitive but validated, provided adequate (10 % local value) discrimination of main aspects of the mean velocity and voidage profiles at representative streamwise station i.e L/ D = 40. Our results can be divided into three categories of behaviour. For vertical flow (0°) the evidence is inconclusive as to whether bubbles are preferentially trapped within the wall-layer as found in some, may be most earlier experimental works. Thus, the 4-mm bubbles showed indication of voidage retention but the 2-mm bubbles did not. For nearly vertical flow (5°) there was pronounced profiling of voidage especially with 4-mm bubbles but the transverse transport was not suppressed sufficiently to induce any obvious layering. In this context, we also refer to similarities with previous work on one-phase vertical and nearly vertical mixed convection flows displaying buoyancy inhibited mean shear turbulence. However, with inclined flow (10+ degrees) a distinctively layered pattern was invariably manifested in which voidage confinement increased with increasing inclination. In this paper we address flow behavior at near vertical conditions. Eulerian, mixed and VOF models were used to compute voidage and mean velocity profiles.

  10. Growth of textured MgO through e-beam evaporation and inclined substrate deposition

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Lei, C. H.; Ma, B.; Evans, H.; Efstathiadis, H.; Manisha, R.; Massey, M.; Balachandran, U.; Bhattacharya, R.

    2006-08-01

    Long length textured MgO template on Hastelloy C276™ (HC) has been successfully deposited in a reel-to-reel (R2R) electron beam (e-beam) evaporation system by inclined substrate deposition (ISD). High deposition rate up to 10 nm s-1 with exposure length of 7 cm has been realized. The MgO template showed good in-plane texture of 9.5°-11.5° measured from the (002) phi scans. Experimental results reveal that MgO in-plane texture is formed by the preferred growth direction of [11n]\\parallel \\mathrm {substrate} normal and one of the MgO {200} planes rotates to the in-flux direction. A new expression, termed the 'two-thirds relationship', between the inclination angle α and the tilted angle of the (00l) plane from the substrate normal, β, has been summarized. YBa2Cu3O7-δ (YBCO) film deposited by pulsed laser deposition (PLD) on strontium ruthenate (SRO) buffered ISD MgO showed Tc of 91 K with transition width of 1 K. Critical current measurement indicated an Ic of 110 A cm-1 at 77 K in self-field for 0.68 µm YBCO film, corresponding to a Jc of 1.6 MA cm-2.

  11. Hydrodynamics and heat transfer of thin films on inclined structured plates

    NASA Astrophysics Data System (ADS)

    Loeffler, Karsten; Yu, Hongyi; Gambaryan-Roisman, Tatiana; Stephan, Peter

    2007-11-01

    Thin liquid films flowing down vertical and inclined plates are widely used in industrial applications, e.g. in falling film evaporators for concentrating of sugar solutions. Falling films exhibit very complex wavy patterns, which depend on various parameters. Using structured, in particular, grooved plates is a promising way to enhance the heat transfer rate in thin film evaporators. The influence of the plate topography on the wave motion is still not completely understood. In the present work the evolution of the water film thickness on smooth and structured (longitudinal and sinusoidal grooves and herringbone structures) plates has been experimentally investigated for different inclination angles, Reynolds numbers and at various distances from the inlet. A confocal chromatic sensoring technique was used to measure the film dynamics. Additionally, the temperature distribution at the heated wall has been measured with thermocouples and the liquid-gas interface has been observed with infrared thermography for different heat fluxes. The heat flux has been gradually increased until film rupture occurred. The effect of the wall topography on the film stability has been quantified. It has been found that the wall topography significantly affects the wave pattern, the heat transport and the film stability.

  12. Advanced Communications Technology Satellite (ACTS) Used for Inclined Orbit Operations

    NASA Technical Reports Server (NTRS)

    Bauer, Robert A.

    2000-01-01

    The Advanced Communications Technology Satellite (ACTS) is operated by the NASA Glenn Research Center at Lewis Field 24 hours a day, 7 days a week. ACTS, which was launched in September 1993, is in its 7th year of operations, far exceeding the system s planned 2 years of operations and 4 years of designed mission life. After 5 successful years of operating as a geostationary satellite, the spacecraft s North-South stationkeeping was discontinued in August 1998. The system is now operating in an inclined orbit that increases at a rate of 0.8 /yr. With only scarce fuel remaining, operating in this mode extends the usage of the still totally functional payload. Although tracking systems are now needed on the experimenter Earth stations, experiment operations have continued with very little disruption. This is the only known geosynchronous Ka-band (30/20 GHz) spot-beam satellite operating in an inclined orbit. The project began its transition from geostationary operations to inclined operations in August 1998. This did not interrupt operations and was transparent to the experimenters on the system. For the space segment, new daily procedures were implemented to maintain the pointing of the system s narrow 0.3 spot beams while the spacecraft drifts in the North-South direction. For the ground segment, modifications were designed, developed, and fielded for the three classes of experimenter Earth stations. With the next generation of commercial satellite systems still being developed, ACTS remains the only operational testbed for Ka-band geosynchronous satellite communications over the Western hemisphere. Since inclined orbit operations began, the ACTS experiments program has supported 43 investigations by industry, Government, and academic organizations, as well as four demonstrations. The project s goals for inclined-orbit operations now reflect a narrower focus in the types of experiments that will be done. In these days of "faster, better, cheaper," NASA is seeking

