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1

Detection of a Large Flare in the RS CVn Star WY Cnc  

NASA Astrophysics Data System (ADS)

We report detection of an optical flare in the RS CVn spotted star WY Cnc. The flare duration is 64 min, the amplitude is 0.134 mag and the energy is 1 * 10^35 erg in the B band. The WY Cnc spot activity before and during the flare is analyzed.

Kozhevnikova, A. V.; Alekseev, I. Yu.; Heckert, P. A.; Kozhevnikov, V. P.

2006-08-01

2

HI and CO in the circumstellar environment of the S-type star RS Cnc  

E-print Network

This paper presents interferometric and single-dish CO observations along with HI data obtained for the oxygen-rich semi-regular variable RS Cnc, in order to probe its circumstellar environment at different scales. With the Plateau de Bure Interferometer and the IRAM 30-m telescope, we detect both the CO(1-0) and the CO(2-1) rotational lines from RS Cnc. The line profiles are composite, with two components of half-width ~2 km/s and ~8 km/s respectively. Whereas the narrow velocity component seems to originate from an equatorial disk in the central part of the CO envelope, the broad component reveals a bipolar structure, with a north-south velocity gradient. In addition, we obtain new HI data on the source and around it in a field of almost 1 square degree. The HI line is centered at v_LSR = 7 km/s in agreement with CO observations. A new reduction process reveals a complex extended structure in the northwest direction, of estimated size ~18 arcmin, with a PA (~310 degrees) opposite to the direction of the ste...

Libert, Yannick; Bertre, Thibaut Le; Gérard, Eric; Matthews, Lynn D

2010-01-01

3

Long-term starspot activity of three short-period RS CVn stars: BH Vir, WY Cnc and CG Cyg  

NASA Astrophysics Data System (ADS)

We present starspot analyses of CG Cyg, BH Vir and WY Cnc on the basis of our new photometric observations as well as published photometric data spanning almost 40 years. The spotted regions were concentrated at low latitudes up to 32°, the spots covered up to 29% of the stellar surface and all three stars show non-axisymmetric spot distributions (active longitude structures separated by approximately half the orbital period). We found that the variations in the brightness and spottedness of CG Cyg are probably cyclic with a period of about 20 years. We detected a large flare on WY Cnc (1.02×1035 erg in the B band) and analysed the WY Cnc spot activity before and during the flare.

Kozhevnikova, A. V.; Alekseev, I. Yu.; Heckert, P. A.; Kozhevnikov, V. P.

2007-02-01

4

The multi-scale environment of RS Cnc from CO and HI observations  

E-print Network

We present a detailed study of the circumstellar gas distribution and kinematics of the semi-regular variable star RS Cnc on spatial scales ranging from ~1" (~150 AU) to ~6' (~0.25 pc). New modeling of CO1-0 and CO2-1 imaging observations leads to a revised characterization of RS Cnc's previously identified axisymmetric molecular outflow. Rather than a simple disk-outflow picture, we find that a gradient in velocity as a function of latitude is needed to fit the spatially resolved spectra, and in our preferred model, the density and the velocity vary smoothly from the equatorial plane to the polar axis. In terms of density, the source appears quasi-spherical, whereas in terms of velocity the source is axi-symmetric with a low expansion velocity in the equatorial plane and faster outflows in the polar directions. The flux of matter is also larger in the polar directions than in the equatorial plane. An implication of our model is that the stellar wind is still accelerated at radii larger than a few hundred AU,...

Hoai, D T; Winters, J M; Nhung, P T; Gérard, E; Libert, Y; Bertre, T Le

2014-01-01

5

On the central symmetry of the circumstellar envelope of RS Cnc  

E-print Network

We present a phenomenological study of CO(1-0) and CO(2-1) emission from the circumstellar envelope (CSE) of the Asymptotic Giant Branch (AGB) star RS\\,Cnc. It reveals departures from central symmetry that turn out to be efficient tools for the exploration of some of the CSE properties. We use a wind model including a bipolar flow with a typical wind velocity of $\\sim$8 km\\,s$^{-1}$ decreasing to $\\sim$2 km\\,s$^{-1}$ near the equator to describe Doppler velocity spectral maps obtained by merging data collected at the IRAM Plateau de Bure Interferometer and Pico Veleta single dish radio telescope. Parameters describing the wind morphology and kinematics are obtained, together with the radial dependence of the gas temperature in the domain of the circumstellar envelope probed by the CO observations. Significant north-south central asymmetries are revealed by the analysis, which we quantify using a simple phenomenological description. The origin of such asymmetries is unclear.

Nhung, Pham Tuyet; Winters, Jan Martin; Darriulat, Pierre; Gérard, Eric; Bertre, Thibaut Le

2014-01-01

6

Infrared photometry of the RS CVn short-period systems - XY UMa and WY Cnc  

SciTech Connect

Infrared J and K light curves of two RS CVn short-period systems, XY UMa and WY Cnc, are presented. Both systems show similar variability in the infrared to that observed in the visual. From the colors an infrared excess is inferred for the primary component of both systems. A new determination of their geometrical elements is presented and the resulting parameters are compared to those previously obtained from visible photometry. The light curves show peculiarities that may indicate the presence of gas streams in the systems. 27 refs.

Arevalo, M.J.; Lazaro, C. (Instituto de Astrofisica de Canarias, La Laguna (Spain))

1990-03-01

7

RS CVn stars - Chromospheric phenomena  

NASA Technical Reports Server (NTRS)

The observational information regarding chromospheric emission features in surface-active RS CVn stars is reviewed. Three optical features are considered in detail: Ca II H and K, Balmer H-alpha and He I 10830 A. While the qualitative behavior of these lines is in accord with solar-analogy/rotation-activity ideas, the quantitative variation and scaling are very poorly understood. In many cases, the spectroscopic observations with sufficient SNR and resolution to decide these questions have simply not yet been made. The FK Com stars, in particular, present extreme examples of rotation that may well tax present understanding of surface activity to its limits.

Bopp, B. W.

1983-01-01

8

The shortest modulation period Blazhko RR Lyrae star: SS Cnc  

E-print Network

Extended BV(RI)c CCD observations of SS Cnc, a short period RRab star are presented. Nearly 1400 data points in each band have been obtained spanning over 79 days during the spring of 2005. The star exhibits light curve modulation, the so called Blazhko effect with small amplitude (B maximum brightness varies 0.1 mag) and with the shortest modulation period (5.309 d) ever observed. In the Fourier spectrum of the V light curve the pulsation frequency components are detected up to the 24th harmonic order, and modulation side lobe frequencies with significantly asymmetric amplitudes are seen up to the 15th and 9th orders for the lower and higher frequency components, respectively. Detailed comparison of the modulation behavior of SS Cnc and RR Gem, the two recently discovered small amplitude, short modulation period Blazhko stars is presented. The modulation frequency (f_m) appears in the Fourier spectrum of both stars with similar amplitude. We also demonstrate that the modulation frequencies have basically different properties as the pulsation and modulation side lobe frequencies have, indicating that the physics behind these frequency components are not the same. The discovery of small amplitude modulations of RRab stars cautions that the large photometric surveys (MACHO, OGLE) may seriously underestimate the number of modulated RR Lyrae stars.

J. Jurcsik; B. Szeidl; Á. Sódor; I. Dékány; Zs. Hurta; K. Posztobányi; K. Vida; M. Váradi; A. Szing

2006-03-20

9

Infrared observations of RS CVn stars  

NASA Technical Reports Server (NTRS)

The paper presents infrared photometry of the RS CVn binary stars AR Lac (1.2-10 microns) and MM Her (1.2-3.5 microns) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 microns) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 microns). An analysis of these and published V data based on flux ratio diagrams (linear analogues of color-color diagrams) shows that G and K stars supply the infrared light of these systems. In AR Lac, the combined light of a G5-K0 subgiant and either a late F dwarf or an early F subgiant can account for the observed visual and infrared light curves. None of these systems shows infrared emission from circumstellar matter. This result is simply understood: dust grains would not be expected to form in the physical conditions surrounding the subgiant, and the corona and chromosphere (whose properties have been deduced from spectroscopic X-ray observations) should not produce appreciable infrared emission.

Berriman, G.; De Campli, W. M.; Werner, M. W.; Hatchett, S. P.

1983-01-01

10

Legislation may support STaRS  

NASA Astrophysics Data System (ADS)

Congressman Vernon Ehlers (R, MI) has offered three bills in the House of Representatives that support K-12 science, math, engineering, and technology (SMET) education (Eos, April 18, 2000). Although no dollar amounts are mentioned, the three bills contain numerous provisions for improving and expanding SMET education activities at the Department of Education and the National Science Foundation, and for tax incentives for pre-service teacher education and in-service professional development. Of particular interest is Section 15 of H.R. 4271, the National Science Education Act, which directs the NSF to provide scholarships for K-12 teachers to participate in research programs in government agencies, colleges and universities, or private research establishments. Such scholarships could support AGU's Science Teacher and Research Scientist (STaRS) effort, which is intended to provide opportunities for teachers to participate in research under the direction of AGU scientists, and for those same scientists to participate in science teaching under the teachers' direction.

11

Beryllium abundances in parent stars of extrasolar planets: 16 Cyg A & B and rho 1 Cnc  

E-print Network

The Be II 3131 A doublet has been observed in the solar-type stars 16 Cyg A & B and in the late G-type star rho 1 Cnc, to derive their beryllium abundances. 16 Cyg A & B show similar (solar) beryllium abundances while 16 Cyg B, which has been proposed to have a planetary companion of ~2 M_Jup, is known to be depleted in lithium by a factor larger than 6 with respect to 16 Cyg A. Differences in their rotational histories which could induce different rates of internal mixing of material, and the ingestion of a similar planet by 16 Cyg A are discussed as potential explanations. The existence of two other solar-type stars which are candidates to harbour planetary-mass companions and which show lithium and beryllium abundances close to those of 16 Cyg A, requires a more detailed inspection of the peculiarities of the 16 Cyg system. For rho 1 Cnc, which is the coolest known object candidate to harbour a planetary-mass companion (M > 0.85 M_Jup), we establish a precise upper limit for its beryllium abundance, showing a strong Be depletion which constrains the available mixing mechanisms. Observations of similar stars without companions are required to asses the potential effects of the planetary companion on the observed depletion. It has been recently claimed that rho 1 Cnc appears to be a subgiant. If this were the case, the observed strong Li and Be depletions could be explained by a dilution process taking place during its post-main sequence evolution.

R. J. Garcia Lopez; M. R. Perez de Taoro

1998-03-03

12

Theoretical studies of the RS Canum Venaticorum stars  

NASA Technical Reports Server (NTRS)

The activity in RS Canum Venaticorum (CVn) is investigated. Models for chromospheric structure are developed and the role of magnetic fields both in the photosphere as well as in the chromosphere and upper atmosphere are examined. T Tau stars are also studied from the same points of view. The properties of magnetic field loops are used to help understand the atmospheric structure in RS CVn stars. The concepts developed in the case of these stars appear to be applicable over a much broader region of the HR diagram. The absence of stable magnetic loops in the atmospheres of late type giant stars suggests that the atmospheres of RS CVn active components are qualitatively distinct from the solar atmosphere.

Mullan, D. J.

1982-01-01

13

MOA-2010-BLG-523: 'FAILED PLANET' = RS CVn STAR  

SciTech Connect

The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing light curve near the peak of an A {sub max} {approx} 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spectrum taken near peak to demonstrate that this is an RS CVn variable, so that planetary microlensing is not required to explain the light-curve deviations. This is the first spectroscopically confirmed RS CVn star discovered in the Galactic bulge.

Gould, A.; Yee, J. C.; Pinsonneault, M. H.; Dong, Subo; Gaudi, B. S.; Hung, L.-W. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)] [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Bond, I. A. [Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand)] [Institute for Information and Mathematical Sciences, Massey University, Private Bag 102-904, Auckland 1330 (New Zealand); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)] [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)] [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Jorgensen, U. G. [Niels Bohr Institutet, Kobenhavns Universitet, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)] [Niels Bohr Institutet, Kobenhavns Universitet, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Greenhill, J. [University of Tasmania, School of Mathematics and Physics, Private Bag 37, Hobart, TAS 7001 (Australia)] [University of Tasmania, School of Mathematics and Physics, Private Bag 37, Hobart, TAS 7001 (Australia); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States)] [Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States); Bensby, T. [Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund (Sweden)] [Lund Observatory, Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund (Sweden); Allen, W. [Vintage Lane Observatory, Blenheim (New Zealand)] [Vintage Lane Observatory, Blenheim (New Zealand); Almeida, L. A.; Jablonski, F. [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, Avenida dos Astronautas, 1758 Sao Jose dos Campos, 12227-010 SP (Brazil)] [Divisao de Astrofisica, Instituto Nacional de Pesquisas Espaciais, Avenida dos Astronautas, 1758 Sao Jose dos Campos, 12227-010 SP (Brazil); Bos, M. [Molehill Astronomical Observatory, North Shore (New Zealand)] [Molehill Astronomical Observatory, North Shore (New Zealand); Christie, G. W. [Auckland Observatory, Auckland (New Zealand)] [Auckland Observatory, Auckland (New Zealand); DePoy, D. L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States)] [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States); Lee, C.-U. [Korea Astronomy and Space Science Institute, 776 Daedukdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, 776 Daedukdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Collaboration: muFUN Collaboration; MOA Collaboration; OGLE Collaboration; MiNDSTEp Consortium; RoboNet Collaboration; PLANET Collaboration; and others

2013-02-15

14

cnc-11 cnc-5 cnc-4 cnc-3 Cbr-R09B5.12  

E-print Network

cnc-1 cnc-11 cnc-5 cnc-4 cnc-3 cnc-2 elegans briggsae remanei R09B5.12 srj-23 Cbr-R09B5.12 Cre-R09B5.12 R09B5.11 Cre-R09B5.11 Cbr-cnc-5.2 Cbr-cnc-5.1 Cbr-cnc-11 Cbr-cnc-4 Cbr-cnc-3 Cbr-cnc-2 Cre-cnc-5.2 Cre-cnc-5.1 Cre-cnc-11 Cre-cnc-4 Cre-cnc-3 Cre-cnc-2 Cre-cnc-1 R09B5.11 NcoI EcoNI cnc-11 cnc-1

Ewbank, Jonathan

15

Quiescent and Flaring Structure in RS Canum Venaticorum Stars  

NASA Astrophysics Data System (ADS)

Four of the most active RS CVn stars (V711 Tau, II Peg, ? Gem, and UX Ari) have been observed for a total of 3 Ms with the Extreme Ultraviolet Explorer satellite (EUVE) between 1992 and 2000 January. Flaring and quiescent states of extreme ultraviolet spectra (??70-740) and light curves (??75-175) have been analyzed to provide emission measure distributions (EMD) for these systems in the range logTe(K)~5.6-7.4, based principally on iron lines. Flux measurements obtained with IUE and the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer (ORFEUS) complete the EMD in the lower temperature range [logTe(K)~4.0-5.6]. Frequent flaring activity has been found in the systems, including an increase during the rise phase by a factor of ~9 in the flux of ? Gem, the largest flare enhancement observed with EUVE. Analyses of the EUVE emission in the active single star AB Dor and the low-rotation giant star ? Cet are also included. The EMDs are remarkably similar among all the stars, showing a narrow enhancement or ``bump'' around logTe(K)~6.9. These narrow bumps are apparently unrelated to rotation rate, spectral type, binarity, or evolutionary stage. Significant material is found at logTe(K)>~7.0 for the most active stars. Modulation of the EUV flux outside of flaring occurs in four of the stars (? Gem, V711 Tau, UX Ari, AB Dor). The electron density ranges between Ne~1012 and ~1013 cm-3, measured at logTe(K)~7.0, and may reach higher values during flares. These densities and EMD values imply small scale sizes for emitting regions.

Sanz-Forcada, J.; Brickhouse, N. S.; Dupree, A. K.

2002-05-01

16

Long-term starspot activity of the eclipsing binaries BH Vir and WY Cnc  

NASA Astrophysics Data System (ADS)

We present the results of multicolor photometry of the two spotted, short-period, late-type RS CVn stars BH Vir and WY Cnc. We have derived the parameters of the binaries’ components, and refined their masses, radii, and luminosities. A strong flare of WY Cnc was detected for the first time, and pre-flare variations of the star’s activity studied. Our observations and published data spanning 40 years are analyzed using a zone starspot model. We demonstrate that the spots are always concentrated near the equators and at intermediate latitudes, with maximum spotted areas as large as 29% for BH Vir and 21% for WY Cnc. The temperature differences between spotted regions and the quiet photosphere were 2300 K (BH Vir) and 1800 K (WY Cnc). The detected long-term brightness variations of BH Vir suggest the existence of an activity cycle with a probable period of 22 years. Both stars have starspots concentrated at two active longitudes separated by approximately half of the orbital period during all the studied seasons; these longitudes remained the same (0° and 184°) for BH Vir over 40 years, whereas they migrated in the direction of the stellar rotation at a rate of 3.8°/yr for WY Cnc, suggesting a cycle of 47 years for the migration of the active longitudes.

Kozhevnikova, A. V.; Alekseev, I. Yu.; Heckert, P. A.; Kozhevnikov, V. P.

2007-11-01

17

Five New Variable Stars in the Field of the Old Nova RS Car  

NASA Astrophysics Data System (ADS)

Five new eclipsing binary stars (2MASS J11080308-6145589, 2MASS J11080447-6143290, 2MASS J11080559-6147079, 2MASS J11083782-6146288 and 2MASS J11085087-6143349) have been identified in the field of the 1895 nova RS Car. The phase plots indicate that all five stars are eclipsing binary stars of the EA subtype.

Nicholson, M. P.

2009-04-01

18

Polarization measurement and study of thirty RS CVn stars  

NASA Astrophysics Data System (ADS)

Polarization measurements were made on 30 RS CVn systems using the Berger polarimeter of McDonald Observatory in July-December 1984, of which 26 systems were measured for the first time. The results show that for most RS CVn systems, the optical linear polarization is weak, generally below 0.45 percent, averaging about 0.20 percent. Some systems, like AR Lac, HR 5110, HD 8357, HK Lac, HR 7275, and HR 7428 have polarization above 0.03 percent, which showed time variations by factors between 10 and 30. For HD 8357 and ER Vul, there is a clear connection between the polarization and the orbital phase.

Liu, Xue-Fu; Tan, Hui-Song

1987-09-01

19

Polarization measurement and study of thirty RS CVn stars  

NASA Astrophysics Data System (ADS)

We made polarization measurement on 30 RS CVn systems using the Berger polarimeter of McDonald Observatory in July-December 1984, of which 26 systems were measured for the first time. The results are given here. They show that for most RS CVn systems, the optical linear polarization is weak, generally below 0.45%, averaging about 0.20%. Some systems, like AR Lac, HR 5110, HD 8357, HK Lac, HR 7275 and HR 7428 have polarization above 0.03%, which showed time variations by factors between 10 and 30. For HD 8357 and ER Vul, there is a clear connection between the polarization and the orbital phase.

Liu, Xue-fu; Tan, Hui-Song Yunnan

1987-09-01

20

Optical Flaring on Rs-Canum Stars - the Case of II-Pegasi in 1992SEP  

NASA Astrophysics Data System (ADS)

Recent observational results by Mathioudakis et al. have suggested that optical Uband flares are a frequent occurrence on the RS CVn star, II Peg. We present U-band monitoring of II Peg in 1992 September which failed to show any evidence of flaring to very low limits. We show that these data are inconsistent with the flaring rates reported earlier and suggest that either II Peg was in a state of low flare activity in 1992, or that it was unusually active at the time of Mathioudakis et al.'s observations. Key words: stars: activity - binaries: close - stars: flare - stars: individual: II Peg - stars: late-type.

Byrne, P. B.; Lanzafame, A. C.; Sarro, L. M.; Ryans, R.

1994-09-01

21

NEWS & VIEWS nEutRon StaRS  

E-print Network

-mail: fernando@astro.columbia.edu O n a dark night you can see a thousand stars above, each like the Sun shining by means of nuclear fusion. Every one hundred years, one of the most massive of 1011 such stars in our

Loss, Daniel

22

BVR photometry of a newly identified RS CVn binary star HD 61396  

E-print Network

BVR photometry of a recently identified RS CVn binary star HD61396, carried out during 2001, is presented. The new photometry reveal significant evolution in the shape and amplitude of light curve when compared with those reported earlier by Padmakar etal (2000). The traditional two-starspot model has been used to obtain the spot parameters from the observed light curve. Changes in the spot area and their location on the stellar surface are discernible from the extracted parameters from the new photometry.

Sudhanshu Barway; S. K. Pandey; Padmakar Singh Parihar

2004-08-10

23

Doppler Imagery of the Spotted RS CVn Star HR 1099 (= V711 Tau) from 1981 - 1992  

E-print Network

We present 23 Doppler images of the spotted RS CVn star HR 1099 from 1981 to 1992. HR 1099 shows a large cool polar spot which has persisted for the 11 years of this study and other low-latitude spots which come and go on relatively short timescales. The polar spot has variable protuberances which look very similar to the time-variable vertical extensions of the Sun's polar coronal hole. The area of the polar spot and its extensions shows marginal evidence of being periodically variable in time with a period of ~3 years. On several occasions, isolated prominent spots emerged and then disappeared near the equator. The tracks of two long-lived spots suggest that some spots which emerge at low or intermediate latitudes migrate up to the pole in a clockwise spiral (slower than the orbit), and then apparently merge with the polar spot. Differential rotation as measured from spot movements showed that intermediate and low latitudes rotate slightly slower than the orbital angular velocity, while the pole and highest latitudes appear to be synchronized to the orbit. The differential rotation is of opposite sign and a factor of 50 less than for the Sun. We propose that the starspots on HR 1099 and other rapidly rotating RS CVn stars are, by analogy with solar coronal holes, large unipolar magnetic regions tightly frozen into multi-kilogauss axisymmetric dipole fields in these stars. Since the large cool polar spots, the signature of these dipoles, are not present on more slowly rotating RS CVn stars, we believe that they must be dynamo-induced rather than remnant fossil fields.

Steven S. Vogt; Artie P. Hatzes; Anthony A. Misch; M. Kurster

1997-04-18

24

Spectroscopic and photometric observations of the short-period RS CVn-type star CG Cyg  

NASA Astrophysics Data System (ADS)

Spectroscopic observations around the Halpha line and BVR photometry of the eclipsing short-period RS CVn-star CG Cyg are presented. The solutions of the radial velocity curves and the light curves yielded the following masses and radii of the star components: M1=0.97 Msun, M2=0.80 Msun, R1=1.00 Rsun, R2=0.83 Rsun. The measured rotational broadenings of the observed lines correspond to equatorial velocities V1=80 km s-1 and V2=66 km s-1. The distortions of our multicolor light curve were reproduced by two cool spots on the primary star. The strong absorption feature between the spectral lines of the two stars was explained by extended structure around the mass center of the system. The Halpha emission line of the secondary star in the August spectra was attributed to a prolonged flare of this star. Based on spectral observations at the 2-m Rozhen telescope, operated by the National Astronomical Observatory; the research was supported in part by grants of project No. 1/2002 of Shoumen University.

Kjurkchieva, D. P.; Marchev, D. V.; Ogloza, W.

2003-03-01

25

Southern RS CVn systems - Candidate list. [spectral catalog of variable binary stars  

NASA Technical Reports Server (NTRS)

A list of 43 candidate RS CVn binary systems in the far southern hemisphere of the sky (south of -40 deg declination) is presented. The candidate systems were selected from the first two volumes of the Michigan Spectral Catalog (1975, 1978), which provides MK classifications for southern HD stars and identifies any unusual characteristics noted for individual stellar spectra. The selection criteria used were: (1) the occurrence of Ca II H and K emission; (2) known or suspected binary nature; (3) regular light variations of zero to one magnitude; and (4) spectral type between F0 and K2 and luminosity less than bright giant (II).

Weiler, E. J.; Stencel, R. E.

1979-01-01

26

Very Short-Duration UV-B Optical Flares in RS CVn-type Star Systems  

NASA Astrophysics Data System (ADS)

Very short duration UV-B optical flares were observed during a high-cadence search for conventional flares on three RS CVn type stars: AR Lac, II Peg, and UX Ari. A statistical criterion was developed for isolating these short-duration optical flares from random photon events. Five flares, ranging in duration from 30 to 85 ms with peaks 0.29-0.51 mag. above the mean, were detected within the 132 hours of monitoring time. The time resolution of the observations was 5 ms for AR Lac and 10 ms for II Peg and UX Ari.

Vander Haagen, G. A.

2013-06-01

27

CNC Router Fundamentals Orientation  

NSDL National Science Digital Library

These zipped documents from MatEd provide information on designing a course on CNC Router Fundamentals Orientation. At the end of the course, students will be able to identify manufactured projects or products that are compatible for production on CNC routers, operate a Techno brand CNC router, and have proposed a project to reinforce these concepts. The documents include a draft syllabus, contact information for the author of the course, a sample new course proposal form, and a course outline.

Kraft, Patrick

28

Very Long Baseline Interferometry Imaging of the RS Canum Venaticorum Binary Star System HR 5110  

NASA Astrophysics Data System (ADS)

We present VLBI images of the RS CVn binary star HR 5110 (=BH CVn; HD 118216), obtained from observations made at 8.4 GHz on 1994 May 29/30 in support of the NASA/Stanford Gravity Probe B project. Our images show an emission region with a core-halo morphology. The core was 0.39+/-0.09 mas (FWHM) in size, or 66%+/-20% of the 0.6+/-0.1 mas diameter of the chromospherically active K subgiant star in the binary system. The halo was 1.95+/-0.22 mas (FWHM) in size, or 1.8+/-0.2 times the 1.1+/-0.1 mas separation of the centers of the K and F stars. (The uncertainties given for the diameter of the K star and its separation from the F star each reflect the level of agreement of the two most recent published determinations.) The core increased significantly in brightness over the course of the observations and seems to have been the site of flare activity that generated an increase in the total flux density of ~200% in 12 hr. The fractional circular polarization simultaneously decreased from ~10% to 2.5%.

Ransom, R. R.; Bartel, N.; Bietenholz, M. F.; Ratner, M. I.; Lebach, D. E.; Shapiro, I. I.; Lestrade, J.-F.

2003-04-01

29

Long-term chromospheric activity of non-eclipsing RS CVn-type stars  

E-print Network

Context. The IUE database provides a large number of UV high and low-resolution spectra of RS CVn-type stars from 1978 to 1996. In particular, many of these stars were monitored continuously during several seasons by IUE. Aims. Our main purpose is to study the short and long-term chromospheric activity of the RS CVn systems most observed by IUE: HD 22468 (V711 Tau, HR 1099, K1IV+G5V), HD 21242 (UX Ari, K0IV+G5V) and HD 224085 (II Peg, K2IV). Methods. We first obtain the Mount Wilson index S from the IUE high and low-resolution spectra. Secondly, we analyse with the Lomb-Scargle periodogram the mean annual index S and the amplitude of its rotational modulation. Results. For HD 22468 (V711 Tau, HR 1099), we found a possible chromospheric cycle with a period of 18 years and a shorter cycle with a period of 3 years, which could be associated to a chromospheric "flip-flop" cycle. The data of HD 224085 (II Peg) also suggest a chromospheric cycle of 21 years and a flip-flop cycle of 9 years. Finally, we obtained a possible chromospheric cycle of 7 years for HD 21242 (UX Ari).

Andrea P. Buccino; Pablo J. D. Mauas

2008-12-19

30

CNC Programming I.  

ERIC Educational Resources Information Center

This document contains five units for a course in computer numerical control (CNC) for computer-aided manufacturing. It is intended to familiarize students with the principles and techniques necessary to create proper CNC programs manually. Each unit consists of an introduction, instructional objectives, learning materials, learning activities,…

Casey, Joe

31

Open architecture CNC system  

SciTech Connect

In this paper, an alternative solution to the traditional CNC machine tool controller has been introduced. Software and hardware modules have been described and their incorporation in a CNC control system has been outlined. This type of CNC machine tool controller demonstrates that technology is accessible and can be readily implemented into an open architecture machine tool controller. Benefit to the user is greater controller flexibility, while being economically achievable. PC based, motion as well as non-motion features will provide flexibility through a Windows environment. Up-grading this type of controller system through software revisions will keep the machine tool in a competitive state with minimal effort. Software and hardware modules are mass produced permitting competitive procurement and incorporation. Open architecture CNC systems provide diagnostics thus enhancing maintainability, and machine tool up-time. A major concern of traditional CNC systems has been operator training time. Training time can be greatly minimized by making use of Windows environment features.

Tal, J. [Galil Motion Control Inc., Sunnyvale, CA (United States); Lopez, A.; Edwards, J.M. [Los Alamos National Lab., NM (United States)

1995-04-01

32

FR Cnc Revisited: Photometry, Polarimetry and Spectroscopy  

E-print Network

Here we present the study of FR Cnc, a young, active and spotted star. We performed analysis of ASAS-3 (The All Sky Automated Survey) data for the years 2002-2008 and amended the value of the rotational period to be 0.826518 d. The amplitude of photometric variations decreased abruptly in the year 2005, while the mean brightness remained the same, which was interpreted as a quick redistribution of spots. BVRc and Ic broad band photometric calibration was performed for 166 stars in FR Cnc vicinity. The photometry at Terskol Observatory shows two brightening episodes, one of which occurred at the same phase as the flare of 2006 November 23. Polarimetric BVR observations indicate the probable presence of a supplementary source of polarization. We monitored FR Cnc spectroscopically during the years 2004-2008. We concluded that the RV changes cannot be explained by the binary nature of FR Cnc. We determined the spectral type of FR Cnc as K7V. Calculated galactic space-velocity components (U, V, W) indicate that FR...

Golovin, A; Hernan-Obispo, M; Andreev, M; Barnes, J R; Montes, D; Pavlenko, E; Pandey, J C; Martinez-Arnaiz, R; Medhi, B J; Parihar, P S; Henden, A; Sergeev, A; Zaitsev, S V; Karpov, N

2011-01-01

33

Coronal Variability on Active (RS CVn) Binary Stars from Chandra HETGS Spectroscopy  

NASA Astrophysics Data System (ADS)

The complexity of magnetic fields on active stars inevitably leads to reconnection and flaring. Even on the relatively inactive Sun, magnetic reconnection events occur continuously and flares are frequent. On active binary stars the situation is even more dramatic; these stars have intense magnetic fields covering much of their surfaces and even their quiescent coronal emission is thousands of times stronger than that from the Sun. Huge, long duration (many hours) flare outbursts are frequent on RS CVn binaries. We analyse Chandra HETGS spectra and contemporaneous multi-wavelength data of the active binaries Sigma Gem (K1 III +?), Sigma2 CrB (F6 V + G0 V), and HR1099 (K1 IV + G5 V) to determine the temporal changes in coronal properties and to see if their coronal variability makes sense in terms of processes observed in the solar corona. Different types of flare behaviour are seen on each of the binaries. We are able to study flare rises and decays and to test whether such proxy paradigms as the radio - X-ray Neupert effect actually hold true.

Brown, A.

2006-08-01

34

CNC router modernization  

E-print Network

A large-format CNC router has been stored in the Pappalardo Laboratory wood shop for several years in an unusable state. A need assessment determined that it would be cost effective to bring the router online for use in ...

Doody, Aaron L. (Aaron Lee)

2007-01-01

35

The chromosphere of II Pegasi: multi-line modelling of an RS Canum Venaticorum star  

NASA Astrophysics Data System (ADS)

We present the first simultaneous multi-line fitting of a semi-empirical atmospheric model with a chromosphere and transition region to the H I and Ca II spectra of an RS CVn star (II Peg). The static component of the H? emission core, the line profile of H? , the apparent absence of H? and Hdelta , and the emission core profiles of Ca II K and two of the Ca II IR(3) lines are all approximately fitted by a static 1D model with the following properties: log m at the onset of the transition region is ~ -2.85, and a 6000 K plateau in the upper chromosphere that spans about a decade in log m. In particular, the model is able to reproduce the unusually steep Balmer decrement (compared to the dMe stars), in which H? is strongly in emission and H? is in absorption, without recourse to extra-atmospheric material. The Ca II IR(3) lines are best fit by a model in which T_min is cooler by 300 K and shallower by over half a decade in log m than that which best fits the optical lines. The emergent flux in the IR(3) line cores arises from the T_min region, whereas the other diagnostics arise from layers well above T_min, and it is postulated that this may be the cause of the discrepancy. There has very recently been evidence from other investigators that the metallicity of II Peg may be sub-solar, and we find that models with [{A/ H}]=-0.4 provide a somewhat better fit to all the lines considered.

Short, C. I.; Byrne, P. B.; Panagi, P. M.

1998-10-01

36

The CCD photometric study of the newly identified RS CVn binary star DV Piscium  

NASA Astrophysics Data System (ADS)

This paper presents new CCD BVRI light curves of the newly discovered RS CVn eclipsing binary star DV Psc. From the asymmetric light curves outside the eclipse, we find there are two depressions in the phase ranges 0.3-0.45 and 0.6-0.9, respectively. By analyzing the light curves using the Wilson-Devinney program, the four photometric solutions of the system are obtained and the starspot parameters are also derived. It turns out that the case of two spots being on the primary is most successful in reproducing the light curve distortion of DV Psc. Moreover, analysis the longitudes of spots suggests that there are two active longitude belts (one is about 90°, the other is about 270°). At the same time, on 22 November 2008, the first flare-like event was detected on DV Psc at phase 0.35 whose duration was about 13.5 min. These findings reveal that DV Psc has a high degree of magnetic activity.

Zhang, Liyun; Zhang, Xiliang; Zhu, Zhongzhong

2010-04-01

37

S 10947 Aql = RX J2009.8+1557: A probable RS CVn star which sometimes stops its eclipses  

E-print Network

We report the discovery of a new variable star, called S 10947 Aql, as the likely optical counterpart of RX J2009.8+1557. The optical variability pattern as well as the detected X-ray emission suggest that it is a chromospherically active binary of the RS Canum Venaticorum type. We discovered an occasional disappearance of the eclipsing minima as well as large variations in the eclipse amplitude. We discuss possible causes of this peculiarity.

G. A. Richter; J. Greiner

2000-08-25

38

Carney complex (CNC)  

Microsoft Academic Search

The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is

Jérôme Bertherat

2006-01-01

39

Unusually Increased Activity of GZ Cnc  

E-print Network

GZ Cnc was discovered as a variable star by Takamizawa (Tmz V34), which turned out to a cataclysmic variable (CV). Past studies have shown that this object is a good candidate for a rarely outbursting, long-period dwarf nova. Only three outbursts were recorded between 1999 and 2001. In 2002 March-May, the object suddenly showed a dramatic increase of the outburst frequency. The shortest observed interval was only 11 d. We suggest that the present behavior may be interpreted as a clustering of short outbursts occasionally seen in intermediate polars (magnetic CVs). The present activity can also be comparable to V426 Oph, another dwarf nova which is known to show occasionally increased activities. The resemblances in the X-ray properties and the outburst behavior suggests that GZ Cnc and V426 Oph may comprise a new class of (weakly magnetic) cataclysmic variables.

T. Kato; P. A. Dubovsky; R. Stubbings; M. Simonsen

2002-07-23

40

Characterization of the Transiting Super-Earth 55 Cnc e  

NASA Astrophysics Data System (ADS)

The transiting nature of 55 Cnc e has been recently unveiled independently by the MOST satellite in the visible (Winn et al. 2011) and Warm Spitzer in the infrared (Demory et al. 2011). 55 Cnc e is the only transiting super-Earth orbiting a naked eye star, which makes this planet a true Rosetta stone in the field of low-mass exoplanets. We will present new follow-up observations scheduled during Summer 2011 that will provide better constraints on the internal structure and immediate environment of this intriguing super-Earth.

Demory, Brice-Olivier; Gillon, M.; Deming, D.; Seager, S.

2011-09-01

41

Plage and flare Activity of the RS CVn-type Star UX Arietis during 2001-2002  

NASA Astrophysics Data System (ADS)

The very active RS CVn-type star UX Ari was observed using high-resolution echelle spectrograph attached to the 2.16m telescope of Xinglong station in Nov.-Dec. 2001 and Dec. 2002. By means of synthetic spectral subtraction method, the information about chromospheric activity of the system was obtained through several chromospheric activity indicators HeI D3, NaI D1D2, H?, and CaII IRT lines. Based on the analysis for these activity indicators, we found that the chromospheric activity of UX Ari showed obvious orbital modulation phenomenon, and the favorite active longitudes were around the quadratures of the binary system. During the two observing runs, hot plage and very strong optical flare events were detected, which were always happened around the favorite active longitudes of the system. Moreover, they were linked with the photospheric starspots in spatial structure, and appeared just above the main starspots.

Gu, Sheng-Hong

42

The Distribution of Activity on the RS CVn-Type Star SZ Piscium  

NASA Astrophysics Data System (ADS)

We use contemporaneous spectra and BV light curves to derive a model of the distribution of spots and active regions on the cooler component of SZ Psc for the 1993-1994 season. For that epoch, both spots and active regions were visible at all rotational phases of this chromospherically active star. The lack of large distortions of Doppler profiles of optical lines argues for >~15 spots with angular radii of <~8°-10°. Transition region emission was constant to within +/-12% over the orbit, nor was it eclipsed appreciably. This leads us to estimate that there are at least 20 active regions, perhaps several hundred. Chromospheric Mg II emission seems to have been proportional to the unspotted area of the star, not to the area of spots visible. We detected one strong flare in transition region lines during this program. We also present new light-curve and radial velocity solutions. These solutions find the more massive, cool star very close to its Roche lobe, and the hot star rotating more slowly than synchronously, making SZ Psc an important system for tecent he structure and evolution of binary stars. Changes in the radial velocities over 2 years of subsequent monitoring show that SZ Psc is a triple system. H? emission seems independent of phase on the average, but it can increase markedly for periods of a few orbital cycles.

Eaton, Joel A.; Henry, Gregory W.

2007-03-01

43

MAXI/GSC detection of an active state of the RS CVn type star UX Ari  

NASA Astrophysics Data System (ADS)

We report an X-ray detection with MAXI/GSC from the position consistent with the RS CVn type variable UX Ari. The flux increasing was observed from 2011-04-26 09:36 (UT) (= MJD 55677.414) and the active state lasted at least to the latest transit starting at 2011-04-27 05:42 (UT) (= MJD 55678.238). The active state seems to comprise multiple flares, and the flux maximum was observed at the transit starting from 2011-04-27 01:13 (UT) (= MJD 55678.051) with the preliminary flux of about 130 +-30 mCrab (1-sigma statistical error) in the 4-10 keV band.

Matsumura, T.; Tsuboi, Y.; Yamazaki, K.; Morii, M.; Ueno, S.; Tomida, H.; Kohama, M.; Ishikawa, M.; Mihara, T.; Sugizaki, M.; Serino, M.; Nakahira, S.; Yamamoto, T.; Sootome, T.; Matsuoka, M.; Kawai, N.; Sugimori, K.; Usui, R.; Toizumi, T.; Yoshida, A.; Yamaoka, K.; Tsunemi, H.; Kimura, M.; Kitayama, H.; Negoro, H.; Nakajima, M.; Suwa, F.; Ueda, Y.; Hiroi, K.; Shidatsu, M.

2011-04-01

44

MAXI/GSC detection of a possible flare from the RS CVn type star SZ Psc  

NASA Astrophysics Data System (ADS)

MAXI/GSC detected an increased X-ray emission from the position consistent with the RS CVn type variable, SZ Psc. The significant X-ray flux in the 2-10 keV band had been detected since 2011-11-05 18:20 (UT) (= MJD 55870.764) and the activity continued at least until 2011-11-05 23:03 (UT) (= MJD 55870.960). The maximum flux of about 110 mCrab was observed during a GSC scan transit starting at 2011-11-05 19:53 (UT) (= MJD 55870.828) and the X-ray luminosity is about 3×1033 ergs/s (distance is assumed to 88 pc).

Negoro, H.; Usui, R.; Yamazaki, K.; Tsuboi, Y.; Matsumura, T.; Matsuoka, M.; Sugizaki, M.; Mihara, T.; Serino, M.; Nakahira, S.; Yamamoto, T.; Sootome, T.; Ueno, S.; Tomida, H.; Kohama, M.; Ishikawa, M.; Kawai, N.; Morii, M.; Sugimori, K.; Toizumi, T.; Yoshida, A.; Yamaoka, K.; Tsunemi, H.; Kimura, M.; Kitayama, H.; Nakajima, M.; Suwa, F.; Ueda, Y.; Hiroi, K.; Shidatsu, M.

2011-11-01

45

Failure probabilistic model of CNC lathes  

Microsoft Academic Search

A field failure analysis of computerized numerical control (CNC) lathes is described. Field failure data was collected over a period of two years on approximately 80 CNC lathes. A coding system to code failure data was devised and a failure analysis data bank of CNC lathes was established. The failure position and subsystem, failure mode and cause were analyzed to

Yiqiang Wang; Yazhou Jia; Junyi Yu; Yuhua Zheng; Shangfeng Yi

1999-01-01

46

Stable chaos in the 55Cnc exoplanetary system?  

E-print Network

The five planets discovered around the main-sequence star 55 Cnc may represent a case of stable chaos. By using both the Frequency Map Analysis and MEGNO we find that about 15 % of the systems that can be build from the nominal orbital elements of the system are highly chaotic. However, in spite of the fast diffusion rate in the phase space, the planetary system is not destabilized over 400 Myr and close encounters between the planets are avoided.

Julie Gayon; Francesco Marzari; Hans Scholl

2008-07-08

47

CNC Preparation Meets Manufacturing Opportunity  

ERIC Educational Resources Information Center

This article features the machining technology program at Cape Fear Community College (CFCC) of Wilmington, North Carolina. North Carolina's Cape Fear Community College is working to meet diverse industry needs through its CNC training. The school's program has gained the attention of the local manufacturing community and students when it shifted…

Cassola, Joel

2006-01-01

48

Evolutionary programming of CNC machines  

Microsoft Academic Search

The paper proposes a new concept for programming of CNC machines. The concept based on genetic algorithms assures evolutionary generation and optimization of NC programs on the basis of CAD models of manufacturing environment. The structure, undergoing simulated evolution, is the population of NC programs. The NC programs control the machine which performs simple elementary motions. During the evolution the

M. Kovacic; M. Brezocnik; I. Pahole; J. Balic; B. Kecelj

2005-01-01

49

Rossiter-McLaughlin Observations of 55 Cnc e  

E-print Network

We present Rossiter-McLaughlin observations of the transiting super-Earth 55 Cnc e collected during six transit events between January 2012 and November 2013 with HARPS and HARPS-N. We detect no radial-velocity signal above 35 cm/s (3-sigma) and confine the stellar v sin i to 0.2 +/- 0.5 km/s. The star appears to be a very slow rotator, producing a very low amplitude Rossiter-McLaughlin effect. Given such a low amplitude, the Rossiter-McLaughlin effect of 55 Cnc e is undetected in our data, and any spin-orbit angle of the system remains possible. We also performed Doppler tomography and reach a similar conclusion. Our results offer a glimpse of the capacity of future instrumentation to study low amplitude Rossiter-McLaughlin effects produced by super-Earths.

Lopez-Morales, Mercedes; Rodler, Florian; Dumusque, Xavier; Buchhave, Lars A; Harutyunyan, A; Hoyer, Sergio; Alonso, Roi; Gillon, Michael; Kaib, Nathan A; Latham, David W; Lovis, Christophe; Pepe, Francesco; Queloz, Didier; Raymond, Sean N; Segransan, Damien; Waldmann, Ingo P; Udry, Stephane

2014-01-01

50

Rossiter-McLaughlin Observations of 55 Cnc e  

NASA Astrophysics Data System (ADS)

We present Rossiter-McLaughlin observations of the transiting super-Earth 55 Cnc e collected during six transit events between 2012 January and 2013 November with HARPS and HARPS-N. We detect no radial velocity signal above 35 cm s-1 (3?) and confine the stellar v sin i sstarf to 0.2 ± 0.5 km s-1. The star appears to be a very slow rotator, producing a very low amplitude Rossiter-McLaughlin effect. Given such a low amplitude, the Rossiter-McLaughlin effect of 55 Cnc e is undetected in our data, and any spin-orbit angle of the system remains possible. We also performed Doppler tomography and reach a similar conclusion. Our results offer a glimpse of the capacity of future instrumentation to study low amplitude Rossiter-McLaughlin effects produced by super-Earths.