  13. Evaluation of long-term stability of mesiodistal axial inclinations of maxillary molars through panoramic radiographs in subjects treated with Pendulum appliance

    PubMed Central

    Rocha, Caroline Andrade; de Almeida, Renato Rodrigues; Henriques, José Fernando Castanha; Flores-Mir, Carlos; de Almeida, Marcio Rodrigues

    2016-01-01

    Objective: To evaluate the stability of mesiodistal inclination of maxillary molars produced by a pendulum appliance, five years after completion of orthodontic treatment. Angulation changes were compared to an untreated sample. Methods: The sample consisted of 20 patients (14 females and 6 males) with Class II, Division 1 malocclusion that was treated through molar distalization with a pendulum appliance followed by cervical headgear and full fixed appliances. Maxillary molar inclination was evaluated through panoramic radiograph. The mean age at pretreatment was 14.3 ± 1.6 years, whereas at immediate post-treatment it was 18.6 ± 1.8 years, and at long-term post-treatment it was 23.8 ± 2.0 years. A control group of 16 untreated individuals with untreated normocclusion ranging in age from 12 to 17 years old were used as comparison group. Data were statistically analyzed with independent t-tests and ANOVA test followed by Tukey post-hoc tests. Results: Statistically significant differences were found between T1(94.50) and T2 (98.80) as well as between T2 and T3 (94.70) for maxillary first molars. Maxillary second molars did not show any statistically significant positional changes during the evaluated time periods T1 (107.50), T2 (109.30) and T3 (106.90). Conclusion: Although maxillary first molars underwent distal crown inclination immediately after treatment, approximately five years thereafter their roots tended to upright close to the pretreatment positions. PMID:27007764

  14. Intermediate inclinations of type 2 Coronal-Line Forest AGN

    NASA Astrophysics Data System (ADS)

    Rose, Marvin; Elvis, Martin; Crenshaw, Michael; Glidden, Ana

    2015-07-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [Fe VII], [Fe X] and [Ne V]) in their spectra. Rose, Elvis & Tadhunter suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high-ionization lines is due to a specific AGN-torus inclination angle. Here, we test this suggestion using mid-IR colours (4.6-22 μm) from the Wide-Field Infrared Survey Explorer for the CLiF AGN. We use the Fischer et al. result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5-30 μm colours become bluer. We show that the [W2-W4] colours for the CLiF AGN (<[W2-W4]> = 5.92 ± 0.12) are intermediate between Sloan Digital Sky Survey (SDSS) type 1 (<[W2-W4]> = 5.22 ± 0.01) and type 2 AGN (<[W2-W4]> = 6.35 ± 0.03). This implies that the AGN-torus inclinations for the CLiF AGN are indeed intermediate, supporting the work of Rose, Elvis & Tadhunter. The confirmed relation between CLiF AGN and their viewing angle shows that CLiF AGN may be useful for our understanding of AGN unification.

  15. Collisionless encounters and the origin of the lunar inclination

    NASA Astrophysics Data System (ADS)

    Pahlevan, Kaveh; Morbidelli, Alessandro

    2015-11-01

    The Moon is generally thought to have formed from the debris ejected by the impact of a planet-sized object with the proto-Earth towards the end of planetary accretion. Models of the impact process predict that the lunar material was disaggregated into a circumplanetary disk and that lunar accretion subsequently placed the Moon in a near-equatorial orbit. Forward integration of the lunar orbit from this initial state predicts a modern inclination at least an order of magnitude smaller than the lunar value -- a long-standing discrepancy known as the lunar inclination problem. Here we show that the modern lunar orbit provides a sensitive record of gravitational interactions with Earth-crossing planetesimals that were not yet accreted at the time of the Moon-forming event. The currently observed lunar orbit can naturally be reproduced via interaction with a small quantity of mass (corresponding to 0.0075-0.015 Earth masses eventually accreted to the Earth) carried by a few bodies, consistent with the constraints and models of late accretion. Although the encounter process has a stochastic element, the observed value of the lunar inclination is among the most likely outcomes for a wide range of parameters. The excitation of the lunar orbit is most readily reproduced via collisionless encounters of planetesimals with the Earth-Moon system with strong dissipation of tidal energy on the early Earth. This mechanism obviates the need for previously proposed (but idealized) excitation mechanisms, places the Moon-forming event in the context of the formation of Earth, and constrains the pristineness of the dynamical state of the Earth-Moon system.

  16. Critical Heat Flux in Inclined Rectangular Narrow Gaps

    SciTech Connect

    Jeong J. Kim; Yong H. Kim; Seong J. Kim; Sang W. Noh; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

    2004-06-01

    In light of the TMI-2 accident, in which the reactor vessel lower head survived the attack by molten core material, the in-vessel retention strategy was suggested to benefit from cooling the debris through a gap between the lower head and the core material. The GAMMA 1D (Gap Apparatus Mitigating Melt Attack One Dimensional) tests were conducted to investigate the critical heat flux (CHF) in narrow gaps with varying surface orientations. The CHF in an inclined gap, especially in case of the downward-facing narrow gap, is dictated by bubble behavior because the departing bubbles are squeezed. The orientation angle affects the bubble layer and escape of the bubbles from the narrow gap. The test parameters include gap sizes of 1, 2, 5 and 10 mm and the open periphery, and the orientation angles range from the fully downward-facing (180o) to the vertical (90o) position. The 15 ×35 mm copper test section was electrically heated by the thin film resistor on the back. The heater assembly was installed to the tip of the rotating arm in the heated water pool at the atmospheric pressure. The bubble behavior was photographed utilizing a high-speed camera through the Pyrex glass spacer. It was observed that the CHF decreased as the surface inclination angle increased and as the gap size decreased in most of the cases. However, the opposing results were obtained at certain surface orientations and gap sizes. Transition angles, at which the CHF changed in a rapid slope, were also detected, which is consistent with the existing literature. A semi-empirical CHF correlation was developed for the inclined narrow rectangular channels through dimensional analysis. The correlation provides with best-estimate CHF values for realistically assessing the thermal margin to failure of the lower head during a severe accident involving relocation of the core material.

  17. Collisionless encounters and the origin of the lunar inclination.

    PubMed

    Pahlevan, Kaveh; Morbidelli, Alessandro

    2015-11-26

    The Moon is generally thought to have formed from the debris ejected by the impact of a planet-sized object with the proto-Earth towards the end of planetary accretion. Models of the impact process predict that the lunar material was disaggregated into a circumplanetary disk and that lunar accretion subsequently placed the Moon in a near-equatorial orbit. Forward integration of the lunar orbit from this initial state predicts a modern inclination at least an order of magnitude smaller than the lunar value--a long-standing discrepancy known as the lunar inclination problem. Here we show that the modern lunar orbit provides a sensitive record of gravitational interactions with Earth-crossing planetesimals that were not yet accreted at the time of the Moon-forming event. The currently observed lunar orbit can naturally be reproduced via interaction with a small quantity of mass (corresponding to 0.0075-0.015 Earth masses eventually accreted to the Earth) carried by a few bodies, consistent with the constraints and models of late accretion. Although the encounter process has a stochastic element, the observed value of the lunar inclination is among the most likely outcomes for a wide range of parameters. The excitation of the lunar orbit is most readily reproduced via collisionless encounters of planetesimals with the Earth-Moon system with strong dissipation of tidal energy on the early Earth. This mechanism obviates the need for previously proposed (but idealized) excitation mechanisms, places the Moon-forming event in the context of the formation of Earth, and constrains the pristineness of the dynamical state of the Earth-Moon system. PMID:26607544

  18. S-DARS broadcast from inclined, elliptical orbits

    NASA Astrophysics Data System (ADS)

    Briskman, Robert D.; Prevaux, Robert J.

    2004-04-01

    The first Sirius spacecraft was launched on July 1, 2000. Exactly 5 months later, on December 1, the third spacecraft was launched, completing the three satellite S-DARS (Satellite Digital Audio Radio Service) constellation. The three satellites are deployed in inclined, elliptical, geosynchronous orbits, which allow seamless broadcast coverage to mobile users in the contiguous US. Terrestrial broadcast repeaters provide service in urban cores. The system is in operation, providing the first ever S-DARS service. The constellation design results in satellite ground tracks over North America with two satellites always above the equator. High elevation look angles from the mobile ground terminals to the satellites minimize performance degradation due to blockage, foliage attenuation and multi-path. The spacecraft were built by Space Systems/Loral using the 1300 bus modified for operation in high inclination orbits. Each spacecraft was launched using a dedicated Russian Proton booster. The satellite payload is a bent pipe repeater using 7.1 GHz for the uplink and 2.3 GHz for the broadcast transmission. The repeater high-power amplification stage consists of 32 Traveling Wave Tube Amplifiers phase combined to yield a total radio frequency output power of nearly 4 kW at saturated operation. The satellite antennas are mechanically steered to maintain the transmit beam centered on the Contiguous United States and the receive beam centered on the uplink earth station located in Vernon Valley, New Jersey. The satellite payload design and performance are described. The principal spacecraft bus systems are described with emphasis on improvements made for operation in the inclined, elliptical geosynchronous orbits.