López-Morales, Mercedes; Triaud, Amaury H. M. J.; Rodler, Florian; Dumusque, Xavier; Buchhave, Lars A.; Harutyunyan, Avet; Hoyer, Sergio; Alonso, Roi; Gillon, Michaël; Kaib, Nathan A.; Latham, David. W.; Lovis, Christophe; Pepe, Francesco; Queloz, Didier; Raymond, Sean N.; Ségransan, Damien; Waldmann, Ingo P.; Udry, Stéphane

2014-09-01

51

CNC electrical discharge machining centers  

SciTech Connect

Computer numerical control (CNC) electrical discharge machining (EDM) centers were investigated to evaluate the application and cost effectiveness of establishing this capability at Allied-Signal Inc., Kansas City Division (KCD). In line with this investigation, metal samples were designed, prepared, and machined on an existing 15-year-old EDM machine and on two current technology CNC EDM machining centers at outside vendors. The results were recorded and evaluated. The study revealed that CNC EDM centers are a capability that should be established at KCD. From the information gained, a machine specification was written and a shop was purchased and installed in the Engineering Shop. The older machine was exchanged for a new model. Additional machines were installed in the Tool Design and Fabrication and Precision Microfinishing departments. The Engineering Shop machine will be principally used for the following purposes: producing deep cavities in small corner radii, machining simulated casting models, machining difficult-to-machine materials, and polishing difficult-to-hand polish mold cavities. 2 refs., 18 figs., 3 tabs.

Jaggars, S.R.

1991-10-01

52

MAXI/GSC detection of a possible X-ray flare from an RS CVn star GT Mus (=4U1137-65, HD 101379)  

NASA Astrophysics Data System (ADS)

On 2010-11-10 06:17:27 UT (= MJD 55510.26211), the MAXI/GSC transient alert system triggered on enhanced X-ray emission from the position: (R.A., Dec) = (174.925, 65.498) = (11h 39m 42s, -65d 29m 53s) (J2000) with an error radius (statistical + systematic) of about 0.3 degrees. This location is consistent with that of the RS CVn star GT Mus (=4U 1137-65, HD 101379) (Garcia et al.

Nakajima, M.; Suwa, F.; Negoro, H.; Ozawa, H.; Matsumura, T.; Yamazaki, K.; Uzawa, A.; Kawai, N.; Mihara, T.; Serino, M.; Sugizaki, M.; Nakagawa, Y. E.; Yamamoto, T.; Sootome, T.; Matsuoka, M.; Morii, M.; Sugimori, K.; Usui, R.; Ueno, S.; Tomida, H.; Kohama, M.; Ishikawa, M.; Yoshida, A.; Yamaoka, K.; Nakahira, S.; Tsunemi, H.; Kimura, M.; Ueda, Y.; Isobe, N.; Eguchi, S.; Hiroi, K.; Shidatsu, M.; Daikyuji, A.

2010-11-01

53

The photosphere and chromosphere of the RS Canum Venaticorum star, II Pegasi. II. A multi-wavelength campaign in August/September 1992  

NASA Astrophysics Data System (ADS)

We describe multi-wavelength, simultaneous observations of the RS CVn star, II Pegasi, most of which were obtained during the first three weeks of September 1992. These observations were made using optical and infra-red broad-band photometry, ultraviolet and optical spectroscopy and microwave monitoring. We have detected photospheric spots and chromospheric flares, as well as deriving a description of mean conditions in the quiet chromosphere. One of the flares, observed in optical photometry and ultraviolet spectroscopy is one of the most energetic ever observed on this star. We demonstrate that in its ``quiescent'' state II Peg is continually variable in most of its chromospheric emissions, as well as in its coronal output.

Byrne, P. B.; Abdul Aziz, H.; Amado, P. J.; Arevalo, M. J.; Avgoloupis, S.; Doyle, J. G.; Eibe, M. T.; Elliott, K. H.; Jeffries, R. D.; Lanzafame, A. C.; Lazaro, C.; Murphy, H. M.; Neff, J. E.; Panov, K. P.; Sarro, L. M.; Seiradakis, J. H.; Spencer, R. E.

1998-02-01

54

Field failure database of CNC lathes  

Microsoft Academic Search

To assess and improve the reliability of computerized numerical control (CNC) lathes, it is essential to collect field failure information throughout the products’ life and perform analysis on these data. This paper describes the collection of field failure data, codification of data and establishment of the field failure database for CNC lathes and gives some examples of the kind of

Yiqiang Wang; Yazhou Jia; Junyi Yu; Shangfeng Yi

1999-01-01

55

Composite Concrete Bed for CNC Machine Tool  

Microsoft Academic Search

As the operation speeds of CNC machine tools are increased, the vibration problem has become a major constraint of manufacturing of precision products. The two important functional requirements of CNC machine tool bed are high structural stiffness and high damping. Conventional metallic materials used for bed structure have high stiffness but low damping. Epoxy concrete materials used for bed structure

Ding Jiangmin

2010-01-01

56

EXPERIENCES IN NEW CNC LEARNING INNOVATIONS MARAVELAKIS Emmanuel1  

E-print Network

EXPERIENCES IN NEW CNC LEARNING INNOVATIONS MARAVELAKIS Emmanuel1 , YALDIZ Süleyman2 , SAHIN Mehmet learning innovations in CNC training. The evolution of CNC machine technology and continuous developments in CNC programming, produce an increasing demand for an effective, user-friendly and innovative training

Aristomenis, Antoniadis

57

Research on Component Technology for Reconfigurable CNC System  

Microsoft Academic Search

Reconfigurable CNC system, as an extension of open CNC system, can be rapid designed, easy to integrate new technologies and flexible to fulfill different application requirements. In order to implement the reconfigurable CNC system, component based software engineering appears to be an efficient approach. This paper presents a component model for reconfigurable CNC system, which addresses the special functional and

Shaohua Du; Dong Yu

2009-01-01

58

FR Cnc Nature Revisited M.C. Glvez1, 2 , A. Golovin3, 4, M. Hernn-Obispo2, E. Pavlenko5, M. Andreev6, M., D. Montes2,  

E-print Network

FR Cnc Nature Revisited M.C. Gálvez1, 2 , A. Golovin3, 4, M. Hernán-Obispo2, E. Pavlenko5, M. Saraswati, Hanle, INDIA The results of photometric and spectroscopic monitoring of FR Cnc reported a tricky@astrax.fis.ucm.es FR Cnc is a K5-7V, chromospherically active star. Here we found spectroscopic and photometric

Complutense de Madrid, Universidad

59

TX Cnc AS A MEMBER OF THE PRAESEPE OPEN CLUSTER  

SciTech Connect

We present B-, V-, and I-band CCD photometry of the W UMa-type binary system TX Cnc, which is a member star of the Praesepe open cluster. Based on the observations, new ephemeris and a revised photometric solution of the binary system were derived. Combined with the results of the radial velocity solution contributed by Pribulla et al., the absolute parameters of the system were determined. The mass, radius, and luminosity of the primary component are derived to be 1.35 {+-} 0.02 M {sub sun}, 1.27 {+-} 0.04 R {sub sun}, and 2.13 {+-} 0.11 L {sub sun}. Those for the secondary star are computed as 0.61 {+-} 0.01 M {sub sun}, 0.89 {+-} 0.03 R {sub sun}, and 1.26 {+-} 0.07 L {sub sun}, respectively. Based on these results, a distance modulus of (m - M) {sub V} = 6.34 {+-} 0.05 is determined for the star. It confirms the membership of TX Cnc to the Praesepe open cluster. The evolutionary status and the physical nature of the binary system are discussed compared with the theoretical model.

Zhang, X. B.; Deng, L.; Lu, P. [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, 100012 Beijing (China)

2009-08-15

60

Discovery of phase-locked variable polarization in an RS Canum Venaticorum-like star, HR 5110  

NASA Technical Reports Server (NTRS)

Using measurements on 79 nights in 1980 January-August, it is established that the polarization in the ultraviolet (U band) varies synchronously on the known binary period of 2.6132 days, with a peak-to-peak amplitude of 0.03%. The pattern is mainly second harmonic in character, as typical of binary star examples such as Algol and Upsilon Her. Reflection by the cooler star, by a plasma concentration, or both, is suggested. The scale of the polarization seems to be consistent with Rayleigh scattering by neutral hydrogen on the cooler star, and a roughly lambda to the -4th wavelength dependence should be searched for. The QU curve suggests a sizeable inclination for the system, of about 45 deg, but this is preliminary. Separately, a possible weak periodicity might be present on a subsidiary period, conceivably related to a rotating star spot.

Barbour, M. S.; Kemp, J. C.

1981-01-01

61

The Orbital Architecture of 55 Cnc: An Orbital Resonance, Jupiter Analog, and Transiting Super-Earth  

NASA Astrophysics Data System (ADS)

55 Cnc is the only naked eye star with a known transiting planet (Winn et al. 2011) and one of a few systems with five known planets characterized via Doppler methods. The planets span a wide range of masses and orbital periods. We investigate the orbital architecture, focusing on two of the giant planets near 3:1 mean-motion resonance and the potential impact on the dynamical effects on the other planets. To quantify the uncertainty in the orbital parameters of the 55 Cnc system requires exploring a high-dimensional ( 35) parameter space and using self-consistent N-body integrations, both of which are computationally demanding. To surmount these challenges, we apply a differential evolution Markov chain Monte Carlo algorithm to characterize the orbital properties and masses. We present these results and discuss the implications on the dynamical evolution of the 55 Cnc system.

Nelson, Benjamin E.; Payne, M.; Ford, E.; Wright, J.

2011-09-01

62

A Benchmark Infrared Characterisation of the Super-Earth 55 Cnc e  

NASA Astrophysics Data System (ADS)

The Kepler mission and radial-velocity surveys have revealed that super-Earth exoplanets are not only ubiquitous in our galaxy but also very diverse in terms of physical properties. However, very little is known about their nature because of the paucity of suitable targets amenable to detailed characterization. Two super-Earths, GJ1214b and 55Cnc e, orbit stars that are bright enough to enable detailed atmospheric and interior composition studies, which are crucial to improve our understanding of this class of exoplanets. As of today, 55Cnc e is the only super Earth amenable to occultation and phase curve infrared photometry, as well as a prime target to understand the nature of highly irradiated super Earths. In the past two years, Spitzer observations of 55 Cnc e resulted in photometric lightcurves of unprecedented quality, thanks to the brightness of its host star. We propose an observing program of 180 hours to pursue this effort. Our main goal is to determine whether 55 Cnc e harbors an atmosphere or not. We propose to obtain four orbital phase curves of 55 Cnc e at 4.5 microns and four other at 3.6 microns. Our observations will unambiguously determine whether 55 Cnc e is volatile-poor or volatile-rich. We will also measure for the first time the 3D climate patterns in a super-Earth atmosphere. Finally, our program will deliver precise transit, occultation and phase-curve photometry that will constitute an important legacy regarding the characterization of a super-Earth exoplanet, well in advance of JWST.

Demory, Brice-Olivier; Kataria, Tiffany; Lewis, Nikole; Krick, Jessica; Queloz, Didier; Gillon, Michael; Stamenkovic, Vlada; Madhusudhan, Nikku; Fortney, Jonathan; de Wit, Julien; Kane, Stephen

2014-12-01

63

Monitoring of FR Cnc Flaring Activity  

E-print Network

Being excited by the detection of the first ever-observed optical flare in FR Cnc, we decided to continue photometrical monitoring of this object. The observations were carried out at Crimean Astrophysical Observatory (Crimea, Ukraine; CrAO - hereafter) and at the Terskol Observatory (Russia, Northern Caucasus). The obtained lightcurves are presented and discussed. No distinguishable flares were detected that could imply that flares on FR Cnc are very rare event.

A. Golovin; M. Andreev; E. Pavlenko; Yu. Kuznyetsova; V. Krushevska; A. Sergeev

2007-12-10

64

Improving Energy Efficiency in CNC Machining  

NASA Astrophysics Data System (ADS)

We present our work on analyzing and improving the energy efficiency of multi-axis CNC milling process. Due to the differences in energy consumption behavior, we treat 3- and 5-axis CNC machines separately in our work. For 3-axis CNC machines, we first propose an energy model that estimates the energy requirement for machining a component on a specified 3-axis CNC milling machine. Our model makes machine-specific predictions of energy requirements while also considering the geometric aspects of the machining toolpath. Our model - and the associated software tool - facilitate direct comparison of various alternative toolpath strategies based on their energy-consumption performance. Further, we identify key factors in toolpath planning that affect energy consumption in CNC machining. We then use this knowledge to propose and demonstrate a novel toolpath planning strategy that may be used to generate new toolpaths that are inherently energy-efficient, inspired by research on digital micrography -- a form of computational art. For 5-axis CNC machines, the process planning problem consists of several sub-problems that researchers have traditionally solved separately to obtain an approximate solution. After illustrating the need to solve all sub-problems simultaneously for a truly optimal solution, we propose a unified formulation based on configuration space theory. We apply our formulation to solve a problem variant that retains key characteristics of the full problem but has lower dimensionality, allowing visualization in 2D. Given the complexity of the full 5-axis toolpath planning problem, our unified formulation represents an important step towards obtaining a truly optimal solution. With this work on the two types of CNC machines, we demonstrate that without changing the current infrastructure or business practices, machine-specific, geometry-based, customized toolpath planning can save energy in CNC machining.

Pavanaskar, Sushrut S.

65

MAXI/GSC detection of a possible X-ray flare from an RS CVn star CF Tuc  

NASA Astrophysics Data System (ADS)

On 2012-01-30 08:25:38 UT (=MJD 55956.351), the MAXI/GSC transient alert system triggered on enhanced X-ray emission from the position consistent with the CF Tuc (RS CVn system). The significant X-ray flux in the 2-20 keV band had been detected at 2012-01-30 03:45 (UT)(=MJD 55956.157) and activity continued about 3 hours. The maximum X-ray flux and the luminosity are about 60 mCrab and 2×1033 ergs/s in 2-20 keV band, respectively, if the distance is assumed to be 89 pc.

Yamamoto, T.; Yamazaki, K.; Tsuboi, Y.; Nakahira, S.; Serino, M.; Mihara, T.; Sugizaki, M.; Sootome, T.; Matsuoka, M.; Ueno, S.; Tomida, H.; Kohama, M.; Ishikawa, M.; Kawai, N.; Morii, M.; Sugimori, K.; Usui, R.; Toizumi, T.; Aoki, Y.; Song, S.; Yoshida, A.; Yamaoka, K.; Tsunemi, H.; Kimura, M.; Kitayama, H.; Negoro, H.; Nakajima, M.; Suwa, F.; Asada, M.; Sakakibara, H.; Ueda, Y.; Hiroi, K.; Shidatsu, M.; Matsumura, T.; Yamauchi, M.; Nishimura, Y.; Hanayama, T.

2012-01-01

66

BD Andromedae: A New Short-period RS CVn Eclipsing Binary Star with a Distant Tertiary Body in a Highly Eccentric Orbit  

NASA Astrophysics Data System (ADS)

A photometric study of BD And was made through the analysis of two sets of new BVR light curves. The light curves with migrating photometric waves outside eclipse show that BD And is a short-period RS CVn-type binary star. The analysis of all available timings reveals that the orbital period has varied in a strictly cyclical way with a period of 9.2 yr. The periodic variation most likely arises from the light-time effect due to a tertiary moving in a highly elliptical orbit (e 3 = 0.76). The Applegate mechanism could not operate properly in the eclipsing pair. The light curves were modeled with two large spots on the hotter star and a large third light amounting to about 14% of the total systemic light. BD And is a triple system: a detached binary system consisting of two nearly equal solar-type stars with an active primary star and a G6-G7 tertiary dwarf. The absolute dimensions of the eclipsing pair and tertiary components were determined. The three components with a mean age of about 5.8 Gyr are located at midpositions in main-sequence bands. The radius of the secondary is about 17% larger than that deduced from stellar models. The orbital and radiometric characteristics of the tertiary are intensively investigated. One important feature is that the mutual inclination between two orbits is larger than 60°, implying that Kozai cycles had occurred very efficiently in the past. The possible past and future evolutions of the BD And system, driven by KCTF and MBTF, are also discussed.

Kim, Chun-Hwey; Song, Mi-Hwa; Yoon, Jo-Na; Han, Wonyong; Jeong, Min-Ji

2014-06-01

67

Rotational modulation and flares on RS CVn and BY Dra stars. III - IUE observations of V711 Tau (= HR 1099), II Peg, and AR Lac  

NASA Technical Reports Server (NTRS)

Observations of three RS CVn stars, which were obtained over the stellar rotation cycles with the IUE satellite, are presented. Emission lines from high-temperature transition regions and chromospheres analogous to those observed in the solar spectrum were observed. The only visible component of II Peg and both components of V711 Tau and AR Lac appear to be chromospherically active. For the latter systems, the Mg II line surface flux from the G-type star is higher than that from the K subgiant, which dominates the observed UV line flux. Moreover, evidence of long-term ultraviolet variability is presented for AR Lac. The emission line fluxes for II Peg and, marginally, for the other two systems were observed to vary in antiphase with the optical variations at the time of the IUE observations. By comparing the results of Rodono et al. (1986) for two-spot models with the variation of UV line flux, evidence of a close spatial correlation between spot and plagelike features is found.

Rodono, M.; Byrne, P. B.; Neff, J. E.; Linsky, J. L.; Simon, T.

1987-01-01

68

Review on CNC-Rapid Prototyping  

NASA Astrophysics Data System (ADS)

This article reviewed developments of Computerized Numerical Control (CNC) technology in rapid prototyping process. Rapid prototyping (RP) can be classified into three major groups; subtractive, additive and virtual. CNC rapid prototyping is grouped under the subtractive category which involves material removal from the workpiece that is larger than the final part. Richard Wysk established the use of CNC machines for rapid prototyping using sets of 2½-D tool paths from various orientations about a rotary axis to machine parts without refixturing. Since then, there are few developments on this process mainly aimed to optimized the operation and increase the process capabilities to stand equal with common additive type of RP. These developments include the integration between machining and deposition process (hybrid RP), adoption of RP to the conventional machine and optimization of the CNC rapid prototyping process based on controlled parameters. The article ended by concluding that the CNC rapid prototyping research area has a vast space for improvement as in the conventional machining processes. Further developments and findings will enhance the usage of this method and minimize the limitation of current approach in building a prototype.

Z, M. Nafis O.; Y, Nafrizuan M.; A, Munira M.; J, Kartina

2012-09-01

69

Posted 4/19/12 CNC Instructor Job Announcement  

E-print Network

% of students achieve the NIMS MMS and CNC Operator Mill and Lathe credentials and 90% of students attainPosted 4/19/12 CNC Instructor Job Announcement About the Position: Reporting to the Career & Community Program Director of the Center for Labor & Community Research (CLCR), the CNC Instructor

Heller, Barbara

70

A new reconfigurable logic for CNC lathe controllers  

Microsoft Academic Search

Reconfigurable devices have been developed to implement the control algorithms in Computer Numerically Controlled (CNC) systems recently. Reconfigurable devices provide high execution performance of CNC and flexibilities to the system design. However, little work was done on the implementation of reconfigurable logic in a CNC lathe. This paper developed a new resampling algorithm for the synchronized movement in threading and

Jingchuan Dong; Yunfeng Wang; Zijing Wang; Taiyong Wang

2009-01-01

71

PROMOTING A VIRTUAL TRAINING ENVIRONMENT FOR CNC Faruk nsaar  

E-print Network

PROMOTING A VIRTUAL TRAINING ENVIRONMENT FOR CNC MACHINING Faruk �nsaçar Mechanical Department of Crete, 73133 Chania, Greece antoniadis@chania.teicrete.gr Abstract: Today CNC programming is becoming in the CNC machinery produce a continuous demand on enhancing the programming and technical capabilities

Aristomenis, Antoniadis

72

The CnC Programmimg Model Zoran Budimlic1  

E-print Network

The CnC Programmimg Model Zoran Budimli´c1 Michael Burke1 Vincent Cav´e1 Kathleen Knobe2 Geoff Rice University 2 Intel Corporation 3 UCLA Abstract We introduce the Concurrent Collections (CnC) programming model. CnC supports flexible combinations of task and data parallelism while retaining determinism

Palsberg, Jens

73

Towards CNC Programming Using Haskell , C. Ochoa2  

E-print Network

Towards CNC Programming Using Haskell G. Arroyo1 , C. Ochoa2 , J. Silva2 , and G. Vidal2 1 CIIDET,jsilva,gvidal}@dsic.upv.es Abstract. Recent advances in Computerized Numeric Control (CNC) have allowed the manufacturing of products with high quality standards. Since CNC programs consist of a series of assembler-like instructions, several

Vidal, Germán

74

MULTIBAND PHOTOMETRIC AND SPECTROSCOPIC ANALYSIS OF HV Cnc  

SciTech Connect

In this paper, radial velocity and VI- and JHK{sub S} - (Two Micron All Sky Survey) band photometric data of the detached system HV Cnc have been analyzed. The primary component of HV Cnc, which is a member of the M67 cluster, is suspected to be either a blue straggler or turn-off star. The system is a single-lined spectroscopic binary and its light curve shows a total eclipse. Spectroscopic observations of the system revealed the third component, which shows contribution to the total light of the system. Light curve and radial velocity data have been analyzed using the Wilson-Devinney (W-D) code and JHK{sub S} filter definitions computed for the W-D code in this work. Our analysis shows that the mass and radius of the primary and secondary components are 1.31 M {sub ?}, 0.52 M {sub ?}, 1.87 R {sub ?}, and 0.48 R {sub ?}, respectively. All results are compared with previously published literature values and discussed.

Gökay, G.; Gürol, B.; Derman, E., E-mail: ggokay@science.ankara.edu.tr [Astronomy and Space Sciences Department, Faculty of Science, Ankara University, 06100 Tando?an, Ankara (Turkey)

2013-11-01

75

Spectroscopic Analyses of the Planetary System Candidates: 55 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762  

E-print Network

The stars 55 Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762 have recently been proposed to harbor planetary mass companions. Using spectrospic methods we find that 55 Cnc and 51 Peg are super metal- rich, 47 UMa and 70 Vir have roughly solar metallicities, and HD 114762 is metal-poor. Otherwise, the abundance patterns, expressed as [X/Fe], are approximately solar. The ages of 47 UMa and 51 Peg are similar to that of the Sun; 70 Vir is slightly older, and 55 Cnc and HD 114762 are at least 10 Gyr old. Our estimates of vsini for the parent stars are 1.4, 1.8, 2.0, Cnc, 51 Peg, 47 UMa, 70 Vir, and HD 114762, respectively. Using these data and estimates for the rotation periods and radii, the corresponding masses of the companions are: > 0.6, 0.51, 4.6, > 20, and > 8.5 MJ. The systems appear to fall into three groups: roughly Jupiter mass companions with small circular orbits with metal-rich parent stars (55 Cnc and 51 Peg), larger companions with larger circular orbits (47 UMa), and much more massive companions with large eccentric orbits around moderately metal- poor parent stars (70 Vir and HD 114762). Our findings are consistent with the recently proposed mechanism whereby a gas giant migrates to within a few hundredths of an AU of its parent star during the formative epoch of the planetary system. During this process the material between the giant planet and the star is accreted onto the latter. If the accreted material is depleted in H and He, then the photospheric composition of the parent star might be altered significantly.

Guillermo Gonzalez

1996-09-20

76

An intelligent CNC machine control system architecture  

SciTech Connect

Intelligent, agile manufacturing relies on automated programming of digitally controlled processes. Currently, processes such as Computer Numerically Controlled (CNC) machining are difficult to automate because of highly restrictive controllers and poor software environments. It is also difficult to utilize sensors and process models for adaptive control, or to integrate machining processes with other tasks within a factory floor setting. As part of a Laboratory Directed Research and Development (LDRD) program, a CNC machine control system architecture based on object-oriented design and graphical programming has been developed to address some of these problems and to demonstrate automated agile machining applications using platform-independent software.

Miller, D.J.; Loucks, C.S.

1996-10-01

77

RS Canum Venaticorum  

NASA Astrophysics Data System (ADS)

RSCVn=RS Canum Venaticorum (BD +36° 2344, HD 114519; ?1950.0=13h08m18s, ?1950.0=+36°12'.0; ?d=2.79 s yr-1, ??=-0.319' yr-1) is a detached CLOSE BINARY STAR (F5 V+K2 IV) in the CANES VENATICI constellation (cf Rodonò et al 1995 for a discussion of the spectral classification). In addition to the canonical eclipse-related light variability, early photometric observations had already shown uneven o...

Rodonò, M.; Murdin, P.

2000-11-01

78

Development of Lathe Attachment for a CNC Machine  

NASA Astrophysics Data System (ADS)

A lathe attachment has been developed for an existing CNC machine (installed with rapid prototyping attachment) using conceptual design. The CNC machine operates on mechatronic controls and a computer interface called CAMSOFT, and is used as a CNC Lathe after installing the respective attachment to it. The conceptual design phase, starts from an idea and different components of the lathe are designed as attachment using CAD modelling and is followed by fabrication phase. The lathe attachment is successfully developed and is installed to the CNC machine. The working of the CNC Lathe attachment is checked by making some machining operation like turning and thread cutting. The machining operations are successfully done. The CNC machine becomes multifunctional with the presently developed lathe attachment and the existing RP (rapid prototyping) attachment, and can be used accordingly by installing the respective attachment to it. The CNC machine is useful for carrying research work in both the fields, when installed with the appropriate attachment.

Roy, V.; Kumar, S.

2013-04-01

79

The photosphere and chromosphere of the RS Canum Venaticorum star, II Pegasi I. Spots and chromospheric emission in 1991.  

NASA Astrophysics Data System (ADS)

We report on high-resolution spectroscopy of the RSCVn binary IIPeg, along with contemporaneous UBV(RI)_KC_ photometry, including partly simultaneous U-band flare monitoring, during the third quarter of 1991. The spectroscopy was taken at two epochs separated by more than 6(1)/(2) weeks or seven rotations of IIPeg. At the first epoch we have observed the three chromospheric lines, H?, H? and HeID_3_, over a single rotation and at the second epoch we observed almost the entire visible region, for a substantial fraction of one rotation, including H?-H? and CaIIH. Our photometric results show that there was an unusually complicated spot distribution at this epoch, with at least three centres of activity discernable. We demonstrate, for the first time on a spotted late-type star, that these centres of spot activity have significantly different mean temperatures from one another. Furthermore, our derived spot temperatures are markedly lower than those previously derived from such multicolour photometry and more similar to those derived spectroscopically. Using multiple repeat exposures on each spectral line within each night, we are confident that we have derived a mean, non-flaring spectrum at each observational phase. Furthermore, the line flux variations at the two epochs repeat very well, suggesting that the mean global chromospheric structures are stable on a 1(1)/(2) months time scale. We discuss the implications of the mean spectra for the non-flaring atmosphere of IIPeg and conclude that, in the region of formation of the H? line, velocity fields are required to account for the line profile. These results suggest upward motions of the deep chromosphere with a less dramatic downflow in the high chromosphere. We examine the variation of the chromospheric line fluxes as a function of spot visibility and conclude that there is only a very loose spatial correlation of chromsopheric heating with spots. The motions suggested from the H? profile variations appear to be spot-associated.

Byrne, P. B.; Panagi, P. M.; Lanzafame, A. C.; Avgoloupis, S.; Huenemoerder, D. P.; Kilkenny, D.; Marang, F.; Panov, K. P.; Roberts, G.; Seiradakis, J. H.; van Wyk, F.

1995-07-01

80

A new tooling mechanism for CNC lathes  

Microsoft Academic Search

The paper describes details of the development of a new CNC lathe tooling mechanism with on-line adjustable cutting edge inclination angle, which is one of the major tool geometry parameters in machining operations. The mechanism is based on the combination of (i) three linkages which adjust the tool inclination angle automatically and continuously, (ii) three curved slots which work simultaneously

X. Daniel Fang; N. J Lee

2001-01-01

81

Optical studies of X-ray peculiar chromosphereically active stars  

NASA Astrophysics Data System (ADS)

A multiwavelength study of the late-type active stars, selected on the basis of their X-ray and radio luminosities is presented in this thesis. For FR Cnc, a photometric period 0.8267 +/- 0.0004 d has been established. The strong variation in the phase and amplitude of the FR Cnc light curves when folded on this period implies the presence of evolving and migrating spots or spot groups on its surface. A photometric period of 18.802 +/- 0.074 has been discovered in the star HD 81032. The shape and amplitude of the photometric light curves of FR Cnc, HD 81032, HD 95559 and LO Peg are observed to be changing from one epoch to another. The change in the amplitude is mainly due to a change in the minimum of the light curve, and this May be due to a change in the spot coverage. This indicates that photometric variability is due to the presence of dark spots on the surface of active star. Two groups of spots are identified for FR Cnc and LO Peg. The spots are found to migrate, and migration periods of 0.97 year and 0.93 year are determined from the 4 years of data. A migration period of 1.12 years for one group of spots in LO Peg is also determined. Formation of a new group of spots in the star HD 95559 was also seen during our observations. A single large group of spots is found to migrate, and a migration period of 7.32 +/- 0.04 years is determined for HD 81032. The stars FR Cnc, HD 81032, HD 160934 and LO Peg are seen to be redder at the light minimum and we interpret this is due to the relatively cooler temperature of the darker regions present in the visible hemisphere. We find the lack of color-brightness correlation in the star HD 95559 and this May be due to the presence of bright faculae and plages like regions accompanied by dark spots in any one component of the this binary system. The optical spectroscopy of FR Cnc and HD 81032 carried out during 2002-2003, reveals the presence of strong and variable Ca II H and K, Halpha and Hbeta emission features indicative of high level of chromospheric activity. The chromospheric line emission for both stars seems to correlate with the photometric light curve, i.e. maximum at the light curve minimum, or minimum at the light curve maximum. The value of 5.3 for the ratio of the excess emission in Halpha to Hbeta, EHalpha/EHbeta for the star FR Cnc, suggests that the chromospheric emission May arise from an extended off-limb region. We have searched for the presence of color excesses in the near-IR JHK bands of these stars using 2MASS data, but none of them appear to have any significant color excess. The kinematics of the stars FR Cnc, HD 95559, HD 160934 and LO Peg suggest that these are younger than 0.6 Gyrs. The archival X-ray observations of HD 81032, HD 95559, HD 160934 and LO Peg carried out by with the ROSAT observatory were also analyzed. We did not find any significant variability in the X-ray light curve of the stars HD 95559. However, it appears from the X-ray light curve of HD 81032 that a moderate flare occurred during the RASS observations, with a peak of about 0.6 ct s^{-1} at approximately JD=244806.95 and half decay time of 2.6 x 10^4 s. A similar flare was also observed in HD 160934 with a peak about 0.2 ct s^{-1} (above its mean level) at JD = 2448123.12. A significant variability was found in the X-ray light curve of LO Peg. Rotational modulation appears to be present in the X-ray light curve of LO Peg. The best fit models to their X-ray spectra imply the presence of two coronal plasma components of differing temperatures and with sub-solar metal abundances. The inferred emission measures and temperatures of HD 95559 and LO Peg are similar to those found for other active dwarf stars. The observed X-ray spectrum and the inferred coronal plasma parameters for HD 81032 are typical of those seen in active stars such as RS CVn binaries. All of the optical and X-ray properties found for FR Cnc, HD 95559, HD 160934 and LO Peg are most consistent to the BY Dra type. However, for HD 81032 these properties suggest that it being an evolved RS! CVn binary of the long-peri

Pandey, J. C.

2006-02-01

82

Developing an integrated STEP-compliant CNC prototype  

Microsoft Academic Search

STEP-compliant CNC is the next-generation CNC controller, taking the STEP-NC data model as the interface scheme between CAM and CNC and carrying out various intelligent functions. At the moment, efforts are being made worldwide to establish an international standard for the new interface scheme (so-called STEP-NC), formalized as ISO 14649. In the near future, the new interface scheme will be

S. H Suh; D. H Chung; B. E Lee; J. H Cho; S. U Cheon; H. D Hong; H. S Lee

2002-01-01

83

Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo  

E-print Network

We present very sensitive polarimetry of 55 Cnc and tau Boo in an attempt to detect the partially polarised reflected light from the planets orbiting these two stars. 55 Cnc is orbited by a hot Neptune planet (55 Cnc e) at 0.038 AU, a hot Jupiter planet (55 Cnc b) at 0.11 AU, and at least 3 more distant planets. The polarisation of this system is very stable, showing no sign of the periodic variations that would be expected if a short period planet were detected. The measured standard deviation of the night averaged Stokes Q/I and U/I parameters is 2.2x10^{-6}. We derive upper limits on the geometric albedo, A_G and planetary radius using Monte Carlo multiple scattering simulations of a simple model atmosphere. We assume Rayleigh-like scattering (scaled by the maximum polarisation, p_m at 90 degrees) and pressure insensitive extinction. Atmospheres in which multiple scattering plays only a small role have an almost linear relation between polarisation and A_G. In this case, the 4 sigma upper limits is A_GCnc e. This suggests that 55 Cnc e is relatively small and not a pure H-He planet. The data do not give a useful upper limit for 55 Cnc b. tau Boo is orbited by an unusually massive hot Jupiter planet. The standard deviation in the night averaged Stokes Q/I and U/I polarisation parameters is 5.1x10^{-6}. The 4 sigma upper limit is A_G<0.37(R/1.2 R_{Jup})^{-2}p_m^{-1} for tau Boo b. This extends the similar upper limits reported previously for this planet to longer wavelengths. The larger scatter in the tau Boo data may be due to the spot activity detected photometrically by the MOST satellite. These results contrast markedly with the recent claim of a 3 sigma detection of a periodic polarisation signal from HD189733 with amplitude P=2x10^{-4}, attributed to the planet HD189733 b.

P. W. Lucas; J. H. Hough; J. A. Bailey; M. Tamura; E. Hirst; D. Harrison

2008-11-04

84

CNC Turning Technician. A Competency-Based Instructional System.  

ERIC Educational Resources Information Center

This competency-based curriculum guide for instructing students in using computer numerically controlled (CNC) turning machines is one of a series of instructional guides for the machinist field developed in Oklahoma. Although developed jointly with Baxter Technologies Corporation and oriented toward the Baxter Vo-Tec 2000 Future Builder CNC

Sloan, Kelly; Hilley, Robert

85

Advanced CNC Programming (EZ-CAM). 439-366.  

ERIC Educational Resources Information Center

This document contains two units for an advanced course in computer numerical control (CNC) for computer-aided manufacturing. It is intended to familiarize students with the principles and techniques necessary to create proper CNC programs using computer software. Each unit consists of an introduction, instructional objectives, learning materials,…

Casey, Joe

86

Development of FPGA-based arithmetic module in CNC system  

Microsoft Academic Search

Many complex computational problems have to be overcome in the Computer Numerical Control (CNC) system, such as tool compensation calculation, contour interpolation, speed decomposition, position control and so on. If all the functions are accomplished by software, the corresponding execution time will affect the velocity of the CNC system. This paper has put forward a scheme of software hardening technique

Mulan Wang; Xinghua Zhu; Baosheng Wang; Xiaoxia Li

2011-01-01

87

Design and implementation of CNC controllers using reconfigurable hardware  

Microsoft Academic Search

The reconfigurable hardware has been widely applied in Computer Numerically Controlled (CNC) systems. The reconfigurable hardware provides high performance and flexibilities for the designer. This work presented a novel CNC controller architecture using reconfigurable hardware. Several logic modules, including a new resampling module for threading, are designed to support the reconfiguration process. By employing different type of logic modules, the

Jingchuan Dong; Xingzhao Yang; Qingjian Liu; Zijing Wang; Taiyong Wang

2009-01-01

88

Strategic advantages of interoperability for global manufacturing using CNC technology  

Microsoft Academic Search

In the domain of manufacturing, computer numerically controllers (CNC) technology is a major contributor to the production capacity of the enterprises. The advances in CNC technology coupled with enhancements in computing systems have provided the basis to re-examine the way in which computer-aided systems (CAx) can be used to enable global manufacturing. Interoperability of the various components of the CAx

S. T. Newman; A. Nassehi; X. W. Xu; R. S. U. Rosso; L. Wang; Y. Yusof; L. Ali; R. Liu; L. Y. Zheng; S. Kumar; P. Vichare; V. Dhokia

2008-01-01

89

ULTRACAM photometry of the eclipsing cataclysmic variables GY Cnc, IR Com and HT Cas  

E-print Network

We present high-speed, three-colour photometry of the eclipsing cataclysmic variables GY Cnc, IR Com and HT Cas. We find that the sharp eclipses in GY Cnc and IR Com are due to eclipses of the white dwarf. There is some evidence for a bright spot on the edge of the accretion disc in GY Cnc, but not in IR Com. Eclipse mapping of HT Cas is presented which shows changes in the structure of the quiescent accretion disc. Observations in 2002 show the accretion disc to be invisible except for the presence of a bright spot at the disc edge. 2003 observations, however, clearly show a bright inner disc and the bright spot to be much fainter than in 2002. Although no outburst was associated with either set of quiescent observations, the system was ~0.6 mJy brighter in 2003, mainly due to the enhanced emission from the inner disc. We propose that these changes are due to variations in the mass transfer rate from the secondary star and through the disc. The disc colours indicate that it is optically thin in both its inner and outer regions. We estimate the white dwarf temperature of HT Cas to be 15 000 +/- 1000 K in 2002 and 14 000 +/- 1000 K in 2003.

W. J. Feline; V. S. Dhillon; T. R. Marsh; C. A. Watson; S. P. Littlefair

2005-10-14

90

Effect of cellulose nanocrystals (CNC) on rheological and mechanical properties and crystallization behavior of PLA/CNC nanocomposites.  

PubMed

In earlier work, we reported that spray freeze drying of cellulose nanocrystals (CNC) yields porous agglomerate structures. On the other hand, the conventional spray dried CNC (CNCSD) and the freeze dried CNC (CNCFD) produce compact solid structures with very low porosity. As it is rather difficult to obtain direct microscopic evidence of the quality of dispersion of CNC in polymer nanocomposites, it was shown that supporting evidence of the quality and influence of dispersion in a polypropylene (PP)/CNC nanocomposite could be obtained by studying the rheological behavior, mechanical properties and crystallization characteristics of PP/CNC nanocomposites. In an effort to produce a sustainable, fully biosourced, biodegradable nanocomposite, this manuscript presents the results of a study of the rheological, mechanical and crystallization behavior of PLA/CNCSFD nanocomposites obtained by melt processing. The results are analyzed to determine CNC network formation, rheological percolation threshold concentrations, mechanical properties in the rubbery and glassy states, and the effect of CNCSFD on crystalline nucleation and crystallization rates of PLA. These results suggest that the porosity and network structure of CNCSFD agglomerates contribute significantly to good dispersion of CNC in the PLA matrix. PMID:25843840

Kamal, Musa R; Khoshkava, Vahid

2015-06-01

91

Very low luminosity stars with very large amplitude flares  

NASA Technical Reports Server (NTRS)

CCD frames of CZ Cnc, KY Cep, the gamma-ray burster optical transient, and NSV 12006 are analyzed. Also studied are 549 archival photographic plates of the CZ Cnc field. These observations are compared with the data of Lovas (1976). Flare events on CZ Cnc are examined. Based on the data it is noted that CZ Cnc is a main-sequence star, has a magnitude of 16.1, a distance of 100 pc, occasional large-amplitude flares, and frequent flares with amplitudes greater than 4 mag.

Schaefer, Bradley E.

1990-01-01

92

Very low luminosity stars with very large amplitude flares  

SciTech Connect

CCD frames of CZ Cnc, KY Cep, the gamma-ray burster optical transient, and NSV 12006 are analyzed. Also studied are 549 archival photographic plates of the CZ Cnc field. These observations are compared with the data of Lovas (1976). Flare events on CZ Cnc are examined. Based on the data it is noted that CZ Cnc is a main-sequence star, has a magnitude of 16.1, a distance of 100 pc, occasional large-amplitude flares, and frequent flares with amplitudes greater than 4 mag. 36 refs.

Schaefer, B.E. (NASA, Goddard Space Flight Center, Greenbelt, MD (USA))

1990-04-01

93

Study of Accuracy of CNC Machine Tools  

NSDL National Science Digital Library

The dimensional accuracies as well as surface finishes of parts produced by a CNC machine tool are strongly dependent on the motion accuracy of each axis of the machine. The overall accuracy of the machine tool is decided by the mechanical characteristics of the machine as well as the characteristics if the control system driving the individual axes. A CNC Machine is programmed to travel along a predetermined or contour, and any deviation from the programmed path is referred as the contouring error. A typical test that is used is a circular test in which the machine is programmed to travel along a circle, and the difference between the programmed path and the measured actual path is compared. The purpose of this study is to identify the various contributors to this contouring error, and in particular estimate the error due to stick slip motion using analytical techniques. It is planned to measure the errors experimentally making use of capacitance probes. The study is intended to develop an appreciation for the sources of different errors produced in a machine tool and as such forms a module in a typical semester long class devoted to manufacturing processes.

Chattopadhyay, Sonnath

94

Rotational modulation and flares on RS CVn and BY Dra stars. VI - Physical parameters of the chromospheres/transition regions of V 711 Tau (HR 1099), II Peg and AR Lac during October 1981  

NASA Technical Reports Server (NTRS)

Ground-based optical and IUE satellite-ultraviolet observations of three RS CVn stars are combined with density sensitive line ratios and differential emission measure curves to describe the physical conditions in their outer atmospheres. Solar-like densities are found to be representative of average conditions on two of the stars, V 711 Tau and AR Lac. The total radiative losses from these two stars are estimated and found to be larger than the sun by at least two orders of magnitude. Consideration of the volume emitting in two of the principal transition region lines suggests a possible relation between the disk 'filling factor' for these two lines and the dynamo-related Rossby number. Only one hemisphere of the star II Peg, the one showing least evidence of starspots, is similar. On the opposite hemisphere the presence of a discrete emitting region is deduced which is almost coincident in phase with the passage of the dominant optical spot group across the visible disk. The dimensions of this region, and an illustrative interpretation in terms of a large emitting magnetic loop, are discussed. It is compared to large active region loops on the sun.

Byrne, P. B.; Doyle, J. G.; Brown, A.; Linsky, J. L.; Rodono, M.

1987-01-01

95

Close binary stars in the solar-age Galactic open cluster M67  

E-print Network

We present multi-colour time-series CCD photometry of the solar-age galactic open cluster M67 (NGC 2682). About 3600 frames spread over 28 nights were obtained with the 1.5 m Russian-Turkish and 1.2 m Mercator telescopes. High-precision observations of the close binary stars AH Cnc, EV Cnc, ES Cnc, the $\\delta$ Scuti type systems EX Cnc and EW Cnc, and some long-period variables belonging to M67 are presented. Three full multi-colour light curves of the overcontact binary AH Cnc were obtained during three observing seasons. Likewise we gathered three light curves of EV Cnc, an EB-type binary, and two light curves of ES Cnc, a blue straggler binary. Parts of the light change of long-term variables S1024, S1040, S1045, S1063, S1242, and S1264 are obtained. Period variation analysis of AH Cnc, EV Cnc, and ES Cnc were done using all times of mid-eclipse available in the literature and those obtained in this study. In addition, we analyzed multi-colour light curves of the close binaries and also determined new fre...

Yakut, K; Kalomeni, B; Van Winckel, H; Waelkens, C; De Cat, P; Bauwens, E; Vuckovic, M; Saesen, S; Guillou, L Le; Parmaksizoglu, M; Uluc, K; Khamitov, I; Raskin, G; Aerts, C

2009-01-01

96

A hybrid type small 5-axis CNC milling machine  

E-print Network

5-axis CNC milling machines are important in a number of industries ranging from aerospace to consumer-die-mold machining because they can deliver high machining accuracy with a spindle tilting capacity. Most of these ...

Son, Seung-Kil, 1964-

2002-01-01

97

An active axis control system for a conventional CNC machine  

Microsoft Academic Search

A non-invasive approach to implement an active axis controller for a conventional CNC machine is presented. To develop the system a two-stage approach has been taken. In stage one, a generic external axis controller is designed to bring the machine under the real-time control of an external computer. The external controller is interfaced to the CNC machine via the Manual

Daniel Hanafi; Michal Tordon; Jayantha Katupitiya

2003-01-01

98

Real-time CNC interpolators for Pythagorean-hodograph curves  

Microsoft Academic Search

CNC machining requires “interpolation” algorithms that accurately and efficiently generate sequences of reference positions, distributed according to a prescribed feedrate function, along the tool paths. CNC interpolators have traditionally accommodated only linear and circular trajectories, on account of the absence of easily-calculable relations between the arc length s and parameter ? for free-form parametric curves. With the Pythagorean-hodograph (PH) curves,

Rida T. Farouki; Sagar Shah

1996-01-01

99

CNC tool path in terms of B-spline curves  

Microsoft Academic Search

We present an accurate and efficient method to generate a CNC tool path for a smooth free-form surface in terms of planar cubic B-spline curves which will be fed into a free-form curve interpolator. We assume the use of a three-axis CNC machine tool with a ball end-mill cutter. We first interpolate break points, which are generated by computing the

Claire Lartigue; François Thiebaut; Takashi Maekawa

2001-01-01

100

A high speed machining algorithm for CNC machine tools  

Microsoft Academic Search

This paper introduces a high speed machining algorithm based on a look-ahead interpolation technique for the machining of 3D surface obtained by a CAD\\/CAM system. Generally, specification of CNC system for high speed machining requires an additional hardware and it burdens end users with additional cost. The purpose of this research is to develop the low cost CNC controller having

Guk-Chan Han; Dong-II Kim; Hyo-Gyu Kim; Kibeohn Nam; Byeong-Kap Choi; Sung-Kwun Kim

1999-01-01

101

Intelligent Programming of CNC Turning Operations using Genetic Algorithm  

Microsoft Academic Search

CAD\\/CAM systems are nowadays tightly connected to ensure that CAD data can be used for optimal tool path determination and\\u000a generation of CNC programs for machine tools. The aim of our research is the design of a computer-aided, intelligent and genetic\\u000a algorithm(GA) based programming system for CNC cutting tools selection, tool sequences planning and optimisation of cutting\\u000a conditions. The first

Joze Balic; Miha Kovacic; Bostjan Vaupotic

2006-01-01

102

ULTRACAM Photometry of the ultracompact binaries V407 Vul and HM Cnc  

E-print Network

V407 Vul (RXJ1914.4+2456) and HM Cnc (RXJ0806.3+1527) are X-ray emitting stars with X-ray light curves that are 100% modulated on periods of 569 and 321 seconds respectively. These periods are thought possibly to represent the orbital periods of close pairs of white dwarfs. In this paper we present optical light curves taken with the high-speed CCD camera ULTRACAM on the 4.2m WHT in May 2003 and August 2005 and with the VLT in November 2005. The optical and X-ray light curves of HM Cnc have been reported as being in anti-phase, but we find that in fact the X-rays peak around 0.2 cycles after the maximum of the optical light, as seen also in V407 Vul. The X-ray/optical phase shifts are well explained under the accreting models of the systems if most of the optical modulation comes from the heated faces of the mass donors and if the X-ray emitting spots are positioned in advance of the mass donors, as is expected given the angular momentum of the accreting material. Some optical emission may also come from the vicinity of the X-ray spot, and we further show that this can explain the non-sinusoidal lightcurves of HM Cnc. The only significant difference between the two stars is that V407 Vul is observed to have the spectrum of a G star. The variation in position on the sky of a blend of a variable and a constant star can be used as a measure of their separation, and is sensitive to values well below the limit set by seeing. We apply "pulsation astrometry" to deduce that the G star is separated from the variable by about 0.027'' and hence plays no role in the variability of V407 Vul. We show that light travel time variations could influence the period change in V407 Vul if it forms a triple system with the G star.