  19. On the highly inclined vW leptokurtic asteroid families

    NASA Astrophysics Data System (ADS)

    Carruba, V.; Domingos, R. C.; Aljbaae, S.; Huaman, M.

    2016-08-01

    vW leptokurtic asteroid families are families for which the distribution of the normal component of the terminal ejection velocity field vW is characterized by a positive value of the γ2 Pearson kurtosis, i.e., they have a distribution with a more concentrated peak and larger tails than the Gaussian one. Currently, eight families are known to have γ2(vW) > 0.25. Among these, three are highly inclined asteroid families, the Hansa, Barcelona, and Gallia families. As observed for the case of the Astrid family, the leptokurtic inclination distribution seems to be caused by the interaction of these families with node secular resonances. In particular, the Hansa and Gallia family are crossed by the s - sV resonance with Vesta, that significantly alters the inclination of some of their members. In this work we use the time evolution of γ2(vW) for simulated families under the gravitational influence of all planets and the three most massive bodies in the main belt to assess the dynamical importance (or lack of) node secular resonances with Ceres, Vesta, and Pallas for the considered families, and to obtain independent constraints on the family ages. While secular resonances with massive bodies in the main belt do not significantly affect the dynamical evolution of the Barcelona family, they significantly increase the γ2(vW) values of the simulated Hansa and Gallia families. Current values of the γ2(vW) for the Gallia family are reached over the estimated family age only if secular resonances with Vesta are accounted for.

  20. Mechanics and energetics of incline walking with robotic ankle exoskeletons.

    PubMed

    Sawicki, Gregory S; Ferris, Daniel P

    2009-01-01

    We examined healthy human subjects wearing robotic ankle exoskeletons to study the metabolic cost of ankle muscle-tendon work during uphill walking. The exoskeletons were powered by artificial pneumatic muscles and controlled by the user's soleus electromyography. We hypothesized that as the demand for net positive external mechanical work increased with surface gradient, the positive work delivered by ankle exoskeletons would produce greater reductions in users' metabolic cost. Nine human subjects walked at 1.25 m s(-1) on gradients of 0%, 5%, 10% and 15%. We compared rates of O(2) consumption and CO(2) production, exoskeleton mechanics, joint kinematics, and surface electromyography between unpowered and powered exoskeleton conditions. On steeper inclines, ankle exoskeletons delivered more average positive mechanical power (P<0.0001; +0.37+/-0.03 W kg(-1) at 15% grade and +0.23+/-0.02 W kg(-1) at 0% grade) and reduced subjects' net metabolic power by more (P<0.0001; -0.98+/-0.12 W kg(-1) at 15% grade and -0.45+/-0.07 W kg(-1) at 0% grade). Soleus muscle activity was reduced by 16-25% when wearing powered exoskeletons on all surface gradients (P<0.0008). The ;apparent efficiency' of ankle muscle-tendon mechanical work decreased from 0.53 on level ground to 0.38 on 15% grade. This suggests a decreased contribution from previously stored Achilles' tendon elastic energy and an increased contribution from actively shortening ankle plantar flexor muscle fibers to ankle muscle-tendon positive work during walking on steep uphill inclines. Although exoskeletons delivered 61% more mechanical work at the ankle up a 15% grade compared with level walking, relative reductions in net metabolic power were similar across surface gradients (10-13%). These results suggest a shift in the relative distribution of mechanical power output to more proximal (knee and hip) joints during inclined walking. PMID:19088208

  1. Flow of Slurry in the Inclined Closed Channel

    NASA Astrophysics Data System (ADS)

    Ashrafi Khorasani, Nariman; Piroozram, Parastoo

    2015-11-01

    The flow of slurry in a closed inclined circular channel is examined. The viscoelastic fluid is modeled as a derivative of typical Oldroyd-B relation of stress and velocity gradient. First, gravity is considered as the driving force for the fluid flow to simulate the existing sewage system. The complete flow field is evaluated for this case. Next, a pressure gradient is introduced to observe its effects on the flow. Velocity profile as well as stress distributions are given for different scenarios of the nonlinear fluid flowing in a closed channel with and without pressure gradient.