S. C. C. Barros; T. R. Marsh; V. S. Dhillon; P. J. Groot; S. Littlefair; G. Nelemans; G. Roelofs; D. Steeghs; P. J. Wheatley

2006-11-03

103

Detection of a transit of the super-Earth 55 Cnc e with Warm Spitzer  

E-print Network

We report on the detection of a transit of the super-Earth 55 Cnc e with Warm Spitzer in IRAC's 4.5-micron band. Our MCMC analysis includes an extensive modeling of the systematic effects affecting Warm Spitzer photometry, and yields a transit depth of 450 +- 50 ppm, which translates to a planetary radius of 2.13 +- 0.14 Earth Radii as measured in IRAC 4.5-micron channel. A planetary mass of 7.98 +- 0.69 Earth Masses is derived from an extensive set of radial-velocity data, yielding a planetary density of 0.83 +- 0.18 Earth density. Interestingly, the derived radius is 1.3 times larger than the one recently reported in the visible by Winn et al. Thanks to the brightness of its host star (V=6, K=4), 55 Cnc e is a unique target for the thorough characterization of a super-Earth orbiting around a solar-type star.

Demory, B -O; Deming, D; Valencia, D; Seager, S; Benneke, B; Lovis, C; Cubillos, P; Harrington, J; Stevenson, K B; Mayor, M; Pepe, F; Queloz, D; Segransan, D; Udry, S

2011-01-01

104

Ground-based Transit Observations of the Super-Earth 55 Cnc e  

NASA Astrophysics Data System (ADS)

We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2 m class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ~700 and ~250, spanning the Johnson BVR photometric bands. We find a white light planet-to-star radius ratio of 0.0190-0.0027+0.0023 from the 2013 observations and 0.0200-0.0018+0.0017 from the 2014 observations. The two data sets combined result in a radius ratio of 0.0198-0.0014+0.0013. These values are all in agreement with previous space-based results. Scintillation noise in the data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-sized telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite around bright stars. We expect it also will be possible to place constraints on the atmospheric characteristics of those planets by devising observational strategies to minimize scintillation noise.

de Mooij, E. J. W.; López-Morales, M.; Karjalainen, R.; Hrudkova, M.; Jayawardhana, Ray

2014-12-01

105

MOST satellite photometry of stars in the M67 field: Eclipsing binaries, blue stragglers and delta-Scuti variables  

E-print Network

We present two series of MOST (Microvariability & Oscillations of STars) space-based photometry, covering nearly continuously 10 days in 2004 and 30 days in 2007, of selected variable stars in the upper Main Sequence of the old open cluster M67. New high-precision light curves were obtained for the blue-straggler binary/triple systems AH Cnc, ES Cnc and EV Cnc. The precision and phase coverage of ES Cnc and EV Cnc is by far superior to any previous observations. The light curve of ES Cnc is modelled in detail, assuming two dark photospheric spots and Roche geometry. An analysis of the light curve of AH Cnc indicates a low mass ratio (q about 0.13) and a high inclination angle for this system. Two new long-period eclipsing binaries, GSC 814-323 and HD75638 (non-members of M67) were discovered. We also present ground-based DDO spectroscopy of ES Cnc and of the newly found eclipsing binaries. Especially interesting is HD75638, a member of a visual binary, which must itself be a triple or a higher-multiplicity system. New light curves of two delta Scuti pulsators, EX Cnc and EW Cnc, have been analyzed leading to detection of 26 and 8 pulsation frequencies of high temporal stability.

Theodor Pribulla; Slavek Rucinski; Jaymie M. Matthews; Rainer Kuschnig; Jason F. Rowe; David B. Guenther; Anthony F. J. Moffat; Dimitar Sasselov; Gordon A. H. Walker; Werner W. Weiss

2008-09-02

106

Optical, UV and Radio Observations of RS Canum Venaticorum  

NASA Astrophysics Data System (ADS)

Preliminary results are reported on optical, UV and radio observations of the binary system RS Canum Venaticorum carried out in March 1984, as a part of the international coordinated programme on solar-like activity in late type stars.

Catalano, S.; Rodono, M.; Linsky, J. L.; Carpenter, K.; Gibson, D.; Gary, D.; Butler, J.

107

CNC grinding of valve housing piston holes  

SciTech Connect

Grinding has traditionally been used for machining operations requiring close dimensional tolerances and better surface finishes than can be obtained from other metal removal techniques. Using a grinding process for the last metal removal operation, the close tolerances and surface finishes can be easily held while eliminating the adverse conditions from the current metal removal processes. Pre-machined test parts were sent to a machine tool supplier to have the critical inside features of a typical piston bore finish machined using an internal CNC grinder equipped with high-frequency spindles. The piston bore and sealing angle were ground using a standard 120-grit silicon carbide wheel. The wafer step was machined using a solid carbide tool designed and built at Allied-Signal Inc., Kansas City Division (KCD). Six consecutive parts were machined for evaluation. The repeatability on all six parts was within print requirements. The inside corner radii was less than 0.002 in. and the surface finish was 8.2 arithmetical average or better as defined by ANSI B46.1, Surface Texture. Machining parts by this grinding process would eliminate bellmouth, chatter, waviness, and traveler polishing operations. It would produce a superior surface finish, small inside radii, and small easily removable burrs. It would also hold tolerances closer and significantly reduce scrap, rework, rejects, and deviations. 1 fig.

Ashbaugh, F.A.

1991-11-01

108

Final Report: CNC Micromachines LDRD No.10793  

SciTech Connect

The three-year LDRD ''CNC Micromachines'' was successfully completed at the end of FY02. The project had four major breakthroughs in spatial motion control in MEMS: (1) A unified method for designing scalable planar and spatial on-chip motion control systems was developed. The method relies on the use of parallel kinematic mechanisms (PKMs) that when properly designed provide different types of motion on-chip without the need for post-fabrication assembly, (2) A new type of actuator was developed--the linear stepping track drive (LSTD) that provides open loop linear position control that is scalable in displacement, output force and step size. Several versions of this actuator were designed, fabricated and successfully tested. (3) Different versions of XYZ translation only and PTT motion stages were designed, successfully fabricated and successfully tested demonstrating absolutely that on-chip spatial motion control systems are not only possible, but are a reality. (4) Control algorithms, software and infrastructure based on MATLAB were created and successfully implemented to drive the XYZ and PTT motion platforms in a controlled manner. The control software is capable of reading an M/G code machine tool language file, decode the instructions and correctly calculate and apply position and velocity trajectories to the motion devices linear drive inputs to position the device platform along the trajectory as specified by the input file. A full and detailed account of design methodology, theory and experimental results (failures and successes) is provided.

JOKIEL JR., BERNHARD; BENAVIDES, GILBERT L.; BIEG, LOTHAR F.; ALLEN, JAMES J.

2003-04-01

109

78 FR 50135 - CNC Development, Ltd., Exousia Advanced Materials, Inc., and South American Minerals, Inc.; Order...  

Federal Register 2010, 2011, 2012, 2013, 2014

...SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] CNC Development, Ltd., Exousia Advanced Materials, Inc., and...current and accurate information concerning the securities of CNC Development, Ltd. because it has not filed any periodic...

2013-08-16

110

Architecture and implementation of a shop-floor programming system for STEP-compliant CNC  

Microsoft Academic Search

STEP-NC (formalized as ISO 14649 and ISO 10303 AP238) is a new interface (or language) standard for the CAD–CAM–CNC chain, currently under establishment by ISO TC184 SC1 and SC4. Upon completion, it will replace ISO 6983, so called M & G codes used for CNC since 1950s. As the new language is being established, a new CNC controller called STEP-CNC

Suk-hwan Suh; Byeong-eon Lee; Dae-hyuck Chung; S. U. Cheon

2003-01-01

111

CNC Turning Center Advanced Operations. Computer Numerical Control Operator/Programmer. 444-332.  

ERIC Educational Resources Information Center

This student guide provides materials for a course designed to introduce the student to the operations and functions of a two-axis computer numerical control (CNC) turning center. The course consists of seven units. Unit 1 presents course expectations and syllabus, covers safety precautions, and describes the CNC turning center components, CNC

Skowronski, Steven D.; Tatum, Kenneth

112

Multidimensional force spectra of CNC machine tools and their applications, part two: reliability design of elements  

Microsoft Academic Search

This paper deals with the reliability design of elements of computerized numerical control (CNC) machine tools and the practical applications of multidimensional force spectra of CNC machine tools described in part one of this paper. To illustrate the application of multidimensional force spectra, part two considers the design example of an S1-273 CNC lathe. First the force distribution of transmission

Yiqiang Wang; Guixiang Shen; Yazhou Jia

2003-01-01

113

A fast tool servo design for precision turning of shafts on conventional CNC lathes  

Microsoft Academic Search

A technique for precision turning of shafts on conventional CNC turning centers is presented. The shaft is semi-turned on a conventional CNC lathe. The precision finish turning operation is delivered by a piezoelectric based fast tool servo which is mounted on the same CNC lathe's turret. The precision tool tip motion is delivered by a proposed sliding mode controller which

Wen-Hong Zhu; Martin B. Jun; Yusuf Altintas

2001-01-01

114

CNC Machine Tool's Wear Diagnostic and Prognostic by Using Dynamic Bayesian Networks  

E-print Network

CNC Machine Tool's Wear Diagnostic and Prognostic by Using Dynamic Bayesian Networks D.A. Tobon of the health condition of a Computer Numerical Control (CNC) tool machine and the estimation of its Remaining of a CNC tool. Simulation results are obtained and discussed at the end of the paper. Keywords: Diagnostic

Paris-Sud XI, Université de

115

Measuring the Overhead of Intel C++ CnC over TBB for Gauss-Jordan Elimination  

E-print Network

Measuring the Overhead of Intel C++ CnC over TBB for Gauss-Jordan Elimination Peiyi Tang Department only by the data dependencies be- tween the tasks. Both Intel C++ Concurrent Col- lections (CnC algorithm and implemented it in TBB. We compare the performances of TBB and CnC, which is built on top

Tang, Peiyi

116

Maximum Feedrate Interpolator for Multi-axis CNC Machining with Jerk Constraints  

E-print Network

Maximum Feedrate Interpolator for Multi-axis CNC Machining with Jerk Constraints X. Beudaert, S name@lurpa.ens-cachan.fr Abstract A key role of the CNC is to perform the feedrate interpolation which for the next point along the path is computed. Examples and comparisons with an industrial CNC demonstrate

Paris-Sud XI, Université de

117

ME/AE 381 Mechanical and Aerospace Control Systems MINI CNC LABORATORY  

E-print Network

ME/AE 381 ­ Mechanical and Aerospace Control Systems MINI CNC LABORATORY The objective of this laboratory is to design controllers that will regulate the position of three linear axes in a table top CNC tracking controllers in the laboratory using the mini CNC Rapid Development System. Plot the linear axis

Landers, Robert G.

118

Precise Gouging-free Tool Orientations for 5-Axis CNC Machining Yong-Joon Kima  

E-print Network

Precise Gouging-free Tool Orientations for 5-Axis CNC Machining Yong-Joon Kima , Gershon Elbera-free tool paths for 5-axis CNC machining of freeform NURBS surfaces using flat-end and rounded-end (bull modeling and have been widely used in a variety of applications. Consequently, CNC machining of NURBS

Pottmann, Helmut

119

Making CNC machine tools more open, interoperable and intelligent - a review of the technologies  

Microsoft Academic Search

The aim of the next generation of computer numerically controlled (CNC) machines is to be portable, interoperable and adaptable. Over the years, G-codes (ISO 6983) have been extensively used by the CNC machine tools for part programming and are now considered as a bottleneck for developing next generation of CNC machines. A new standard known as STEP-NC is being developed

X. W. Xu; Stephen T. Newman

2006-01-01

120

Direct Trajectory Interpolation on the Surface using an Open CNC Xavier Beudaert Sylvain Lavernhe Christophe Tournier  

E-print Network

Direct Trajectory Interpolation on the Surface using an Open CNC Xavier Beudaert · Sylvain Lavernhe format of the industrial CNC. Then, during the tool path interpolation, marks on fin- ished surfaces can of the data exchange between CAD/CAM and CNC opens new ways to optimize the manufacturing process. The Direct

Paris-Sud XI, Université de

121

Rotational Modulation and Flares on Rs-Canum and By-Draconis Stars - Part Seventeen - Ultraviolet Spectroscopy and Optical Photometry of Au-Microscopii in 1986  

NASA Astrophysics Data System (ADS)

We present IUE spectroscopy and optical photometry of the active late type star AU Mic. The UV spectroscopy allow us to measure the chromospheric and transition region line fluxes. No detectable variations attributable to rotational modulation were evident in either the chromospheric lines or optical bands. We have produced an emission measure curve for the quiescent state of AU Mic, which spans a temperature range 4.0 ? log Te ? 7.6 when coupled with previous X-ray flux measurements. The quiescent radiative losses per unit surface area over the above temperature range is ?8 1O7 erg cm-2 s-1

Quin, D. A.; Doyle, J. G.; Butler, C. J.; Byrne, P. B.; Swank, J. H.

1993-05-01

122

Ground-Based Transit Observations of the Super-Earth 55 Cnc e  

E-print Network

We report the first ground-based detections of the shallow transit of the super-Earth exoplanet 55 Cnc e using a 2-meter-class telescope. Using differential spectrophotometry, we observed one transit in 2013 and another in 2014, with average spectral resolutions of ~700 and ~250, spanning the Johnson BVR photometric bands. We find a white-light planet-to-star radius ratio of 0.0190 -0.0027+0.0023 from the 2013 observations and 0.0200 -0.0018+0.0017 from the 2014 observations. The two datasets combined results in a radius ratio of 0.0198 -0.0014+0.0013. These values are all in agreement with previous space-based results. Scintillation noise in the data prevents us from placing strong constraints on the presence of an extended hydrogen-rich atmosphere. Nevertheless, our detections of 55 Cnc e in transit demonstrate that moderate-size telescopes on the ground will be capable of routine follow-up observations of super-Earth candidates discovered by the Transiting Exoplanet Survey Satellite (TESS) around bright st...

de Mooij, E J W; Karjalainen, R; Hrudkova, M; Jayawardhana, R

2014-01-01

123

Optical flares and flaring oscillations on the M-type eclipsing binary CU Cnc  

E-print Network

We report here the discovery of an optical flare observed in R band from the red-dwarf eclipsing binary CU Cnc whose component stars are at the upper boundary of full convection (M1=0.43 and M2=0.4M0, M0 is the solar mass). The amplitude of the flare is the largest among those detected in R band (~0.52mag) and the duration time is about 73 minutes. As those observed on the Sun, quasi-periodic oscillations were seen during and after the flare. Three more R-band flares were found by follow up monitoring. In total, this binary was monitored photometrically by using R filter for 79.9 hours, which reveals a R-band flare rate about 0.05 flares per hour. These detections together with other strong chromospheric and coronal activities, i.e., very strong H_alpha and H_beta emission features and an EUV and X-ray source, indicate that it has very strong magnetic activity. Therefore, the apparent faintness (~1.4 magnitude in V) of CU Cnc compared with other single red dwarfs of the same mass can be plausibly explained by...

-B., Qian S; Zhu, L -Y; Liu, L; Liao, W -P; Zhao, E -G; He, J -J; Li, L -J; Li, K; Dai, Z -B

2012-01-01

124

Capturing and Composing Parallel Patterns with Intel CnC Ryan Newton Frank Schlimbach Mark Hampton Kathleen Knobe  

E-print Network

Capturing and Composing Parallel Patterns with Intel CnC Ryan Newton Frank Schlimbach Mark Hampton to encapsulate only a single pattern. Thus we explore the use of Intel CnC as a single frame- work for capturing. In this paper, we consider Intel Concurrent Collections (CnC)[9]. as a candidate substrate for patterns. CnC

Gummadi, Ramakrishna

125

Very Low Compliance Force Control on a CNC Lathe Machine  

Microsoft Academic Search

This work demonstrates how to carry out contact operations in a very stiff contact situation. The experimental set up used is a CNC machine that carries out metals spinning. The controlled forces are the metal forming forces. The designed controller operates in a dynamic environment. The complete control system operates in a manner similar to reaction compensation. The force controller

Daniel Hanafi; Jayantha Katupitiya

2006-01-01

126

Automatic cutting-tool condition monitoring on CNC lathes  

Microsoft Academic Search

This paper addresses the problem of automatically defining cutting-tool wear on CNC lathes. The problem is solved by analysing the axial force during the pressing of the cutting edge of an insert into the workpiece while the cutting process is stopped. During machining the feed movement is interrupted and the position of the cutting tool at this moment becomes a

Tamas Szecsi

1998-01-01

127

Enhanced CNC lathe capability by addition of a grinding spindle  

Microsoft Academic Search

CNC grinding machines are widely used to obtain a good surface finish and tight tolerances. However, these machines are expensive, therefore manufacturers are considering adding a grinding spindle, interchangeable with a boring bar, to a turning lathe. To facilitate this, complex software is required because the programmer must control the whole surface of the grinding wheel not just the tool

A. T. Abbas

2003-01-01

128

A Cascaded Adaptive Controller for CNC Lathe Spindle Drives  

Microsoft Academic Search

In modern computer numerically controlled (CNC) lathes the spindle drives often have an infinitely variable speed range to allow constant horsepower cutting. Such spindle drives are typically powered by direct current (dc) servo motors which are conventionally controlled by an analog speed regulator in the form of pseudo-derivative feedback (PDF). The PDF controller contains an integral action to compensate for

H. A. Pak

1988-01-01

129

Implementation of Additive Rapid Prototyping on Retrofit CNC Mill  

Technology Transfer Automated Retrieval System (TEKTRAN)

Freeform fabrication techniques are gaining popularity as a means of making parts. Layered additive methods are associated with rapid prototyping. Many rapid prototyping methods are commercially proprietary and may cost thousands of dollars. Using a retrofit CNC mill for layered fabrication and C...

130

Design and performance of a small precision CNC turning machine  

Microsoft Academic Search

This paper describes the design of a CNC turning machine that is capable of machining workpieces up to 100 mm in diameter with a high contour accuracy and a very low surface roughness. Two nearly identical machines have been built and put into operation using this design, one for serial parts manufacture and the other for research into improving the

R. R. Donaldson; D. C. Thompson; E LOEWEN

1986-01-01

131

Simulation of thermal behavior of a CNC machine tool spindle  

Microsoft Academic Search

The thermal deformations of a CNC machine tool spindle are the major contributor of thermal error. It is very significant both theoretically and practically to study how to accurately simulate the thermal error of the spindle. Firstly, this paper proposes a method for computing the coefficient of convection heat transfer of the spindle surface by referencing the theory on computing

Zhao Haitao; Yang Jianguo; Shen Jinhua

2007-01-01

132

Forming strategies and Process Modelling for CNC Incremental Sheet Forming  

Microsoft Academic Search

Incremental Sheet Forming (ISF) is a process capable of producing complex sheet components by the CNC movement of a simple tool in combination with simplified dies. Earlier work revealed two major process limits, namely the limitation on the maximum achievable wall angle, and the occurrence of geometric deviations. The work detailed in this paper focuses on forming strategies to overcome

G. Hirt; J. Ames; M. Bambach; R. Kopp

2004-01-01

133

Determination of Optimal Parameters for SKD11 CNC Turning Process  

Microsoft Academic Search

This study investigated the optimization of a CNC turning process for SKD11 (JIS). The design of experiments (DOE) method with an orthogonal array was applied. Nine experimental runs were performed based on the orthogonal array. The surface properties of roughness average and roughness maximum and the roundness were studied; the analysis of variance (ANOVA) was adapted to investigate which parameters

Chorng-Jyh Tzeng; Yung-Kuang Yang

2008-01-01

134

Surface characteristics generated in CNC chip breaking tool paths  

Microsoft Academic Search

One method for creating broken chips in turning processes involves oscillating the cutting tool in the feed direction utilizing the CNC machine axes. Using computer simulations it is possible to combine the motion of the axes with the geometry of the cutting tool to predict the surface characteristics, mapping surface parameters for a wide range of chip breaking situations. These

S. Smith; J. McFarland; T. Assaid; D. Tursky; W. Barkman; E. Babelay

2010-01-01

135

Two X-Ray Bright Cataclysmic Variables with Unusual Activities: GZ Cnc and NSV 10934  

E-print Network

We report on a discovery of unexpected activities in two X-ray bright dwarf novae. GZ Cnc showed an anomalous clustering of outbursts in 2002, in contrast to a low outburst frequency in the past record. The activity resembles an increased activity seen in some intermediate polars or candidates. We identified NSV 10934, X-ray selected high-amplitude variable star, as a dwarf nova with unusually rapid decline. The outburst characteristics make NSV 10934 a twin of recently discovered intermediate polar (HT Cam) with dwarf nova-type outbursts. We propose that these activities in X-ray strong dwarf novae may be a previously overlooked manifestation of outburst activities in magnetic cataclysmic variables.

T. Kato; P. A. Dubovsky; R. Stubbings; M. Simonsen; H. Yamaoka; P. Nelson; B. Monard; A. Pearce; G. Garradd

2002-10-01

136

Generation of gear tooth surfaces by application of CNC machines  

NASA Astrophysics Data System (ADS)

This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

Litvin, F. L.; Chen, N. X.

1994-04-01

137

Generation of gear tooth surfaces by application of CNC machines  

NASA Technical Reports Server (NTRS)

This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

Litvin, F. L.; Chen, N. X.

1994-01-01

138

CNC subaperture polishing process arrangement for microroughness minimisation  

NASA Astrophysics Data System (ADS)

The aim of this study was to determine the optimal subaperture polishing procedure for aspherical surfaces on the Optotech MCP 250 CNC machine. Due to the fact that the CNC subaperture polishing process runs along well defined paths, certain frequencies develop on the polished surface, which can be limiting for the resulting microroughness. A proper sequence of polishing steps in different tool motion control modes can minimize these frequencies and help to substantially reduce microroughness. In this context, various tool motion control modes ("Spiral spindle mode", "Spiral axis mode" and "Raster mode") in combination with different tools were tested. The resulting microroughness values were observed in the defined mid-frequency and high-frequency areas. The best results, i.e. the lowest microroughness values were obtained using a combination of the processes "Ball spiral axis mode", "FEM raster mode", "spiral spindle 2D FEM correction mode" and "AFJ spiral axis mode"

Prochaska, F.; Matousek, O.; Tomka, D.; Polak, J.; Poláková, I.

2015-01-01

139

Retrofitment of a CNC machine for hybrid layered manufacturing  

Microsoft Academic Search

Subtractive manufacturing [computer numerical controlled (CNC) machining] has high quality geometric and material properties\\u000a but is slow, costly, and infeasible in some cases. On the contrary additive manufacturing (rapid prototyping) has total automation\\u000a but compromises quality. A hybrid layered manufacturing process presented in this study combines the best features of both\\u000a these approaches. It uses arc weld deposition for building

K. P. Karunakaran; S. Suryakumar; Vishal Pushpa; Sreenathbabu Akula

2009-01-01

140

Off-line adaptive optimization of CNC lathe turning  

Microsoft Academic Search

This paper discusses the results obtained from a micro-computer program SIMTUP developed at the National University of Singapore for off-line adaptive optimization of a multi-pass CNC lathe-turning process. An initial estimation based on empirical models is conducted to obtain the total amount of time, cost and resources required for production. These models are to be updated with a view to

E. H. T. WEE; A. Y. C. NEE; T. N. GOH

1990-01-01

141

Competitive parameter optimization of multi-quality CNC turning  

Microsoft Academic Search

Surface roughness, tool wear, and material removal rate (MRR) are major intentions in the modern computer numerical controlled\\u000a (CNC) machining industry. In this paper, the $${\\\\text{L}}_9 \\\\left( {3^4 } \\\\right)$$ orthogonal array of a Taguchi experiment is selected for four parameters (cutting depth, feed rate, speed, and tool nose\\u000a runoff) with three levels (low, medium, and high) in optimizing the

Tian-Syung Lan; Ming-Yung Wang

2009-01-01

142

A Framework for an Intelligent CNC and Data Model  

Microsoft Academic Search

In this paper, we present a conceptual framework for designing and implementing an intelligent CNC system. The architecture\\u000a and functional modules are derived from requirement analysis, and they are designed to have a thinking capability before,\\u000a during, and after the execution of the manufacturing task, so that the assigned task can be effectively executed while dealing\\u000a with unexpected changes occurring

S.-H. Suh; S.-U. Cheon

2002-01-01

143

An Internet-Based Virtual CNC Milling System  

Microsoft Academic Search

This paper addresses the importance of integrating a virtual Manufacturing (VM) system with the Internet and proposes a web-based,\\u000a scalable and distributed architecture for developing a platform-independent VM system. A prototype web-based virtual CNC milling\\u000a system has been developed using Virtual Reality Modelling Language and Java. The user can easily set up machining conditions,\\u000a operate the virtual milling machine in

S. K. Ong; L. Jiang; A. Y. C. Nee

2002-01-01

144

Incremental sheet metal forming on CNC milling machine-tool  

Microsoft Academic Search

Incremental sheet metal forming is a promising process providing a short and inexpensive way of forming products having a relatively simple but interesting shape. The paper presents the process controlled by CNC milling machine-tool together with CAD\\/CAM Master Cam system and a smooth forming tool. With experimental testing and measurements the limits of forming without a full-size model were defined.

J. Kopac; Z. Kampus

2005-01-01

145

Real-time NURBS command generators for CNC servo controllers  

Microsoft Academic Search

This study proposes a real-time Non-Uniform Rational B-Spline (NURBS) motion command generator for computer numerical control (CNC) machines to achieve the goal of high-speed and highly accurate machining. Different numerical algorithms for implementing the NURBS motion command generator are compared on the basis of both the computation time and the precision of geometric representation. In addition, to reduce the computation

M.-Y. Cheng; M.-C. Tsai; J.-C. Kuo

2002-01-01

146

Realization of CNC System on Middle-Convex and Varying Oval Piston Machining  

Microsoft Academic Search

To machine non-circular middle-convex and varying oval (NMVO) pistons with computer numerical control (CNC) turning system,\\u000a the cutter must reciprocate in X-axis with high-speed and high-precision to tracking the rotating of spindle. A CNC turning\\u000a system for NMVO piston machining is designed. The CNC system consisted of a normal turning system and an ellipse section turning\\u000a module. The turning system

Hongen Wu; Guili Li; Daguang Shi; Chengrui Zhang

147

A three-ply reconfigurable CNC system based on FPGA and field-bus  

Microsoft Academic Search

To reconfigure computer numerical control (CNC) system, the authors divide the reconfiguration technology of CNC system into\\u000a three interactive levels: hardware system reconfiguration, software system reconfiguration, and module reconfiguration. On\\u000a the software–hardware platform of CNC system designed in this study, hardware system reconfiguration is based on a rapid field\\u000a programming of Field-Programmable Gate Array (FPGA) and performed with different FPGA

Tao Wang; Liwen Wang; Qingjian Liu

148

Accuracy enhancement of five-axis CNC machines through real-time error compensation  

Microsoft Academic Search

Although error modeling and compensation have given significant results for three-axis CNC machine tools, a few barriers have prevented this promising technique from being applied in five-axis CNC machine tools. One crucial barrier is the difficulty of measuring or identifying link errors in the rotary block of five-axis CNC machine tools. The error model is thus not fully known. To

W. T Lei; Y. Y Hsu

2003-01-01

149

Modeling and control of cnc machines using a PC-based open architecture controller  

Microsoft Academic Search

A PC-based open architecture computer numerical controller (CNC) is introduced to control milling machines. The controller is implemented on two systems: (1) a single-axis high speed milling machine using analog control signals where the PC-based controller assumes all CNC functions and (2) a three-axis milling machine controlled by digital signals where the existing CNC continues to monitor peripheral functions but

Stephen J. Rober; Yung C. Shin

1995-01-01

150

Autonomously Proficient CNC Controller for High-Performance Machine Tools Based on an Open Architecture Concept  

Microsoft Academic Search

The paper deals with the new controller for the high performance CNC machine tools. The controller proposed is referred to as “TRUE-CNC.” “TRUE” means Transparent, Transportable and Transplantable, Revivable, User-reconfigurable, and Evolving. TRUE-CNC allows the operator to achieve the maximum productivity and highest possible quality of the machined parts in a given environment with autonomous capturing of the machining operation

Kazuo Yamazaki; Yoshimaro Hanaki; Masahiko Mori; Kazusaka Tezuka

1997-01-01

151

Research on the thermal load of CNC milling machine  

NASA Astrophysics Data System (ADS)

Machine tool accuracy is the assurance of top-quality products in machining processes. In the all kinds of errors related to machine tools, thermal errors of machine tools' parts play an important role in machining accuracy and directly influence both the surface finish and the geometric shape of the finished workpiece. Therefore the objective of this work was to analyze the temperature field and thermal deformation in some parts of CNC machine tools. In this paper, the thermal boundary condition of main spindle and driving ball screw in CNC milling machine are discussed, some parameters in heat transfer process are calculated. Based on steady heat transfer process, the thermal analysis about spindle and ball screw is carried out under ANSYS environment, and their temperature fields are obtained when milling machine is working. Then the deformations of main spindle and ball screw are acquired by applying the thermal structure coupling element. Furthermore, in order to decrease main parts' deformations and improve the accuracy of CNC milling machine, some suggests are proposed.

Nie, Xue-Jun; Wu, Ping-Dong

2011-05-01

152

Research on the thermal load of CNC milling machine  

NASA Astrophysics Data System (ADS)

Machine tool accuracy is the assurance of top-quality products in machining processes. In the all kinds of errors related to machine tools, thermal errors of machine tools' parts play an important role in machining accuracy and directly influence both the surface finish and the geometric shape of the finished workpiece. Therefore the objective of this work was to analyze the temperature field and thermal deformation in some parts of CNC machine tools. In this paper, the thermal boundary condition of main spindle and driving ball screw in CNC milling machine are discussed, some parameters in heat transfer process are calculated. Based on steady heat transfer process, the thermal analysis about spindle and ball screw is carried out under ANSYS environment, and their temperature fields are obtained when milling machine is working. Then the deformations of main spindle and ball screw are acquired by applying the thermal structure coupling element. Furthermore, in order to decrease main parts' deformations and improve the accuracy of CNC milling machine, some suggests are proposed.

Nie, Xue-Jun; Wu, Ping-Dong

2010-12-01

153

Resonance line of B II in IUE spectra of chemically peculiar stars  

SciTech Connect

High-dispersion IUE spectroscopic observations of the B II resonance line at 1362.46 A are presented for six HgMn stars (kappa Cnc, ..mu.. Lep, 46 Draiola, CrB, HR 4072, and chi Lup), two magnetic peculiar stars (..cap alpha../sup 2/ CVn and HD 32633), and one normal B9.5 V star (..nu.. Cap). The B II line is present in great strength in kappa Cnc. It is absent from the five other HgMn stars. It is probably present, though unresolved and weak, in the magnetic stars. Its strength in ..nu.. Cap is consistent with a normal boron abundance.

Leckrone, D.S.

1981-11-15

154

o Consonant-Nucleus-Consonant (CNC) o 50 phonetically balanced one-syllable words (list phonetically balanced to  

E-print Network

Stimuli o Consonant-Nucleus-Consonant (CNC) o 50 phonetically balanced one-syllable words (list) as a function of run number METHODS Figure 1: Testing screen consisting of 50 CNC words. Figure 3. Acute adult

Litovsky, Ruth

155

Command Shaping for Micro-Mills and CNC Controllers Joel Fortgang*, William Singhose*, Juan de Juanes Marquez**, Jesus Perez**  

E-print Network

Command Shaping for Micro-Mills and CNC Controllers Joel Fortgang*, William Singhose*, Juan de-mill which can be implemented with a standard CNC controller. The robustness of this technique to modelling

Singhose, William

156

Study on Dynamical Characteristics of Spindle System of CNC Machine Based on Experimental Mode Analysis  

Microsoft Academic Search

For CNC machine of certain type, its vibration modes are quite denseness because the machine tool belongs to a large and complex structure. In order to obtain dynamical characteristics of the spindle system in typical cutting condition, the testing scheme of pseudo random relative excitation and measure system are used in the paper. The theoretical model of precise CNC machine

Licheng Yang; Jingxiang Hu; Caijie Wei; Liwei Ning

2009-01-01

157

An innovation design of CNC lathe integrated scheme based on the genetic algorithm  

Microsoft Academic Search

Based on the genetic algorithm (GA), a model of CNC lathe integrated scheme innovation design system is researched and presented. In this paper, particular emphasis is placed on the fact that CNC lathe systems generally have hierarchical structures. Via treating the integrated scheme designs as the solution to design spaces, a new hierarchical genotype representation is developed with the genetic

Li-xin Wang; Da-yong Li; Lin-juan Du

2011-01-01

158

Prediction and control of surface roughness in CNC lathe using artificial neural network  

Microsoft Academic Search

In this study, a neural network approach is presented for the prediction and control of surface roughness in a computer numerically controlled (CNC) lathe. Experiments have been performed on the CNC lathe to obtain the data used for the training and testing of a neural network. The parameters used in the experiment were reduced to three cutting parameters which consisted

Durmus Karayel

2009-01-01

159

Failure probabilistic model of CNC lathe based on support vector machine  

Microsoft Academic Search

In this paper, support vector machine (SVM) have been applied to the failure probabilistic model of CNC lathe, and two methodologies (SVM and least square method) have been compared for the analysis of the failure data collected from eighty CNC lathes. The proposed failure probabilistic model based on SVM was more accurate and reliable than that of least square. Hence,

Xiu-Hua Yuan; Yi-Qiang Wang; Yan-Juan Hu

2010-01-01

160

A generalized approach for the acceleration and deceleration of industrial robots and CNC machine tools  

Microsoft Academic Search

Many techniques for the acceleration and deceleration of industrial robots and computer numerical control (CNC) machine tools have been proposed in order to make industrial robots and CNC machine tools perform given tasks efficiently. Although the techniques selecting polynomial functions can generate various acceleration and deceleration characteristics, the major problem is the computational load. The digital convolution techniques are more

Jae Wook Jeon; Young Youl Ha

2000-01-01

161

FPGA based acceleration and deceleration circuit for industrial robots and CNC machine tools  

Microsoft Academic Search

In order to make industrial robots and computer numerical control (CNC) machine tools perform tasks efficiently, many techniques for the acceleration and deceleration of industrial robots and CNC machine tools have been proposed. Polynomial technique can generate velocity profiles of various acceleration and deceleration characteristics, but it requires a lot of computations. Digital convolution technique can generate efficiently velocity profiles,

Jae Wook Jeon; Yun-Ki Kim

2002-01-01

162

CNC incremental sheet forming of an axially symmetric specimen and the locus of optimization  

Microsoft Academic Search

CNC incremental sheet forming is a new flexible sheet forming process. It does not need a dedicated die and can form sheet parts with a higher forming limit and of complicated shape by use of a CNC device. This process is suited to the forming of sheet parts of small volume, diversification and complicated shape in space-flight, automobile and civil

Kun Dai; Z. R Wang; Yi Fang

2000-01-01

163

Prediction of surface roughness in CNC face milling using neural networks and Taguchi's design of experiments  

Microsoft Academic Search

In this paper, a neural network modeling approach is presented for the prediction of surface roughness (Ra) in CNC face milling. The data used for the training and checking of the networks’ performance derived from experiments conducted on a CNC milling machine according to the principles of Taguchi design of experiments (DoE) method. The factors considered in the experiment were

P. G Benardos; G. C Vosniakos

2002-01-01

164

Design and Implementation of CNC Machine Remote Monitoring and Controlling System Based on Embedded Internet  

Microsoft Academic Search

The network control of CNC machine is the inexorable development trend of modern manufacturing industry, and the combination of embedded technology with network has become a research hot. This paper puts forward a novel design idea of remote monitoring and controlling system of CNC machine based on embedded Internet, presents its architecture principle design and software-hardware implementation procedure of the

Zhai Wen-zheng; Hu Yue-li

2010-01-01

165

International Conference on E-Portfolio Process in Vocational Education-EPVET 2007 REVISITING CNC TRAINING A "VIRTUAL TRAINING CENTRE  

E-print Network

International Conference on E-Portfolio Process in Vocational Education- EPVET 2007 REVISITING CNC TRAINING ­ A "VIRTUAL TRAINING CENTRE FOR CNC" Mehmet ahin*1 , Nikolaos Bilalis2 , Süleyman Yaldiz1, Technological Educational Institute of Crete, Chania, Greece Abstract CNC Training has been a scope of interest

Aristomenis, Antoniadis

166

Department of Industrial and Manufacturing Engineering Fall 2012 Enabling CNC-RP in PSU's IE FAME Lab  

E-print Network

PENNSTATE Department of Industrial and Manufacturing Engineering Fall 2012 Enabling CNC-RP in PSU's IE FAME Lab Overview In this project, CNC-RP capability has been installed and developed in the Penn be built with this particular method. After finding the limitations of this process, this CNC-RP capability

Demirel, Melik C.

167

CNC water-jet machining and cutting center  

SciTech Connect

CNC water-jet machining was investigated to determine the potential applications and cost-effectiveness that would result by establishing this capability in the engineering shops of Allied-Signal Inc., Kansas City Division (KCD). Both conductive and nonconductive samples were machined at KCD on conventional machining equipment (a three-axis conversational programmed mill and a wire electrical discharge machine) and on two current-technology water-jet machines at outside vendors. These samples were then inspected, photographed, and evaluated. The current-technology water-jet machines were not as accurate as the conventional equipment. The resolution of the water-jet equipment was only {plus minus}0.005 inch, as compared to {plus minus}0.0002 inch for the conventional equipment. The principal use for CNC water-jet machining would be as follows: Contouring to near finished shape those items made from 300 and 400 series stainless steels, titanium, Inconel, aluminum, glass, or any material whose fabrication tolerance is less than the machine resolution of {plus minus}0.005 inch; and contouring to finished shape those items made from Kevlar, rubber, fiberglass, foam, aluminum, or any material whose fabrication specifications allow the use of a machine with {plus minus}0.005 inch tolerance. Additional applications are possible because there is minimal force generated on the material being cut and because the water-jet cuts without generating dust. 12 figs.

Bartlett, D.C.

1991-09-01

168

The large outbursts studied by small telescopes - the case of RS Oph  

NASA Astrophysics Data System (ADS)

Cataclysmic variables (CVs) are one of the dominant part in astronomical research. Small telescopes are widely used to search for the sudden brightening of such stars. We present our experience with observations of the RS Ophiuchi (RS Oph) and analyses of the light curves. RS Oph is a binary system with 6 recorded outbursts classified as a recurrent nova (RN). We used the telescopes of AI SAS to measure the brightness of RS Oph after its last outburst occurred on February 12, 2006. The new observations indicate the ongoing mass transfer. % and the estimation of the mass transfer rate allow to make a prediction of the %next outburst of this RN.

Kundra, E.; Hric, L.

2014-03-01

169

The moderately interacting Algol binary RS Cephei  

NASA Technical Reports Server (NTRS)

In agreement with previous observers, it is found that the eclipsing binary RS Cep is an Algol-type semidetached system. From IUE spectra and Lick Observatory optical scans, the spectral types of the components are determined as B9.7e V + G8 III-IV. The effective temperature of the primary star is found to be 9670 K (with an uncertainty of about 150 K). From the photometric elements, the spectral types, and the semidetached nature of the system, a satisfactory model of the system is developed, giving masses 2.4 and 0.4 solar mass, radii 2.3 and 7.6 solar radii, and separation of the components 32 solar radii. This model leads to a distance of 910 pc; the color excess is E(B - V) = 0.03 mag. Balmer emission lines are observed in the optical scans, so that the system is a Be star. An IUE spectrum obtained during the total primary eclipse reveals a number of UV emission lines, typical for interacting Algols and W Ser stars. Power emitted in these lines is about twice as high as that in TT Hya or U Cep, therefore, RS Cep is a relatively active Algol system. A broad 'bulge' of excess relative flux is observed roughly between wavelengths 210 and 270 nm in the totality spectrum, and interpreted as broad blends of emission lines of Fe II; the same Fe II lines, formed in a circumstellar shell or disk, cause additional absorption in the out-of-eclipse spectra.

Plavec, Mirek J.; Dobias, Jan J.

1987-01-01

170

Finishing of EUV photomask substrates by CNC precessed bonnet polisher  

NASA Astrophysics Data System (ADS)

The progressive transition from Excimer to EUV lithography is driving a need for flatter and smoother photomasks. It is proving difficult to meet this next generation specification with the conventional chemical mechanical polishing technology commonly used for finishing photomasks. This paper reports on the application of sub-aperture CNC precessed bonnet polishing technology to the corrective finishing of photomask substrates for EUV lithography. Fullfactorial analysis was used to identify process parameters capable of delivering 0.5 nm rms surface roughness whilst achieving removal rates above 0.1 mm3/min. Experimental results show that masks pre-polished to 300~600 nm P-V flatness by CMP can then be improved down to 50~100 nm P-V flatness using the automated technology described in this paper. A series of edge polishing experiments also hints at the possibility of increasing the quality area beyond the 5 mm defined in the official EUV photomask specification.

Beaucamp, Anthony T. H.; Namba, Yoshiharu; Charlton, Phillip; Freeman, Richard R.

2013-09-01

171

Design and performance of a small precision CNC turning machine  

SciTech Connect

This paper describes the design of a CNC turning machine that is capable of machining workpieces up to 100 mm in diameter with a high contour accuracy and a very low surface roughness. Two nearly identical machines have been built and put into operation using this design, one for serial parts manufacture and the other for research into improving the accuracy of single-point machining; information based on this operational experience is also presented. The first machine has demonstrated an accuracy of 0.1 ..mu..m peak-to-valley on contoured workpieces, while the second machine has produced surface roughnesses of 1 nm rms in flat facing of electroless nickel with a diamond tool.

Donaldson, R.R.; Thompson, D.C.

1986-02-26

172

Time-optimal CNC tool paths : a mathematical model of machining  

E-print Network

Free-form surface machining is a fundamental but time-consuming process in modern manufacturing. The central question we ask in this thesis is how to reduce the time that it takes for a 5-axis CNC (Computer Numerical ...

Kim, Taejung, 1969-

2001-01-01

173

Application of Ball Bar System and Genetic Algorithms for CNC Lathe Contouring Compensation  

Microsoft Academic Search

There is considerable interest in the development and improvement of contouring test devices for CNC machines. When ball bar\\u000a systems are employed to test CNC lathes, the eccentricity cannot be determined accurately from the sampled quadrant contouring\\u000a data via the least-squares method. Geometric errors, such as squareness and deformation errors, are underestimated, causing\\u000a significant errors in eccentricity values. Thus, one

Wen-Yuh Jywe; Chien-Hong Liu

2001-01-01

174

A new failure mode and effects analysis model of CNC machine tool using fuzzy theory  

Microsoft Academic Search

Failure mode analysis is important in CNC machine tool. In order to assess the failure mode of CNC machine tool, this paper described a new fuzzy FMEA model integrating with fuzzy linguistic scale method. The model proposed a risk-space diagram to explicit the relationship of S,O and D. On the basis of the risk-space diagram, risk priority number is calculated

Zhaojun Yang; Binbin Xu; Fei Chen; Qingbo Hao; Xiaocui Zhu; Yazhou Jia

2010-01-01

175

Springback behaviour in bending of ultra-high-strength steel sheets using CNC servo press  

Microsoft Academic Search

The springback behaviour of ultra-high-strength steel sheets in bending was investigated under controlled conditions using a CNC servo press. Although the ultra-high-strength steel sheets are attractive in reducing weight of cars, the amount of springback of the ultra-high-strength steel sheets in the forming is very large due to high strength. The CNC servo press has the function of accurately controlling

K. Mori; K. Akita; Y. Abe

2007-01-01

176

Kernel software for efficiently building, re-configuring, and distributing an open CNC controller  

Microsoft Academic Search

Several open control architectures have been proposed to enable the incorporation of new technologies into existing CNC controllers.\\u000a However, complex interfaces and communications among heterogeneous hardware and software platforms have yet to be resolved\\u000a to reduce development time and cost. We propose a piece of kernel software that facilitates the development, reconfiguration,\\u000a and distribution of CNC controllers. Assuming that various

Sun-Ho Kim; Hyunbo Cho

2006-01-01

177

Time-resolved Spectroscopy of RS Canum Venaticorum Short-Period Systems. II. RT Andromedae, WY Cancri, and XY Ursae Majoris  

NASA Astrophysics Data System (ADS)

We present the second part of the results of our spectroscopic study of orbital phase resolution of short-period active binaries. In this paper we present the observations of the binaries RT And, WY Cnc, and XY UMa, for which we obtained simultaneous low-resolution spectra in the H?, H?, and Ca II infrared triplet (IRT; 8498 and 8542 Å) lines, and higher resolution spectra in H? for WY Cnc and XY UMa. H? and H? emission excess was found in all the observed orbital phases of WY Cnc and XY UMa, while RT And showed H? emission only during some orbital phases. We measure a clear Ca II (IRT) excess in all the spectra of the three binaries. The ratio of the flux excesses derived for these binaries, E_H?/E_H?~= 1-3 and E_8542/E_8498~= 1-3, give low values typical of solar plage structures. In the higher resolution H? spectra, we found emissions that can be associated with both stellar components of XY UMa and WY Cnc, indicating that the faint secondary stars in both binaries are active late-type dwarfs. Some H? emission components, which could originate in extended structures between the stars, were detected in both systems.

Arévalo, M. J.; Lázaro, C.

1999-08-01

178

PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity in Latvians, Lithuanians and Taiwanese  

PubMed Central

PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity was investigated in 1438 unrelated subjects from Latvia, Lithuania and Taiwan. In general, polymorphism of each individual locus showed tendencies similar to determined previously in HapMap populations. Main differences concern Taiwanese and include presence of rs2277460 rare allele A not found before in Asians and absence of rs2295827 rare alleles homozygotes TT observed in all other human populations. Observed patterns of SNPs and haplotype diversity were compatible with expectation of neutral model of evolution. Linkage disequilibrium between the rs2295826 and rs2295827 was detected to be complete in Latvians and Lithuanians (D? = 1; r2 = 1) and slightly disrupted in Taiwanese (D? = 0.978; r2 = 0.901). Population differentiation (FST statistics) was estimated from pairwise population comparisons of loci variability, five locus haplotypes and PSMA6 and PSMC6 two locus haplotypes. Latvians were significantly different from all Asians at each of 5 SNPs and from Lithuanians at the rs1048990 and PSMC6 loci. Lithuanian and Asian populations exhibited similarities at the PSMC6 loci and were different at the PSMA6 and PSMA3 SNPs. Considering five locus haplotypes all European populations were significantly different from Asian; Lithuanian population was different from both Latvian and CEU. Allele specific patterns of transcription factor binding sites and splicing signals were predicted in silico and addressed to eventual functionality of nucleotide substitutions and their potential to be involved in human genome evolution and geographical adaptation. Current study represents a novel step toward a systematic analysis of the proteasomal gene genetic diversity in human populations. PMID:25606411

Sjakste, Tatjana; Paramonova, Natalia; Wu, Lawrence Shi-Shin; Zemeckiene, Zivile; Sitkauskiene, Brigita; Sakalauskas, Raimundas; Wang, Jiu-Yao; Sjakste, Nikolajs

2014-01-01

179

PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity in Latvians, Lithuanians and Taiwanese.  

PubMed

PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity was investigated in 1438 unrelated subjects from Latvia, Lithuania and Taiwan. In general, polymorphism of each individual locus showed tendencies similar to determined previously in HapMap populations. Main differences concern Taiwanese and include presence of rs2277460 rare allele A not found before in Asians and absence of rs2295827 rare alleles homozygotes TT observed in all other human populations. Observed patterns of SNPs and haplotype diversity were compatible with expectation of neutral model of evolution. Linkage disequilibrium between the rs2295826 and rs2295827 was detected to be complete in Latvians and Lithuanians (D? = 1; r(2) = 1) and slightly disrupted in Taiwanese (D? = 0.978; r(2) = 0.901). Population differentiation (FST statistics) was estimated from pairwise population comparisons of loci variability, five locus haplotypes and PSMA6 and PSMC6 two locus haplotypes. Latvians were significantly different from all Asians at each of 5 SNPs and from Lithuanians at the rs1048990 and PSMC6 loci. Lithuanian and Asian populations exhibited similarities at the PSMC6 loci and were different at the PSMA6 and PSMA3 SNPs. Considering five locus haplotypes all European populations were significantly different from Asian; Lithuanian population was different from both Latvian and CEU. Allele specific patterns of transcription factor binding sites and splicing signals were predicted in silico and addressed to eventual functionality of nucleotide substitutions and their potential to be involved in human genome evolution and geographical adaptation. Current study represents a novel step toward a systematic analysis of the proteasomal gene genetic diversity in human populations. PMID:25606411

Sjakste, Tatjana; Paramonova, Natalia; Wu, Lawrence Shi-Shin; Zemeckiene, Zivile; Sitkauskiene, Brigita; Sakalauskas, Raimundas; Wang, Jiu-Yao; Sjakste, Nikolajs

2014-12-01

180

H I Observations of the Asymptotic Giant Branch Star X Herculis: Discovery of an Extended Circumstellar Wake Superposed on a Compact High-velocity Cloud  

NASA Astrophysics Data System (ADS)

We report H I 21 cm line observations of the asymptotic giant branch (AGB) star X Her obtained with the Robert C. Byrd Green Bank Telescope (GBT) and the Very Large Array. We have unambiguously detected H I emission associated with the circumstellar envelope of the star, with a mass totaling M H I ? 2.1 × 10-3 M sun. The H I distribution exhibits a head-tail morphology, similar to those previously observed around the AGB stars Mira and RS Cnc. The tail is elongated along the direction of the star's space motion, with a total extent of >~ 6farcm0 (0.24 pc) in the plane of the sky. We also detect a systematic radial velocity gradient of ~6.5 km s-1 across the H I envelope. These results are consistent with the H I emission tracing a turbulent wake that arises from the motion of a mass-losing star through the interstellar medium (ISM). GBT mapping of a 2° × 2° region around X Her reveals that the star lies (in projection) near the periphery of a much larger H I cloud that also exhibits signatures of interaction with the ISM. The properties of the cloud are consistent with those of compact high-velocity clouds. Using 12CO J = 1-0 observations, we have placed an upper limit on its molecular gas content of N H2 < 1.3 × 1020 cm-2. Although the distance to the cloud is poorly constrained, the probability of a chance coincidence in position, velocity, and apparent position angle of space motion between X Her and the cloud is extremely small, suggesting a possible physical association. However, the large H I mass of the cloud (gsim2.4 M sun) and the blueshift of its mean velocity relative to X Her are inconsistent with an origin tied directly to ejection from the star.

Matthews, L. D.; Libert, Y.; Gérard, E.; Le Bertre, T.; Johnson, M. C.; Dame, T. M.

2011-02-01

181

Spatial augmented reality on industrial CNC-machines  

NASA Astrophysics Data System (ADS)

In this work we present how Augmented Reality (AR) can be used to create an intimate integration of process data with the workspace of an industrial CNC (computer numerical control) machine. AR allows us to combine interactive computer graphics with real objects in a physical environment - in this case, the workspace of an industrial lathe. ASTOR is an autostereoscopic optical see-through spatial AR system, which provides real-time 3D visual feedback without the need for user-worn equipment, such as head-mounted displays or sensors for tracking. The use of a transparent holographic optical element, overlaid onto the safety glass, allows the system to simultaneously provide bright imagery and clear visibility of the tool and workpiece. The system makes it possible to enhance visibility of occluded tools as well as to visualize real-time data from the process in the 3D space. The graphics are geometrically registered with the workspace and provide an intuitive representation of the process, amplifying the user's understanding and simplifying machine operation.

Olwal, Alex; Gustafsson, Jonny; Lindfors, Christoffer

2008-02-01

182

The design of an ultra-precision CNC measuring machine  

SciTech Connect

A specialized ultra-precision CNC measuring machine is being developed to provide an inspection capability compatible with existing precision turning machines. The instrument is to be applied to the inspection of the inner and outer surfaces of hemispherical shells and other axisymmetric parts, with diameters of up to 400 mm. The overall accuracy of the machine operating in continuous path contouring mode is to be less than 0.75 micrometre (p-v) per surface, including both instrument and process-related errors. In addition, an accuracy of 1.75 micrometres is required for the inspection of wall thickness on some categories of parts, which in some instances may be distorted by gravity loading. This latter requirement dictates a single setup for the inspection of inner and outer surfaces, and effectively eliminates a standard Coordinate Measuring Machine (CMM) configuration for the new gauge. The new instrument is known as the Certification of Process (COP) Gauge. 9 refs., 5 figs., 2 tabs.

Thompson, D.C.

1989-01-01

183

Synthesis of chemical cross-linked gelatin hydrogel reinforced with cellulose nanocrystals (CNC)  

NASA Astrophysics Data System (ADS)

A novel method was performed to obtain hydrogel with superior sensitivity towards changes in pH and temperature by incorporation of CNC into gelatin based hydrogel. Glutaraldehyde was used as cross-linker due to its high chemical reactivity towards NH2 group on gelatin. Different ratio of gelatin / CNC hydrogel was produced in order to study the effects of CNC towards the swelling behaviour of hydrogel at different pH and temperature. Swelling tests were performed at different pH range from pH 3 to pH 11. Temperature swelling tests were performed at 25 °C and 37 °C. The hydrogel showed impressive pH sensitivity and maximum swelling was obtained at pH 3. Higher swelling ratio was observed at higher temperature. SEM micrographs showed that the pore size of hydrogel decreased with increasing CNC content due to formation of more rigid hydrogel structure. The characteristics of the hydrogel to respond to different pH and temperature suggest that gelatin / CNC hydrogel are promising candidates to be developed as drug carrier.

Yin, Ooi Shok; Ahmad, Ishak; Amin, Mohd. Cairul Iqbal Mohd

2014-09-01

184

76 FR 39156 - C&NC Railroad, LLC-Lease Renewal Exemption-Norfolk Southern Railway Company  

Federal Register 2010, 2011, 2012, 2013, 2014

...payments by receiving a credit for each car interchanged with NSR. C&NC notes that NSR initially proposed a fixed rental payment with no option to reduce the...opportunity for C&NC to earn a lower rental payment so it would be able to...

2011-07-05

185

**Notice of Job Opportunity: Reynolds Manufacturing Company ** Reynolds Manufacturing company is looking for a CNC Programmer and Set up person. For details see  

E-print Network

Programmer and Set up person. Candidates must have experience in operating CNC lathes and mills. Other requirements involve setting up and programming CNC lathes and mills. Must have experience in using SolidCam from prints or models. Document set up sheets and perform set ups on CNC lathes and mills. Email

Saniie, Jafar

186

9th Biannual Joint Technical Day of CIE/USA and CNC/CIE, Davis, CA, 7 Nov. 2013 Improving Traceability of  

E-print Network

9th Biannual Joint Technical Day of CIE/USA and CNC/CIE, Davis, CA, 7 Nov. 2013 Improving/CIE and CNC/CIE Technical Day 7 November 2013 Joanne Zwinkels, William Neil and Mario Noël Measurement Science and Standards National Research Council of Canada #12;9th Biannual Joint Technical Day of CIE/USA and CNC

California at Davis, University of

187

INT. J. PROD.RES.,2000, VOL.38, NO. 7, 1677 1687 CNC tool path planning for multi-patch sculptured surfaces  

E-print Network

INT. J. PROD.RES.,2000, VOL.38, NO. 7, 1677± 1687 CNC tool path planning for multi-patch sculptured surfaces J. H. CHO{, J. W. KIM{ and K. KIM}* A new CNC tool path generation method for a multi representation methods in the CAD system, the next step is to obtain CNC tool paths (CL ® le) for the given

Kim, Jongwon

188

An iterative learning control method with application for CNC machine tools  

SciTech Connect

A proportional, integral, and derivative (PID) type iterative learning controller is proposed for precise tracking control of industrial robots and computer numerical controller (CNC) machine tools performing repetitive tasks. The convergence of the output error by the proposed learning controller is guaranteed under a certain condition even when the system parameters are not known exactly and unknown external disturbances exist. As the proposed learning controller is repeatedly applied to the industrial robot or the CNC machine tool with the path-dependent repetitive task, the distance difference between the desired path and the actual tracked or machined path, which is one of the most significant factors in the evaluation of control performance, is progressively reduced. The experimental results demonstrate that the proposed learning controller can improve machining accuracy when the CNC machine tool performs repetitive machining tasks.

Kim, D.I.; Kim, S. [Samsung Electronics, Suwon (Korea, Republic of)

1996-01-01

189

The in-situ 3D measurement system combined with CNC machine tools  

NASA Astrophysics Data System (ADS)

With the development of manufacturing industry, the in-situ 3D measurement for the machining workpieces in CNC machine tools is regarded as the new trend of efficient measurement. We introduce a 3D measurement system based on the stereovision and phase-shifting method combined with CNC machine tools, which can measure 3D profile of the machining workpieces between the key machining processes. The measurement system utilizes the method of high dynamic range fringe acquisition to solve the problem of saturation induced by specular lights reflected from shiny surfaces such as aluminum alloy workpiece or titanium alloy workpiece. We measured two workpieces of aluminum alloy on the CNC machine tools to demonstrate the effectiveness of the developed measurement system.

Zhao, Huijie; Jiang, Hongzhi; Li, Xudong; Sui, Shaochun; Tang, Limin; Liang, Xiaoyue; Diao, Xiaochun; Dai, Jiliang

2013-06-01

190

X-ray observations through the outburst cycle of the dwarf nova YZ Cnc  

E-print Network

We have observed YZ Cnc at two day intervals from 6 to 24 April 1998, covering two full outburst cycles. The 0.1-2.4 keV flux is lower during optical outburst than in quiescence, and lowest at the end of the outburst. The decline of the X-ray flux in the quiescent interval appears to be in contrast to prediction of simple models for accretion-disk instabilities. Variability on \\~hour time scales is present, but appears not related to the orbital phase. YZ Cnc was less luminous in X-rays during our 1998 observations than in earlier ROSAT observations.

Frank Verbunt; Peter J. Wheatley; Janet A. Mattei

1999-03-15

191

Radio emission of cataclysmic variable stars  

NASA Technical Reports Server (NTRS)

Eight cataclysmic variable stars were observed at 6 cm wavelength using the Very Large Array (VLA). The objects were: CN-Ori, SS-Aur, YZ-Cnc, SU-Uma, Z-Cam, V603-Aql, EM-Cyg, and RZ-Sge. Most of these objects were in optical high stage, but none were detected beyond flux limits between 0.1 and 0.3 mJy.

Fuerst, E.; Benz, A.; Hirth, W.; Geffert, M.; Kiplinger, A.

1986-01-01

192

s rsrt r t rs Pstr5  

E-print Network

rs t tr trsrt s t t t r t rs sr r t s st t t r s sss t t Pr ttt rss s t rr rs trsrt r trs rt s ss rs t rss s rst t s r t t rss s trsrt sr trsr trt t s t t t s t rsts t trsrt rs r t tt trsr r t t sr t t r t t trt t r rss r t s strt ts st t rst t r t ss

Paris-Sud XI, Université de

193

MM Herculis - An eclipsing binary of the RS CVn  

NASA Technical Reports Server (NTRS)

V, B and U differential photoelectric photometry has been obtained for the RS Canum Venaticorum-class eclipsing binary star MM Her, with the light outside the eclipse being Fourier-analyzed to study wave migration and amplitude. These, together with the mean light level of the system, have been monitored from 1976 through 1980. Observations within the eclipse have revealed eclipses to be partial, rather than total as previously thought. The geometric elements of the presently rectified light curve are forced on the pre-1980 light curves and found to be compatible. With these elements, and previously obtained double line radial velocity curves, new absolute dimensions of 1.18 solar masses and 1.58 solar radii are calculated for the hotter star and 1.27 solar masses and 2.83 solar radii for the cooler star. The plotting of color indices on the color-color curve indicates G2V and K2IV spectral types.

Sowell, J. R.; Hall, D. S.; Henry, G. W.; Burke, E. W., Jr.; Milone, E. F.

1983-01-01

194

RS-232 Data Diode Tutorial and Reference Manual  

E-print Network

RS-232 Data Diode Tutorial and Reference Manual DRAFTDRAFTDRAFTDRAFTDRAFTDRAFTDRAFTDRAFTDRAFTDRAFT-232 Data Diode . . . . . . 1 Cables . . . . . . . . . . 2 Signal Definitions for the DB9 RS-232 the RS-232 Data Diode . . . . . . . 5 The RS-232 Data Diode Transmitter . . . . . . 6 Transmitter

Jones, Douglas W.

195

A Large Millimeter Flare on the RS CVn Binary ? Geminorum  

NASA Astrophysics Data System (ADS)

The flaring behavior of active RS CVn binaries has been studied extensively at centimeter wavelengths, but very little has been published concerning RS CVn flares in the millimeter region, where the nonthermal gyrosynchrotron emission is much more likely to be optically thin. We present 3 mm (99 GHz) observations of a large flare on the active binary ? Gem using the Owens Valley Millimeter Array. Two 3 hr observations in 2004 February showed only 3 ? upper limits of 3 mJy, while the third observation on 2004 April 22 showed a large flare outburst that filled the 6 hr observation and reached a peak flux density of 90 mJy. The strongest brightening was preceded by at least a 4 hr period of significantly elevated emission at 20-40 mJy. These observations demonstrate the feasibility of detailed multifrequency studies of nonthermal electron distributions in active star coronae with the next generation of millimeter and centimeter radio arrays.

Brown, Joanna M.; Brown, Alexander

2006-02-01

196

Emisión H? en sistemas binarios cromosféricamente activos (RS CVn y BY Dra)  

NASA Astrophysics Data System (ADS)

We report here high and medium resolution Balmer H? line profiles for 11 chromospherically active binary systems including the class of RS Canum Venaticorum binaries (RS CVn) and BY Draconis (BY Dra) with a total range of rotation periods from 0.8 to 24 days. We have obtained different types of H? line profiles: strong emission line, weak emission line with strong superposed absorption profile and filled-in absorption line profile. We have measured the H? equivalent width of the program stars and the H? core emission was determined by subtraction of the equivalent width of a presumably inactive star with the same spectral type and luminosity class.

Fernández-Figueroa, M. J.; Montes, D.; de Castro, E.

1992-05-01

197

White Dwarfs in Binary Systems A white dwarf orbiting another star can become active  

E-print Network

White Dwarfs in Binary Systems A white dwarf orbiting another star can become active when the other becomes incandescent. #12;H and He from the companion build up on the white dwarf's surface. Classical. Explosions from White Dwarf Star RS Oph #12;Classical Novae: RS Ophiuci Recurrent Nova RS Ophiuci Explosions

Barnes, Joshua Edward

198

Rotational modulation and flares on RS CVn and BY Dra-type stars. I - Photometry and spot models for BY Dra, AU Mic, AR Lac, II Peg and V 711 Tau (= HR 1099)  

NASA Technical Reports Server (NTRS)

Multicolor wide-band photometry of five active stars is presented. The observations were carried out at several places before, during and after the period of IUE observations for the purpose of determining the location, sizes, and evolution of photospheric spots at the time when chromospheric, transition region, and coronal activity data were obtained from UV and radio observations. II Peg, BY Dra, and AU Mic show fairly stable quasi-sinusoidal light curves, while AR Lac and V 711 Tau show double-peaked light curves. For V 711 Tau, a remarkable evolution of the spotted area extent and/or longitude distribution is found. Small, but definite color variations that are consistent with the cool spot hypothesis have also been detected for BY Dra, II Peg and V 711 Tau.

Rodono, M.; Cutispoto, G.; Pazzani, V.; Catalano, S.; Byrne, P. B.

1986-01-01

199

Delta Scuti stars in the Praesepe cluster observed by the MOST satellite  

NASA Astrophysics Data System (ADS)

The Praesepe cluster contains a number of ? Sct and ? Dor pulsators. Asteroseismology of cluster stars is simplified by the common distance, age and stellar abundances. Since asteroseismology requires a large number of known frequencies, the small pulsation amplitudes of these stars require space satellite campaigns. The present study utilizes photometric MOST satellite measurements in order to determine the pulsation frequencies of two evolved (EP Cnc, BT Cnc) and two main-sequence (BS Cnc, HD 73872) ? Sct stars in the Praesepe cluster. The frequency analysis of the 2008 and 2009 data detected up to 34 frequencies per star with most amplitudes in the submillimag range. In BS Cnc, two modes showed strong amplitude variability between 2008 and 2009. The frequencies ranged from 0.76 to 41.7 cd-1. After considering the different evolutionary states and mean stellar densities of these four stars, the differences and large ranges in frequency remain. Based on data from the MOST satellite, a Canadian Space Agency mission, jointly operated by Dynacon Inc., the University of Toronto Institute for Aerospace Studies and the University of British Columbia with the assistance of the University of Vienna.

Breger, M.; Hareter, M.; Endl, M.; Kuschnig, R.; Weiss, W. W.; Matthews, J. M.; Guenther, D. B.; Moffat, A. F. J.; Rowe, J. F.; Rucinski, S. M.; Sasselov, D.

2012-02-01

200

Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)  

NASA Astrophysics Data System (ADS)

The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat; Amin, Mohd. Cairul Iqbal Mohd

2014-09-01

201

Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)  

SciTech Connect

The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat [Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Amin, Mohd. Cairul Iqbal Mohd [Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

2014-09-03

202

Design and manufacture of a CNC desktop lathe for use in a project-based class  

E-print Network

The objective of this project is to evolve the design of a CNC desktop lathe for use in a project-based class and then fabricate a prototype to confirm the functionality of the design. This iteration of the lathe effectively ...

Hsieh, Jonathan C

2008-01-01

203

Basic CNC Operation. Training Workbook [and] Assessment and Training Guide [and] Hands-on Assessment.  

ERIC Educational Resources Information Center

This workbook is intended for students taking a course in basic computer numerical control (CNC) operation that was developed during a project to retrain defense industry workers at risk of job loss or dislocation because of conversion of the defense industry. The workbook contains daily training guides for each of the course's 13 sessions. Among…

Anoka-Hennepin Technical Coll., Minneapolis, MN.

204

Technical and Symbolic Knowledge in CNC Machining: A Study of Technical Workers of Different Backgrounds.  

ERIC Educational Resources Information Center

Performances of 45 individuals with varying degrees of formal and informal training in machining and programming were compared on tasks designed to tap intellectual changes that may occur with the introduction of computer numerical control (CNC). Participants--30 machinists, 8 machine operators, and 7 engineers--were asked background questions and…

Martin, Laura M. W.; Beach, King

205

CNC Turning Center Operations and Prove Out. Computer Numerical Control Operator/Programmer. 444-334.  

ERIC Educational Resources Information Center

This student guide provides materials for a course designed to instruct the student in the recommended procedures used when setting up tooling and verifying part programs for a two-axis computer numerical control (CNC) turning center. The course consists of seven units. Unit 1 discusses course content and reviews and demonstrates set-up procedures…

Skowronski, Steven D.

206

Virtual Training Centre For CNC: a Sample Virtual Training Environment Mehmet Sahin1  

E-print Network

Virtual Training Centre For CNC: a Sample Virtual Training Environment Mehmet Sahin1 , Süleyman bilalis@dpem.tuc.gr Abstract It is a fact that virtual training has been a scope of interest for vocational training for a very long time. However, it needs more time to be more common in all specific

Aristomenis, Antoniadis

207

Computer-aided optimization of multi—pass turning operations for continuous forms on CNC lathes  

Microsoft Academic Search

The Computer Numerical Control (CNC) machine is one of the most effective production facilities used in manufacturing industry. Determining the optimal machining parameters is essential in the machining process planning since the machining parameters significantly affect production cost and quality of machined parts. Previous studies involving machining optimization of turning operations concentrated primarily on developing machining models for bar components.

CHAO-TON SU; MU-CHEN CHEN

1999-01-01

208

Monitoring the wear of cutting tools in CNC-lathes with artificial neural networks  

Microsoft Academic Search

One of the most important tasks of automatic tool monitoring systems for CNC-lathes is the supervision of a tool's wear. Considering the state of wear and the actual working process (e.g. rough or finish turning) it is possible to exchange a tool (or only the insert) just in time, which offers significant economic advantages. This paper presents a new method

Bernhard Sick; W. Grass

1997-01-01

209

A study of backlash on the motion accuracy of CNC lathes  

Microsoft Academic Search

In this paper, an analytical solution is reported to explain the experimentally observed backlash behaviors on the motion accuracy of CNC lathes. It is found that backlash occurs when the feed direction is reversed. Due to the imperfect transient response of the driving mechanism, not only the static backlash error but also the dynamic backlash error is generated on the

J. Y. Kao; Z. M. Yeh; Y. S. Tarng; Y. S. Lin

1996-01-01

210

Real-Time, CNC Machine Tool Control with Linux: A Senior Design Project at MUSE  

Microsoft Academic Search

As machine tools age and their existing controllers fail, the machine tools must be either modernized or scrapped. This paper details the infusion of new technology and the resulting extended useful life of a computer numerical controlled (CNC) tabletop lathe. This work was undertaken as a senior design project by a group of senior engineers at Mercer University School of

Tie Duan; Ronnie Baroud; Daniel Amato; Albert LaRoe

211

Hydraulic Micro-feed Actuator for Precision Machining on Conventional CNC Turning Centers  

Microsoft Academic Search

In order to improve the current precision of machining, a hydraulic micro-feed actuator for precision turning used in lathe or conventional CNC turning centers is introduced and the design formulas of important structure are given. The characteristics of the actuator such as displacement, natural frequency, cutting are researched by using the finite element analysis and experimental methods. The results show

Wang Shu-lin; Chen Xing-hua; Liu Gang; Li Zun-dong

2010-01-01

212

Data acquisition and monitoring in machine tools with CNC of open architecture using internet  

Microsoft Academic Search

This paper presents a proposed system for data acquisition and monitoring of manufacturing process in machine tools with CNC of open architecture, using the Internet. It was applied to evaluate workpiece dimension and, indirectly, tool wear, as well as sharing shop floor information, in real time, in any place through Intranet and\\/or Internet, aiding the whole integration of the manufacturing

F. Ferraz Jr; R. T. Coelho

2005-01-01

213

Real time monitoring of input force for high speed power chucks used in CNC Lathes  

Microsoft Academic Search

It is very important to monitor the chucking condition of the power chucks for safety consideration in CNC Lathes, especially high speed lathes. Measuring the pressure of the oil supplied to the rotary cylinder is a widely used method to monitor the input force of the power chuck. This paper proposes a direct input force measuring method for real time

Cheng Zhou; Huayong Yang; Likui Yang

2010-01-01

214

Development of a low cost Touch Trigger Probe for CNC Lathes  

Microsoft Academic Search

The use of Touch Trigger Probes for CNC Machine Tools has become a world standard, mainly due to the reduction of machine setup time and the ability to promote workpiece accuracy on-machine measurements. However, some barriers still need to be transposed, like the measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about

Marcelo Del Guerra; Reginaldo Teixeira Coelho

2006-01-01

215

Repetitive control and its application to linear servo unit for CNC machining of elliptical pistons  

Microsoft Academic Search

In this paper, the basic theory of repetitive control are summarized and modified repetitive controllers are introduced. The steady-state error and asymptotic stability condition are presented. A CNC precision lathe implemented with the repetitive control system for machining elliptical pistons is constructed, which consists of a precision linear servomechanism, computer controlled repetitive controller and machine-tool. The cutting tool driven directly

Huixing Zhoul; Linna Zhang; Xiankui Wangl; Jinling Liu

1996-01-01

216

Computer-aided optimization of multi-pass turning operations for continuous forms on CNC lathes  

Microsoft Academic Search

The Computer Numerical Control (CNC) machine is one of the most effective production facilities used in manufacturing industry. Determining the optimal machining parameters is essential in the machining process planning since the machining parameters significantly affect production cost and quality of machined parts. Previous studies involving machining optimization of turning operations concentrated primarily on developing machining models for bar components.

CHAO-TON Su; MU-CHEN Chen

1999-01-01

217

A new type of machine control system to replace traditional CNC  

Microsoft Academic Search

This paper discusses the rationale behind a new form of machine tool control system which has been developed at the Key Centre for Computer Integrated Manufacture (CIM Centre) in Melbourne Australia. The new control system is based upon standard computer hardware and is intended as a replacement for computer numerical control (CNC), which has severe limitations in the CIM environment.

Andrew M. Luscombe; Dario J. Toncich; William Thompson; Richard Dluzniak

1994-01-01

218

Statistical optimization and assessment of a thermal error model for CNC machine tools  

Microsoft Academic Search

The objective of a thermal error compensation system for CNC machine tools is improved machining accuracy through real time error compensation. The compensation capability depends on the accuracy of the thermal error model. A thermal error model can be obtained using an appropriate combination of temperature variables. In this study, the thermal error modeling is based on a correlation grouping

Jin-Hyeon Lee; Seung-Han Yang

2002-01-01

219

Development of a high-speed CNC cutting machine using linear motors  

Microsoft Academic Search

The traditional approach to construct CNC machine tools has been to use rotary drive motors and ballscrews to achieve table motion. Linear motors offer several advantages over this approach, including low inertia, better performance, increased accuracy and reduced complexity. This article describes how a low cost, high-speed cutting machine was built using linear motors in order to conduct machining tests

Seamus Gordon; Michael T. Hillery

2005-01-01

220

High speed CNC system design. Part II: modeling and identification of feed drives  

Microsoft Academic Search

Accurate modeling and identification of the feed drives' dynamics is an important step in designing a high performance CNC. This paper presents a method for identifying the dynamic parameters, as well as the friction characteristics of machine tool drives. The inertia and viscous friction are estimated through an unbiased least squares scheme. The friction model is developed by observing the

Kaan Erkorkmaz; Yusuf Altintas

2001-01-01

221

CCD Photometric Study of the Contact Binary TX Cnc in the Young Open Cluster NGC 2632  

E-print Network

TX Cnc is a member of the young open cluster NGC 2632. In the present paper, four CCD epochs of light minimum and a complete V light curve of TX Cnc are presented. A period investigation based on all available photoelectric or CCD data showed that it is found to be superimposed on a long-term increase ($dP/dt=+3.97\\times{10^{-8}}$\\,days/year), and a weak evidence suggests that it includes a small-amplitude period oscillation ($A_3=0.^{d}0028$; $T_3=26.6\\,years$). The light curves in the V band obtained in 2004 were analyzed with the 2003 version of the W-D code. It was shown that TX Cnc is an overcontact binary system with a degree of contact factor $f=24.8%(\\pm0.9%)$. The absolute parameters of the system were calculated: $M_1=1.319\\pm0.007M_{\\odot}$, $M_2=0.600\\pm0.01M_{\\odot}$; $R_1=1.28\\pm0.19R_{\\odot}$, $R_2=0.91\\pm0.13R_{\\odot}$. TX Cnc may be on the TRO-controlled stage of the evolutionary scheme proposed by Qian (2001a, b; 2003a), and may contains an invisible tertiary component ($m_3\\approx0.097M_{\\o...

Liang, Liu; Soonthornthum, BOONRUCKSAR; Liying, Zhu; Jiajia, He; Yuan, J -Z

2011-01-01

222

A comprehensive method for calibration of volumetric positioning accuracy of CNC-machines  

Microsoft Academic Search

A comprehensive method for measuring the systematic errors of CNC-machine tools has been studied. The method used for measurement and calibration of machine tool errors should be general and efficient. The objectives of this study include:1.Volumetric error modelling.2.Experimental procedure for error measurement.3.A tool position and path compensation method.4.The verification method.

Eung-Suk Leer; Suk-Hwan Suh; Jin-Wook Shon

1998-01-01

223

A real-time NURBS surface interpolator for precision three-axis CNC machining  

Microsoft Academic Search

Due to the fact that the cutting occurs around the cutter contact (CC) point, the efficiency and quality of CNC machining can be improved significantly if the CC velocity along the surface is kept costant. Conventional approaches to machining mainly maintain a constant cutter location (CL) velocity, so that the CC velocity along the surface is often not constant and

M.-C. Tsai; C.-W. Cheng; M.-Y. Cheng

2003-01-01

224

An iterative learning control method with application for CNC machine tools  

Microsoft Academic Search

A proportional, integral, and derivative (PID) type iterative learning controller is proposed for precise tracking control of industrial robots and computer numerical controller (CNC) machine tools performing repetitive tasks. The convergence of the output error by the proposed learning controller is guaranteed under a certain condition even when the system parameters are not known exactly and unknown external disturbances exist.

Dong-Il Kim; Sungkwun Kim

1996-01-01

225

A real-time scheme of cubic parametric curve interpolations for CNC systems  

Microsoft Academic Search

In this paper, the popular finite forward differencing algorithm for fast evaluation of points on a cubic parametric curve is modified for its application to CNC systems so that the inherent accumulative error in the calculation of one piece of curve will not propagate to the whole composite curve. Using specified tolerances, a computationally non-intensive method of analysis for the

Behnam Bahr; Xiaomao Xiao; Krishnan Krishnan

2001-01-01

226

Integration and diversity of the regulatory network composed of Maf and CNC families of transcription factors  

Microsoft Academic Search

Recent progress in the analysis of transcriptional regulation has revealed the presence of an exquisite functional network comprising the Maf and Cap ’n’ collar (CNC) families of regulatory proteins, many of which have been isolated. Among Maf factors, large Maf proteins are important in the regulation of embryonic development and cell differentiation, whereas small Maf proteins serve as obligatory heterodimeric

Hozumi Motohashi; Tania O'Connor; Fumiki Katsuoka; James Douglas Engel; Masayuki Yamamoto

2002-01-01

227

Computer-aided accuracy enhancement for multi-axis CNC machine tool  

Microsoft Academic Search

A computer-aided error compensation scheme has been developed to enhance the accuracy of multi-axis CNC machine tools by compensating for machine geometric and thermal errors in software way. Stationary geometric errors including the coupling effect of linkage errors between machine slides are calibrated off line. Dynamic thermal errors are predicted on line by an artificial neural network model. Because machine

Jenq-Shyong Chen

1995-01-01

228

Frame based system combination and a comparison with weighted ROVER and CNC  

Microsoft Academic Search

In this paper we present a novel ASR system combination technique able to combine systems producing word graphs of dif- ferent structure and with different segmentations. The new method is based on the definition of a time frame-wise word error cost function in a minimum Bayes risk framework. In contrast to confusion network combination (CNC), it preserves both the word

Björn Hoffmeister; Tobias Klein; Ralf Schlüter; Hermann Ney

2006-01-01

229

Temperature control and machine dynamics in chip breaking using CNC toolpaths  

Microsoft Academic Search

The use of oscillating CNC toolpaths has been shown to provide a reliable chip breaking alternative to conventional methods. This paper builds on that work by assessing the effect of the oscillating toolpaths on the temperature during the cutting process. Keeping the interface temperature below a critical threshold reduces tool wear. This is particularly useful for machining in difficult materials

S. Smith; B. Woody; W. Barkman; D. Tursky

2009-01-01

230

Improved precision on the radius of the nearby super-Earth 55 Cnc e  

E-print Network

We report on new transit photometry for the super-Earth 55?Cnc?e obtained with Warm Spitzer/IRAC at 4.5 ?m. An individual analysis of these new data leads to a planet radius of [superscript 2.21]+0.15 [over] -0.16 R[subscript ...

Gillon, M.

231

X-ray spectra and the rotation-activity connection of RS Canum Venaticorum binaries  

NASA Astrophysics Data System (ADS)

Results are presented from a survey of RS CVn binaries which were observed with the imaging proportional counter (IPC) on board the Einstein Observatory. Spectral analyses of the IPC pulse height spectra show that the coronae of RS CVn binaries always contain hot gas with temperatures in excess of 10 to the 7th K, similar to active late-type main-sequence stars, and that at least two temperature components are necessary to account for the higher quality IPC spectra (when absorption is unimportant). It is argued that these bimodal temperature distributions found by the IPC are indicative of true distributions of emission measure versus temperature that are continuous (just as is the case of magnetically confined coronal plasma loops observed on the sun). It is further shown that none of the derivable X-ray characteristics of RS CVn binaries depend on rotation period, implying that previous claims of period-activity relationships in RS CVn binaries were unfounded.

Majer, P.; Schmitt, J. H. M. M.; Golub, L.; Harnden, F. R., Jr.; Rosner, R.

1986-01-01

232

Stick-slip mechanism study of CNC heavy-duty horizontal lathe feed systems based on dynamics  

Microsoft Academic Search

—When CNC heavy-duty horizontal lathe feed systems is running at a low velocity, the stick-slip phenomenon will be introduced. The stick-slip phenomenon will seriously affect the working accuracy, work piece surface roughness and position accuracy. In this paper, structural characteristic of the feed system of CNC heavy-duty horizontal lathe is analyzed and gear rotor systems dynamics is applied to study

Peilin Yang; Wanli Zheng; Shuzhuang Hao; Kun Chen

2011-01-01

233

Facile synthesis of CNC-MnO2 hybrid as a supercapacitor electrode  

NASA Astrophysics Data System (ADS)

A facile and efficient hydrothermal approach has been developed to synthesize three dimensional hybrid of manganese dioxide (MnO2) and carbon nanocoils (CNCs) as a kind of electrode materials for supercapacitors. This hybrid is prepared by anchoring uniformly porous MnO2 nanowiskers over the surface of CNCs. The electrochemical properties of CNC-MnO2 electrode have been measured by a three electrode configuration, which exhibits high specific capacitance with values up to 387 F/g at a scan rate of 10 mV/s and good cycling stability. These results suggest that the CNC-MnO2 hybrid is comparable or superior to other carbon-based materials coated with MnO2 nanowiskers.

Su, Deqiao; Pan, Lujun; Fu, Xin; Ma, He

2015-01-01

234

Research on efficient and stable milling using CNC small size tool  

NASA Astrophysics Data System (ADS)

In order to mill efficiently and stably using small size tool on computer numerical control machine(CNC machine), the paper establishes dual-objective function on the basis of the minimum tool wear and the largest cutting efficiency. Meanwhile, the influence of diameter and length of tool suspended on stability is considered under the guidance of chatter stability analysis relationship. Research results show that, Pareto solution set which has two factors into account conflicting can be obtained by Genetic Algorithms, combined Pareto solution set with the frequency response function (FRF) chatter stability diagram, Pareto solutions of the smaller range of options, the milling parameters which meet the requirements of efficient and stable milling of CNC machine tools can be optimized conveniently and accurately. When the tool suspended length increases, the system stiffness decreases and the chatter stability domain graphic drops down, Stability region narrows.

Luo, Yongxin; Zhao, Beichen; Long, Hua; Yu, Nanlin

2010-12-01

235

Research on efficient and stable milling using CNC small size tool  

NASA Astrophysics Data System (ADS)

In order to mill efficiently and stably using small size tool on computer numerical control machine(CNC machine), the paper establishes dual-objective function on the basis of the minimum tool wear and the largest cutting efficiency. Meanwhile, the influence of diameter and length of tool suspended on stability is considered under the guidance of chatter stability analysis relationship. Research results show that, Pareto solution set which has two factors into account conflicting can be obtained by Genetic Algorithms, combined Pareto solution set with the frequency response function (FRF) chatter stability diagram, Pareto solutions of the smaller range of options, the milling parameters which meet the requirements of efficient and stable milling of CNC machine tools can be optimized conveniently and accurately. When the tool suspended length increases, the system stiffness decreases and the chatter stability domain graphic drops down, Stability region narrows.

Luo, Yongxin; Zhao, Beichen; Long, Hua; Yu, Nanlin

2011-05-01

236

An Upper Limit to the Mass of rho1 Cnc's Radial Velocity Companion  

E-print Network

Doppler spectroscopy of rho1 Cnc has detected evidence of a companion with an orbital period of 14.65 days and a minimum mass of 0.88 Jupiter masses. Astrometric observations performed with the Hubble Space Telescope Fine Guidance Sensor 1r using a novel new observing technique have placed an upper limit on the astrometric reflex motion of rho1 Cnc in a time period of only one month. These observations detected no reflex motion induced by the 14.65 day period radial velocity companion, allowing us to place a 3-sigma upper limit of \\~0.3 milliarcseconds on the semi-major axis of this motion, ruling out the preliminary Hipparcos value of 1.15 milliarcseconds. The corresponding upper limit on the true mass of the companion is ~30 Mj, confirming that it is a sub-stellar object.

Melissa A. McGrath; Edmund Nelan; David C. Black; George Gatewood; Keith Noll; Al Schultz; Stephen Lubow; Inwoo Han; Tomasz F. Stepinski; Thomas Targett

2001-12-03

237

Chatter prediction based on frequency domain solution in CNC pocket milling  

Microsoft Academic Search

Chatter has been a problem in CNC machining process especially during pocket milling process using an end mill with low stiffness.\\u000a Since an iterative time-domain chatter solution consumes a computing time along tool paths, a fast chatter prediction algorithm\\u000a for pocket milling process is required by machine shop-floor for detecting chatter prior to real machining process. This paper\\u000a proposes the

Jeong Hoon Ko; Kah Chuan Shaw

2009-01-01

238

Spiral tool-path generation with constant scallop height for sheet metal CNC incremental forming  

Microsoft Academic Search

A spiral tool-path generation method with constant scallop height for the sheet metal CNC incremental forming was proposed\\u000a based on triangular mesh model. On the basis of the curvatures estimation of triangular mesh model, the calculation method\\u000a of spiral tool-path interval with constant scallop height was discussed. Moreover, the algorithms for generation of spiral\\u000a drive path using the polygon boundary

Hu Zhu; Zhijun Liu; Jianhui Fu

2011-01-01

239

Estimation of the cutting torque without a speed sensor during CNC turning  

Microsoft Academic Search

In this paper, the cutting torque of a CNC machine tool during machining is monitored through the internet. To estimate the\\u000a cutting torque precisely, the spindle driving system is divided into two parts: electrical induction motor part and mechanical\\u000a part. A magnetized current is calculated from the measured three-phase stator currents and used for the total torque estimation\\u000a generated by

Won Tae Kwon; Ik jun Hong

2005-01-01

240

Research on remote intelligent fault-diagnosis of CNC lathe based on bayesian networks  

Microsoft Academic Search

Considering the development of smart machine tools and Internet-based manufacturing and in order to manage the manufacturing process more efficiently, a unit of remote intelligent fault-diagnosis based on Bayesian Networks (BN) was designed and software based on internet was realized as well as the case study concerning CNC lathe. It is a compensation of machine tool's self-detection whose major job

Yuchun Li; Jianzhong Fu; Xinhua Yao; Jiao Huifeng

2010-01-01

241

Knife-Edge Scanning Microscope Using an Ultra-Precision 3Axis CNC Diamond Turning Lathe  

Microsoft Academic Search

A knife-edge scanning microscope (KESM) is comprised of three components: (1) a precision CNC (computer numerical controlled) nanomachining system, which uses a diamond knife to section a workpiece containing plastic-embedded tissue, such as small-animal brains; (2) an image capture system, for imaging newly cut tissue as it passes over the edge of the knife and is concurrently imaged in turn

Bruce H. McCormick; Marian Wiercigroch; David Mayerich

2005-01-01

242

System integrated product design, CNC programming and postprocessing for three-axis lathes  

Microsoft Academic Search

New three-axis CNC turning machines have been installed on shop floors of factories in the last few years. Although the machines are still particularly adapted to cylindrical work, they are also used for non-cylindrical machining. The third axis, C or Y, and separately driven, additional milling cutters have eliminated traditional limitations and opened new machining possibilities, i.e. turning and milling

Stanislaw Zietarski

2001-01-01

243

Computer-based estimation and compensation of diametral errors in CNC turning of cantilever bars  

Microsoft Academic Search

This paper aims to introduce a computer-based estimation and compensation method for diametral errors in cantilever bar turning\\u000a without additional hardware requirements. In the error estimation method, the error characteristics of workpieces are determined\\u000a experimentally depending on cutting speed, depth of cut, feed rate, workpiece diameter, length from the chuck and the geometric\\u000a error sum of CNC lathe. An Artificial

Eyüp Sabri Topal; Can Ço?un

244

Contour machining of free-form surfaces with real-time PH curve CNC interpolators  

Microsoft Academic Search

Two strategies for contour milling of free-form surfaces, using real-time CNC interpolators for Pythagorean-hodograph (PH) curves, are described. The first method, applicable to convex surfaces, employs a flat-end mill and approximates the surface section curves by planar PH quintics. The second approach, which employs a ball-end mill, approximates the tool-center trajectory by quintic PH space curves, and can accommodate nonconvex

Rida T. Farouki; Yi-feng Tsai; Guo-feng Yuan

1999-01-01

245

Comparison between predicted and actual accuracies for an Ultra-Precision CNC measuring machine  

SciTech Connect

At the 1989 CIRP annual meeting, we reported on the design of a specialized, ultra-precision CNC measuring machine, and on the error budget that was developed to guide the design process. In our paper we proposed a combinatorial rule for merging estimated and/or calculated values for all known sources of error, to yield a single overall predicted accuracy for the machine. In this paper we compare our original predictions with measured performance of the completed instrument.