  2. Nonlocal effects in sand flows on an inclined plane.

    PubMed

    Malloggi, F; Andreotti, B; Clément, E

    2015-05-01

    The flow of sand on a rough inclined plane is investigated experimentally. We directly show that a jammed layer of grains spontaneously forms below the avalanche. Its properties and its relation with the rheology of the flowing layer of grains are presented and discussed. In a second part, we study the dynamics of erosion and deposition solitary waves in the domain where they are transversally stable. We characterize their shapes and velocity profiles. We relate their translational velocity to the stopping height and to the mass trapped in the avalanche. Finally, we use the velocity profile to get insight into the rheology very close to the jamming limit. PMID:26066168

  3. Trigonometric series representations of the orbital inclination function.

    NASA Astrophysics Data System (ADS)

    Awad, Mervat El-Sayed

    1986-08-01

    In this paper, new trigonometric series representations of the orbital inclination function Flmp(i) in multiples of cosines or sines are established for all possible values of l, m, and p. For such representations, the literal analytical expressions and the recurrence formulae satisfied by their coefficients are established. Moreover, an economic algorithm for the table formulation of these coefficients for the possible values of l, m, and p is given. Finally, numerical examples of the representations for l = 2(1)4; m = 0(1)l; p = 0(1)l are also included.

  4. The flow around an inclined flat plate of finite width

    NASA Astrophysics Data System (ADS)

    Narumi, A.; Kato, S.; Terada, K.; Izumi, R.; Yanase, T.

    1985-07-01

    The flow around an inclined finite width plate was experimentally studied using oil film and oil point techniques. At the front surface, leading edge separation does not occur and the flow becomes more laminar than in the case with angle of incidence zero, though the flow yaws towards the side edge and separates from it. The flow at the back surface is characterized by a side edge vortex, a flow separated near the side edge of the leading edge, and a flow separated at the middle of the leading edge. The characteristics of these flows are discussed.

  5. Modeling tree crown dynamics with 3D partial differential equations.

    PubMed

    Beyer, Robert; Letort, Véronique; Cournède, Paul-Henry

    2014-01-01

    We characterize a tree's spatial foliage distribution by the local leaf area density. Considering this spatially continuous variable allows to describe the spatiotemporal evolution of the tree crown by means of 3D partial differential equations. These offer a framework to rigorously take locally and adaptively acting effects into account, notably the growth toward light. Biomass production through photosynthesis and the allocation to foliage and wood are readily included in this model framework. The system of equations stands out due to its inherent dynamic property of self-organization and spontaneous adaptation, generating complex behavior from even only a few parameters. The density-based approach yields spatially structured tree crowns without relying on detailed geometry. We present the methodological fundamentals of such a modeling approach and discuss further prospects and applications. PMID:25101095

  6. [Application of low noble alloys in telescoped crowns].

    PubMed

    Susulić, T

    1989-01-01

    It is known that low noble alloys (Hera SG, Aurea-Heraus, Stabilor-Degussa, Midgold-Bego etc.) are used woredwide for the preparation of prosthetic constructions. For this reason attempts to produce low noble alloys with the properties equal to those of more expensive high noble alloys, are justified, as they are cheap and available to a great number of patients. The Yugoslav producer of dental materials "Zlatarna Celje" has produced a low noble alloy named Midor S. The comparative investigations of resistance to the mouth, performed at the University School of Dentistry in Ljubljana and in the Laboratory of Metallurgy of "Zlatarna Celje", have shown that this alloy was more resistant to corrosion than 22 karat, high noble alloy. In our Department Mikdor S was experimentally tested on telescoped crowns. The obtained results showed the satisfactory hardness and resistance to attrition between the internal and external crowns within the limits of tolerance which made it suitable for use. PMID:2489991

  7. Effect of sandblasting on fracture load of titanium ceramic crowns

    PubMed Central

    Moldi, Arvind I.; Bhandari, Kishor Singh; Nagral, Sharanbassapa; Deshpandey, Sumit; Kulkarni, Pawan

    2015-01-01

    Purpose of the Study: It is difficult to achieve a reliable bond between the titanium and veneering porcelain. The aim of this study was to evaluate the bond strength between titanium ceramic crowns. Materials and Methods: The surfaces of titanium copings were divided in two groups. Group A sandblasted with 250 um (n = 10) and Group B without sandblasting (n = 10). Low-fusing porcelain was bonded over copings. A universal testing machine was used to determine the fracture load (N) of the crowns. All data were compared using Student's t-test. Results: There was a significant difference in fracture toughness between two groups (P = 0.05). The mean value of fracture strength for Group A was 721.66 N and for Group B was 396.39 N. Conclusions: Sandblasting improves the bond strength between titanium, and ceramic, mechanical bonding plays a crucial role in the bonding between titanium and ceramic. PMID:26929517

  8. Fabrication of all-ceramic crowns by a new method.

    PubMed

    Masuda, Takayuki; Kakimoto, Kazutoshi; Takahashi, Kazuya; Komasa, Yutaka

    2016-01-01

    A new method of all-ceramic production using alumina coping has been developed. The present study investigates the influence of secondary firing (glass infiltration firing) conditions. Samples of porcelain build-up without secondary firing were also assessed. The suitability of coping that included secondary firing was found to be affected by the rate of temperature increase during the secondary firing. However, cracking developed in the fired porcelain if porcelain was built up onto secondarily-fired coping. In contrast, cracking did not occur with coping that was not secondarily fired. The bending strength after porcelain build-up was 70 MPa or higher, suggesting the possibility of clinical applications as an anterior crown. These findings establish that this is method of producing all-ceramic crowns that allows for low-cost manufacture in a short period of about 1 h. PMID:27041020

  9. Crown Gall Disease and Hairy Root Disease 1

    PubMed Central

    Gelvin, Stanton B.