Thompson, D.C.; Fix, B.L.

1995-05-30

246

Real-time generation and control of cutter path for 5-axis CNC machining  

Microsoft Academic Search

This paper presents a new approach to real-time generation and control of the cutter path for 5-axis machining applications. The cutter path generation method comprises real-time algorithms for cutter-contact path interpolation, cutter offsetting, and coordinate conversion. In addition, a global feedback loop is closed by the CNC interpolator so as to augment the controlled accuracy in practical cutter path generation.

Chih-Ching Lo

1999-01-01

247

Five-axis CNC milling for effective machining of sculptured surfaces  

Microsoft Academic Search

In machining of sculptured surfaces on five-axis CNC milling machines, determination of the direction vector of the milling cutter is very important. The direction vector is obtained from the fact that the bottom part of the milling cutter rides on free-form surfaces using a z-map method, and this can be applied to all geometric types of sculptured surfaces. After generating

H. D. CHO; Y. T. JUN; M. Y. YANG

1993-01-01

248

STEP-compliant CNC system for turning: Data model, architecture, and implementation  

Microsoft Academic Search

STEP-NC, a new data model for CAD–CAM–CNC chain, is expected to encompass the whole scope of e-manufacturing. The new data model formalized as ISO 14649 is under development by ISO TC184 SC1 and SC4 for the replacement of the old standard so-called G&M codes, formalized as ISO 6983 which has been used since the 1950s. As the new data model

Suk-hwan Suh; Dae-hyuck Chung; Byeong-eon Lee; Seungjun Shin; Injun Choi; Kwang-myung Kim

2006-01-01

249

Performance analysis of CNC interpolators for time-dependent feedrates along PH curves  

Microsoft Academic Search

Virtually any desired time variation V(t) of the feedrate along a curved path can be realized by real-time CNC interpolator algorithms for the Pythagorean-hodograph (PH) curves: the only stipulation is that V(t) should admit a closed-form indefinite integral F(t). Different feedrate variations V(t) can be accommodated with minimal modifications to the core algorithm by employing a modular function call to

Yi-feng Tsai; Rida T. Farouki; Bryan Feldman

2001-01-01

250

Thread milling on N/C and CNC milling machines. Final report  

SciTech Connect

A unique thread-cutting tool design has been developed which permits threading of internal or external features; right- or left-hand threads; and standard, metric, or special pitches within a given size range without changing tools. One of the major advantages of the technique is the ability to produce small threads on N/C and CNC milling manchines. This study presents results showing fabrication of quality threads as small as number 0-80 in selected materials.

Ashbaugh, F.A.; Murry, K.R.

1985-12-01

251

Exact Taylor series coefficients for variable-feedrate CNC curve interpolators  

Microsoft Academic Search

Abstract Recent papers [Yang DCH, Kong T. Computer Aided Design 1994;26:225?34; Yeh S-S, Hsu P-L. Computer Aided Design 1999;31:349? 57] formulate real-time CNC interpolators for variable feedrates along parametric curves. These interpolators employ,truncated Taylor series to compute successive reference-point parameter values, but in both papers an erroneous coefficient for the highest (quadratic) term is cited. The derivation of the proper

Rida T. Farouki; Yi-feng Tsai

2001-01-01

252

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

Microsoft Academic Search

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel

Yunn-Shiuan Liao; Shun-Tong Chen; Chang-Sheng Lin

2005-01-01

253

VLT Phase Resolved Optical Spectroscopy of the Ultra-Compact Binary HM Cnc  

E-print Network

A 321.5 s modulation was discovered in 1999 in the X-ray light curve of HM Cnc. In 2001 and 2002, optical photometric and spectroscopic observations revealed that HM Cnc is a very blue object with no intrinsic absorptions but broad (FWHM 1500 km s^-1) low equivalent width emission lines (EW 1-6A), which were first identified with the HeII Pickering series. The combination of X-ray and optical observations pictures HM Cnc as a double degenerate binary hosting two white dwarfs, and possibly being the shortest orbital period binary discovered so far. The present work is aimed at studying the orbital motion of the two components by following the variations of the shape, centroid and intensity of the emission lines through the orbit. In February 2007, we carried out the first phase resolved optical spectroscopic study with the VLT/FORS2 in the High Time Resolution (HIT) mode, yielding five phase bins in the 321 s modulation. Despite the low SNR, the data show that the intensity of the three most prominent emission...

Mason, Elena; Dall'Osso, S; Stella, L; Munari, U; Marconi, G; O'Brian, K; Covino, S; Fugazza, D

2010-01-01

254

Search for RS-gravitons at CDF  

SciTech Connect

We present a search for Randall-Sundrum (RS) gravitons decaying to diphotons or dielectrons or dimuons, performed with the CDF II detector and using up to 5.7 fb{sup -1} of integrated luminosity. The respective mass spectra are consistent with the ones expected by the standard model. For the RS-model parameter k/{bar M}{sub Pl} = 0.1, RS-gravitons with mass less than 1111 GeV/c{sup 2} are excluded at 95% CL.

Strologas, John; /New Mexico U.

2011-09-01

255

Ares V and RS-68B  

NASA Technical Reports Server (NTRS)

Ares V is the heavy lift vehicle NASA is designing for lunar and other space missions. It has significantly more lift capability than the Saturn V vehicle used for the Apollo missions to the moon. Ares V is powered by two recoverable 5.5 segment solid rocket boosters and six RS-68B engines on the core stage. The upper stage, designated as the Earth Departure Stage, is powered by a single J-2X engine. This paper provides an overview of the Ares V vehicle and the RS-68B engine, an upgrade to the Pratt & Whitney Rocketdyne RS-68 engine developed for the Delta IV vehicle.

Creech, Steve; Taylor, Jim; Bellamy, Scott; Kuck, Fritz

2008-01-01

256

Association between DRD2 (rs1799732 and rs1801028) and ANKK1 (rs1800497) polymorphisms and schizophrenia: a meta-analysis.  

PubMed

The role of dopamine D2 receptor (DRD2) polymorphisms in schizophrenia remains controversial. We performed a meta-analysis to determine whether DRD2 polymorphisms influence the risk of schizophrenia and examined the relationship between rs1799732, rs1801028, and rs1800rs028 an23381d rs1800497 genetic variants and the etiology of schizophrenia. Relevant case-control studies were retrieved by database searches and selected according to established inclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the associations. Meta-regression, subgroup analysis, sensitivity analysis, and cumulative meta-analysis were performed. A total of 76 studies with 16096 cases and 18965 controls were included. Specifically, 24 studies with 6075 cases and 6643 controls involved rs1799732, 36 studies with 8043 cases and 10194 controls involved rs1801028 and 16 studies with 1978 cases and 2128 controls involved rs1800497. No significant associations were observed between rs1799732 and rs1800rs732 and rs1800497 and schizophrenia. The rs1801028 locus was associated with schizophrenia, with a pooled OR of 1.221 (95% CI = 1.037-1.438, P = 0.016). This meta-analysis indicates that the rs1801028 locus may be associated with schizophrenia. These data provide possible references for future case-control studies related to schizophrenia. PMID:25504812

Yao, Jun; Pan, Yu-qing; Ding, Mei; Pang, Hao; Wang, Bao-jie

2015-01-01

257

57ime CONGRS CANADIEN DE GOTECHNIQUE 57TH CANADIAN GEOTECHNICAL CONFERENCE 5ime CONGRS CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE  

E-print Network

CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE GENERALIZED DIRECTIONAL PEAK SHEAR STRESS CRITERION résistance au cisaillement des joints cisaillés à contrainte normale constante (CNC) ou à rigidité normale

Aubertin, Michel

258

Visualization of the Drosophila dKeap1-CncC interaction on chromatin illumines cooperative, xenobiotic-specific gene activation.  

PubMed

Interactions among transcription factors control their physiological functions by regulating their binding specificities and transcriptional activities. We implement a strategy to visualize directly the genomic loci that are bound by multi-protein complexes in single cells in Drosophila. This method is based on bimolecular fluorescence complementation (BiFC) analysis of protein interactions on polytene chromosomes. Drosophila Keap1 (dKeap1)-CncC complexes localized to the nucleus and bound chromatin loci that were not bound preferentially by dKeap1 or CncC when they were expressed separately. dKeap1 and CncC binding at these loci was enhanced by phenobarbital, but not by tert-butylhydroquinone (tBHQ) or paraquat. Endogenous dKeap1 and CncC activated transcription of the Jheh (Jheh1, Jheh2, Jheh3) and dKeap1 genes at these loci, whereas CncC alone activated other xenobiotic response genes. Ectopic dKeap1 expression increased CncC binding at the Jheh and dKeap1 gene loci and activated their transcription, whereas dKeap1 inhibited CncC binding at other xenobiotic response gene loci and suppressed their transcription. The combinatorial chromatin-binding specificities and transcriptional activities of dKeap1-CncC complexes mediated the selective activation of different sets of genes by different xenobiotic compounds, in part through feed-forward activation of dKeap1 transcription. PMID:25063457

Deng, Huai; Kerppola, Tom K

2014-08-01

259

It's a dramatic scene--the kind played out with precision and compassion at the new University of Utah Clinical Neurosciences Center (CNC). Unparalleled advances in our understanding of the  

E-print Network

of Utah Clinical Neurosciences Center (CNC). Unparalleled advances in our understanding of the brain in the Intermountain West is the University's CNC, which for the first time unites the School of Medicine's departments and Huntsman Cancer Hospital. Also affiliated with the CNC are the largest pediatric neurosurgery service

Capecchi, Mario R.

260

Wisconsin Longitudinal Study SNPs Gene rs # disease/behavior notes  

E-print Network

rs4986852 Breast Cancer exonic, missense, 0.03 heterozygosity, previously linked BRCA-2 rs144848, missense, 0.18 heterozygosity BRCA-1 rs1799966 Breast Cancer exonic, missense, 0.41 heterozygosity BRCA-1 Breast Cancer exonic, missense, 0.41 heterozygosity, previously linked CHRM2 rs8191992 Cognition 3' UTR

Wisconsin at Madison, University of

261

EUV Emission from RS Canum Venaticorum binaries.  

NASA Astrophysics Data System (ADS)

We performed a study of 104 RS CVn systems in the extreme ultraviolet (EUV) using the all-sky survey data obtained by the Extreme Ultraviolet Explorer (EUVE). The present sample includes several new RS CVn detections; 11 more than in the published EUVE catalogs, and 8 more than in the ROSAT Wide Field Camera catalog. The ratio of detections to non-detections remained constant throughout the sky, implying that our detections are not limited by the exposure time but are most likely limited by absorption from the interstellar medium. A general trend of increasing Lex/B (50-180Å) flux with decreasing rotational period is clear. The dwarf systems exhibit a leveling-off for the faster rotators. In contrast, the evolved systems exhibit no such effect. For the RS CVn systems the losses in the EUV represent a smaller fraction of the coronal radiative losses, as compared to active late-type dwarfs.

Mitrou, C. K.; Mathioudakis, M.; Doyle, J. G.; Antonopoulou, E.

1997-02-01

262

H I OBSERVATIONS OF THE ASYMPTOTIC GIANT BRANCH STAR X HERCULIS: DISCOVERY OF AN EXTENDED CIRCUMSTELLAR WAKE SUPERPOSED ON A COMPACT HIGH-VELOCITY CLOUD  

SciTech Connect

We report H I 21 cm line observations of the asymptotic giant branch (AGB) star X Her obtained with the Robert C. Byrd Green Bank Telescope (GBT) and the Very Large Array. We have unambiguously detected H I emission associated with the circumstellar envelope of the star, with a mass totaling M{sub HI} {approx} 2.1 x 10{sup -3} M{sub sun}. The H I distribution exhibits a head-tail morphology, similar to those previously observed around the AGB stars Mira and RS Cnc. The tail is elongated along the direction of the star's space motion, with a total extent of {approx}> 6.'0 (0.24 pc) in the plane of the sky. We also detect a systematic radial velocity gradient of {approx}6.5 km s{sup -1} across the H I envelope. These results are consistent with the H I emission tracing a turbulent wake that arises from the motion of a mass-losing star through the interstellar medium (ISM). GBT mapping of a 2{sup 0} x 2{sup 0} region around X Her reveals that the star lies (in projection) near the periphery of a much larger H I cloud that also exhibits signatures of interaction with the ISM. The properties of the cloud are consistent with those of compact high-velocity clouds. Using {sup 12}CO J = 1-0 observations, we have placed an upper limit on its molecular gas content of N{sub H2} < 1.3 x 10{sup 20} cm{sup -2}. Although the distance to the cloud is poorly constrained, the probability of a chance coincidence in position, velocity, and apparent position angle of space motion between X Her and the cloud is extremely small, suggesting a possible physical association. However, the large H I mass of the cloud ({approx}>2.4 M{sub sun}) and the blueshift of its mean velocity relative to X Her are inconsistent with an origin tied directly to ejection from the star.

Matthews, L. D.; Johnson, M. C. [MIT Haystack Observatory, Off Route 40, Westford, MA 01886 (United States); Libert, Y. [IRAM, 300 Rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d'Heres (France); Gerard, E. [GEPI, UMR 8111, Observatoire de Paris, 5 Place J Janssen, F-92195 Meudon Cedex (France); Le Bertre, T. [LERMA, UMR 8112, Observatoire de Paris, 61 av. de l'Observatoire, F-75014 Paris (France); Dame, T. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-42, Cambridge, MA 02138 (United States)

2011-02-15

263

Using RS CVn Binaries as a Novel Approach to Measuring Gravity Darkening  

NASA Astrophysics Data System (ADS)

Faint companions of bright giant stars (e.g. RS CVn binaries) are often undetected by direct observations due to small angular distances and large flux ratios. Taking advantage of recent upgrades to the Michigan Infrared Combiner (MIRC) at the CHARA Array allowing for milliarcsecond resolution and large flux ratio detections (>250:1), we make the first detections of the faint main-sequence companions to the giant primary stars of RS CVn systems. These observations give orbital parameter determinations, which lead to model-independent component mass measurements and more accurate evolutionary state estimates. Using the new orbital parameters and 25 years of archival photometry, we have identified weak ellipsoidal variations allowing for a new look at gravity darkening.

Roettenbacher, Rachael M.; Monnier, John D.; Korhonen, Heidi; Harmon, Robert O.; Henry, Gregory W.; Chara Collaboration

2015-01-01

264

Impact of COX-2 rs5275 and rs20417 and GPIIIa rs5918 polymorphisms on 90-day ischemic stroke functional outcome: a novel finding.  

PubMed

We hypothesized that polymorphisms in 5 genes related to thrombolytic and inflammation pathways will independently influence occurrence, severity, and 3-month functional outcome in patients with ischemic stroke. This was a case-control design with ischemic stroke patients recruited from 4 public hospitals (n = 640) and community controls (n = 627). Baseline clinical data were collected, and follow-up telephone interviews were conducted with 520 patients at 90 days postevent to determine stroke outcome using the Barthel Index (BI), Modified Rankin Scale (mRS) and Glasgow Outcome Scale (GOS). Blood samples were collected and genotyped for polymorphisms in platelet glycoprotein Ib? (GPIb?) rs224309 and rs6065, glycoprotein IIIa (GPIIIa) rs5918, tissue plasminogen activator (tPA) rs63020761, plasminogen activating inhibitor (PAI-1) rs72578597, and cyclooxygenase-2 (COX-2) rs5275 and rs20417. COX-2 polymorphism rs5275 demonstrated a significant association with poststroke mRS, with a dominant genetic model demonstrating the best fit (CC + TC) (adjusted odds ratio [aOR] = 1.61; P = .026). The COX-2 rs20417 C allele showed an association with GOS (aOR = 1.95; P = .012), and again a dominant genetic model demonstrated the best fit (CC + GC). GPIIIa rs5918 (A1A2) was associated with poststroke BI, with a dominant model demonstrating the best fit (A1A2 + A2A2) (aOR = 0.56; P = .014). There was a significant association between stroke severity and tPA rs63020761 TT allele (aOR = 1.96; 95% CI = 1.03-3.72; P = .040). This is the first study to demonstrate associations between stroke functional outcome and 2 COX-2 variants (rs20417 and rs5275) and a GPIIIa variant (rs5918). PMID:20472470

Maguire, Jane; Thakkinstian, Ammarin; Levi, Christopher; Lincz, Lisa; Bisset, Linda; Sturm, Jonathan; Scott, Rodney; Whyte, Scott; Attia, John

2011-01-01

265

Association of the four common polymorphisms in interleukin-10 (rs1800890, rs1800896, rs1800871, and rs1800872) with non-Hodgkin’s lymphoma risk: a meta-analysis  

PubMed Central

Interleukin-10 (IL-10) single nucleotide polymorphisms (SNPs) have been indicated to be correlated with Non-Hodgkin’s lymphoma (NHL) susceptibility. However, the results of these studies on the association remain inconsistent. This meta-analysis was conducted to derive a more accuracy estimation of the association between the common SNPs (rs1800890, rs1800896, rs1800871 and rs1800872) in IL-10 and NHL risk. Meta-analyses were performed on 21 studies with 7,749 cases and 8584 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the NHL risk. Meta-analyses showed that rs1800890, rs1800871 and rs1800872 polymorphisms had no association with NHL risk. However, rs1800896 polymorphism has association with NHL risk based on the following comparison models (G vs. A: OR = 1.14, 95% CI = 1.00-1.29; AG vs. AA: OR = 1.20, 95% CI = 1.05-1.37; GG+AG vs. AA: OR = 1.22, 95% CI = 1.08-1.39). In the ethnic subgroup analysis, rs1800896 had an increased NHL risk in Caucasians based on the heterozygote model (OR = 1.21, 95% CI = 1.04-1.41) and dominant model (OR = 1.22, 95% CI = 1.00-1.48). When stratified by subtypes, rs1800890, rs1800896 and rs1800872 polymorphisms were found significant association with an increased risk of diffuse large B-cell Lymphoma (DLBCL) in different comparison models, whereas negative results were obtained for Follicular Lymphoma (FL) and chronic lymphocytic Leukemia/small lymphocytic Lymphoma (CLL/SLL) in all genetic models. Our meta-analysis suggested that the rs1800896 polymorphism had an increased risk with NHL susceptibility, where as the rs1800890, rs1800871 and rs1800872 had no association with NHL risk. Among the common subtypes of NHL, three polymorphisms (rs1800890, rs1800896 and rs1800872) had significant association with DLBCL risk. PMID:25663969

Dai, Zhi-Ming; He, Ai-Li; Zhang, Wang-Gang; Liu, Jie; Cao, Xing-Mei; Chen, Yin-Xia; Ma, Xiao-Rong; Zhao, Wan-Hong; Dai, Zhi-Jun

2014-01-01

266

Fast manufacturing of E-ELT mirror segments using CNC polishing  

NASA Astrophysics Data System (ADS)

We report on the first-ever demonstration of grinding and polishing full-size, off-axis aspheric, mirror segments as prototypes for an extremely large telescope, processed entirely in the final hexagonal shape. We first describe the overall strategy for controlling form and mid spatial frequencies, at levels in the vicinity of <10nm RMS surface. This relies first on direct CNC grinding of the base-form of these 1.4m segments, using the Cranfield BoX™ machine. The segments are then mounted on a custom designed (Optic Glyndwr Optoelectronic Engineering Group) three segment hydraulic support, and CNC polished on a Zeeko IRP 1600 machine using a variety of custom tooling. We overview the fullaperture and sub-aperture metrology techniques used to close the process-loop and certify quality, all of which operate with the segment in-situ on the IRP1600. We then focus on the pristine edge-definition achieved by the combination of tool-lift and smoothing operations; results never previously demonstrated on full-size pre-cut hexagonal segments. Finally, the paper discusses the feasibility of scaling the process to deliver 931 segments in seven years, as required for the E-ELT project.

Gray, C.; Baker, I.; Davies, G.; Evans, R.; Field, N.; Fox-Leonard, T.; Messelink, W.; Mitchell, J.; Rees, P.; Waine, S.; Walker, D. D.; Yu, G.

2013-09-01

267

AT Cnc: A Second Dwarf Nova with a Classical Nova Shell  

NASA Astrophysics Data System (ADS)

We are systematically surveying all known and suspected Z Cam-type dwarf novae for classical nova shells. This survey is motivated by the discovery of the largest known classical nova shell, which surrounds the archetypal dwarf nova Z Camelopardalis. The Z Cam shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts, in accord with the hibernation scenario of cataclysmic binaries. Here we report the detection of a fragmented "shell," 3 arcmin in diameter, surrounding the dwarf nova AT Cancri. This second discovery demonstrates that nova shells surrounding Z Cam-type dwarf novae cannot be very rare. The shell geometry is suggestive of bipolar, conical ejection seen nearly pole-on. A spectrum of the brightest AT Cnc shell knot is similar to that of the ejecta of the classical nova GK Per, and of Z Cam, dominated by [N II] emission. Galaxy Evolution Explorer FUV imagery reveals a similar-sized, FUV-emitting shell. We determine a distance of 460 pc to AT Cnc, and an upper limit to its ejecta mass of ~5 × 10-5 M ?, typical of classical novae.

Shara, Michael M.; Mizusawa, Trisha; Wehinger, Peter; Zurek, David; Martin, Christopher D.; Neill, James D.; Forster, Karl; Seibert, Mark

2012-10-01

268

Experimental Investigation of Parameters of CNC Turning by Taguchi based Grey Relational Analysis  

NASA Astrophysics Data System (ADS)

The AISI H13, a chromium based hot work tool Steel has a wide variety of applications in aluminum casting and extrusion dies, forging dies, hot nut tools, hot header dies, extrusion mandrels, plastic molds, cores, die holder blocks, hot press dies and specially hot work punches etc. In this study, the optimization of two response parameters (Surface roughness and Material Removal Rate) by three machining parameters (cutting speed, feed rate and depth of cut) is investigated in high speed turning of H13 in dry conditions. Taguchi's L'18 orthogonal array and analysis of variance (ANOVA) are used for individual optimization. The simultaneous optimization is done by Grey Relational Analysis approach. The different levels of all machining parameters are used and experiments are done on HMT STALLION-100 HS CNC lathe machine. The optimum condition for combined effects was found V5-F1-D1 and the optimal value of the surface roughness (Ra) comes out to be 0.85 (μm) and of MRR is 488.8 (mm³/sec). The optimum results are also verified with the help of confirmation experiments. Keywords: CNC Turning, O

Sharma, Pankaj; Bhambri, Kamaljeet

2013-03-01

269

Research on test techniques of fault forewarning and diagnosis for high-end CNC machine tool  

NASA Astrophysics Data System (ADS)

With the progress of modern science and technique, the manufacturing industry becomes more and more complex and intelligent. It is the challenge for stable, safe running and economical efficiency of machining equipment such as high-quality numerical control because of its complex structure and integrated functions, and the potential faults are easy to happen. How to ensure the equipment runs stably and reliably becomes the key problem to improve the machining precision and efficiency. In order to prolong the average no-fault time, stable running and machining precision of numerical control, it is very important to make relative test and research on acquisition of data of numerical control sample and establishment of sample database. Take high-end CNC Machine Tool for example, the research on test techniques for data acquisition of sample of typical functional parts in CNC Machine Tool will be made and test condition will be set up; the test methods for sample acquisition on running state monitoring and fault forewarning and diagnosis of numerical control is determined; the test platform for typical functional parts of numerical control is established; the sample database is designed and the sample base and knowledge mode is made. The test and research provide key test techniques to disclosure dynamic performance of fault and precision degeneration, and analyze the impact factors to fault.

Ren, Bin; Xu, Xiaoli

2010-12-01

270

Placement of the material temperature sensor during measuring the accuracy of CNC machine tools  

NASA Astrophysics Data System (ADS)

In view of the dispute on the placement of material sensor when measuring the positional accuracy of a linear axis of a CNC machine tool, this paper presents the method and principle of deciding where to put the material temperature sensor. The positional accuracy of the linear axis of the machine tool is one of the most important performance parameters, and it must be measured when setup and check. The placement of the material temperature sensor has great influence on the measurement accuracy. At present, there are two main views on this issue: one is to place the sensor on the table of the machine tool, the other is to place it on the feedback system. This conflict between these two debates often makes the measurers feel confused and as a result influences the measure quality, sometimes. This thesis attempts to classify the CNC machine tools positional accuracy measurement according to its different purposes, then further presents the best placement. The thesis also elaborates other relevant questions of the placement of the material temperature sensor.

Zhao, Dong-sheng; Jia, Min-qiang; Zhang, Jian; Sun, Lei; Li, Wei-jun

2013-10-01

271

AT Cnc: A SECOND DWARF NOVA WITH A CLASSICAL NOVA SHELL  

SciTech Connect

We are systematically surveying all known and suspected Z Cam-type dwarf novae for classical nova shells. This survey is motivated by the discovery of the largest known classical nova shell, which surrounds the archetypal dwarf nova Z Camelopardalis. The Z Cam shell demonstrates that at least some dwarf novae must have undergone classical nova eruptions in the past, and that at least some classical novae become dwarf novae long after their nova thermonuclear outbursts, in accord with the hibernation scenario of cataclysmic binaries. Here we report the detection of a fragmented 'shell', 3 arcmin in diameter, surrounding the dwarf nova AT Cancri. This second discovery demonstrates that nova shells surrounding Z Cam-type dwarf novae cannot be very rare. The shell geometry is suggestive of bipolar, conical ejection seen nearly pole-on. A spectrum of the brightest AT Cnc shell knot is similar to that of the ejecta of the classical nova GK Per, and of Z Cam, dominated by [N II] emission. Galaxy Evolution Explorer FUV imagery reveals a similar-sized, FUV-emitting shell. We determine a distance of 460 pc to AT Cnc, and an upper limit to its ejecta mass of {approx}5 Multiplication-Sign 10{sup -5} M {sub Sun }, typical of classical novae.

Shara, Michael M.; Mizusawa, Trisha; Zurek, David [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192 (United States); Wehinger, Peter [Steward Observatory, the University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Martin, Christopher D.; Neill, James D.; Forster, Karl [Department of Physics, Math and Astronomy, California Institute of Technology, 1200 East California Boulevard, Mail Code 405-47, Pasadena, CA 91125 (United States); Seibert, Mark [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

2012-10-20

272

V474 Car: A RARE HALO RS CVn BINARY IN RETROGRADE GALACTIC ORBIT  

SciTech Connect

We report the discovery that the star V474 Car is an extremely active, high velocity halo RS CVn system. The star was originally identified as a possible pre-main-sequence star in Carina, given its enhanced stellar activity, rapid rotation (10.3 days), enhanced Li, and absolute magnitude which places it above the main sequence (MS). However, its extreme radial velocity (264 km s{sup -1}) suggested that this system was unlike any previously known pre-MS system. Our detailed spectroscopic analysis of echelle spectra taken with the CTIO 4 m finds that V474 Car is both a spectroscopic binary with an orbital period similar to the photometric rotation period and metal-poor ([Fe/H] {approx_equal}-0.99). The star's Galactic orbit is extremely eccentric (e {approx_equal} 0.93) with a perigalacticon of only {approx}0.3 kpc of the Galactic center-and the eccentricity and smallness of its perigalacticon are surpassed by only {approx}0.05% of local F/G-type field stars. The observed characteristics are consistent with V474 Car being a high-velocity, metal-poor, tidally locked, chromospherically active binary, i.e., a halo RS CVn binary, and one of only a few such specimens known.

Bubar, Eric J.; Mamajek, Eric E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States); Jensen, Eric L. N. [Swarthmore College, Department of Physics and Astronomy, 500 College Avenue, Swarthmore, PA 19081 (United States); Walter, Frederick M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)

2011-04-15

273

Advanced CNC and CAM Series. Educational Resources for the Machine Tool Industry. Course Syllabi, Instructor's Handbook [and] Student Laboratory Manual.  

ERIC Educational Resources Information Center

This package consists of course syllabi, an instructor's handbook, and student laboratory manual for a 1-year vocational training program to prepare students for entry-level positions as advanced computer numerical control (CNC) and computer-assisted manufacturing (CAM) technicians.. The program was developed through a modification of the DACUM…

Texas State Technical Coll. System, Waco.

274

[A study on individual mandibular prostheses according to 3D reconstruction of CT images and CNC simulation method].  

PubMed

The new method of manufacturing individual mandibular prostheses, in combination with CT data and CNC technique, can duplicate bone tissues accurately, and can have the individual mandibular prosthesis made to order, and repair the mandibular defect (especially the lager mandibular segmental defect). PMID:17552166

Pan, Liu-guo; Sun, Li-qun

2007-03-01

275

Prediction of CNC Heavy-duty Horizontal Lathe position precision and its application based on evaluation of uncertainty  

Microsoft Academic Search

According to type B evaluation of uncertainty, A method is presented to predict position precision of CNC Heavy-duty Horizontal Lathe. A case studying on X axle feeding system, mathematical model of position precision which is based on standard uncertainty is established. Calculation results are compared with experiment truth-value, model's feasibility is proved. It provides a theoretical basis for further enhance

Sheng Wang

2010-01-01

276

Taking the lab into the classroom: Using mobile technology to monitor and receive data from CNC machines  

Microsoft Academic Search

Technology education requires students to understand how theory relates to practice. This relation is established during laboratory sessions carried out during the course. Unfortunately, this laboratory work is often conducted in after-class sessions, limiting the opportunity for the professor to show in theory and practice in parallel, losing the opportunity to maximize learning. The present work shows how a CNC

Victor M. Monroy; Juan de Dios Calderón

2005-01-01

277

Fuzzy Petri nets with neural networks to model products quality from a CNC-milling machining centre  

Microsoft Academic Search

This paper presents a Petri net approach for the modeling of a CNC-milling machining centre. Next, by utilizing fuzzy logic with Petri nets (fuzzy Petri nets), a technique based on 9 fuzzy rules is developed. This paper demonstrates how fuzzy input variables, fuzzy marking, fuzzy firing sequences, and a global output variable should be defined for use with fuzzy Petri

Moheb M. Hanna; Arthur Buck; Roger Smith

1996-01-01

278

Comprehensive reliability allocation method for CNC lathes based on cubic transformed functions of failure mode and effects analysis  

NASA Astrophysics Data System (ADS)

Reliability allocation of computerized numerical controlled(CNC) lathes is very important in industry. Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components, which is not applicable in some conditions. Aiming at solving the problem of CNC lathes reliability allocating, a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis(FMEA) is presented. Firstly, conventional reliability allocation methods are introduced. Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated. Subsequently, a cubic transformed function is established in order to overcome these limitations. Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence. Designers can choose appropriate transform amplitudes according to their requirements. Finally, a CNC lathe and a spindle system are used as an example to verify the new allocation method. Seven criteria are considered to compare the results of the new method with traditional methods. The allocation results indicate that the new method is more flexible than traditional methods. By employing the new cubic transformed function, the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.

Yang, Zhou; Zhu, Yunpeng; Ren, Hongrui; Zhang, Yimin

2015-03-01

279

Hydrogenation of imines catalysed by ruthenium(II) complexes based on lutidine-derived CNC pincer ligands.  

PubMed

The preparation of new Ru(II) complexes incorporating fac-coordinated lutidine-derived CNC ligands is reported. These derivatives are selectively deprotonated by (t)BuOK at one of the methylene arms of the pincer, leading to catalytically active species in the hydrogenation of imines. PMID:23044914

Hernández-Juárez, Martín; Vaquero, Mónica; Álvarez, Eleuterio; Salazar, Verónica; Suárez, Andrés

2013-01-14

280

Comprehensive reliability allocation method for CNC lathes based on cubic transformed functions of failure mode and effects analysis  

NASA Astrophysics Data System (ADS)

Reliability allocation of computerized numerical controlled(CNC) lathes is very important in industry. Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components, which is not applicable in some conditions. Aiming at solving the problem of CNC lathes reliability allocating, a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis(FMEA) is presented. Firstly, conventional reliability allocation methods are introduced. Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated. Subsequently, a cubic transformed function is established in order to overcome these limitations. Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence. Designers can choose appropriate transform amplitudes according to their requirements. Finally, a CNC lathe and a spindle system are used as an example to verify the new allocation method. Seven criteria are considered to compare the results of the new method with traditional methods. The allocation results indicate that the new method is more flexible than traditional methods. By employing the new cubic transformed function, the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.

Yang, Zhou; Zhu, Yunpeng; Ren, Hongrui; Zhang, Yimin

2015-02-01

281

The Use of Patent Data for Technological Forecasting: The Diffusion of CNC-Technology in the Machine Tool Industry  

Microsoft Academic Search

In the 1980s, a dramatic change in the competitive structure of the machine tool industry through the development and implementation of CNC-technology occurred. For the individual company, the timely anticipation and forecast of these technological challenges has been of vital importance in order to incorporate these technological changes into its strategic planning process. This paper assesses the suitability of patent

H. Ernst

1997-01-01

282

Star Trek Songbook Issue 3  

E-print Network

on a Humor Theme ((both from "The Trouble with Tribbles," although the same theme was used in several second season shows.)) 1. 1 *r*.*=s^ tete^^rivffrir^rirr^!BEmm=m 2. staccatom . cl c ^^ \\ ^^ o 0 -A- _A- m??bjtbmw i Animation Star Trek Theme...

Multiple Contributors

1976-01-01

283

Documentation for the machine-readable version of the Catalogue of Nearby Stars, edition 1969  

NASA Technical Reports Server (NTRS)

The Catalogue of Nearby Stars, Edition 1969 (Gliese 1969) contains a number of modifications and additions to the 1957 catalog. It should be mentioned that the 1969 edition lists: (1) all 915 stars of the first edition, even though newer parallaxes place some of the stars below the catalog limit; (2) almost all known stars having trigonometric parallaxes or = 0.045 deg, although in some cases the mean values of trigonometric and spectral or photometric parallaxes are or = 0.045 deg. Pleiades stars and the carbon star X Cnc have been omitted; and (3) all stars with mean (resulting) parallaxes or = 0.045 deg. The resulting catalog contains 1529 single stars and systems with a total of 1890 components (not including spectroscopic and astrometric companions). The machine-readable version of the catalog is described. It is intended to enable users to read and process the data without problems or guesswork.

Warren, W. H., Jr.

1982-01-01

284

PTK2 rs7460 and rs7843014 polymorphisms and exceptional longevity: a functional replication study.  

PubMed

Focal adhesion is critical for cell survival. The focal adhesion kinase (FAK, or PTK2) is an important component of the human interactome and thus is a potential longevity-related protein. Here we studied the association between two PTK2 gene single-nucleotide polymorphisms (SNPs) (rs7843014, rs7460) and exceptional longevity (EL). In addition to gaining insight into their functionality by determining luciferase gene reporter activity, we studied the genotype/allele frequency of these two SNPs among three different cohorts: (1) Spanish centenarians (n=175, 100-111 years, 144 women) and healthy controls (n=355, 20-50 years, 284 women); (2) Italian centenarians (n=79, 100-104 years, 40 women) and controls (n=316, 29-50 years, 156 women); and (3) Japanese centenarians (n=742, 100-116 years, 623 women) and healthy controls (n=499, 23-59 years, 356 women). Both SNPs had functional significance, with the A allele up-regulating luciferase activity compared to the other allele (rs7460 T allele and rs7843014 C allele, respectively). The A allele of both SNPs was negatively associated with EL in the Spanish cohort (rs7460, odds ratio [OR] adjusted by sex=0.40, 95% confidence intervals [CI] 0.3, 0.6, p<0.001); rs7843014, OR=0.37, 95% CI 0.3, 0.5, p<0.001). The OR of being a centenarian if having the rs7460-TT genotype was 6.68 (95% CI 4.1, 10.8, p<0.001). The rs7843014 CC genotype was also positively associated with EL (OR=7.58, 95% CI 4.6, 12.3, p<0.001]. No association was, however, found for the Italian or Japanese cohorts. Thus, two genotypes of the FAK gene, rs7460 TT and rs7843014 CC, are possibly associated with lower gene expression and might favor the likelihood of reaching EL in the Spanish population. Further research is needed to unveil the mechanisms by which FAK expression could perhaps influence the rate of aging. PMID:24930376

Garatachea, Nuria; Fuku, Noriyuki; He, Zi-Hong; Tian, Ye; Arai, Yasumichi; Abe, Yukiko; Murakami, Haruka; Miyachi, Motohiko; Yvert, Thomas; Venturini, Letizia; Santiago, Catalina; Santos-Lozano, Alejandro; Rodríguez, Gabriel; Ricevuti, Giovanni; Pareja-Galeano, Helios; Sanchis-Gomar, Fabian; Emanuele, Enzo; Hirose, Nobuyoshi; Lucia, Alejandro

2014-10-01

285

Beam shaping optics for YAG laser by using a CNC lathe  

NASA Astrophysics Data System (ADS)

A method for a beam shaping optics is proposed to convert a laser beam profile into required intensity distribution. A beam shaper with aspherical surface is calculated by Snell's law converted from measured irradiate beam profile to required profile. An acrylic resin is cut by a ball type grinding wheel consisted on diamond powder and polished by a cone type felt buff with alumina ceramics powder. A CNC lathe is used to control these tools position. A shaper with 4mm of thickness works to convert multi-mode beam profile with 13mm of diameter into a flat top cylinder with 1mm of diameter. Its working distance is 60mm. Its transmittance is over 98%.It suceed to generate uniform melting mark of 0.6mm diameter on the steel target by YAG laser process.

Kuwano, Ryoichi; Tokunaga, Tsuyoshi; Kataoka, Yoshihiro; Otani, Yukitoshi; Miyazaki, Toshiyuki

2003-10-01

286

Performance Monitoring Of A Computer Numerically Controlled (CNC) Lathe Using Pattern Recognition Techniques  

NASA Astrophysics Data System (ADS)

On-line monitoring of the cutting process in CNC lathe is desirable to ensure unattended fault-free operation in an automated environment. The state of the cutting tool is one of the most important parameters which characterises the cutting process. Direct monitoring of the cutting tool or workpiece is not feasible during machining. However several variables related to the state of the tool can be measured on-line. A novel monitoring technique is presented which uses cutting torque as the variable for on-line monitoring. A classifier is designed on the basis of the empirical relationship between cutting torque and flank wear. The empirical model required by the on-line classifier is established during an automated training cycle using machine vision for off-line direct inspection of the tool.

Daneshmend, L. K.; Pak, H. A.

1984-02-01

287

Study on grinding of free-form optics surface in three-axis CNC machine  

NASA Astrophysics Data System (ADS)

Due to the glass is a type of brittle material, so the high-precision free-form optics of glass material is usually machined by the technical of grinding. In this paper, for the characteristics of the diamond grinding wheel, analyzing the grinding path of free-form optics and mathematical model of the path is established based on the three-axis CNC grinding device. Moreover, the cause of the interference in the process of grinding is analyzed and the methods of avoiding. Finally, based on the above analysis results, through the experiment, the free-form optics surface accuracy was reached to 3.6um, realize the machining of the free-form optics.

Yang, Haicheng; Zhang, Yun-long; Zhang, Feng; Wang, Zhibin; Bao, Long-xiang; Su, Ying; Guo, Rui; Liu, Xuan-min

2014-08-01

288

The resonance line of B II in IUE spectra of chemically peculiar stars  

NASA Technical Reports Server (NTRS)

A description is presented of high-dispersion spectroscopic observations of eight chemically peculiar stars including Kappa Cnc and Mu Lep, and of one normal comparison star, Nu Cap, in the vicinity of 1362 A. The reported data were obtained with the International Ultraviolet Explorer during the first 15 months of its operation. The initial reduction of the data, which were originally described in a qualitative summary by Leckrone (1980), was affected by a serious error in the calibration of the instrument's intensity transfer function. This error has been corrected in the currently presented data. The results of spectrum syntheses of the 1362 A feature are also described for several of the stars.

Leckrone, D. S.

1981-01-01

289

Concurrent Collections (CnC): A new approach to parallel programming  

SciTech Connect

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment’s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

None

2010-05-07

290

Concurrent Collections (CnC): A new approach to parallel programming  

ScienceCinema

A common approach in designing parallel languages is to provide some high level handles to manipulate the use of the parallel platform. This exposes some aspects of the target platform, for example, shared vs. distributed memory. It may expose some but not all types of parallelism, for example, data parallelism but not task parallelism. This approach must find a balance between the desire to provide a simple view for the domain expert and provide sufficient power for tuning. This is hard for any given architecture and harder if the language is to apply to a range of architectures. Either simplicity or power is lost. Instead of viewing the language design problem as one of providing the programmer with high level handles, we view the problem as one of designing an interface. On one side of this interface is the programmer (domain expert) who knows the application but needs no knowledge of any aspects of the platform. On the other side of the interface is the performance expert (programmer or program) who demands maximal flexibility for optimizing the mapping to a wide range of target platforms (parallel / serial, shared / distributed, homogeneous / heterogeneous, etc.) but needs no knowledge of the domain. Concurrent Collections (CnC) is based on this separation of concerns. The talk will present CnC and its benefits. About the speaker Kathleen Knobe has focused throughout her career on parallelism especially compiler technology, runtime system design and language design. She worked at Compass (aka Massachusetts Computer Associates) from 1980 to 1991 designing compilers for a wide range of parallel platforms for Thinking Machines, MasPar, Alliant, Numerix, and several government projects. In 1991 she decided to finish her education. After graduating from MIT in 1997, she joined Digital Equipment?s Cambridge Research Lab (CRL). She stayed through the DEC/Compaq/HP mergers and when CRL was acquired and absorbed by Intel. She currently works in the Software and Services Group / Technology Pathfinding and Innovation.

None

2011-10-06

291

40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...Exemptions From Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens...

2010-07-01

292

40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...Exemptions From Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens...

2013-07-01

293

40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...Exemptions From Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens...

2011-07-01

294

40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...Exemptions From Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens...

2012-07-01

295

40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...Exemptions From Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens...

2014-07-01

296

The Metallicity and Lithium Abundances of the Recurring Novae T CrB and RS Oph  

NASA Astrophysics Data System (ADS)

We report on high-resolution spectra of the two recurring novae, T CrB and RS Oph, obtained in 2004 when no outbursts were in progress. Selected regions of the spectra between 6500 and 8800 Åwere measured for equivalent widths and analyzed for metallicity. Lines of Fe I, Ni I, Si I, and Ti I were used to establish the effective temperature. The metallicity as derived using models is near solar with an uncertainty estimated to be near a factor of 2 for both stars. Both stars show a strong lithium line at 6707.8 . Approximate Li abundances were derived using model atmospheres for a direct comparison with the nearby Fe I line at 6710.31 Å and the Ca I ground level line at 6572.78 Å. The Li abundances are near log N(Li) = 1.2 for RS Oph and 0.8 for T CrB on the scale of log N(H) = 12.0. Such Li abundances are high for single K and M giants. A survey of symbiotic stars with cool components of types K and M showed no recognizable Li line in 28 stars with high quality spectra. This makes the two repeating novae different from the other symbiotics that consist of a red giant and a white dwarf.