    1990-01-01

    The neoplastic diseases crown gall and hairy root are incited by the phytopathogenic bacteria Agrobacterium tumefaciens and Agrobacterium rhizogenes, respectively. Although the molecular mechanism of T-DNA transfer to the plant most likely is the same for both species, the physiological basis of tumorigenesis is fundamentally different. Crown gall tumors result from the over-production of the phytohormones auxin and cytokinin specified by A. tumefaciens T-DNA genes. Although the T-DNA of some Riplasmids of A. rhizogenes contains auxin biosynthetic genes, these loci are not always necessary for hairy root formation. Recent experiments suggest that hairy root tumors result from the increased sensitivity of transformed cells to endogenous auxin levels. An understanding of hairy root tumorigenesis will likely result in an increased knowledge of plant developmental processes. Images Figure 1 PMID:16667272

  10. Rolling and slipping down Galileo{close_quote}s inclined plane: Rhythms of the spheres

    SciTech Connect

    Crawford, F.S.

    1996-05-01

    In ``Two New Sciences`` (TNS) Galileo presents a number of theorems and propositions for smooth solid spheres released from rest and rolling a distance {ital d} in time {ital t} down an incline of height {ital H} and length {ital L}. We collect and summarize his results in a single grand proportionality {ital P}: {ital d}{sub 1}/{ital d}{sub 2}=({ital t}{sup 2}{sub 1}/{ital t}{sup 2}{sub 2})({ital H}/{ital L}){sub 1}/({ital H}/{ital L}){sub 2}. ({ital P}) From TNS it is clear that what we call {ital P} is assumed by Galileo to hold for all inclinations including vertical free fall with {ital H}/{ital L}=1. But in TNS he describes only experiments with gentle inclinations {ital H}/{ital L}{lt}1/2. Indeed he cannot have performed the vertical free fall ({ital H}={ital L}) experiment, because we (moderns) know that as we increase {ital H}/{ital L}, {ital P} starts to break down when {ital H}/{ital L} exceeds about 0.5, because the sphere, which rolls without slipping for small {ital H}/{ital L}, starts to slip, whence {ital d} starts to exceed the predictions of {ital P}, becoming too large by a factor of 7/5 for vertical free fall at {ital H}/{ital L}=1. In 1973 Drake and in 1975 Drake and MacLachlan published their analysis of a previously unpublished experiment that Galileo performed that (without his realizing it) directly compared rolling without slipping to free fall. In the experiment, a sphere that has gained speed {ital v}{sub 1} while rolling down a gentle incline is deflected so as to be launched horizontally with speed {ital v}{sub 1} into a free fall orbit discovered by Galileo to be a parabola. The measured horizontal distance {ital X}{sub 2} traveled in this parabolic orbit (for a given vertical distance fallen to the floor) was smaller than he expected, by a factor 0.84. But that is exactly what we (moderns) expect, since we know that Galileo did not appreciate the difference between rolling without slipping, and slipping on a frictionless surface.

  11. GAPS IN PROTOPLANETARY DISKS AS SIGNATURES OF PLANETS. II. INCLINED DISKS

    SciTech Connect

    Jang-Condell, Hannah; Turner, Neal J.

    2013-07-20

    We examine the observational appearance of partial gaps being opened by planets in protoplanetary disks, considering the effects of the inclination relative to the line of sight. We model the disks with static {alpha}-models with detailed radiative transfer, parameterizing the shape and size of the partially cleared gaps based on the results of hydrodynamic simulations. As in previous work, starlight falling across the gap leads to high surface brightness contrasts. The gap's trough is darkened by both shadowing and cooling, relative to the uninterrupted disk. The gap's outer wall is brightened by direct illumination and also by heating, which puffs it up so that it intercepts more starlight. In this paper, we examine the effects of inclination on resolved images of disks with and without gaps at a wide range of wavelengths. The scattering surface's offset from the disk midplane creates a brightness asymmetry along the axis of inclination, making the disk's near side appear brighter than the far side in scattered light. Finite disk thickness also causes the projected distances of equidistant points on the disk surface to be smaller on the near side of the disk as compared to the far side. Consequently, the gap shoulder on the near side of the disk should appear brighter and closer to the star than on the far side. However, if the angular resolution of the observation is coarser than the width of the brightened gap shoulder, then the gap shoulder on the far side may appear brighter because of its larger apparent size. We present a formula to recover the scale height and inclination angle of an imaged disk using simple geometric arguments and measuring disk asymmetries. Resolved images of circumstellar disks have revealed clearings and gaps, such as the transitional disk in LkCa 15. Models created using our synthetic imaging attempting to match the morphology of observed scattered light images of LkCa 15 indicate that the H-band flux deficit in the inner {approx}0

  12. [Feeding habitat of red-crowned crane and white-napped crane during their courtship period in Zhalong wetland].

    PubMed

    Zou, Hongfei; Wu, Qingming

    2006-03-01

    By the methods of fixed-spot observation, GPS positioning, plot sampling measurement and factor analysis, a comparative study was made on the feeding habitat of red-crowned and white-napped crane during their courtship period (from March to April) in Zhalong Nature Reserve in 2003 and 2004. The results showed that red-crowned crane preferred unique habitat for feed, mostly focused on water field (e. g., reed marsh). During its selection of microhabitat, food factor played a crucial role, followed by concealment factor, water factor, and identification factor. The feeding habitat of white-napped crane was of diversification, and dry field, e. g., Carex marsh, farmland and burned field, was the priority. White-napped crane had a strict requirement in selecting feeding microhabitat, with "valid food" factor as the most important ingredient, and disturbance and water factors as the subordinate one. PMID:16724740

  13. [Cervical discrepancies and closeness of marginal fit of full cast crowns in correlation with the luting agent used].

    PubMed

    Utz, K H; Grüner, M; Vothknecht, R

    1989-11-01

    In an in-vitro study 75 extracted teeth were prepared with a chamfer and a 12 degree convergence angle. After corrective impression taking and preparation of the dies accurately fitting caps were made of "Stabilor G" alloy. The marginal defects were measured at 4 points on each tooth under the light-microscope before and after cementing with three different luting agents. Before cementation the mean values and standard deviation of the cervical discrepancies were 105 +/- 43 microns. The crowns fixed by means of zinc oxyphosphate cement (Harvard) exhibited marginal defects of 142 +/- 33 microns, those fixed with Fuji-Ionomer type I glass polyalkenoate cement had 159 +/- 20 microns, and the crowns cemented with Ketac-Cem had 127 +/- 6 microns. After exposing the specimens to thermal cycling, additional data on the sealing capacity of these cements could be obtained which showed zinc oxyphosphate cement to have the most favorable properties. PMID:2639008

  14. Electric field gradient and electronic properties of crown thioether compounds

    NASA Astrophysics Data System (ADS)

    Lima, Filipe Camargo Dalmatti Alves; Nascimento, Rafael Rodrigues Do; Gonçalves, Marcos Brown; Cottenier, Stefaan; Caldas, Marília Junqueira; Petrilli, Helena Maria

    2010-04-01

    We compare published TDPAC experiments on 111Cd in the crown thioether C6H12S3AgCl with ab-initio electronic structure calculations performed within the framework of the Density Functional Theory using the Projector Augmented Wave method. We conclude from this comparison that the Cd atom at the very moment of the TDPAC experiment is positively charged, and we point out to a methodological difference between reproducing experimental electric-field gradients in molecules versus solid metals.

  15. Increasing the thermopower of crown-ether-bridged anthraquinones.

    PubMed

    Ismael, Ali K; Grace, Iain; Lambert, Colin J

    2015-11-01

    We investigate strategies for increasing the thermopower of crown-ether-bridged anthraquinones. The novel design feature of these molecules is the presence of either () crown-ether or () diaza-crown-ether bridges attached to the side of the current-carrying anthraquinone wire. The crown-ether side groups selectively bind alkali-metal cations and when combined with TCNE or TTF dopants, provide a large phase-space for optimising thermoelectric properties. We find that the optimum combination of cations and dopants depends on the temperature range of interest. The thermopowers of both and are negative and at room temperature are optimised by binding with TTF alone, achieving thermpowers of -600 μV K(-1) and -285 μV K(-1) respectively. At much lower temperatures, which are relevant to cascade coolers, we find that for , a combination of TTF and Na(+) yields a maximum thermopower of -710 μV K(-1) at 70 K, whereas a combination of TTF and Li(+) yields a maximum thermopower of -600 μV K(-1) at 90 K. For , we find that TTF doping yields a maximum thermopower of -800 μV K(-1) at 90 K, whereas at 50 K, the largest thermopower (of -600 μV K(-1)) is obtain by a combination TTF and K(+) doping. At room temperature, we obtain power factors of 73 μW m(-1) K(-2) for (in combination with TTF and Na(+)) and 90 μW m(-1) K(-2) for (with TTF). These are higher or comparable with reported power factors of other organic materials. PMID:26426840