Wallerstein, George; Harrison, Tanya; Munari, Ulisse; Vanture, Andrew

2008-05-01

297

Association of Adiponectin rs1501299 and rs266729 Gene Polymorphisms With Nonalcoholic Fatty Liver Disease  

PubMed Central

Background Genetic and environmental factors are important for the development of nonalcoholic fatty liver disease (NAFLD). Adiponectin is a white and brown adipose tissue hormone, and have been found to play essential roles in the regulation of energy homoeostasis. Recent reports have identified a possible role of adiponectin in NAFLD via PPAR? pathway. Objectives The present study was designed to find out the impact of adiponectin rs1501299 (276G/T) and rs266729 (-11377C/G) gene polymorphisms in NAFLD. Patients and Methods Eighty-three patients with diagnosis of NAFLD, and 93 healthy subjects were included in the study. Tetra ARMS-PCR was designed to detect single nucleotide polymorphisms. Results A significant difference was found between NAFLD and control group regarding the rs266729 polymorphism (?2 = 7.35, P = 0.025). The rs266729 polymorphism increased the risk of NAFLD in codominant (CC vs. CG: OR = 2.18, 95% CI = 1.16 - 4.12, P = 0.016) and dominant (CC vs. CG/GG: OR = 2.31, 95% CI = 1.25 - 4.27; P = 0.008) inheritance tested models. The G allele increased the risk of NAFLD (OR = 1.63, 95% CI = 1.03 - 2.57, P = 0.037) in comparison with C allele. No significant difference was found between the groups concerning adiponectin rs1501299 gene polymorphism (?2 = 0.70, P = 0.697). Conclusions adiponectin rs266729 polymorphism might be a candidate gene, which determines the susceptibility to NAFLD. Larger studies are necessary to confirm these findings in various populations. PMID:23922565

Hashemi, Mohammad; Hanafi Bojd, Hamideh; Eskandari Nasab, Ebrahim; Bahari, Ali; Hashemzehi, Noor Allah; Shafieipour, Sara; Narouie, Behzad; Taheri, Mohsen; Ghavami, Saeid

2013-01-01

298

A&A 503, 165176 (2009) DOI: 10.1051/0004-6361/200911918  

E-print Network

of the close binary stars AH Cnc, EV Cnc, ES Cnc, the Scuti type systems EX Cnc and EW Cnc, and some long Cnc were obtained during three observing seasons. Likewise we gathered three light curves of EV Cnc, an EB-type binary, and two light curves of ES Cnc, a blue straggler binary. Parts of the light change

299

Optical and X-ray studies of chromospherically active stars: FR Cancri, HD 95559 and LO Pegasi  

NASA Technical Reports Server (NTRS)

We present a multiwavelength study of three chromospherically active stars, namely FR Cnc (= BD +16 degrees 1753), HD 95559 and LO Peg (=BD +22 degrees 4409), including newly obtained optical photometry, (for FR Cnc) low-resolution optical spectroscopy, as well as archival IR and X-ray observations. The BVR photometry carried out during the years 2001 - 2004 has found significant photometric variability to be present in all three stars. For FR Cnc, a photometric period 0.826685 +/- 0.000034 d has been established. The strong variation in the phase and amplitude of the FR Cnc light curves when folded on this period implies the presence of evolving and migrating spots or spot groups on its surface. Two independent spots with migration periods of 0.97 and 0.93 years respectively are inferred. The photometry of HD 95559 suggests the formation of a spot (group) during the interval of our observations. We infer the existence of two independent spots or groups in the photosphere of LO Peg, one of which has a migration period of 1.12 years. The optical spectroscopy of FR Cnc carried out during 2002-2003, reveals the presence of strong and variable Ca I1 H and K, H(sub beta) and H(sub alpha) emission features indicative of high level of chromospheric activity. The value of 5.3 for the ratio of the excess emission in H(sub alpha) to H(sub beta), EH(sub alpha)/EH(sub beta), suggests that the chromospheric emission may arise from an extended off-limb region. We have searched for the presence of color excesses in the near-IR JHK bands of these stars using 2MASS data, but none of them appear to have any significant color excess. We have also analyzed archival X-ray observations of HD 95559 and LO Peg carried out by with the ROSAT observatory. The best fit models to their X-ray spectra imply the presence of two coronal plasma components of differing temperatures and with sub-solar metal abundances. The inferred emission measures and temperatures of these systems are similar to those found for other active dwarf stars. The kinematics of FR Cnc suggest that it is a very young (35 - 55 Myrs) main-sequence star and a possible member of the IC 2391 supercluster. LO Peg also has young disk-type kinematics and has been previously suggested to be a member of the 100 Mys old Local Association (Pleiades Moving Group). The kinematics of HD 95559 indicate it is a possible member of the 600 Myrs old Hyades supercluster.

Pandey, J. C.; Singh, K. P.; Drake, S. A.; Sagar, R.

2005-01-01

300

Interferometer observations of RS Canum Venaticorum binaries  

NASA Astrophysics Data System (ADS)

We present radio flux measurements at 5 GHz for a sample of RS CVn-type chromospherically active binary systems made from 1988 to 1992 using the Nuffield Radio Astronomy Laboratories (NRAL) broad-band interferometer (BBI). The derived radio luminosities are consistent with previous observations but show that radio flaring is a common feature which will effect the results of rotation-activity studies. The mean brightness temperature for our sample, assuming a radio source size equal to twice the radius of the active stellar component, is consistent with a gyrosynchrotron emission process from mildly relativistic electrons.

Gunn, A. G.; Spencer, R. E.; Abdul Aziz, H.; Doyle, J. G.; Davis, R. J.; Pavelin, P. E.

1994-11-01

301

Development of a 3-axis desktop milling machine and a CNC system using advanced modern control algorithms  

Microsoft Academic Search

In this paper, we introduce a desktop-size 3-axis milling machine and a CNC system which was developed to operate the 3-axis\\u000a milling machine. The 3-axis milling machine has a mini-desktop size of 200×300×200 mm3 and its cutting volume is 20×20×20 mm3. The vertically installed XY stage is driven by voice-coil motors, and for the zaxis, a magnetically preloaded air bearing

Byung-Sub Kim; Seung-Kook Ro; Jong-Kweon Park

2010-01-01

302

Open-architecture system based on a reconfigurable hardware-software multi-agent platform for CNC machines  

Microsoft Academic Search

New generation of manufacturing systems endows their intelligence and reconfigurability to the computerized numerical controller (CNC) machines. This paper presents an open-architecture platform based on multi-agent hardware–software units, by developing a novel Multi-Agent Distributed CONtroller (MADCON) system. This system intends to fulfill the requirements of reconfigurability for the next generation of intelligent machines. The design of intelligent drives for this

Luis Morales-Velazquez; René de Jesús Romero-Troncoso; Roque Alfredo Osornio-Rios; Gilberto Herrera-Ruiz; Eduardo Cabal-Yepez

2010-01-01

303

Closed-loop CAPP\\/CAM\\/CNC process chain based on STEPand STEP-NC inspection tasks  

Microsoft Academic Search

The object-oriented STEP-NC programming interface supports a bi-directional data exchange between computer-aided manufacturing (CAM) systems and computerized numerical controllers (CNCs), and by that helps to integrate the CNC into the CAx (Computer Aided technologies in general) world. In this context the current paper introduces the integration of measuring technology into the STEP-NC-based process chain, to be able to preserve the

C. Brecher; M. Vitr; J. Wolf

2006-01-01

304

A study of coronal abundances in RS CVn binaries%  

NASA Astrophysics Data System (ADS)

We present XMM-Newton data of several RS CVn binary systems. High-resolution X-ray spectra obtained with the Reflection Grating Spectrometers have been interpreted simultaneously with the European Photon Imaging Camera spectra. Highly active stars show a depletion of elements with a low first ionization potential (FIP) relative to high-FIP elements, whereas intermediately active binaries show either no FIP bias or a possible solar-like FIP effect. We find that the low-FIP abundance ratios to oxygen vary with the coronal average temperature whereas the ratios for high-FIP elements stay constant. Since we observe that the absolute Fe (low-FIP) abundance increases with decreasing activity, this suggests that the abundances of elements with low FIP vary with the coronal activity level. Compared with laboratory measurements of the intensity ratios of the Fe Xvii lambda lambda 15.01 and 15.26 Å lines, the coronal plasmas are in the optically thin regime. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA).

Audard, M.; Güdel, M.; Sres, A.; Raassen, A. J. J.; Mewe, R.

2003-02-01

305

STEP-compliant NC research: the search for intelligent CAD\\/CAPP\\/CAM\\/CNC integration  

Microsoft Academic Search

Since the first generation of Numerically Controlled (NC) machine tools was developed in the 1950s, there have been many developments which make today's NC machines completely unrecognizable from their early ancestors. Further developments, however, are now being significantly limited by the current programming language (ISO6983 or RS274D) that has been supporting NC manufacture since day one. Today a new standard,

X. W. Xu; H. Wang; J. Mao; S. T. Newman; T. R. Kramer; F. M. Proctor; J. L. Michaloski

2005-01-01

306

A SUPER-EARTH TRANSITING A NAKED-EYE STAR  

SciTech Connect

We have detected transits of the innermost planet 'e' orbiting 55 Cnc (V = 6.0), based on two weeks of nearly continuous photometric monitoring with the MOST space telescope. The transits occur with the period (0.74 days) and phase that had been predicted by Dawson and Fabrycky, and with the expected duration and depth for the crossing of a Sun-like star by a hot super-Earth. Assuming the star's mass and radius to be 0.963{sup +0.051}{sub -0.029} M{sub sun} and 0.943 {+-} 0.010 R{sub sun}, the planet's mass, radius, and mean density are 8.63 {+-} 0.35 M{sub +}, 2.00 {+-} 0.14 R{sub +}, and 5.9{sup +1.5}{sub -1.1} g cm{sup -3}, respectively. The mean density is comparable to that of Earth, despite the greater mass and consequently greater compression of the interior of 55 Cnc e. This suggests a rock-iron composition supplemented by a significant mass of water, gas, or other light elements. Outside of transits, we detected a sinusoidal signal resembling the expected signal due to the changing illuminated phase of the planet, but with a full range (168 {+-} 70 ppm) too large to be reflected light or thermal emission. This signal has no straightforward interpretation and should be checked with further observations. The host star of 55 Cnc e is brighter than that of any other known transiting planet, which will facilitate future investigations.

Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Matthews, Jaymie M.; Kallinger, Thomas; Dragomir, Diana [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Dawson, Rebekah I.; Holman, Matthew J.; Sasselov, Dimitar [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Fabrycky, Daniel [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Kuschnig, Rainer; Weiss, Werner W. [University of Vienna, Institute for Astronomy, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria); Guenther, David B. [Department of Astronomy and Physics, Saint Mary's University, Halifax, NS B3H 3C3 (Canada); Moffat, Anthony F. J. [Department de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, QC H3C 3J7 (Canada); Rowe, Jason F. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Rucinski, Slavek [Department of Astronomy and Astrophysics, University of Toronto, 50 St George Street, Toronto, ON M5S 3H4 (Canada)

2011-08-10

307

A Super-Earth Transiting a Naked-eye Star  

NASA Astrophysics Data System (ADS)

We have detected transits of the innermost planet "e" orbiting 55 Cnc (V = 6.0), based on two weeks of nearly continuous photometric monitoring with the MOST space telescope. The transits occur with the period (0.74 days) and phase that had been predicted by Dawson & Fabrycky, and with the expected duration and depth for the crossing of a Sun-like star by a hot super-Earth. Assuming the star's mass and radius to be 0.963+0.051 - 0.029 M sun and 0.943 ± 0.010 R sun, the planet's mass, radius, and mean density are 8.63 ± 0.35 M ?, 2.00 ± 0.14 R ?, and 5.9+1.5 - 1.1 g cm-3, respectively. The mean density is comparable to that of Earth, despite the greater mass and consequently greater compression of the interior of 55 Cnc e. This suggests a rock-iron composition supplemented by a significant mass of water, gas, or other light elements. Outside of transits, we detected a sinusoidal signal resembling the expected signal due to the changing illuminated phase of the planet, but with a full range (168 ± 70 ppm) too large to be reflected light or thermal emission. This signal has no straightforward interpretation and should be checked with further observations. The host star of 55 Cnc e is brighter than that of any other known transiting planet, which will facilitate future investigations. Based on data from the MOST satellite, a Canadian Space Agency mission, jointly operated by Dynacon Inc., the University of Toronto Institute for Aerospace Studies, and the University of British Columbia, with the assistance of the University of Vienna.

Winn, Joshua N.; Matthews, Jaymie M.; Dawson, Rebekah I.; Fabrycky, Daniel; Holman, Matthew J.; Kallinger, Thomas; Kuschnig, Rainer; Sasselov, Dimitar; Dragomir, Diana; Guenther, David B.; Moffat, Anthony F. J.; Rowe, Jason F.; Rucinski, Slavek; Weiss, Werner W.

2011-08-01

308

The ROSAT All-Sky Survey of active binary coronae. I - Quiescent fluxes for the RS Canum Venaticorum systems  

NASA Astrophysics Data System (ADS)

One hundred and thirty-six RS CV(n) active binary systems were observed with the ROSAT Position Sensitive Proportional Counter (PSPC) during the All-Sky Survey component of the mission. The entire sky was surveyed, which represents the largest sample of RS CV(n) systems observed to date at any wavelength, including X-rays. X-ray surface fluxes for the RS CV(n) systems are found to lie in the range 10 exp 4 to 10 exp 8 ergs/sq cm seconds. Surface flux as a function of (B - V) color is reported. A decrease in surface flux with increasing rotation period for the entire sample is observed. The rotation period provides the best stellar or orbital parameter to predict the X-ray surface flux level. The absence of correlation of F(x) or L(x) with Gamma is noted due to the fact that the coronal heating mechanism for these active stars must be magnetic in character, and the magnetic field depends on the interaction between convection and differential rotation inside the star. X-ray properties of the RS CV(n) systems with 6 cm radio and C IV UV emission systems is compared.

Dempsey, Robert C.; Linsky, Jeffrey L.; Fleming, Thomas A.; Schmitt, J. H. M. M.

1993-06-01

309

An RS-170 to 700 frame per second CCD camera  

SciTech Connect

A versatile new camera, the Los Alamos National Laboratory (LANL) model GY6, is described. It operates at a wide variety of frame rates, from RS-170 to 700 frames per second. The camera operates as an NTSC compatible black and white camera when operating at RS-170 rates. When used for variable high-frame rates, a simple substitution is made of the RS-170 sync/clock generator circuit card with a high speed emitter-coupled logic (ECL) circuit card.

Albright, K.L.; King, N.S.P.; Yates, G.J.; McDonald, T.E. [Los Alamos National Lab., NM (United States); Turko, B.T. [Lawrence Berkeley Lab., CA (United States)

1993-08-01

310

Time Resolved, High-Dispersion Spectroscopy of RS CVn Binary V711 Tau  

NASA Astrophysics Data System (ADS)

To investigate the mechanisms of stellar flares, we carried out spectroscopic observations of an RS CVn binary V711 Tau with a high dispersion (R=30,000) and a high time resolution (about 30 sec) as well as simultaneous photometric observations. Although no large flare was unfortunately detected during our observations, time-dependent variations in the H? region were found by correlation-analyses. We conclude that these variations probably originate from the rotation of the primary star with an active region strongly emitting H?. In addition, unprecedented time dependent variations in the Na D doublet were found.

Tohiguchi, M.; Iwai, Y.; Sugita, H.; Nogami, D.; Hirata, R.; Masuda, S.

2007-06-01

311

Development of Intelligent Identification of Cutting States by Spectrum Analysis for CNC Turning  

NASA Astrophysics Data System (ADS)

In order to realize the intelligent machine tools, which can autonomously determine the cutting states and can change them automatically as required due to changes in the environmental conditions, an in-process monitoring and identification of cutting states is developed for CNC turning machine to check and improve the stability of the processes. The method developed utilizes the power spectrum density, or PSD of dynamic cutting force measured during cutting. Experimental results suggested that there are basically three types of patterns of PSD when the cutting states are the continuous chip formation, the broken chip formation, and the chatter. The broken chip formation is desired in order to realize safe and reliable machining. The proposed method introduces three ratios, which are calculated from three dynamic cutting force components and obtained by taking the ratio of cumulative power spectrum density for a certain frequency range corresponding to the states of cutting to that of the whole frequency range of each dynamic cutting force component, to classify the cutting states of continuous chip formation, broken chip formation, and chatter. The algorithm was developed to calculate the values of three ratios during the process in order to obtain the proper threshold values for classification of the cutting states. The method developed has been proved by series of cutting experiments that the states of cutting are well identified regardless of the cutting conditions. The broken chips are easily obtained by changing the cutting conditions during the processes referring to the algorithm developed.

Tangjitsitcharoen, Somkiat

312

Development of a CNC 5KW CO{sub 2} laser processing equipment  

SciTech Connect

This paper introduces the fundamental compositions and functions of a newly developed 5KW CO{sub 2} laser processing equipment CGJ-93 controlled by microcomputer in CIOM (Changchun Institute of Optics and Fine Mechanics). The laser processing equipment consists of a 5KW CO{sub 2} laser, multifunction beam guidance system, modular processing machine, water cooling system and CNC system. The equipment has ability to heat-treat not only the internal holes and outer circular surfaces but also space holes and three dimensional curved surfaces. The equipment can heat-treat workpieces up to 3,000 mm length, 1,500mm diameter and 3,000kg weight. The longitudinal table allows moving speed of 0.8--12,000mm per minute with 3,600mm effective moving range and 0.069mm position accuracy. The transverse table allows moving speed of 5--1,2000mm per minute with 1,000mm effective moving range and 0.028 mm position accuracy. The laser head allows longitudinal moving speed of 0.1--1,2000mm per minute, its effective moving range and position accuracy are 540mm and 0.03mm respectively.

Zhang Shuren; Lu Boliang; Zhang Hong; Shao Wushan [Changchun Inst. of Optics and Fine Mechanics (China). Dept. of Mechanical Engineering

1996-12-31

313

Improved precision on the radius of the nearby super-Earth 55 Cnc e  

E-print Network

We report on new transit photometry for the super-Earth 55 Cnc e obtained with Warm Spitzer/IRAC at 4.5 microns. An individual analysis of these new data leads to a planet radius of 2.21-0.16+0.15 Rearth, in good agreement with the values previously derived from the MOST and Spitzer transit discovery data. A global analysis of both Spitzer transit time-series improves the precision on the radius of the planet at 4.5 microns to 2.20+-0.12 Rearth. We also performed an independent analysis of the MOST data, paying particular attention to the influence of the systematic effects of instrumental origin on the derived parameters and errors by including them in a global model instead of performing a preliminary detrending-filtering processing. We deduce from this reanalysis of MOST data an optical planet radius of 2.04+-0.15 Rearth that is consistent with our Spitzer infrared radius. Assuming the achromaticity of the transit depth, we performed a global analysis combining Spitzer and MOST data that results in a plane...

Gillon, M; Benneke, B; Valencia, D; Deming, D; Seager, S; Lovis, C; Mayor, M; Pepe, F; Queloz, D; Segransan, Damien; Udry, S

2011-01-01

314

Spectroscopic Study of SU UMa-type Dwarf Nova YZ Cnc during its 2002 Superoutburst  

E-print Network

We report time-resolved spectroscopic observations of the SU Ursae Majoris dwarf nova, YZ Cnc, for 2 nights over 11 hrs during its 2002 January superoutburst. The spectra only show absorption-line profiles in the first day. But the lines display blue and red troughs, with ``W'' profiles in the second day. The radial velocity curve of the absorption troughs and emission peaks of H$\\beta$ has an amplitude of $49\\pm10$ km s$^{-1}$ and a phase offset of $-0.07\\pm0.04$, which are very similar to those measured in quiescence; however, the $\\gamma$ velocity deviates strongly from the systemic velocity measured in quiescence, showing variation of the order of $\\pm$60 km s$^{-1}$. And large shifts of $\\sim$70 km s$^{-1}$ and $\\sim$0.09, for the orbital-averaged velocity and phase respectively, are also found in our observations. All these phenomena can be well explained with a precession of an eccentric disk and we conclude that these phenomena are the characteristic products of an eccentric accretion disk.

Ying-he Zhao; Zong-yun Li; Xiao-an Wu; Qiu-he Peng

2005-07-11

315

XMM-Newton observations of the dwarf nova YZ Cnc in quiescence  

E-print Network

We present results from the XMM observations of the dwarf nova YZ Cnc in a quiescent state. We have performed a detailed time series analysis of the resulting light curves. Unusually, we do not detect any orbital modulation in the UV, with only marginal evidence for X-ray modulation on this period. Although there are peaks in the X-ray periodograms at periods less than 5000 s, we attribute them to red noise effects and assign significance to them using a novel approach. The variability in the UV and optical bands can also be modelled as a result of aperiodic variability (red noise) in the system. There is evidence that the UV and X-ray fluxes are anti-correlated with a time delay of about 100 s, with the UV lagging behind the X-ray emission. This anti-correlation is intriguing, but is only present on two occasions lasting several 1000 s each. The X-ray spectrum shows similar emission features to other dwarf novae and is well fitted using a multi-temperature emission model. We measure a relatively high X-ray luminosity of ~1.4x10^{32} ergs/s, although this is consistent with a low binary inclination. Finally, we find evidence for a possible -1200km/s blue shift in the fitted Fe K line energies, possibly indicating the presence of an outflow in this low inclination system.

Pasi Hakala; Gavin Ramsay; Peter Wheatley; Emilios Harlaftis; C. Papadimitriou

2004-03-08

316

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

NASA Astrophysics Data System (ADS)

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

2005-02-01

317

RORA gene rs12912233 and rs880626 polymorphisms and their interaction with SCN1A rs3812718 in the risk of epilepsy: A case-control study in Malaysia.  

PubMed

RAR-related orphan receptors A (RORA) and B (RORB) and voltage-gated sodium channel type 1 (SCN1A) genes play critical roles in the regulation of the circadian clock. Evidence has shown an association of RORA and RORB polymorphisms with susceptibility to autism and depression. Hence, we tested the association of RORA rs12912233, rs16943429, rs880626, rs2290430, and rs12900948; RORB rs1157358, rs7022435, rs3750420, and rs3903529; and SCN1A rs3812718 with epilepsy risk in the Malaysians. DNA was genotyped in 1789 subjects (39% epilepsy patients) by using MassARRAY (Sequenom). Significant association was obtained for rs12912233 in Malaysian Chinese (p=0.003). Interaction between rs12912233-rs880626 and rs3812718 was associated with the epilepsy risk in the subjects overall (p=0.001). Results show that RORA rs12912233 alone might be a possible risk variant for epilepsy in Malaysian Chinese, but that, together with RORA rs880626 and SCN1A rs3812718, this polymorphism may have a synergistic effect in the epilepsy risk in Malaysians. PMID:25668517

Haerian, Batoul Sadat; Sha'ari, Hidayati Mohd; Tan, Hui Jan; Fong, Choong Yi; Wong, Sau Wei; Ong, Lai Choo; Raymond, Azman Ali; Tan, Chong Tin; Mohamed, Zahurin

2015-04-01

318

Genetic Variations rs11892031 and rs401681 Are Associated with Bladder Cancer Risk in a Chinese Population  

PubMed Central

Genome-wide association studies (GWAS) have identified a number of genetic variants associated with risk of bladder cancer in populations of European descent. Here, we assessed association of two of these variants, rs11892031 (2q37.1 region) and rs401681 (5p15.33 region) in a Chinese case-control study, which included 367 bladder cancer cases and 420 controls. We found that the AC genotype of rs11892031 was associated with remarkably decreased risk of bladder cancer (adjusted odds ratio (OR), 0.27; 95% confidence interval (CI), 0.09–0.81; p = 0.019), compared with the AA genotype of rs11892031; and that CT/CC genotypes of rs401681 were associated with significantly increased risk of bladder cancer (adjusted OR, 1.79; 95% CI, 1.10–2.91; p = 0.02), compared with the TT genotype of rs401681. We further conducted stratification analysis to examine the correlation between single nucleotide polymorphism (SNP) rs11892031/rs401681 and tumor grade/stage. Results showed that heterogeneity in ORs of tumor categories was not significant for either rs11892031 or rs401681 (p > 0.05), indicating that the two SNPs seemingly do not associate with tumor grade and stage of bladder cancer in our study population. The present study suggests that the SNPs rs11892031 and rs401681 are associated with bladder cancer risk in a Chinese population. Future analyses will be conducted with more participants recruited in a case-control study. PMID:25347272

Zhang, Yu; Sun, Yan; Chen, Tao; Hu, Hailong; Xie, Wanqin; Qiao, Zhihui; Ding, Na; Xie, Linguo; Li, Sheng; Wang, Wenlong; Xing, Chen; Wang, Yihan; Qie, Yunkai; Wu, Changli

2014-01-01

319

Structure of the ArgRS-GlnRS-AIMP1 complex and its implications for mammalian translation.  

PubMed

In higher eukaryotes, one of the two arginyl-tRNA synthetases (ArgRSs) has evolved to have an extended N-terminal domain that plays a crucial role in protein synthesis and cell growth and in integration into the multisynthetase complex (MSC). Here, we report a crystal structure of the MSC subcomplex comprising ArgRS, glutaminyl-tRNA synthetase (GlnRS), and the auxiliary factor aminoacyl tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1)/p43. In this complex, the N-terminal domain of ArgRS forms a long coiled-coil structure with the N-terminal helix of AIMP1 and anchors the C-terminal core of GlnRS, thereby playing a central role in assembly of the three components. Mutation of AIMP1 destabilized the N-terminal helix of ArgRS and abrogated its catalytic activity. Mutation of the N-terminal helix of ArgRS liberated GlnRS, which is known to control cell death. This ternary complex was further anchored to AIMP2/p38 through interaction with AIMP1. These findings demonstrate the importance of interactions between the N-terminal domains of ArgRS and AIMP1 for the catalytic and noncatalytic activities of ArgRS and for the assembly of the higher-order MSC protein complex. PMID:25288775

Fu, Yaoyao; Kim, Youngran; Jin, Kyeong Sik; Kim, Hyun Sook; Kim, Jong Hyun; Wang, DongMing; Park, Minyoung; Jo, Chang Hwa; Kwon, Nam Hoon; Kim, Doyeun; Kim, Myung Hee; Jeon, Young Ho; Hwang, Kwang Yeon; Kim, Sunghoon; Cho, Yunje

2014-10-21

320

1CIE/USA-CNC/CIE 2013 CIE/USA-CNC/CIE Biennial Joint Meeting, Davis, CA, Nov. 7-8, 2013  

E-print Network

. D., NIST Fellow, IESNA Fellow, CIE VPTechnical 2 Psychology Department, Oberlin College, Oberlin, Ohio, USA NIST Guest Researcher under NIST Summer Undergraduate Research Fellowship Program Vision Seminar NIST Spectrally Tunable Lighting Facility #12;8A*STAR NMC Seminar NIST Spectrally Tunable Lighting

California at Davis, University of

321

Detection of a sub-milliarcsecond radio component in the RS CVn system HR 1099  

NASA Technical Reports Server (NTRS)

The RS CVn system HR 1099 was observed with a five station VLBI array at a frequency of 8.4 GHz during a strong radio outburst of approximately 400 mJy. The data are consistent with a circular Gaussian source of 0.8 + or - 0.12 milli-arcsec (FWHM), corresponding to a linear size of 4 + or - 0.6 x 10 to the 11th cm. This is comparable to the distance between the surfaces of the two stars, or to 75 percent of the diameter of the chromospherically active K star. Extrapolation of published photometric data shows that the starspot formation of HR 1099 was facing toward the observers at the times of observations. The high equivalent brightness temperature, approximately 10 billion K, is consistent with gyrosynchrotron emission from a power-law energy distribution of electrons in a magnetic field of strength about 30 gauss.

Mutel, R. L.; Phillips, R. B.; Webber, J. C.; Niell, A. E.; Preston, R. A.; Lestrade, J.-F.

1984-01-01

322

To: PE&RS Authors From: Mike Renslow  

E-print Network

To: PE&RS Authors From: Mike Renslow Technical Editor Thank you for using our online proofing (rkelley@asprs.org). Sincerely, Mike Renslow Technical Editor - PE&RS 2880 Bailey Hill Road Eugene to sustainable development and international carbon reporting (Brown, 2002) as well as more generally

Coburn, Craig

323

High pressure intensification of cassava resistant starch (RS3) yields.  

PubMed

Cassava starch, typically, has resistant starch type 3 (RS3) content of 2.4%. This paper shows that the RS3 yields can be substantially enhanced by debranching cassava starch using pullulanase followed by high pressure or cyclic high-pressure annealing. RS3 yield of 41.3% was obtained when annealing was carried out at 400MPa/60°C for 15min, whereas it took nearly 8h to obtain the same yield under conventional atmospheric annealing at 60°C. The yield of RS3 could be further significantly increased by annealing under 400MPa/60°C pressure for 15min followed by resting at atmospheric pressure for 3h 45min, and repeating this cycle for up to six times. Microstructural surface analysis of the product under a scanning electron microscope showed an increasingly rigid density of the crystalline structure formed, confirming higher RS3 content. PMID:25794725

Lertwanawatana, Proyphon; Frazier, Richard A; Niranjan, Keshavan

2015-08-15

324

RADIAL VELOCITY PLANETS DE-ALIASED: A NEW, SHORT PERIOD FOR SUPER-EARTH 55 Cnc e  

SciTech Connect

Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581 d, the distinction between an alias and the true frequency was the distinction between a frozen, dead planet and a planet possibly hospitable to life. To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876 d and HD 75898 b. We find that the true periods of Gl 581 d and HD 73526 b/c remain ambiguous. We revise the periods of HD 156668 b and 55 Cnc e, which were afflicted by daily aliases. For HD 156668 b, the correct period is 1.2699 days and the minimum mass is (3.1 {+-} 0.4) M{sub +}. For 55 Cnc e, the correct period is 0.7365 days-the shortest of any known planet-and the minimum mass is (8.3 {+-} 0.3) M{sub +}. This revision produces a significantly improved five-planet Keplerian fit for 55 Cnc, and a self-consistent dynamical fit describes the data just as well. As radial velocity techniques push to ever-smaller planets, often found in systems of multiple planets, distinguishing true periods from aliases will become increasingly important.

Dawson, Rebekah I.; Fabrycky, Daniel C., E-mail: rdawson@cfa.harvard.ed, E-mail: daniel.fabrycky@gmail.co [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-10, Cambridge, MA 02138 (United States)

2010-10-10

325

Effect of a gelatin-based edible coating containing cellulose nanocrystals (CNC) on the quality and nutrient retention of fresh strawberries during storage  

NASA Astrophysics Data System (ADS)

Strawberry is a non-climacteric fruit with a very short postharvest shelf-life. Loss of quality in this fruit is mostly due to its relatively high metabolic activity and sensitivity to fungal decay, meanly grey mold (Botrytis cinerea). In this study, the ability of gelatin coatings containing cellulose nanocrystals (CNC) to extend the shelf-life of strawberry fruit (Fragaria ananassa) over 8 days were studied. The filmogenic solution was obtained by the hydration of 5 g of gelatin (GEL) in 100 mL of distillated water containing different amounts of CNC dispersion (10 mg CNC/g of GEL or 50 mg of CNC/g of GEL) for 1 hour at room temperature. After this period, the solution was heated to 70 °C and maintained at this temperature for 10 minutes. The plasticizer (glycerol) (10g/100g of the GEL) was then added with constant, gentle stirring in order to avoid forming air bubbles and also to avoid gelatin denaturation until complete homogenization. Strawberries (purchased at the local market) were immersed in the filmogenic solution for 1 minute and after coated were dried at 15 °C by 24 hours. The strawberries were then kept under refrigeration and characterized in terms of their properties (weight loss, ascorbic acid content, titratable acidity, water content). The results have shown that samples covered with GEL/CNC had a significant improvement in its shelf- life. For instance, for the control sample (without coating) the weight loss after 8 days of storage was around 65%, while covered samples loss in the range of 31-36%. Edible coating was also effective in the retention of ascorbic acid (AA) in the strawberries, while control sample presented a fast decay in the AA content, covered samples showed a slow decay in the AA concentration. Moreover, the use of GEL/CNC edible coating had an antimicrobial effect in the fruits.

Fakhouri, F. M.; Casari, A. C. A.; Mariano, M.; Yamashita, F.; Innocnentini Mei, L. H.; Soldi, V.; Martelli, S. M.

2014-08-01

326

FPGA-Based Fused Smart-Sensor for Tool-Wear Area Quantitative Estimation in CNC Machine Inserts  

PubMed Central

Manufacturing processes are of great relevance nowadays, when there is a constant claim for better productivity with high quality at low cost. The contribution of this work is the development of a fused smart-sensor, based on FPGA to improve the online quantitative estimation of flank-wear area in CNC machine inserts from the information provided by two primary sensors: the monitoring current output of a servoamplifier, and a 3-axis accelerometer. Results from experimentation show that the fusion of both parameters makes it possible to obtain three times better accuracy when compared with the accuracy obtained from current and vibration signals, individually used. PMID:22319304

Trejo-Hernandez, Miguel; Osornio-Rios, Roque Alfredo; de Jesus Romero-Troncoso, Rene; Rodriguez-Donate, Carlos; Dominguez-Gonzalez, Aurelio; Herrera-Ruiz, Gilberto

2010-01-01

327

FPGA-based fused smart-sensor for tool-wear area quantitative estimation in CNC machine inserts.  

PubMed

Manufacturing processes are of great relevance nowadays, when there is a constant claim for better productivity with high quality at low cost. The contribution of this work is the development of a fused smart-sensor, based on FPGA to improve the online quantitative estimation of flank-wear area in CNC machine inserts from the information provided by two primary sensors: the monitoring current output of a servoamplifier, and a 3-axis accelerometer. Results from experimentation show that the fusion of both parameters makes it possible to obtain three times better accuracy when compared with the accuracy obtained from current and vibration signals, individually used. PMID:22319304

Trejo-Hernandez, Miguel; Osornio-Rios, Roque Alfredo; de Jesus Romero-Troncoso, Rene; Rodriguez-Donate, Carlos; Dominguez-Gonzalez, Aurelio; Herrera-Ruiz, Gilberto

2010-01-01

328

Gravitational quantization of exoplanet orbits in 55 Cnc, $\\upsilon$ And, Kepler-11, Kepler-20, and Kepler-90  

E-print Network

In the framework of the so-called "global polytropic model", we assume hydrostatic equilibrium for a planetary system, and solve the resulting Lane--Emden differential equation in the complex plane. We thus obtain polytropic spherical shells defined by succesive roots of the real part $\\mathrm{Re}(\\theta)$ of the Lane-Emden function $\\theta$. These shells seem to provide hosting orbits for the planets of the system(s) under consideration. In the present investigation, we study within this framework the exoplanet systems 55 Cnc, $\\upsilon$ And, Kepler-11, Kepler-20, and Kepler-90.

Geroyannis, Vassilis S

2014-01-01

329

The evolution of the Three Rs.  

PubMed

Whilst the whole world is celebrating the bicentenary of the birth of Charles Darwin and the 150th anniversary of the publication of his renowned book, The Origin of Species, another anniversary should not be forgotten - the publication of The Principles of Humane Experimental Technique by W.M.S. Russell and R.L. Burch. The concomitance of the anniversaries of the two publications is not a coincidence, since, as reflected by the numerous quotes chosen by Russell from Darwin's masterpiece, numerous analogies can be found between the two works and the new ideas they describe. From a discrete birth, and after decades of struggle, the Three Rs concept can now celebrate its 50th anniversary, the result of its evolution through harsh selection and adaptation. The emergence of new types of techniques, in combination with the descent of modified old ones, testify to the undeniable change in our society toward a more efficient and more ethical science, through the progressive replacement of animal models. Both Darwin and Russell would no doubt have welcomed such progress, not only in terms of science, but also of moral values. One could also expect that, if Russell could have foreseen the incredible technological advances achieved 50 years later, where Replacement becomes a reality, as illustrated by some edifying examples, The Principles of Humane Experimental Technique would have probably been defined as the One R concept. PMID:19678725

Farnaud, Sebastien

2009-07-01

330

Unravelling the Nature of HD 81032 - A New RS CVn Binary  

NASA Astrophysics Data System (ADS)

VR photometric and quasi-simultaneous optical spectro-scopic observations of the star HD81032 have been carried out during the years 2000-2004. A photometric period of 18,802±0,07d has been detected for this star. A large group of spots with a migration period of 7,43±0,07 years is inferred from the first three years of the data. H? and CaII H and K emissions from the star indicate high chromospheric activity. The available photometry in the BVRIJHK bands is consistent with the spectral type of K0 IV previously found for this star. We have also examined the spectral energy distribution of HD81032 for the presence of an infrared colour excess using the 2MASS JHK and IRAS photometry, but found no significant excess in any band above the normal values expected for a star with this spectral type. We have also analyzed the X-ray emission properties of this star using data obtained by the ROSAT X-ray observatory during its All-Sky Survey phase. An X-ray flare of about 12 hours duration was detected during the two days of X-ray coverage obtained for this star. Its X-ray spectrum, while only containing 345 counts, is inconsistent with a single-temperature component solar-abundance coronal plasma model, but implies either the presence of two or more plasma components, non-solar abundances, or a combination of both of these properties. All of the above properties of HD81032 suggest that it is a newly identified, evolved RS CVn binary.

Pandey, J. C.; Singh, K. P.; Drake, S. A.; Sagar, R.

2005-12-01

331

Leukocyte Telomere Length-Related rs621559 and rs398652 Genetic Variants Influence Risk of HBV-Related Hepatocellular Carcinoma  

PubMed Central

Recent genome-wide association studies (GWAS) have identified eleven leukocyte telomere length (LTL)-related single nucleotide polymorphisms (SNPs). Since LTL has been associated with risk of many malignancies, LTL-related SNPs may contribute to cancer susceptibility. To test this hypothesis in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), we genotyped these eleven LTL-related SNPs in a case-control set including 1186 HBV-related HCC cases, 508 chronic HBV carriers and 1308 healthy controls at the discovery stage. The associations of HCC risk with these SNPs were further confirmed in an independent case-control set. We found that 1p34.2 rs621559 and 14q21 rs398652 were significantly associated with HBV-related HCC risk (both P<0.005 after Bonferroni corrections). There was no significant difference of either rs621559 or rs398652 genotypes between chronic HBV carriers and healthy controls, demonstrating that the association was not due to predisposition to HBV infection. In the pooled analyses (1806 HBV-related HCC cases and 1954 controls), we observed a decreased HCC risk, 0.72-times, associated with the 1p34.2 rs621559 AA genotype compared to the GG genotype (P?=?1.6×10?6). Additionally, there was an increased HCC risk, 1.27-fold, associated with the rs398652 GG genotype (P?=?3.3×10?6). A statistical joint effect between the rs621559 GG and rs398652 GG genotypes may exist in elevating risk of HBV-related HCC. We show, for the first time, that rs398652 and rs621559 might be marker genetic variants for risk of HBV-related HCC in the Chinese population. PMID:25365256

Shi, Juan; Lu, Chao; Wei, Jinyu; Li, Lichao; Zhou, Changchun; Yuan, Qipeng; Zhou, Liqing; Yang, Ming

2014-01-01

332

A study of short-period RS Canum Venaticorum and W Ursae Majoris binary systems - The global nature of H-alpha  

NASA Astrophysics Data System (ADS)

The author presents the rotation versus emission characteristics of the H? line for several short-period (P ? 1d) RS CVn and W UMa binary systems. Estimates for the chromospheric emission arising from each component star were obtained by subtraction of "nonactive" model spectra constructed from comparison stars. Enhanced H? emission compared to the nonactive comparison stars is seen on all components of the short-period RS CVn systems studied, while a similar enhancement is only typically seen on the primary components of the W-type W UMa systems. A possible correlation between LHα/Lbol and the Rossby number (the ratio between the rotational period and the convective time scale) is seen for those components showing emission.

Barden, S. C.

1985-08-01

333

Theoretical and experimental research on machine tool servo system for ultra-precision position compensation on CNC lathe  

NASA Astrophysics Data System (ADS)

The theories and techniques for improving machining accuracy via position control of diamond tool's tip and raising resolution of cutting depth on precise CNC lathes have been extremely focused on. A new piezo-driven ultra-precision machine tool servo system is designed and tested to improve manufacturing accuracy of workpiece. The mathematical model of machine tool servo system is established and the finite element analysis is carried out on parallel plate flexure hinges. The output position of diamond tool's tip driven by the machine tool servo system is tested via a contact capacitive displacement sensor. Proportional, integral, derivative (PID) feedback is also implemented to accommodate and compensate dynamical change owing cutting forces as well as the inherent non-linearity factors of the piezoelectric stack during cutting process. By closed loop feedback controlling strategy, the tracking error is limited to 0.8 ?m. Experimental results have shown the proposed machine tool servo system could provide a tool positioning resolution of 12 nm, which is much accurate than the inherent CNC resolution magnitude. The stepped shaft of aluminum specimen with a step increment of cutting depth of 1 ?m is tested, and the obtained contour illustrates the displacement command output from controller is accurately and real-time reflected on the machined part.

Ma, Zhichao; Hu, Leilei; Zhao, Hongwei; Wu, Boda; Peng, Zhenxing; Zhou, Xiaoqin; Zhang, Hongguo; Zhu, Shuai; Xing, Lifeng; Hu, Huang

2010-08-01

334

MAPT rs242562 and GSK3B rs334558 are associated with Parkinson’s Disease in central China  

PubMed Central

Background Microtubule-associated protein tau (MAPT) is a neuronal protein involved in the pathogenesis of several neurodegenerative diseases including Parkinson’s Disease (PD). Glycogen synthase kinase 3 beta (GSK3B) catalyzes phosphorylation in multiple sites of tau protein. However, whether or not there is any association between the GSK3B gene alteration, MAPT haplotype and PD remains unexplored in Chinese population, especially in central Chinese population. Results Here, we aimed at studying the effect of MAPT rs242562 and GSK3B rs334558 on the risk of PD by performing a case-control association study in central China. Our data showed that all PD patients and controls were of MAPT H1/H1 diplotype in our study, thus confirming that the distribution of the MAPT H1 haplotype is common in China. GG genotype of MAPT rs242562 serves protection effect on PD risk in central Chinese population, while genotype of GSK3B rs334558 showed no difference between PD patients and controls. Conclusions We conclude that the MAPT rs242562 is associated with PD in central China in the background of MAPT H1/H1 diplotype. The GG genotype of rs242562 displays protection against PD in subgroup with GSK3B rs334558 T carrier. PMID:24779391

2014-01-01

335

Quantitative analysis of the association between CRP rs2808630 and rs1417938 polymorphisms and cancer risk  

PubMed Central

Accumulating evidence indicates that polymorphisms in the CRP gene are important in the development of cancer. The current meta-analysis was performed to investigate the association between CRP polymorphisms 3407 A>G (rs2808630) and 29 A>T (rs1417938), and the risk of developing cancer. A search of the relevant literature was conducted using the PubMed database to identify eligible studies published up until March 25, 2014. Five case-control studies involving 888 cases and 3,167 controls for the 3407 A>G polymorphism, and six case-control studies involving 3,110 cases and 5,951 controls for the 29 A>T polymorphism were included in the current meta-analysis. The pooled odds ratios with 95% confidence intervals were calculated using the fixed- or random-effects model. Meta-analysis identified no association between the CRP 3407 A>G and 29 A>T polymorphisms, and overall cancer risk. Additional stratified analysis by cancer type did not reveal any significant associations in the genetic models investigated. The findings of the present study indicated that CRP 3407 A>G and 29 A>T polymorphisms are not associated with cancer risk. PMID:25624919

WANG, JIAN-GONG; ZHANG, YANG; XIAO, TIAN-LIN

2015-01-01

336

Enantioselective degradation of (2RS,3RS)-paclobutrazol in peach and mandarin under field conditions.  

PubMed

In this study we investigated the enantioselective degradation of (2RS,3RS)-paclobutrazol in peach and mandarin fruits under field conditions after foliar treatment at 500 mg active ingredient/L using a Lux Cellulose-1 chiral column on a reverse-phase liquid chromatography-tandem mass spectrometry system. Degradations of paclobutrazol in both fruits followed first-order kinetics, with half-lives of about 9 days. Initial deposits were 1.63 mg/kg on peach and 1.99 mg/kg on mandarin; terminal concentrations were lower than 0.05 mg/kg, which was acceptable in most cases. As anticipated, paclobutrazol levels in peels of mature mandarin were about 6.3 times higher than in pulp, indicating the potential risk of peel consumption. We also observed that paclobutrazol degradation in mature mandarin was relatively slow, indicating it might not be efficient enough to hold mandarin fruits on trees for lowering paclobutrazol concentrations. Significant enantioselectivity was observed: the (2R,3R)-enantiomer was preferentially degraded in mandarin (whole fruit, peels, and pulp) but enriched in peach. Because of its more rapid degradation in mandarin and the lower levels observed in pulp compared with peels, potential endocrine-related side effects due to the (2R,3R)-enantiomer pose less of a risk in mandarin than in peach. PMID:24890866

Wang, Xiangyun; Qi, Peipei; Yang, Guiling; Wang, Xinquan; Zhang, Hu; Xu, Hao; Wang, Zhiwei; Wang, Qiang

2014-08-01

337

RS-Predictor models augmented with SMARTCyp reactivities: Robust metabolic regioselectivity predictions for nine CYP isozymes  

PubMed Central

RS-Predictor is a tool for creating pathway-independent, isozyme-specific site of metabolism (SOM) prediction models using any set of known cytochrome P450 substrates and metabolites. Until now, the RS-Predictor method was only trained and validated on CYP 3A4 data, but in the present study we report on the versatility the RS-Predictor modeling paradigm by creating and testing regioselectivity models for substrates of the nine most important CYP isozymes. Through curation of source literature, we have assembled 680 substrates distributed among CYPs 1A2, 2A6, 2B6, 2C19, 2C8, 2C9, 2D6, 2E1 and 3A4, which we believe is the largest publicly accessible collection of P450 ligands and metabolites ever released. A comprehensive investigation into the importance of different descriptor classes for predicting the regioselectivity of each isozyme is made through the generation of multiple independent RS-Predictor models for each set of isozyme substrates. Two of these models include a DFT reactivity descriptor derived from SMARTCyp. Optimal combinations of RS-Predictor and SMARTCyp are shown to have stronger performance than either method alone, while also exceeding the accuracy of the commercial regioselectivity prediction methods distributed by StarDrop and Schrödinger, correctly identifying a large proportion of the metabolites in each substrate set within the top two rank-positions: 1A2(83.0%), 2A6(85.7%), 2B6(82.1%), 2C19(86.2%), 2C8(83.8%), 2C9(84.5%), 2D6(85.9%), 2E1(82.8%), 3A4(82.3%) and merged(86.0%). Comprehensive datamining of each substrate set and careful statistical analyses of the predictions made by the different models revealed new insights into molecular features that control metabolic regioselectivity and enable accurate prospective prediction of likely SOMs. PMID:22524152

Zaretzki, Jed; Rydberg, Patrik; Bergeron, Charles; Bennett, Kristin P.; Olsen, Lars

2012-01-01

338

Niobium in R And (S6, 6e) and HR 1105 (S5, 3). [S star abundance  

NASA Technical Reports Server (NTRS)

Lines of the first multiplet of niobium are strong in R And and HR 1105. These lines are also present in other S stars: HR 8714, R Cam, V Cnc, R CMi, and T Sgr. They are also visible in the M stars, Beta-Peg and Mu-UMa. An approximation to the abundance ratio, Nb/Fe, has been deduced from pairs of lines having nearly equal intensity. In R And, the ratio is about 200 times the solar value. It is hoped that good plates will soon be obtained for the near infrared region, so that the significant Nb/Rb abundance ratio may be determined.