  16. Taphonomic aspects of crowned hawk-eagle predation on monkeys.

    PubMed

    Sanders, William J; Trapani, Josh; Mitani, John C

    2003-01-01

    This study provides a taphonomic analysis of prey accumulations of crowned hawk-eagles (Stephanoaetus coronatus) from Ngogo, Kibale National Park, Uganda, collected over 37 months from below nests of two eagle pairs. Crowned hawk-eagles are powerful predators capable of killing animals much larger than themselves, and are significant predators of cercopithecoid monkeys in forest habitats throughout sub-Saharan Africa. At Ngogo, 81% of the individuals in the kill sample are monkeys. Redtail monkeys (Cercopithecus ascanius) are particularly well represented in the sample, making up 66% of monkeys identified to species. Despite an impressive killing apparatus, crowned hawk-eagles are fastidious eaters that inflict far less damage to bone than mammalian predators. Examination of skeletal material from the Ngogo kill sample reveals that crania, hindlimb elements, and scapulae survive predation better than do other bones. Crania of adults are typically complete and accompanied by mandibles, while crania of young individuals are usually dissociated from mandibles and lack basicrania and faces. Long bones are often whole or show minimal damage. Thin bones, such as crania and innominates, are marked by numerous nicks, punctures, and "can-opener" perforations. Scapular blades are heavily raked and shattered. Along with the strong preference for cercopithecoids, these distinct patterns of bone survival and damage indicate the feasibility of recognizing specific taphonomic signatures of large raptors in fossil assemblages. Berger and Clarke (1995) hypothesized that crowned hawk-eagles or similar large raptors were principally responsible for the accumulation of the late Pliocene fossil fauna from Taung, South Africa, including the type infant skull of Australopithecus africanus. The results of our study suggest that the faunal composition and type of damage to the hominid skull and other bone from Taung are consistent with the predatory activities of large raptors. More

  17. Secondary Li battery incorporating 12-Crown-4 ether

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan (Inventor); Distefano, Salvador (Inventor)

    1992-01-01

    A rechargeable lithium battery which utilizes a polyethylene oxide (PEO) solid polymeric electrolyte complexed with a lithium salt is disclosed. The conductivity is increased an order of magnitude and interfacial charge transfer resistance is substantially decreased by incorporating a minor amount of 12-Crown-4 ether in the PEO-lithium salt solid electrolyte film. Batteries containing the improved electrolyte permit operation at a lower temperature with improved efficiency.

  18. Use of Direct and Indirect Estimates of Crown Dimensions to Predict One Seed Juniper Woody Biomass Yield for Alternative Energy Uses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Throughout the western United States there is increased interest in utilizing woodland biomass as an alternative energy source. We conducted a pilot study to predict one seed juniper (Juniperus monosperma) chip yield from tree-crown dimensions measured on the ground or derived from Very Large Scale ...

  19. The estimation of dynamic contact angle of ultra-hydrophobic surfaces using inclined surface and impinging droplet methods

    NASA Astrophysics Data System (ADS)

    Jasikova, Darina; Kotek, Michal

    2014-03-01

    The development of industrial technology also brings with optimized surface quality, particularly where there is contact with food. Application ultra-hydrophobic surface significantly reduces the growth of bacteria and facilitates cleaning processes. Testing and evaluation of surface quality are used two methods: impinging droplet and inclined surface method optimized with high speed shadowgraphy, which give information about dynamic contact angle. This article presents the results of research into new methods of measuring ultra-hydrophobic patented technology.

  20. Reliability of metalloceramic and zirconia-based ceramic crowns.

    PubMed

    Silva, N R F A; Bonfante, E A; Zavanelli, R A; Thompson, V P; Ferencz, J L; Coelho, P G

    2010-10-01

    Despite the increasing utilization of all-ceramic crown systems, their mechanical performance relative to that of metal ceramic restorations (MCR) has yet to be determined. This investigation tested the hypothesis that MCR present higher reliability over two Y-TZP all-ceramic crown systems under mouth-motion fatigue conditions. A CAD-based tooth preparation with the average dimensions of a mandibular first molar was used as a master die to fabricate all restorations. One 0.5-mm Pd-Ag and two Y-TZP system cores were veneered with 1.5 mm porcelain. Crowns were cemented onto aged (60 days in water) composite (Z100, 3M/ESPE) reproductions of the die. Mouth-motion fatigue was performed, and use level probability Weibull curves were determined. Failure modes of all systems included chipping or fracture of the porcelain veneer initiating at the indentation site. Fatigue was an acceleration factor for all-ceramic systems, but not for the MCR system. The latter presented significantly higher reliability under mouth-motion cyclic mechanical testing. PMID:20660796