Davis, D. N.

1985-01-01

339

Naproxen–eudragit ® RS100 nanoparticles: Preparation and physicochemical characterization  

Microsoft Academic Search

The objective of the present study was to formulate naproxen–eudragit® RS100 nanoparticles and investigate the physicochemical characteristics of the prepared nanoparticles. The nanoparticles of naproxen with eudragit® RS100 were formulated using the solvent evaporation\\/extraction technique (the single emulsion technique). The effect of several process parameters, i.e., drug\\/polymer ratio, aqueous phase volume and speed of homogenization were considered on the size

Khosro Adibkia; Yousef Javadzadeh; Siavoush Dastmalchi; Ghobad Mohammadi; Fatemeh Kari Niri; Mahmood Alaei-Beirami

2011-01-01

340

Design and Implementation of MaRS: A Routing Testbed  

Microsoft Academic Search

This paper presents the design and implementation of MaRS, a discrete-event simulation testbedfor developing routing algorithms for wide-area computer networks. MaRS allows the user to definea network configuration consisting of physical network, routing algorithm and workload. The usercan control its simulation, log the values of selected parameters, and save, load and modify networkconfigurations. To accomodate a variety of network configurations

Cengiz Alaettinoglu

1992-01-01

341

57ime CONGRS CANADIEN DE GOTECHNIQUE 57TH CANADIAN GEOTECHNICAL CONFERENCE 5ime CONGRS CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE  

E-print Network

CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE SIMULATING ACID MINE DRAINAGE THROUGH MINE WASTES Québec ABSTRACT The evolution of acid mine drainage (AMD) from reactive mine wastes is simulated using that sulphide oxidation and acid mine drainage can be significantly reduced using capillary barriers

Aubertin, Michel

342

57ime CONGRS CANADIEN DE GOTECHNIQUE 57TH CANADIAN GEOTECHNICAL CONFERENCE 5ime CONGRS CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE  

E-print Network

CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE PERFORMANCE OF 30 mil PVC GEOMEMBRANE EXPOSED of flexible PVC geomembranes to leachate chemicals is an important factor when PVC geomembranes are being results that evaluate the chemical compatibility of a 0.76 mm (30 mil) thick flexible PVC geomembrane

343

Cloning and heterologous expression of the ftfCNC-2(1) gene from Weissella confusa MBFCNC-2(1) as an extracellular active fructansucrase in Bacillus subtilis.  

PubMed

Fructan-exopolysaccharides (fructan-EPS) (inulin and levan) and their oligosaccharides (fructooligosaccharides, FOS) have drawn considerable interest in the food and pharmaceutical industries. EPS-producing lactic acid bacteria have been reported to produce ?-fructans (inulin and levan), as well as ?-glucans, by the function of sucrase enzymes, i.e., fructansucrase and glucansucrase. A fructansucrase ftfCNC-2(1) gene from Weissella confusa strain MBFCNC-2(1) was previously cloned in Escherichia coli. In this study, we aimed to express the ftf[CNC-2(1)] gene in Bacillus subtilis to obtain the active form of the extracellular recombinant protein FTF[CNC-2(1)]. This cloning was achieved by inserting the gene in-fusion with the signal sequence of the B. subtilis subtilisin E. SDS-polyacrylamide gel electrophoresis analysis and in situ activity assay with Periodic Acid-Schiff staining revealed that the recombinant FTF[CNC-2(1)] was successfully expressed as an extracellular protein from B. subtilis DB403 in its active form, which was confirmed using sucrose and raffinose. PMID:25454699

Malik, Amarila; Hapsari, Maria Tyas; Ohtsu, Iwao; Ishikawa, Shu; Takagi, Hiroshi

2015-05-01

344

57ime CONGRS CANADIEN DE GOTECHNIQUE 57TH CANADIAN GEOTECHNICAL CONFERENCE 5ime CONGRS CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE  

E-print Network

CONJOINT SCG/AIH-CNN 5TH JOINT CGS/IAH-CNC CONFERENCE A GEOMETRICAL APPROACH FOR THE ESTIMATION OF SCALE e are model parameters, which must satisfy the conditions c 0. These parameters can be determined from the following relationships: a = r [2

Aubertin, Michel

345

An open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and industrial CAM software.  

PubMed

China-made 5-axis simultaneous contouring CNC machine tool and domestically developed industrial computer-aided manufacture (CAM) technology were used for full crown fabrication and measurement of crown accuracy, with an attempt to establish an open CAM system for dental processing and to promote the introduction of domestic dental computer-aided design (CAD)/CAM system. Commercially available scanning equipment was used to make a basic digital tooth model after preparation of crown, and CAD software that comes with the scanning device was employed to design the crown by using domestic industrial CAM software to process the crown data in order to generate a solid model for machining purpose, and then China-made 5-axis simultaneous contouring CNC machine tool was used to complete machining of the whole crown and the internal accuracy of the crown internal was measured by using 3D-MicroCT. The results showed that China-made 5-axis simultaneous contouring CNC machine tool in combination with domestic industrial CAM technology can be used for crown making and the crown was well positioned in die. The internal accuracy was successfully measured by using 3D-MicroCT. It is concluded that an open CAM system for dentistry on the basis of China-made 5-axis simultaneous contouring CNC machine tool and domestic industrial CAM software has been established, and development of the system will promote the introduction of domestically-produced dental CAD/CAM system. PMID:22038364

Lu, Li; Liu, Shusheng; Shi, Shenggen; Yang, Jianzhong

2011-10-01

346

Association of rs1568885, rs1813443 and rs4411591 polymorphisms with anti-TNF medication response in Greek patients with Crohn’s disease  

PubMed Central

AIM: To investigate the correlation between rs1568885, rs1813443 and rs4411591 polymorphisms and response to infliximab in a cohort of Greek patients with Crohn’s disease (CD). METHODS: One hundred and twenty-six patients diagnosed with CD based on standard clinical, endoscopic, radiological, and pathological criteria were enrolled in this study at the Gastroenterology Unit of the 2nd Department of Surgery and at the Colorectal Unit of the 1st Department of Propaedeutic Surgery. Infliximab at a dose of 5 mg/kg was administered intravenously at weeks 0, 2, 6 and then every 8 wk. Clinical and serological responses were assessed using the Harvey-Bradshaw Index and serum C-reactive protein (CRP) levels, respectively, and the endoscopic response was evaluated by ileocolonoscopy performed at baseline and after 12-20 wk of therapy. The changes in endoscopic appearance compared to baseline were classified into four categories, and patients were classified as responders and non-responders. Genomic DNA from whole peripheral blood was extracted and genotyping was performed by allele-specific polymerase chain reactions. ?2 test with Yate’s correction based on the S-Plus was used to compare the genotype frequencies. RESULTS: Eighty patients (63.49%) were classified as complete and 32 (25.39%) as partial responders to infliximab, while 14 (11.11%) were primary non-responders. No correlation was found between response to infliximab and patients’ characteristics such as age, gender and disease duration. There was consistency between Harvey-Bradshaw index scores and serum CRP levels. The TT genotype of the rs1568885 polymorphism was significantly related to partial response (P = 0.024) and resistance to infliximab (P = 0.007) while the AT genotype was more frequent in partial responders (P = 0.035) and in primary non-responders (P = 0.032). Regarding rs1813443, the CC genotype was found to be associated with partial response (P = 0.005) and primary resistance (P = 0.002) to infliximab while no association was found between the rs4411591 polymorphism and the clinical response to infliximab. CONCLUSION: Based on our results, the rs1568885 and rs1813443 polymorphisms are associated with clinical and biochemical response to infliximab in Greek patients with Crohn’s disease. PMID:24707144

Thomas, Diamantis; Gazouli, Maria; Karantanos, Theodoros; Rigoglou, Stella; Karamanolis, Georgios; Bramis, Konstantinos; Zografos, George; Theodoropoulos, George E

2014-01-01

347

Naproxen-eudragit RS100 nanoparticles: preparation and physicochemical characterization.  

PubMed

The objective of the present study was to formulate naproxen-eudragit RS100 nanoparticles and investigate the physicochemical characteristics of the prepared nanoparticles. The nanoparticles of naproxen with eudragit RS100 were formulated using the solvent evaporation/extraction technique (the single emulsion technique). The effect of several process parameters, i.e., drug/polymer ratio, aqueous phase volume and speed of homogenization were considered on the size of the nanoformulations. The physicochemical characteristics of nanoparticles were studied applying particle size analysis, differential scanning calorimetry, X-ray crystallography, Fourier transform infrared spectroscopy and scanning electron microscopy. The release rate of naproxen from various drug/polymer nanoparticles was investigated as well. All the prepared formulations using eudragit RS100 resulted in nano-range size particles with relative spherical smooth morphology. The nanoparticles of naproxen-eudragit RS100 displayed lower crystallinity. The intermolecular interaction between naproxen and eudragit RS100 was detected in the FT-IR spectrum of the nanoparticles. All the nanoparticles displayed a slowed release pattern with the reduced burst release in comparison with the intact drug powder and physical mixtures of drug and polymer. According of these findings, formulation of the naproxen-eudragit RS100 nanoparticles was able to improve the physicochemical characteristics of the drug and possibly will increase the anti-inflammatory effects of drug following its ocular or intra-joint administration. PMID:21130612

Adibkia, Khosro; Javadzadeh, Yousef; Dastmalchi, Siavoush; Mohammadi, Ghobad; Niri, Fatemeh Kari; Alaei-Beirami, Mahmood

2011-03-01

348

Star clusters  

Microsoft Academic Search

Star clusters are observed in almost every galaxy. In this thesis we address several fundamental problems concerning the formation, evolution and disruption of star clusters. From observations of (young) star clusters in the interacting galaxy M51, we found that clusters are formed in complexes of stars and star clusters. These complexes share similar properties with giant molecular clouds, from which

M. Gieles

2006-01-01

349

Association of SNPs in GHSR rs292216 and rs509035 on dietary intake in Indonesian obese female adolescents  

PubMed Central

Background: Obesity has been linked to high dietary intake and low physical activity. Studies showed that those factors were not only regulated by environment but also by genetic. However, the relationship is less been understood in obese children and adolescents. Objective: The objective of this study was to examine the role of SNPs in GHSR rs292216 and rs509035 on dietary intake in obese female adolescents. Methods: This is an observational study with cross sectional design. Respondents were obese female adolescents enrolled from obesity screening done in six junior high schools in Yogyakarta. Dietary intake was measured using 6 days 24 hours inconsecutive dietary recall. Genotyping of 2 SNPs from GHSR was done using FRLP-PCR. Results: There were 78 obese female adolescents joined this study. We found that no significant association between SNPs GHSR and dietary intake (p < 0.05). In addition, a SNP-SNP interaction analysis shown there is no difference between combination of GHSR rs292216 and rs509035 on dietary intake (p < 0.05). Conclusion: We concluded that SNPs on GHSR rs292216 and rs509035 were not related to dietary intake in Indonesian obese female adolescents. Further study is necessary to investigate the effect of those genes on dietary intake in the broader population.

Luglio, Harry Freitag; Inggriyani, Cut Gina; Huriyati, Emy; Julia, Madarina; Susilowati, Rina

2014-01-01

350

OxymiRs in Cutaneous Development, Wound Repair and Regeneration  

PubMed Central

The state of tissue oxygenation is widely recognized as a major microenvironmental cue that is known to regulate the expression of coding genes. Recent works have extended that knowledge to demonstrate that the state of tissue oxygenation may potently regulate the expression of microRNAs (miRs). Collectively, such miRs that are implicated in defining biological outcomes in response to a change in the state of tissue oxygenation may be referred to as oxymiRs. Broadly, oxymiRs may be categorized into three groups: (A) the existence (expression and/or turnover) of which is directly influenced by changes in the state of tissue oxygenation; (B) the existence of which is indirectly (e.g. oxygen-sensitive proteins, metabolites, pH etc) influenced by changes in the state of tissue oxygenation; and (C) those that modify biological outcomes to changes in the state of tissue oxygenation by targeting oxygen sensing pathways. This work represents the first review of how oxymiRs may regulate development, repair and regeneration. Currently known oxymiRs may affect the functioning of a large number of coding genes which have hitherto fore never been linked to oxygen sensing. Many of such target genes have been validated and that number is steadily growing. Taken together, our understanding of oxymiRs has vastly expanded the implications of changes in the state of tissue oxygenation. This emerging paradigm has major implications in untangling the complexities underlying diseases associated with ischemia and related hypoxic insult such as chronic wounds. PMID:23063665

Sen, Chandan K.; Roy, Sashwati

2013-01-01

351

Photospheric and chromospheric active regions on three single-lined RS CVn binaries  

NASA Astrophysics Data System (ADS)

A monitoring of three active RS CVn binaries has been performed with medium resolution spectroscopy with the aim of investigating the behavior of chromospheric and photospheric inhomogeneities. Surface temperature, as recovered from line-depth ratios (LDRs), allowed us to map the photospheric spots, while the H? emission has been used as an indicator of chromospheric inhomogeneities. We have found that the rotational modulation of the H? emission is always in anti-phase with the temperature wave, i.e. at the time of our observations active regions at chromospheric and photospheric levels are closely spatially associated in these active stars. The residual H? profiles, obtained as the difference between the observed spectra and non-active templates, are well reproduced by a two Gaussian fitting. The broad emission component, responsible for the wide emission wings in near all the spectra, is often blue-shifted with respect to the center of the stellar disk. The narrow H? emission displays a phase-dependent variation in all stars and is anti-correlated with the photospheric diagnostics, while the broad one displays no or little rotational modulation. We suggest that the broad emission component is mainly related to physical phenomena, like micro-flaring or strong chromospheric velocity fields, occurring all over the star disk, while the central narrow emission is more affected by chromospheric plages. We have also detected a modulation of the intensity of the He I D3 line with the star rotation, suggesting surface features also in the upper chromosphere of these stars.

Biazzo, K.; Frasca, A.; Catalano, S.; Marilli, E.

2006-02-01

352

Association between macrophage migration inhibitory factor rs1007888 and GDM.  

PubMed

We investigated the association between macrophage migration inhibitory factor (MIF) rs1007888 single-nucleotide polymorphisms and the genetic susceptibility to gestational diabetes mellitus (GDM). A total of 240 GDM pregnant women (GDM group) and 330 healthy pregnant women (control group) were included in the study. Differences in the MIF rs1007888 genotype and allele frequencies and differences between fasting blood glucose, fasting insulin, homeostatic model assessment (HOMA)-insulin resistance, and HOMA-b levels of pregnant women with different genotypes were compared. MIF genotype distributions were significantly different in the GDM group compared to the control group (P < 0.05). No significant difference was observed in the allele distributions of MIF rs1007888 between the GDM group and control group (P > 0.05). GDM patients had higher fasting blood glucose, fasting insulin, and HOMA-insulin resistance levels, but lower HOMA-b levels than normal gestational women (P < 0.05). Fasting blood glucose, fasting insulin, and HOMA-insulin resistance in pregnant women with the GG genotype were significantly higher than those with GA and AA genotypes, while HOMA-b in pregnant women with the GG genotype was lower (all P < 0.05). Our findings demonstrated the associations among MIF polymorphism rs1007888, insulin resistance, and pancreatic ? cell functions in GDM patients. The GG genotype of MIF rs1007888 may be a genetic susceptibility factor in the pathogenesis of GDM. PMID:25730019

Zhan, Y; Li, C; Chen, J; Yu, S; Gao, Q; Wang, Y P; Liu, S G

2015-01-01

353

Expression, purification, and characterization of rhTyrRS  

PubMed Central

Background Aminoacyl-tRNA synthetases (AARSs) catalyze the first step of protein synthesis. Emerging evidence indicates that AARSs may have additional functions, playing a role in signal transduction pathways regulating thrombopoiesis and inflammation. Recombinant human tyrosyl-tRNA synthetase (rhTyrRS) is engineered with a single amino acid substitution that unmasks its cytokine activity. An industrial production method that provides high yield as well as high purity, quality, and potency of this protein is required for preclinical research. Results We expressed codon-optimized rhTyrRS in Escherichia coli under fermentation conditions. Soluble protein was purified by a three-step purification method using cation exchange chromatography, gel filtration chromatography, and anion exchange chromatography. We also established a method to test the biological activity of rhTyrRS by measuring aminoacylation and IL-8 release in rhTyrRS-treated HL-60 cells. Conclusions The characterization of purified rhTyrRS indicated that this protein can be used in pharmacodynamic and pharmacokinetic studies. PMID:25027604

2014-01-01

354

Lipoprotein Lipase SNPs rs13702 and rs301 Correlate with Clinical Outcome in Chronic Lymphocytic Leukemia Patients  

PubMed Central

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world and is characterized by a heterogeneous clinical course. This variability in clinical course has spiked the search for prognostic markers able to predict patient evolution at the moment of diagnosis. Markers demonstrated to be of value are the mutation status of the immunoglobulin heavy chain variable region genes (IGHV) and lipoprotein lipase (LPL) expression. High LPL mRNA expression has been associated with short treatment free (TFS) and decreased overall survival (OS) in CLL. The LPL SNPs rs301 (Trs328 (Crs13702 (Trs13702 wild-type T/T genotype had significantly shorter OS than patients with C/C and T/C genotypes (median time until CLL related death: 90 and 156 months respectively, p=0.008). The same was observed for LPL SNP rs301 (median time until CLL related death T/T: 102 and C/C, T/C: 144 months, p=0.03). Both SNPs rs301 and rs13702 were significantly associated with each other and notably, no association was found between IGHV status and presence of the SNP genotypes, indicating that these LPL SNPs are reliable prognostic markers that could add extra prognostic and predictive information to classical markers and help to improve the management of CLL. PMID:25811490

Rombout, Ans; Stamatopoulos, Basile; Lagneaux, Laurence; Lust, Sofie; Offner, Fritz; Naessens, Evelien; Vanderstraeten, Hanne; Verhasselt, Bruno; Philippé, Jan

2015-01-01

355

*Intel and the Intel logo are registered trademarks of Intel Corporation. Other brands and names are the property of their respective owners The Concurrent Collections (CnC) Parallel Programming  

E-print Network

are the property of their respective owners The Concurrent Collections (CnC) Parallel Programming Model and names are the property of their respective owners 8 Influence 1: Streaming ·!CnC is like Streaming

Hazelwood, Kim

356

The 100 Brightest X-Ray Stars within 50 Parsecs of the Sun  

NASA Astrophysics Data System (ADS)

Based on the Hipparcos and Tycho-2 astrometric catalogs and the ROSAT surveys, a sample of 100 stars most luminous in X-rays within or around a distance of 50 pc is culled. The smallest X-ray luminosity in the sample, in units of 1029 ergs s-1, is LX=9.8 the strongest source in the solar neighborhood is II Peg, a RS CVn star, at LX=175.8. With respect to the origin of X-ray emission, the sample is divided into partly overlapping classes of pre-main-sequence, post-T Tauri, and very young ZAMS objects (type XY), RS CVn-type binary stars (type RS), other active short-period binaries, including binary BY Dra-type objects (type XO), apparently single or long-period binary active evolved stars (type XG), contact binaries of WU UMa kind (type WU), apparently single or long-period binary variable stars of BY Dra kind (type BY), and objects of unknown nature (type X?). Chromospherically active, short-period binaries (RS and XO) make up 40% of the brightest X-ray emitters, followed by young stars (XY) at 30% and unknown sources (X?) at 15%. The fraction of spectroscopically single evolved X-ray emitters of spectral classes IV and III is quite large (10%). The sources identified as RS CVn-type stars (RS, 23 objects) are considerably stronger in X-ray than the XY-objects and the other active binaries (XO and WU, 20 objects). Seven objects have LX>100, all RS except one XY, viz., BO Mic. Only five (22%) RS objects have LX<25, while only three (10%) XY stars have LX>25. Formally, the limit of LX=25 could serve as a statistical criterion to differentiate RS and XY stars. However, the other short-period binaries (including eclipsing stars of Algol and ? Lyr type) have a distribution of LX very similar to the XY objects. The contact binaries (WU) appear to be much weaker in X-rays than their detached counterparts of RS type, but the sample of the former is too small (three objects) to reach a firm conclusion. Sources matched with giants (either single or in binaries) are found to be significantly harder, with only 7% of hardness ratios below 0, than subgiants (66% of HR1<0) and dwarfs (59% of HR1<0). Almost all objects in the sample are binary or multiple stars; the fraction of components (FC), defined as the total number of components in all binary and multiple systems divided by the sum of the total number of components and single stars, is at least 0.90. The FC for the XY objects reaches 0.81, and for the unknown type 0.89. About 70% of RS objects have also visual or astrometric companions, which makes them hierarchical multiple systems. The RS objects (mostly old, evolved stars) and the XY stars have quite different kinematics. While the RS objects move at considerable velocities in apparently random directions with respect to the local standard of rest, the young stars have smaller and orderly velocities and tend to comprise expanding mini-associations such as the ? Pic and the Tucana groups. The majority of the young X-ray active stars belong to the Pleiades stream with the mean heliocentric velocity (U,V,W)=(-9.6,-21.8,-7.7) km s-1.

Makarov, Valeri V.

2003-10-01

357

Polymorphisms rs12998 and rs5780218 in KiSS1 Suppressor Metastasis Gene in Mexican Patients with Breast Cancer  

PubMed Central

Aims. KiSS1 is a metastasis suppressor gene associated with inhibition of cellular chemotaxis and invasion attenuating the metastasis in melanoma and breast cancer cell lines. Along the KiSS-1 gene at least 294 SNPs have been described; however the association of these polymorphisms as genetic markers for metastasis in breast cancer studies has not been investigated. Here we describe two simple PCR-RFLPs protocols to identify the rs5780218 (9DelT) and the rs12998 (E20K) KiSS1 polymorphisms and the allelic, genotypic, and haplotypic frequencies in Mexican general population (GP) and patients with benign breast disease (BBD) or breast cancer (BC). Results. The rs5780218 polymorphism was individually associated with breast cancer (P = 0.0332) and the rs12998 polymorphism shows statistically significant differences when GP versus case (BC and BBD) groups were compared (P < 0.0001). The H1 Haplotype (G/-) occurred more frequently in BC group (0.4256) whereas H2 haplotype (G/T) was the most prevalent in BBD group (0.4674). Conclusions. Our data indicated that the rs5780218 polymorphism individually confers susceptibility for development of breast cancer in Mexican population and a possible role as a genetic marker in breast cancer metastasis for H1 haplotype (Wt/variant) in KiSS1 gene must be analyzed in other populations.

Cruz Quevedo, Edhit Guadalupe; Mimendi Aguilar, Gabriela Monserrat; Juárez Aguilar, Luis Anselmo; Gutierrez Rubio, Susan Andrea; Flores Martínez, Silvia Esperanza; Dávalos Rodríguez, Ingrid Patricia; Sánchez Corona, José; Torres Morán, Martha Isabel; Rosales Gómez, Roberto Carlos; Morán Moguel, María Cristina

2015-01-01

358

rs t ts rss t s C = (Cn  

E-print Network

tr strtrs tts rs t ts rss îs ét îs C = (Cn , n ) st st rs és Cn n Z t st rss n t s s îs C (X, A; G) = Hom(C(X, A), G)) ssr C (X, G) ré s ts sr C(A) #12; ts rss r q tt ss r sr r rss tt é îs r C = (C, ) r tt r é G st st t tr 0 --- Ext(Hn-1(C), G) --- Hn (Hom(C, G)) --- Hom

Blanchet, Christian - Institut de Mathématiques de Jussieu, Université Paris 7

359

Strange stars  

NASA Technical Reports Server (NTRS)

Strange matter, a form of quark matter that is postulated to be absolute stable, may be the true ground stage of the hadrons. If this hypothesis is correct, neutron stars may convert to 'strange stars'. The mass-radius relation for strange stars is very different from that of neutron stars; there is no minimum mass, and for mass of 1 solar mass or less, mass is proportional to the cube of the radius. For masses between 1 solar mass and 2 solar masses, the radii of strange stars are about 10 km, as for neutron stars. Strange stars may have an exposed quark surface, which is capable of radiating at rates greatly exceeding the Eddington limit, but has a low emissivity for X-ray photons. The stars may have a thin crust with the same composition as the preneutron drip outer layer of a conventional neutron star crust. Strange stars cool efficiently via neutrino emission.

Alcock, Charles; Farhi, Edward; Olinto, Angela

1986-01-01

360

Stars and Star Myths.  

ERIC Educational Resources Information Center

Myths and tales from around the world about constellations and facts about stars in the constellations are presented. Most of the stories are from Greek and Roman mythology; however, a few Chinese, Japanese, Polynesian, Arabian, Jewish, and American Indian tales are also included. Following an introduction, myths are presented for the following 32…

Eason, Oliver

361

Associations of rs4810485 and rs1883832 polymorphisms of CD40 gene with susceptibility and clinical findings of Behçet's disease.  

PubMed

There are evidences that besides geographic tendency, interactions between genetic and environmental factors play an essential role in the pathogenesis of Behçet's disease (BD). In this study, we have evaluated the associations between rs4810485 and rs1883832 single nucleotide polymorphism (SNP)s of CD40 gene with the susceptibility and clinical findings of BD. Two hundred and eighty-five patients with BD and 225 age-matched healthy controls were enrolled in this study. The clinical findings of patients were noted. The distributions of genotypes, alleles, combined genotypes and haplotypes of these two SNPs in BD patients were compared with those in healthy controls. In further evaluation, we evaluated the patients with and without any of clinical findings with regarding to distribution of genotypes and alleles of these two SNPs. There was no significant difference concerning frequencies of genotypes, alleles, combined genotypes and haplotypes of rs4810485 and rs1883832 between patients and controls (p > 0.05 for all). Frequency of GT genotype of CD40 rs4810485 polymorphism was found to be significantly higher in patients with skin lesions (p < 0.05, OR 1.65, 95 % CI 1.02-2.64). Also, we have found significantly higher frequencies of CC genotype and C allele of CD40 rs1883832 polymorphism in patients with genital ulcers (p < 0.05 for both, OR 2.30, 95 % CI 1.07-4.94 and OR 1.78, 95 % CI 1.06-2.97, respectively). However, these significances were disappeared after Bonferroni correction. We suggest that differences in the expression levels of CD40 because of different genotypes of these two SNPs may take part in the development of skin lesions or genital ulcers in patients with BD. PMID:25373542

?nal, Esra Erkol; Rüstemo?lu, Ayd?n; ?nan?r, Ahmet; Ekinci, Duygu; Gül, Ülker; Yi?it, Serbülent; Ate?, Ömer

2015-05-01

362

Association of Versican (VCAN) gene polymorphisms rs251124 and rs2287926 (G428D), with intracranial aneurysm  

PubMed Central

Intracranial aneurysm (IA) accounts for 85% of Subarachnoid Hemorrhage (SAH) and is mainly caused due to the weakening of arterial wall. The structural integrity of the intracranial arteries is mainly influenced by the extracellular matrix (ECM) remodeling. The Proteoglycan Versican plays an important role in extracellular matrix assembly and plays a major role in the pathogenesis of IA. The linkage studies also indicated VCAN as a putative candidate gene for IA in the 5q22–31 region. Using a case–control study design, we tested the hypothesis whether the variants in VCAN gene, nonsynonymous variants in the coding region of Glycosaminoglycan ? (GAG-?) and GAG-? and two reported SNPs involved in splicing rs251124 and rs173686 can increase the risk of aSAH among South Indian patients, either independently, or by interacting with other risk factors of the disease. We selected 200 radiologically confirmed aneurysmal cases and 250 ethnically, age and sex matched controls from the Dravidian Malayalam speaking population of South India. The present study reiterated the earlier association of rs251124 with intracranial aneurysm (P = 0.0002) and also found a novel association with rs2287926 (G428D) in exon 7 coding for GAG-? with intracranial aneurysm (P = 0.0015). Interestingly, both these SNPs contributed to higher risk for aneurysm in males. In-silico analysis predicted this SNP to have the highest functional relevance in the gene which might have a potentially altered regulatory role in transcription and splicing. Using meta-analysis with available literature rs251124 was found to be the strongest intracranial aneurysm marker for global ethnicities. This study with a novel functional SNP rs2287926 (G428D) further substantiates the potential role of VCAN in the pathogenesis of IA. PMID:25606449

Sathyan, Sanish; Koshy, Linda V.; Balan, Shabeesh; Easwer, H.V.; Premkumar, S.; Nair, Suresh; Bhattacharya, R.N.; Alapatt, Jacob P.; Banerjee, Moinak

2014-01-01

363

Unified error model based spatial error compensation for four types of CNC machining center: Part II-unified model based spatial error compensation  

NASA Astrophysics Data System (ADS)

In this paper, a spatial error compensation method was proposed for CNC machining center based on the unified error model. The spatial error distribution was analyzed in this research. The result shows that the spatial error is relative to each axis of a CNC machine tool. Moreover, the spatial error distribution is non-linear and there is no regularity. In order to improve the modeling accuracy and efficiency, an automatic error modeling application was designed based on the orthogonal polynomials. To realize the spatial error compensation, a multi-thread parallel processing mode based error compensation controller was designed. Using the spatial error compensation method, the machine tools' accuracy is greatly improved compared to that with no compensation.

Fan, Kaiguo; Yang, Jianguo; Yang, Liyan

2014-12-01

364

Interface Conversion Design Based on FPGA-Soft-Macro for EnDat2.2 and RS232\\/RS485  

Microsoft Academic Search

The EnDat2.2 interface protocol developed by HEIDENHAIN company lately with its high-speed, bi-directional and pure digital features can meet the requirement of rapid responses, dramatically cut down the overall system's cost and greatly reduce the space requirements of the system's installation. Therefore, it is widely used in Numerical control system like CNC system and photoelectric encoder. China's first Micro-area X-ray

Yang Jian; Wang Hanbin; Yao Xangqian; Wan Sanghong

2010-01-01

365

Restoring New Agegraphic Dark Energy in RS II Braneworld  

E-print Network

Motivated by recent works [1,2], we investigate new agegraphic model of dark energy in the framework of RS II braneworld. We also include the case of variable gravitational constant in our model. Furthermore, we establish correspondence between the new agegraphic dark energy with other dark energy candidates based on scalar fields.

Mubasher Jamil; Kayoomars Karami; Ahmad Sheykhi

2011-06-14

366

359-06/RDS/rs PERSISTENT SURVEILLANCE FOR  

E-print Network

the basis for a fusion DEMO Power Plant #12;359-06/RDS/rs A Fusion Nuclear Science Facility, ITER nuclear technology development Off-axis current profile control - ECCD (170 GHz) - Lower Hybrid - NBCD of Fusion Research at General Atomics Presented by R.D. Stambaugh Fusion Power Associates Annual Meeting

367

Building a Structured PDB: The RS-PDB Database  

Microsoft Academic Search

A method for automatically analyzing structures deposited in the Protein Data Bank is presented. The method is capable to detect missing atoms, bond length deviations, atom bumps and to correctly identify protein-ligand complexes. The results are organized into a database, called the Rich Structure PDB (RS-PDB in short) from which one can easily select PDB entries satisfying diverse sets of

Zoltan Szabadka; Vince Grolmusz

2006-01-01

368

Connecting RS OPh to [some] Type Ia Supernovae  

E-print Network

Aims: Recurrent nova systems like RS Oph have been proposed as a possible channel to Type Ia Supernova explosions, based on the high mass of the accreting white dwarf. Additional support to this hypothesis has been recently provided by the detection of circumstellar material around SN2006X and SN2007le, showing a structure compatible with that expected for recurrent nova outbursts.In this paper we investigate the circumstellar environment of RS Oph and its structure, with the aim of establishing a firmer and independent link between this class of objects and Type Ia SN progenitors. Methods: We study the time evolution of CaII, NaI and KI absorption features in RS Oph, before, during, and after the last outburst, using multi-epoch, high-resolution spectroscopy, and applying the same method adopted for SN2006X and SN2007le. Results: A number of components, blue-shifted with respect to the systemic velocity of RS Oph, are detected. In particular, one feature strongly weakens in the first two weeks after the outb...

Patat, F; Podsiadlowski, Ph; Mason, E; Melo, C; Pasquini, L

2011-01-01

369

Order Code RS20028 Updated August 25, 2008  

E-print Network

-688, title I 1988 U.S. Public Vessel Medical Waste Anti-Dumping Act of 1988 P.L. 100-688, title III 1990. It utilizes a comprehensive and uniform waste management system to regulate disposal or dumping of allOrder Code RS20028 Updated August 25, 2008 Ocean Dumping Act: A Summary of the Law Claudia Copeland

Laughlin, Robert B.

370

Luminescent Ruthenium(II) Complex Bearing Bipyridine and N-Heterocyclic Carbene-based C(?)N(?)C Pincer Ligand for Live-Cell Imaging of Endocytosis.  

PubMed

Luminescent ruthenium(II)-cyanide complex with N-heterocyclic carbene pincer ligand C(?)N(?)C = 2,6-bis(1-butylimidazol-2-ylidene)pyridine and 2,2'-bipyridine (bpy) shows minimal cytotoxicity to both human breast carcinoma cell (MCF-7) and human retinal pigmented epithelium cell (RPE) in a wide range of concentration (0.1-500??M), and can be used for the luminescent imaging of endocytosis of the complex in these cells. PMID:25765974

Tsui, Wai-Kuen; Chung, Lai-Hon; Wong, Matthew Man-Kin; Tsang, Wai-Him; Lo, Hoi-Shing; Liu, Yaxiang; Leung, Chung-Hang; Ma, Dik-Lung; Chiu, Sung-Kay; Wong, Chun-Yuen

2015-01-01

371

Luminescent Ruthenium(II) Complex Bearing Bipyridine and N-Heterocyclic Carbene-based C?N?C Pincer Ligand for Live-Cell Imaging of Endocytosis  

PubMed Central

Luminescent ruthenium(II)-cyanide complex with N-heterocyclic carbene pincer ligand C?N?C = 2,6-bis(1-butylimidazol-2-ylidene)pyridine and 2,2?-bipyridine (bpy) shows minimal cytotoxicity to both human breast carcinoma cell (MCF-7) and human retinal pigmented epithelium cell (RPE) in a wide range of concentration (0.1–500??M), and can be used for the luminescent imaging of endocytosis of the complex in these cells. PMID:25765974

Tsui, Wai-Kuen; Chung, Lai-Hon; Wong, Matthew Man-Kin; Tsang, Wai-Him; Lo, Hoi-Shing; Liu, Yaxiang; Leung, Chung-Hang; Ma, Dik-Lung; Chiu, Sung-Kay; Wong, Chun-Yuen

2015-01-01

372

A STUDY OF FAULT MONITORING IN CNC MACHINING OF FREE-FORM SURFACES BASED ON NN-WAVELET ANALYSIS–TECHNICAL COMMUNICATION  

Microsoft Academic Search

? Tool breakage and overcut are common fault patterns in the process of the free-form surface computer numerical control (CNC) machining. Starting from the analysis of the interactive relationship between the tool and the free-form surface, the geometrical model of the overcut fault is set up in this paper. By using superior time-frequency localization feature of the wavelet transformation and

Shuxin Xu; Yiqiang Wang; Ji Zhao; Guan Le

2008-01-01

373

Luminescent Ruthenium(II) Complex Bearing Bipyridine and N-Heterocyclic Carbene-based C?N?C Pincer Ligand for Live-Cell Imaging of Endocytosis  

NASA Astrophysics Data System (ADS)

Luminescent ruthenium(II)-cyanide complex with N-heterocyclic carbene pincer ligand C?N?C = 2,6-bis(1-butylimidazol-2-ylidene)pyridine and 2,2'-bipyridine (bpy) shows minimal cytotoxicity to both human breast carcinoma cell (MCF-7) and human retinal pigmented epithelium cell (RPE) in a wide range of concentration (0.1-500 ?M), and can be used for the luminescent imaging of endocytosis of the complex in these cells.

Tsui, Wai-Kuen; Chung, Lai-Hon; Wong, Matthew Man-Kin; Tsang, Wai-Him; Lo, Hoi-Shing; Liu, Yaxiang; Leung, Chung-Hang; Ma, Dik-Lung; Chiu, Sung-Kay; Wong, Chun-Yuen

2015-03-01

374

Taguchi and Gauss elimination method: A dual response approach for parametric optimization of CNC wire cut EDM of PRAlSiCMMC  

Microsoft Academic Search

Machining parameters tables provided by the machine tool manufacturers often do not meet the operator requirements and sometimes\\u000a even do not provide efficient guidelines to manufacturing engineers. Hence, a suitable selection of machining parameters of\\u000a CNC wire cut electrical discharge machining (EDM) process is necessary. This paper present a reliable set of parameters that\\u000a demonstrate versatility, and numerous and diverse

A. Manna; B. Bhattacharyya

2006-01-01

375

Possible selective formation of CNC/sup +/ and CCN/sup +/ in the interstellar reactions of C/sup +/ with HCN and HNC/sup +/  

SciTech Connect

The molecular structures of CNC/sup +/ and CCN/sup +/ have been determined by double zeta self-consistent field (SCF) calculations. Their standard heats of formation are theoretically estimated to be 372 +- 20 and 421 +- 25 kcal mol/sup -1/, respectively, the latter determined by double zeta plus polarization SCF-CI (configuration interaction) calculation of the isomerization energy for CNC/sup +/..-->..CCN/sup +/. Using these results, the available appearance potential data for these ions in the mass spectra of HC/sub 3/N and C/sub 2/N/sub 2/ can be explained by simple reactions, and the numerical agreement between the corresponding experimental and theoretical heats of formation is excellent. With this thermochemical information and mechanistic considerations of C/sup +/ reactions with HCN and HNC, we propose that CNC/sup +/ may be selectively made from HCN, and CCN/sup +/ from HNC, and that this selectivity may play an important role in the chemistry of the interstellar medium. For the polar isomer CCN/sup +/ we report an SCF prediction of its rotational constant (11.93 +- 0.5 GHz) and a higher-level (CI) calculation of its electric dipole moment (2.50 +- 0.2 debye) and nitrogen nuclear quadrupole coupling constant (-4.95 +- 0.5 MHz).

Haese, N.N.; Woods, R.C.

1981-05-15

376

Fixed-Phase Observations of RS Canum Venaticorum and BY Draconis Systems  

NASA Astrophysics Data System (ADS)

We present our data set of same-hemisphere, or fixed-phase, observations of five RS Canum Venaticorum and BY Draconis binaries made with the Solar-Stellar Spectrograph at Lowell Observatory. The purpose of this study is to evaluate the level of intrinsic variability in the components of these systems, and to compare it with variability arising from rotational modulation and from long-term, activity cycle-related variability. We obtain fixed-phase observations by observing tidally locked binaries with near-integral-day periods. The fixed-phase observations reveal that the intrinsic variability of the stellar hemispheres is significantly less than the variability induced by rotational modulation or by long-term, activity-cyclic evolution, but only when several spectral features are considered in tandem. Fixed-phase ``flickering'' of the stellar hemispheres is often apparent at a higher level than the rotational or long-term modulation in individual activity indicators. Interpretation of rotational or long-term modulation in active, late-type stars using data that do not allow quantification of the fixed-phase variability of the stars (i.e., data that do not span several rotational periods) is extremely risky.

Hall, Jeffrey C.; Wolovitz, Jeffrey B.

1998-06-01

377

Luminescent organoplatinum(II) complexes with functionalized cyclometalated C^N^C ligands: structures, photophysical properties, and material applications.  

PubMed

A series of [(R'-C^N^C-R'')Pt(L)] complexes with doubly deprotonated cyclometalated R'-C^N^C-R'' ligands (R'-C^N^C-R''=2,6-diphenylpyridine derivatives) functionalized with carbazole, fluorene, or thiophene unit(s) have been synthesized and their photophysical properties studied. The X-ray crystal structures reveal extensive intermolecular ?···? and C-H···? interactions between the cyclometalated C^N^C ligands. Compared to previously reported cyclometalated platinum(II) complexes [(C^N^C)Pt(L)], which are non-emissive in solution at room temperature, the carbazole-, fluorene- and thiophene-functionalized [(R'-C^N^C-R'')Pt(L)] (L=DMSO 1-9, C?N-Ar, 1a-9a) complexes are emissive in solution at room temperature with ?(max) at 564-619 nm and ?=0.02-0.26. The emissions of the [(R'-C^N^C-R'')Pt(L)] complexes are attributed to electronic excited states with mixed (3)MLCT and (3)IL character. The carbazole/fluorene/thiophene unit(s) allow the tuning of the electronic properties of the [(R'-C^N^C-R'')Pt] moiety, with the emission maxima in a range of 564-619 nm. These are the first examples of organoplatinum(II) complexes bearing doubly deprotonated cyclometalated C^N^C ligands that are emissive in solution at room temperature. In non-degassed DMSO, the emission intensities of 6a-9a are enhanced upon exposure to ambient light. This phenomenon is caused by reacting photogenerated (1)O(2) with a DMSO molecule to form dimethyl sulfone, leading to the removal of dissolved oxygen in solution. Self-assembled nanowires and nanorods are obtained from precipitation of 3a in THF/H(2)O and 8a in DMSO/Et(2)O, respectively. The [(R'-C^N^C-R'')Pt(L)] complexes are soluble in common organic solvents with a high thermal stability (>300 °C), rendering them as phosphorescent dopants for organic light-emitting diode (OLEDs) applications. Red OLEDs with CIE coordinates of (0.65±0.01, 0.35±0.01) were fabricated from 7a or 8a. A maximum external efficiency (?(Ext)) of 12.6% was obtained for the device using 8a as emitter. PMID:22170325

Kui, Steven C F; Hung, Faan-Fung; Lai, Shiu-Lun; Yuen, Mai-Yan; Kwok, Chi-Chung; Low, Kam-Hung; Chui, Stephen Sin-Yin; Che, Chi-Ming

2012-01-01

378

OPMILL - MICRO COMPUTER PROGRAMMING ENVIRONMENT FOR CNC MILLING MACHINES THREE AXIS EQUATION PLOTTING CAPABILITIES  

NASA Technical Reports Server (NTRS)

OPMILL is a computer operating system for a Kearney and Trecker milling machine that provides a fast and easy way to program machine part manufacture with an IBM compatible PC. The program gives the machinist an "equation plotter" feature which plots any set of equations that define axis moves (up to three axes simultaneously) and converts those equations to a machine milling program that will move a cutter along a defined path. Other supported functions include: drill with peck, bolt circle, tap, mill arc, quarter circle, circle, circle 2 pass, frame, frame 2 pass, rotary frame, pocket, loop and repeat, and copy blocks. The system includes a tool manager that can handle up to 25 tools and automatically adjusts tool length for each tool. It will display all tool information and stop the milling machine at the appropriate time. Information for the program is entered via a series of menus and compiled to the Kearney and Trecker format. The program can then be loaded into the milling machine, the tool path graphically displayed, and tool change information or the program in Kearney and Trecker format viewed. The program has a complete file handling utility that allows the user to load the program into memory from the hard disk, save the program to the disk with comments, view directories, merge a program on the disk with one in memory, save a portion of a program in memory, and change directories. OPMILL was developed on an IBM PS/2 running DOS 3.3 with 1 MB of RAM. OPMILL was written for an IBM PC or compatible 8088 or 80286 machine connected via an RS-232 port to a Kearney and Trecker Data Mill 700/C Control milling machine. It requires a "D:" drive (fixed-disk or virtual), a browse or text display utility, and an EGA or better display. Users wishing to modify and recompile the source code will also need Turbo BASIC, Turbo C, and Crescent Software's QuickPak for Turbo BASIC. IBM PC and IBM PS/2 are registered trademarks of International Business Machines. Turbo BASIC and Turbo C are trademarks of Borland International.

Ray, R. B.

1994-01-01

379

A catalog of chromospherically active binary stars  

NASA Astrophysics Data System (ADS)

The authors have compiled a catalog of 168 chromospherically active binary stars including the class of RS Canum Venaticorum binaries, BY Draconis binaries and other binaries which show "strong" Ca II H and K emission in their spectra. The catalog contains information on the photometric, spectroscopic, orbital and physical properties of the systems as well as the space motions and positions. Summarized in a candidate list are an additional 37 stars having similar characteristics but which are not definitely known binaries or have not had H and K emission observed. A bibliography and notes for each star are included to direct interested workers to primary references for each of the systems. The catalog contains stars in both the northern and the southern sky.

Strassmeier, K. G.; Hall, D. S.; Zeilik, M.; Nelson, E.; Eker, Z.; Fekel, F. C.

1988-02-01

380

Structures of Binary Star Coronae  

NASA Astrophysics Data System (ADS)

Stellar coronae in binary star systems offer both a puzzle and an opportunity. While one might expect that large magnetic loop structures on close binaries such as RS CVn systems and contact binaries would show evidence for interactions. While some radio studies support this scenario there is surprisingly little evidence from EUV and X-ray observations for differences between binary and single star systems. Meanwhile the binary systems offer observational opportunities through rotational modulation and eclipses of flaring and non-flaring regions. Localizing the sources of coronal emission is key to making the magnetic connection to the underlying photosphere. We discuss the structure of stellar coronae from the perspective of studies of binary systems.

Brickhouse, N. S.

2004-01-01

381

Hybrid Stars  

E-print Network

Recently there have been important developments in the determination of neutron star masses which put severe constraints on the composition and equation of state (EOS) of the neutron star matter. Here we study the effect of quark and nuclear matter mixed phase on mass radius relationship of neutron stars employing recent models from two classes of EOS's and discuss their implications.

Ashok Goyal

2003-03-21

382

Circumpolar Stars  

Microsoft Academic Search

Stars that never set as seen from a particular location. The requirement for this to happen is that the star's polar distance is less than the observer's latitude---thus from a location in latitude 52° North, stars of NPD less than 52° (i.e. with declinations of between 0° and +38°) are circumpolar and will be seen to circle around the north

P. Murdin

2000-01-01

383

Tidal dissipation and eccentricity pumping: Implications for the depth of the secondary eclipse of 55 Cnc e  

E-print Network

We use the super Earth 55 Cnc e as a case study to address an observable effect of tidal heating. We investigate whether planet-planet interactions can force the eccentricity of this planet to a level affecting the eclipse depth observed with Spitzer. Using the constant time lag tidal model, we first calculate the observed planet flux as a function of albedo and eccentricity, for different tidal dissipation constants and for two extreme cases: a planet with no heat redistribution and a planet with full heat redistribution. We derive the values of albedo and eccentricity that match the observed transit depth. We then perform N-body simulations of the planetary system including tides and General Relativity to follow the evolution of the eccentricity of planet e. We compare the range of eccentricities given by the simulations with the eccentricities required to alter the eclipse depth. We find that the eccentricity of planet e can be large enough to contribute at a measurable level to the thermal emission measur...

Bolmont, Emeline; Raymond, Sean N; Leconte, Jeremy; Hersant, Franck; Maurin, Anne-Sophie; Pericaud, Jessica

2013-01-01

384

Flank wears Simulation by using back propagation neural network when cutting hardened H-13 steel in CNC End Milling  

NASA Astrophysics Data System (ADS)

High speed milling has many advantages such as higher removal rate and high productivity. However, higher cutting speed increase the flank wear rate and thus reducing the cutting tool life. Therefore estimating and predicting the flank wear length in early stages reduces the risk of unaccepted tooling cost. This research presents a neural network model for predicting and simulating the flank wear in the CNC end milling process. A set of sparse experimental data for finish end milling on AISI H13 at hardness of 48 HRC have been conducted to measure the flank wear length. Then the measured data have been used to train the developed neural network model. Artificial neural network (ANN) was applied to predict the flank wear length. The neural network contains twenty hidden layer with feed forward back propagation hierarchical. The neural network has been designed with MATLAB Neural Network Toolbox. The results show a high correlation between the predicted and the observed flank wear which indicates the validity of the models.

Hazza, Muataz Hazza F. Al; Adesta, Erry Y. T.; Riza, Muhammad

2013-12-01

385

Synthetic Direct Impact Light Curves of the Ultracompact AM CVn Binary Systems V407 Vul and HM Cnc  

E-print Network

The interacting binary white dwarf (AM CVn) systems HM Cnc and V407 have orbital periods of 5.4 min and 9.5 min, respectively. The two systems are characterized by an "on/off" behaviour in the X-ray light curve, and optical light curves that are nearly sinusoidal and which lead the X-ray light curves in phase by about 0.2 in both systems. Of the models that have been proposed to explain the observations, the one that seems to require the least fine tuning is the direct impact model of Marsh & Steeghs (2002). In this model, the white dwarf primary is large enough relative to the semi-major axis that the accretion stream impacts the surface of the primary white dwarf directly without forming an accretion disc. Marsh & Steeghs proposed that in this situation there could be a flow set up around the equator with a decreasing surface temperature the further one measured from the impact point. In this study, we estimate the light curves that might result from such a temperature distribution, and find them to...

Wood, Matt A

2009-01-01

386

Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e  

E-print Network

Radial velocity measurements of stellar reflex motion have revealed many extra-solar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case of Gl 581d, the distinction between an alias and the true frequency was the distinction between a dead, frozen planet and a planet likely hospitable to life (Udry et al. 2007; Mayor et al. 2009). To improve the characterization of planetary systems, we describe how aliases originate and present a new approach for distinguishing between orbital frequencies and their aliases. Our approach harnesses features in the spectral window function to compare the amplitude and phase of predicted aliases with peaks present in the data. We apply it to confirm prior alias distinctions for the planets GJ 876d and HD 75898b. We find that the true periods of Gl 581c and HD 73526b/c remain ambiguous. We revise the periods of HD 156668b and 55 Cnc e, which were afflicted by daily aliases. For...

Dawson, Rebekah I

2010-01-01

387

Spectroscopy of Nine Cataclysmic Variable Stars  

NASA Astrophysics Data System (ADS)

We present optical spectroscopy of nine cataclysmic binary stars, mostly dwarf novae, obtained primarily to determine orbital periods Porb. The stars and their periods are LX And, 0.1509743(5) days; CZ Aql, 0.2005(6) days; LU Cam, 0.1499686(4) days; GZ Cnc, 0.0881(4) days; V632 Cyg, 0.06377(8) days; V1006 Cyg, 0.09903(9) days; BF Eri, 0.2708804(4) days; BI Ori, 0.1915(5) days; and FO Per, for which Porb is either 0.1467(4) or 0.1719(5) days. Several of the stars proved to be especially interesting. In BF Eri, we detect the absorption spectrum of a secondary star of spectral type K3 +/- 1 subclass, which leads to a distance estimate of ~1 kpc. However, BF Eri has a large proper motion (~100 mas yr-1), and we have a preliminary parallax measurement that confirms the large proper motion and yields only an upper limit for the parallax. BF Eri's space velocity is evidently large, and it appears to belong to the halo population. In CZ Aql, the emission lines have strong wings that move with large velocity amplitude, suggesting a magnetically channeled accretion flow. The orbital period of V1006 Cyg places it squarely within the 2 to 3 hr ``gap'' in the distribution of cataclysmic binary orbital periods. Based on observations obtained at the MDM Observatory, operated by Dartmouth College, Columbia University, Ohio State University, Ohio University, and the University of Michigan.

Sheets, Holly A.; Thorstensen, John R.; Peters, Christopher J.; Kapusta, Ann B.; Taylor, Cynthia J.

2007-05-01

388

RS485 serial port pseudo-full-duplex communication research and application  

Microsoft Academic Search

The RS-485 serial port communication is very popular in a monitoring and controlling system. A concept of RS-485 free port pseudo-full-duplex communication is presented in this paper, that is, RS-485 can not only send timed messages continuously but also receive messages at any moment from the host computer. Since RS-485 serial port has the advantage of far distance communication and

Su Xunwen; Wang Shaoping; Zhu Dongmei; Qishen Zhu

2010-01-01

389

Narcolepsy goes to school: the three Rs for school nurses.  

PubMed

The sleep disorder narcolepsy most often first appears in the teen years. It can dash the dreams of optimistic, intelligent students. It can make some students the target of nasty jokes and bullying, leaving them depressed and socially isolated. It can challenge children's self-esteem, and lowered self-esteem may last a lifetime. Typically, children with narcolepsy gain weight and have no interest in participating in anything. Many constantly feel extreme tiredness, and they may experience cataplexy. School nurses and teachers can help if they know the symptoms and practice the 3 Rs of narcolepsy: Recognize the symptoms of narcolepsy; Respect that narcolepsy is a lifelong, serious sleep disorder that needs treatment; and Refer students who exhibit symptoms to medical professionals. The 3 Rs will help students living with this lifelong disorder to get a fair shake in life's academic, social, and career arenas. PMID:24707660

Gow, Monica

2014-03-01

390

Radiation Dry Bias of the Vaisala RS92 Humidity Sensor  

NASA Technical Reports Server (NTRS)

The comparison of simultaneous humidity measurements by the Vaisala RS92 radiosonde and by the Cryogenic Frostpoint Hygrometer (CFH) launched at Alajuela, Cosla Rica, during July 2005 reveals a large solar radiation dry bias of the Vaisala RS92 humidity sensor and a minor temperature-dependent calibration error. For soundings launched at solar zenith angles between 10" and 30 , the average dry bias is on the order of 9% at the surface and increases to 50% at 15 km. A simple pressure- and temperature-dependent correction based on the comparison with the CFH can reduce this error to less than 7% at all altitudes up to 15.2 km, which is 700 m below the tropical tropopause. The correction does not depend on relative humidity, but is able to reproduce the relative humidity distribution observed by the CFH.

Vomel, H.; Selkirk, H.; Miloshevich, L.; Valverde-Canossa, J.; Valdes, J.; Kyro, E.; Kivi, R.; Stolz, W.; Peng, G.; Diaz, J. A.

2007-01-01

391

359-06/RDS/rs PERSISTENT SURVEILLANCE FOR  

E-print Network

Plant #12;359- 06/ RDS/ rs Integration of Advanced Tokamak Physics, Burning Plasmas, and Fusion Nuclear 301 401 356 1755 Plant Power MW 507 362 395 482 536 Pn/Awall MW/m2 2.0 1.0 1.9 2.5 3.3 0.5 3.3 Qplasma sites for fusion nuclear technology development Off-axis current profile control - ECCD (170 GHz

392

Association of vitamin D receptor BsmI (rs1544410), Fok1 (rs2228570), TaqI (rs731236) and ApaI (rs7975232) gene polymorphism with the nephrolithiasis susceptibility.  

PubMed

Association of vitamin D receptor (VDR) gene polymorphism with the risk of nephrolithiasis from the published reports is still conflicting. This study was conducted to evaluate the relationship between VDR BsmI (rs1544410), Fok1 (rs2228570), TaqI (rs731236) and ApaI (rs7975232) gene polymorphism and the risk of nephrolithiasis using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on 1 April 2014, and eligible investigations were included and synthesized using meta-analysis method. Six reports were recruited into this meta-analysis for the association of VDR BsmI, Fok1, TaqI and ApaI gene polymorphism with nephrolithiasis susceptibility. In this meta-analysis, VDR BsmI, Fok1, TaqI and ApaI gene polymorphism were not associated with nephrolithiasis susceptibility for overall populations and in Caucasians. However, the Fok1 f allele and ff genotype were associated with the risk of nephrolithiasis in Asians, but the FF genotype not. Furthermore, TaqI TT genotype was associated with the risk of nephrolithiasis in Asians, but the t allele and tt genotype not. However, ApaI gene polymorphism was not associated with nephrolithiasis susceptibility in Asians. In conclusion, VDR BsmI, Fok1, TaqI and ApaI gene polymorphism were not associated with nephrolithiasis risk in overall populations and in Caucasians. But, the Fok1 f allele and ff genotype, TaqI TT genotype, ApaI gene polymorphism were associated with the risk of nephrolithiasis in Asians. However, more studies should be conducted to confirm it. PMID:25051494

Zhou, Tian-Biao; Jiang, Zong-Pei; Li, Ai-Hua; Ju, Lang

2015-04-01

393

R.S. Peters’ ‘The justification of education’ revisited  

Microsoft Academic Search

In his 1973 paper ‘The Justification of Education’ R.S. Peters aspired to give a non-instrumental justification of education. Ever since, his so-called ‘transcendental argument’ has been under attack and most critics conclude that it does not work. They have, however, thrown the baby away with the bathwater, when they furthermore concluded that Peters’ justificatory project itself is futile. This article

Stefaan E. Cuypers

2012-01-01

394

Telomere Reverse Transcriptase (TERT) rs2735940 Increases Cancer Risk  

PubMed Central

Background Telomerase reverse transcriptase (TERT) rs2735940 polymorphism was found to be associated with increased cancer risk. However, recent studies reported controversial results. The aim of our study was to detect its relationship with cancer risk. Material/Methods EMBASE and PubMed databases were searched for all publications until October 2014. ORs and 95% CIs were applied to investigate the association in the random-effects model. Results Thirteen case-control studies with 19385 cases and 17558 controls were included in this study. We found a significant association between cancer risk and TERT rs2735940 polymorphism (OR=1.06, 95% CI 1.02–1.11, P=0.005). In the subgroup analysis by ethnicity, a marginal association was found in Caucasians (OR=1.05, 95% CI 1.00–1.10, P=0.05), but not in Asians (OR=1.01, 95% CI 0.82–1.24, P=0.93). In the subgroup analysis by cancer site, this polymorphism was significantly associated with lung cancer risk (OR=1.08, 95% CI 1.02–1.13, P=0.004). Conclusions TERT rs2735940 polymorphism was significantly associated with cancer risk, especially lung cancer. PMID:25716168

Yang, Hui; Li, Jing; Tang, Ruihua; Liu, Yaxiong; Shao, Yan; Huang, Qingsheng; Shi, Junling

2015-01-01

395

mGluRs Head to Toe in Pain.  

PubMed

Metabotropic glutamate receptors (mGluRs) and their role in modulating pain throughout the peripheral and central nervous system are the focus of this chapter. Because these receptors are so prolifically involved in pain signaling throughout the neuraxis, we will use them as a vehicle to explore the totality of the neuraxis. These diverse receptors can increase or decrease pain depending on the subtype of receptor involved and anatomical location of activity. We will cover the basic molecular structure and function of mGluRs and then evaluate the role of different mGluRs at each level of the pain neuraxis. Similar to the functional anatomy involved in the processing of exogenous noxious stimuli, we will start from the peripheral nociceptive terminal and end in higher brain centers that are involved in the cognitive and emotional components of pain. We will conclude by examining the cutting-edge technology involved in the development of mGluR agents for the treatment of pain. PMID:25744677

Kolber, Benedict J

2015-01-01

396

Telomere Reverse Transcriptase (TERT) rs2735940 Increases Cancer Risk.  

PubMed

Background Telomerase reverse transcriptase (TERT) rs2735940 polymorphism was found to be associated with increased cancer risk. However, recent studies reported controversial results. The aim of our study was to detect its relationship with cancer risk. Material and Methods EMBASE and PubMed databases were searched for all publications until October 2014. ORs and 95% CIs were applied to investigate the association in the random-effects model. Results Thirteen case-control studies with 19385 cases and 17558 controls were included in this study. We found a significant association between cancer risk and TERT rs2735940 polymorphism (OR=1.06, 95% CI 1.02-1.11, P=0.005). In the subgroup analysis by ethnicity, a marginal association was found in Caucasians (OR=1.05, 95% CI 1.00-1.10, P=0.05), but not in Asians (OR=1.01, 95% CI 0.82-1.24, P=0.93). In the subgroup analysis by cancer site, this polymorphism was significantly associated with lung cancer risk (OR=1.08, 95% CI 1.02-1.13, P=0.004). Conclusions TERT rs2735940 polymorphism was significantly associated with cancer risk, especially lung cancer. PMID:25716168

Yang, Hui; Li, Jing; Tang, Ruihua; Liu, Yaxiong; Shao, Yan; Huang, Qingsheng; Shi, Junling

2015-01-01

397

Hadron star models. [neutron stars  

NASA Technical Reports Server (NTRS)

The properties of fully relativistic rotating hadron star models are discussed using models based on recently developed equations of state. All of these stable neutron star models are bound with binding energies as high as about 25%. During hadron star formation, much of this energy will be released. The consequences, resulting from the release of this energy, are examined.

Cohen, J. M.; Boerner, G.

1974-01-01

398

Period04 FCAPT uvby Photometric Studies of Eight Magnetic CP Stars  

NASA Astrophysics Data System (ADS)

We present Four College Automated Photometric Telescope (FCAPT) differential Stromgren uvby photometry of 8 magnetic CP (mCP) stars: HD 5797 (V551 Cas), HD 26792 (DH Cam), HD 27309 (56 Tau, V724 Tau), HD 49713 (V740 Mon), HD 74521 (49 Cnc, BI Cnc), HD 120198 (84 UMa, CR UMa), HD 171263 (QU Ser), and HD 215441 (GL Lac, Babcock's star). Our data sets are larger than those of most mCP stars in the literature. These are the first FCAPT observations of HD 5797, HD 26792, HD 49713, and HD 171263. Those for the remaining four stars substantially extend published FCAPT data. The FCAPT observed some stars for a longer time range and with greater accuracy than other optical region automated photometric telescopes.Our goals were to determine very accurate periods, the u, v, b, and y amplitudes, and if there were any long period periods. In addition we wanted to compare our results with those of magnetic field measurements to help interpret the light curves.We used the Period04 computer program to analyze the light curves. This program provides errors for the derived quantities as it fits the light curve. Our derived periods of 68.046 +/- 0.008 days for HD 5797, 3.80205 +/- 0.00006 days for HD 26792, 1.56889 +/- 0.000002 days for HD 27309, 2.13536 +/- 0.00002 days for HD 49713, 7.0505 +/- 0.0001 days for HD 74521, 1.38577 +/- 0.000004 days for HD 120198, 3.9974 +/- 0.0001days for HD 171263, and 9.487792 +/- 0.00005 days for HD 215441 are refinements of the best determinations in the literature.

Adelman, Saul J.; Dukes, Robert J.

2014-06-01

399

Sea-launched TacSats for Responsive Space (STaRS)  

Microsoft Academic Search

The Responsive Space community has focused on Responsive Launch as an area of improvement that would help space become more responsive. Unfortunately, developing a Responsive Launch capability is fraught with difficulties. American launch facilities (i.e., Eastern Range, Western Range, Kwajalein, etc.) have numerous logistical and physical limitations that restrict U.S ability to quickly launch a satellite, including: restricted launch fans,

Robert Carneal

400

The long-period Galactic Cepheid RS Puppis. III. A geometric distance from HST polarimetric imaging of its light echoes  

NASA Astrophysics Data System (ADS)

As one of the most luminous Cepheids in the Milky Way, the 41.5-day RS Puppis is an analog of the long-period Cepheids used to measure extragalactic distances. An accurate distance to this star would therefore help anchor the zero-point of the bright end of the period-luminosity relation. But, at a distance of about 2 kpc, RS Pup is too far away for measuring a direct trigonometric parallax with a precision of a few percentage points with existing instrumentation. RS Pup is unique by being surrounded by a reflection nebula whose brightness varies as pulses of light from the Cepheid propagate outward. We present new polarimetric imaging of the nebula obtained with HST/ACS. The derived map of the degree of linear polarization pL allows us to reconstruct the three-dimensional structure of the dust distribution. To retrieve the scattering angle from the pL value, we consider two different polarization models, one based on a Milky Way dust mixture and one assuming Rayleigh scattering. Considering the derived dust distribution in the nebula, we adjust a model of the phase lag of the photometric variations over selected nebular features to retrieve the distance of RS Pup. We obtain a distance of 1910 ± 80 pc (4.2%), corresponding to a parallax of ? = 0.524 ± 0.022 mas. The agreement between the two polarization models that we considered is good, but the final uncertainty is dominated by systematics in the adopted model parameters. The distance we obtain is consistent with existing measurements from the literature, but light echoes provide a distance estimate that is not subject to the same systematic uncertainties as other estimators (e.g., the Baade-Wesselink technique). RS Pup therefore provides an important fiducial for calibrating the systematic uncertainties of the long-period Cepheid distance scale. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13454.Table 1 and Appendix A are available in electronic form at http://www.aanda.org

Kervella, P.; Bond, H. E.; Cracraft, M.; Szabados, L.; Breitfelder, J.; Mérand, A.; Sparks, W. B.; Gallenne, A.; Bersier, D.; Fouqué, P.; Anderson, R. I.

2014-12-01

401

Polymorphism of rs7688672 and rs10033237 in cGKII/PRKG2 and gout susceptibility of Han population in northern China.  

PubMed

Gout is a genetic or acquired metabolic disease caused by increase of uric acid synthesis resulted from purine metabolic abnormalities. Whether cGMP-dependent protein kinase 2 (cGKII/PRKG2) is correlated with gout remains controversial. The objective of the present study was to investigate whether there is a correlation between polymorphism of cGKII/PRKG2 and gout susceptibility of Han population in northern China. Four hundred and five male patients with gout in the case group and 429 controls in the control group were collected from the Department of Endocrinology and Metabolic Disease, the Fourth Affiliated Hospital of Harbin Medical University. A case-control study method was used to study the correlation between cGKII/PRKG2 polymorphism rs7688672 and rs10033237 and gout susceptibility. The genotype frequencies of rs7688672 and rs10033237 polymorphisms of cGKII/PRKG2 in the case group and the control group both were in accordance with Hardy-Weinberg equilibrium. There were significant differences of rs10033237 in the allele frequencies and genotype distributions (P<0.05) between the two groups, while no association was found between rs7688672 and gout. Combined mutation sites AA(?) from rs7688672 and rs10033237 were negatively correlated with gout susceptibility, whereas haplotype GG(?) was positively correlated with gout susceptibility. In conclusion, patients with rs10033237 polymorphism of cGKII/PRKG2 gene are more likely to suffer from gout. With regard to haplotypes of rs10033237 and rs7688672, both AA(?) and GG(?) are related to gout. AA(?) is a gout susceptible gene, whereas GG(?) is a protective gene. PMID:25688884

Guo, Min; Cheng, Zhifeng; Li, Changgui; Li, Shanshan; Li, Ming; Wang, Mingli; Xu, Jinmei; Tang, Yingying; Wang, Yujing; Qiu, Wenli; Liu, Xiaomin

2015-05-10

402

Stationary Star  

NSDL National Science Digital Library

This is an activity about star movement due to the Earth's rotation. Learners will utilize the Sky Tonight online program to find the star that appears stationary in our night sky. They will then draw conclusions about the Earth’s rotation based on the position changes of certain stars. This activity requires the use of a computer with Internet access. This activity is Sky Tonight Activity 2 in a larger resource, Space Update.

2012-08-03

403

Sea Stars  

NSDL National Science Digital Library

At first glance, starfish, more properly called sea stars, aren’t doing much of anything. In this video, Jonathan’s investigations reveal a slow-motion predator that hunts and attacks its prey. Traveling the world, Jonathan investigates sea stars from the tropics to the Antarctic and uses time-lapse photography to reveal an amazing complexity to the world of the sea star. Please see the accompanying study guide for educational objectives and discussion points.

2012-07-28

404

Scintillating Stars  

NSDL National Science Digital Library

Often, a bright planet that is visible over the horizon will be mistaken for a star. Some believe they can tell the difference between a star and a planet because stars twinkle, or scintillate , and planets do not. In actuality however, both will twinkle because any light that passes through our atmosphere, whether it be reflected from a planet or generated by a star, will be interfered with by the atmospheric elements. This month's column sheds light on this "scintillating" subject and engages students in a research activity that revolves around the question: Is Pluto a planet?

Bob Riddle

2003-02-01

405

Lucky Star  

NSDL National Science Digital Library

Watch this video from Cyberchase and then play the Lucky Star game! The Lucky Star game show the will ask you math-related questions and give you four possible answers to choose from. Your goal is to answer the questions correctly and score as many points as you can. You can score points during two different rounds: the pick-a-star round and the lightning round. During the pick-a-star round you have as much time as you want to answer the questions. During the lightning round you have to think fast in order to earn the points. Good luck!

2008-01-01

406

Neutron Stars  

NASA Technical Reports Server (NTRS)

Neutron stars were discovered almost 40 years ago, and yet many of their most fundamental properties remain mysteries. There have been many attempts to measure the mass and radius of a neutron star and thereby constrain the equation of state of the dense nuclear matter at their cores. These have been complicated by unknown parameters such as the source distance and burning fractions. A clean, straightforward way to access the neutron star parameters is with high-resolution spectroscopy. I will present the results of searches for gravitationally red-shifted absorption lines from the neutron star atmosphere using XMM-Newton and Chandra.

Cottam, J.

2007-01-01

407

Diamonds in the Rough: A Cautionary Tale of C/O Ratios in Exoplanet Host Stars  

NASA Astrophysics Data System (ADS)

It is currently unknown how/to what extent the chemical compositions of planetary atmospheres correlate with those of their host stars and if different host star compositions influence planet occurrence. The carbon-to-oxygen abundance ratio is one crucial measurement that may be used to better understand a possible connection between star and planet compositions. In gas giant atmospheres, the C/O ratio indicates the abundances of the primary O and C species, which, along with N species, regulate the climates of Solar System planets. The composition of a planetary atmosphere affects its temperature and chemistry, and therefore its observable signatures. The C/O ratio also establishes interior mineralogy - i.e., whether the planet is Si- or C-rich. Currently C and O are the only elements that can potentially be measured in both star and exoplanet atmospheres. Large samples of planet and host star C/O measurements may reveal trends indicative of processes in the protoplanetary disk or planetary interior that shift the planet's elemental composition away from the star's. However, estimating C/O ratios in transiting exoplanet atmospheres is mostly still based on only a few photometric observations. Moreover, even with high resolution, high S/N spectra, determinations of the stellar C/O ratios can be challenging. There are only a few O abundance indicators available at optical wavelengths and they are weak, blended with other atomic/molecular lines, and/or subject to non-LTE effects. I will present a methodologically consistent sample of C/O ratios measured from high-resolution spectra of transiting exoplanet host stars from several different C and O abundance indicators, using classical stellar abundance analysis techniques (including differential, line-by-line analysis w.r.t. the Sun). I will discuss the difficulties of host star abundance measurements, and what insights into planet formation and composition are possible from such analyses. I will highlight the case of 55 Cnc, a cool and metal-rich star whose O abundance measurements are even more challenging. Our results indicate that this star is not C-rich, as previously suggested, which impacts the proposal that the super-Earth 55 Cnc e is a “diamond” planet.

Teske, Johanna K.; Cunha, K. M.; Schuler, S. C.; Griffith, C. A.; Smith, V. V.

2014-01-01

408

Genome Sequencing of Ralstonia solanacearum Biovar 3, Phylotype I, Strains Rs-09-161 and Rs-10-244, Isolated from Eggplant and Chili in India  

PubMed Central

Ralstonia solanacearum Indian strains Rs-09-161 and Rs-10-244 were isolated from the coastal region of Goa and from the Andaman Islands. We report the draft genome sequences of these representative isolates infecting solanaceous vegetables in India. PMID:24874667

Gaitonde, Sapna; Achari, Gauri; Asolkar, Trupti; Singh, Narendra Pratap; Carrere, Sebastien; Genin, Stephane; Peeters, Nemo

2014-01-01

409

High-Resolution N-Band Observations of the Nova RS Ophiuchi with the Keck Interferometer Nuller  

NASA Technical Reports Server (NTRS)

We report new observations of the nova RS Ophiuchi (RS Oph) using the Keck Interferometer Nulling Instrument, approximately 3.8 days following the most recent outburst that occurred on 2006 February 12. The Keck Interferometer Nuller (KIN) operates in K-band from 8 to 12.5 pm in a nulling mode, which means that the central broad-band interference fringe is a dark fringe - with an angular width of 25 mas at mid band - rather than the bright fringe used ill a conventional optical interferometer. In this mode the stellar light itself is suppressed by the destructive fringe, effectively enhancing the contrast of the circumstellar material located near the star. By subsequently shifting the neighboring bright fringe onto the center of the source brightness distribution and integrating, a second spatial regime dominated by light from the central portion of the source is almost simultaneously sampled. The nulling technique is the sparse aperture equivalent of the conventional corongraphic technique used in filled aperture telescopes. By fitting the unique KIK inner and outer spatial regime data, we have obtained an angular size of the mid-infrared continuum of 6.2, 4.0. or 5.4 mas for a disk profile, gaussian profile (fwhm), and shell profile respectively. The data show evidence of enhanced neutral atomic hydrogen emission located in the inner spatial regime relative to the outer regime. There is also evidence of a 9.7 micron silicate feature seen outside of this region. Importantly, we see spectral lines excited by the nova flash in the outer region before the blast wave reaches these regions. These lines are from neutral, weakly excited atoms which support the following interpretation. We discuss the present results in terms of a unifying model of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. These data show the power and potential of the nulling technique which has been developed for the detection of Earth-like planets around nearby stars for the Terrestrial Planet Finder Mission and Darwin missions.

Barry, R. K.; Danchi, W. C.; Sokoloski, J. L.; Koresko, C.; Wisniewski, J. P.; Serabyn, E.; Traub, W.; Kuchner, M.; Greenhouse, M. A.

2007-01-01

410

An association study between DLGAP1 rs11081062 and EFNA5 rs26728 polymorphisms with obsessive–compulsive disorder in a Chinese Han population  

PubMed Central

Background A recent genome-wide association study indicated that the single nucleotide polymorphisms (SNPs) rs11081062 in DLGAP1 and rs26728 in EFNA5 were associated with obsessive–compulsive disorder (OCD) in Caucasians. The present case–control association study assessed the global relevance of these two SNPs with respect to OCD subtypes in a Chinese Han population. Methods We recruited 320 OCD patients and 431 age- and sex-matched controls from a Chinese Han population. rs11081062 and rs26728 SNPs were genotyped by real-time TaqMan polymerase chain reaction, and the chi-squared test was used to compare allele and genotype frequencies of variants between the two groups. Results No significant differences were found in allele or genotype frequencies of DLGAP1 rs11081062 and EFNA5 rs26728 between the OCD and control groups. Moreover, consistently negative results were observed when classifying by sex, onset age, and comorbidity. However, on analyzing OCD subphenotypes, significant associations were observed between rs11081062 and the presence of contamination obsessions and cleaning compulsions (?2=7.724, P=0.021 by genotype; ?2=3.745, P=0.053 by allele; and ?2=0.821, P=0.365 by genotype, ?2=27.809, P=0.000 by allele, respectively), and rs26728 with the presence of repeating compulsions (?2=8.285, P=0.004 by genotype; ?2=7.512, P=0.006 by allele). Conclusion Although we found no association between DLGAP1 rs11081062 and EFNA5 rs26728 SNPs with OCD in a Chinese Han population, obvious associations were observed with OCD subphenotypes. Therefore, it appears to be useful to divide OCD into more homogeneous subphenotypes to help understand the complex genetic basis of this disorder. Further investigations are needed to replicate these findings using larger sample sizes, different populations, and other polymorphisms. PMID:25897225

Li, Jiang; Cui, Jiajia; Wang, Xiuhai; Ma, Jianhua; Niu, Haitao; Ma, Xu; Zhang, Xinhua; Liu, Shiguo

2015-01-01

411

Impact of G-quadruplex structures and intronic polymorphisms rs17878362 and rs1642785 on basal and ionizing radiation-induced expression of alternative p53 transcripts.  

PubMed

G-quadruplex (G4) structures in intron 3 of the p53 pre-mRNA modulate intron 2 splicing, altering the balance between the fully spliced p53 transcript (FSp53, encoding full-length p53) and an incompletely spliced transcript retaining intron 2 (p53I2 encoding the N-terminally truncated ?40p53 isoform). The nucleotides forming G4s overlap the polymorphism rs17878362 (A1 wild-type allele, A2 16-base pair insertion) which is in linkage disequilibrium with rs1642785 in intron 2 (c.74+38 G>C). Biophysical and biochemical analyses show rs17878362 A2 alleles form similar G4 structures as A1 alleles although their position is shifted with respect to the intron 2 splice acceptor site. In addition basal FSp53 and p53I2 levels showed allele specific differences in both p53-null cells transfected with reporter constructs or lymphoblastoid cell lines. The highest FSp53 and p53I2 levels were associated with combined rs1642785-GG/rs17878362-A1A1 alleles, whereas the presence of rs1642785-C with either rs17878362 allele was associated with lower p53 pre-mRNA, total TP53, FSp53 and p53I2 levels, due to the lower stability of transcripts containing rs1642785-C. Treatment of lymphoblastoid cell with the G4 binding ligands 360A or PhenDC3 or with ionizing radiation increased FSp53 levels only in cells with rs17878362 A1 alleles, suggesting that under this G4 configuration full splicing is favoured. These results demonstrate the complex effects of intronic TP53 polymorphisms on G4 formation and identify a new role for rs1642785 on mRNA splicing and stability, and thus on the differential expression of isoform-specific transcripts of the TP53 gene. PMID:25269805

Perriaud, Laury; Marcel, Virginie; Sagne, Charlotte; Favaudon, Vincent; Guédin, Aurore; De Rache, Aurore; Guetta, Corinne; Hamon, Florian; Teulade-Fichou, Marie-Paule; Hainaut, Pierre; Mergny, Jean-Louis; Hall, Janet

2014-12-01

412

STAT4 rs7574865 G/T and PTPN22 rs2488457 G/C Polymorphisms Influence the Risk of Developing Juvenile Idiopathic Arthritis in Han Chinese Patients  

PubMed Central

Juvenile idiopathic arthritis (JIA) is a common autoimmune disease characterized by environmental influences along with several predisposing genes in the pathogenesis. The protein tyrosine phosphatase nonreceptor 22 (PTPN22) and signal transducer and activator of transcription factor 4 (STAT4) have been recognized as susceptibility genes for numerous autoimmune diseases. Associations of STAT4 rs7574865 G/T and PTPN22 (rs2488457 G/C and rs2476601 C/T) polymorphisms with JIA have repeatedly been replicated in several Caucasian populations. The aim of this study was to investigate the influence of three polymorphisms mentioned above on the risk of developing JIA in Han Chinese patients. Genotyping was performed on a total of 137 Chinese patients with JIA (JIA group) and 150 sex and age frequency-matched healthy volunteers (Control group). The single-nucleotide polymorphisms (SNP) were determined by using direct sequencing of PCR-amplified products. There were significant differences of PTPN22 rs2488457 G/C and STAT4 rs7574865 G/T polymorphisms between both groups. However, no significant difference was observed in distribution frequencies of PTPN22 rs2476601 polymorphism. The association with the PTPN22 rs2488457 G/C polymorphism remained significant in the stratifications by age at onset, ANA status, splenomegaly, lymphadenectasis and involvement joints. As with the STAT4 rs7574865 G/T polymorphisms, the enthesitis-related arthritis and presence of hepatomegaly had strong effect on the association. Our data strengthen STAT4 rs7574865 G/T and PTPN22 rs2488457 G/C polymorphisms as susceptibility factors for JIA. PMID:25781893

Fan, Zhi-Dan; Wang, Fei-Fei; Huang, Hui; Huang, Na; Ma, Hui-Hui; Guo, Yi-Hong; Zhang, Ya-Yuan; Qian, Xiao-Qing; Yu, Hai-Guo

2015-01-01

413

Four New Variable Stars in Ophiuchus  

NASA Astrophysics Data System (ADS)

Four new variable stars were discovered by serendipity in the Ophiuchus constellation during photometric analysis of the NEO Asteroid (1988 PA), pictures taken in July 2010 from A81 Balzaretto Observatory in Rome. Based on their light curves and colour indexes, the stars were classified in their variable class and registered in the Variable Star Index (VSX) hosted in the AAVSO web site, respectively as one eclipsing variable EA-type or short period eclipsing subgroup of RS CVn-type (UCAC3 196-166827), identified as the optical counterpart of 1RXS J180755.7+074717 X-ray source, two eclipsing binaries EW-type (UCAC3 196-166958 and UCAC3 196-167279) and one very likely as pulsating variable High Amplitude δ,, Scuti type (HADS) or SX Phe (UCAC3 196-167073).

Franco, Lorenzo; Marchini, Alessandro; Papini, Riccardo

2011-03-01

414

Double stars  

Microsoft Academic Search

The work devoted to the identification of double and multiple stars for the Hipparcos input catalog is presented. Ground based observations, and photometric and astrometric aspects are included. The aim of the work is to improve the main stream of the data reduction. The tasks performed by the input catalog (INCA) double star working groups are reported. The contents of

J. Dommanget

1989-01-01

415

Star Life  

NSDL National Science Digital Library

Visitors to this site can follow the life cycle of a star, beginning with its formation from matter exploded outward by the Big Bang, followed by its expansion into a red giant as nuclear "fuel" is consumed, and ending with its "death" in a supernova, after which it becomes a neutron star or black hole.

416

Rogue Star  

NSDL National Science Digital Library

This program calculates and depicts the effects of a rogue star coming through our solar system. Users adjust the date, the rogue star's mass, approach distance in astronomical units (AU) and flyby speed to run an animation of what would happen to the planets under the specified conditions.

Douglas Hamilton

417

Accuracy and repeatability of the Polar RS800sd to evaluate stride rate and running speed.  

PubMed

The purpose of this study was to evaluate the accuracy and the repeatability of a new running computer system (RS800sd, Polar, Kempele, Finland) which included the measurement of running speed (RS) and stride rate (SR). Eight well-trained triathletes participated in this study. First, they completed an incremental continuous maximum test on a treadmill (from 12 km x h (-1) to 18 km x h (-1)) at 0% grade. Then the subjects took part in a second test to determine RS800sd intra-reproducibility to evaluate running speed. They ran twice during 5 min at a pace corresponding to their maximal lactate steady-state. During these two tests, RS and SR were recorded by the RS800sd system, by an optical sensor system (for RS) and a force-sensitive device (for SR). No difference was found between the RS800sd system and the reference systems both for RS (ICC=0.95) and SR (ICC=0.69). Moreover RS measures were statistically repeatable. This study provided evidence for the validity of the RS800sd system for measuring the kinematic characteristics of running (speed and frequency). Further investigations are needed to replicate these findings at lower running speeds, notably during walking to assess its capacity to evaluate physical activity in natural conditions. PMID:19277940

Hausswirth, C; Le Meur, Y; Couturier, A; Bernard, T; Brisswalter, J

2009-05-01

418

Star dust.  

PubMed

Infrared astronomy has shown that certain classes of stars are abundant producers of refractory grains, which condense in their atmospheres and are blown into interstellar space by the radiation pressure of these stars. Metallic silicates of the kind that produce terrestrial planets are injected by the oxygen-rich stars and carbon and its refractories by carbon stars. Much of the interstellar dust may be produced by this mechanism. A number of "infrared stars" are completely surrounded by their own dust, and a few of these exhibit a unique morphology that suggests the formation of a planetary system or a stage in the evolution of a planetary nebula. Certain novae also condense grains, which are blown out in their shells. In our own solar system, comets are found to contain the same silicates that are present elsewhere in the galaxy, suggesting that these constituents were present in the primeval solar nebula. PMID:17732279

Ney, E P

1977-02-11

419

Star Journey  

NSDL National Science Digital Library

This National Geographic web-site contains information about the Hubble Space Telescope (HST) along with a star chart and facts about objects in the night sky. The HST section contains details about the building and structure of the HST, how it captures light, positioning the HST to targets, instruments used to record and measure infrared through UV wavelengths, how the HST is powered and communicates with the Earth. Star Attractions discusses properties of constellations, the Milky Way galaxy, other galaxies, star clusters and nebulae. This information is then put together on the National Geographic Star Chart. This chart contains maps of the heavens for the northern and southern hemispheres. The chart contains constellation names, location of stars and other objects, and links to HST images of various galaxies and objects on the chart with names and detailed descriptions. There is an image index to find HST images from the site, details about chart symbol meanings, and links for more information.

Carolyn Anderson

420

The long-period Galactic Cepheid RS Puppis. II. 3D structure and mass of the nebula from VLT/FORS polarimetry  

NASA Astrophysics Data System (ADS)

Context. The southern long-period Cepheid RS Pup is surrounded by a large circumstellar dusty nebula reflecting the light from the central star. Due to the changing luminosity of the central source, light echoes propagate into the nebula. This remarkable phenomenon was the subject of Paper I. The origin and physical properties of the nebula are however uncertain: it may have been created through mass loss from the star itself, or it could be the remnant of a pre-existing interstellar cloud. Aims: Our goal is to determine the three-dimensional structure of the light-scattering nebula, and estimate its mass. This will bring us new clues on the origin of the nebula. Knowing the geometrical shape of the nebula will also allow us to retrieve the distance of RS Pup in an unambiguous manner using a model of its light echoes (in a forthcoming work). Methods: The scattering angle of the Cepheid light in the circumstellar nebula can be recovered from its degree of linear polarization. We thus observed the nebula surrounding RS Pup using the polarimetric imaging mode of the VLT/FORS instrument, and obtained a map of the degree and position angle of linear polarization. Results: From our FORS observations, we derive a three-dimensional map of the distribution of the dust around RS Pup, whose overall geometry is an irregular and geometrically thin layer. The nebula does not present a well-defined central symmetry. Using a simple scattering model, we derive a total dust mass of Mdust = 2.9 ± 0.9 M? for the light-scattering dust within 1.8' of the Cepheid. This translates into a total mass of Mgas + dust = 290 ± 120 M?, assuming a dust-to-gas ratio of Mdust/Mgas = 1.0 ± 0.3%. Conclusions: The high mass of the dusty nebula excludes that it was created by mass-loss from the star. However, the thinness of the dust distribution is an indication that the Cepheid participated to the shaping of the nebula, e.g. through its radiation pressure or stellar wind. RS Pup therefore appears as a regular long-period Cepheid located in an exceptionally dense interstellar environment. Based on observations made with ESO telescopes at La Silla Paranal Observatory, under ESO program 383.D-0623(A).Appendix is available in electronic form at http://www.aanda.org

Kervella, P.; Mérand, A.; Szabados, L.; Sparks, W. B.; Havlen, R. J.; Bond, H. E.; Pompei, E.; Fouqué, P.; Bersier, D.; Cracraft, M.

2012-05-01

421

IFITM3 Polymorphism rs12252-C Restricts Influenza A Viruses  

PubMed Central

The IFITM3 polymorphism rs12252-C, which encodes an IFITM3 isoform (?21 IFITM3) lacking 21 amino acids at the amino terminus, has been controversially associated with poor clinical outcomes in patients with H1N1 influenza A virus (IAV) infections. In vitro studies have shown that ?21 IFITM3 loses its ability to restrict H1N1 IAV. Subsequent research has also revealed that tyrosine 20 is the key determinant for IFITM3 endocytic trafficking, which is essential for the efficient anti-viral activity of IFITM3. In contrast to previous studies, we demonstrated that both ?21 IFITM3 and an IFITM3 variant (Y20A IFITM3), in which tyrosine 20 is substituted with alanine, strongly restricted entry mediated by IAV H1, H3, H5, and H7 proteins. ?21 IFITM3 also efficiently suppressed replication of H1N1 and, to a lesser extent, H3N2 IAV. ?21 IFITM3 and Y20A IFITM3 had broader subcellular distributions than full-length IFITM3 but an abundant amount of both IFITM3 variants still localized to late endosomes and lysosomes. Our data indicate that tyrosine 20 partially regulates the subcellular localization of IFITM3 but is not functionally essential for IFITM3-mediated IAV restriction. They also suggested that mechanisms, other than viral entry restriction, might contribute to variations in clinical outcomes of H1N1 influenza associated with rs12252-C. PMID:25314048

Grotefend, Christopher Robert; Radic, Vladimir; Chung, Changik; Chung, Young-Hwa; Farzan, Michael; Huang, I-Chueh

2014-01-01

422

Information extraction of typical karst landform based on RS  

NASA Astrophysics Data System (ADS)

Guizhou Province is the most typical karst landform area of Southwest China Karst, and how to exactly extract the typical karst landform information is important to the economic development of Guizhou. Not any method based on Remote Sensing (Hereinafter referred to as RS) to extract the karst landform were reported or published. For obtaining the accuracy information of karst landform, 10 meters resolution ALOS image is used to extract the karst landform information in Guanling County of Guizhou Province in this paper. The multiscale segmentations of RS images were finished and typical of karst landform in case study area were classified with the different segmentation rules created on the eCognition Developer platform. For mostly improving the accuracy of extraction information, the experiment areas are focused on the fengcong depressions, fengcong valleys, and fenglin basins. The results show that the fengcong depressions, fengcong valleys, and fenglin basins can be respectively well extracted from the images when the segmentation scale are respectively 280, 480 and 200, shape parameter is 0.8, and tightness parameter is 0.5. We believed the research would provide an important reference to extract the karst landform information in whole Guizhou, China or global level.

Huang, Shufen; Lan, Anjun; Ma, Jiaqiong; Guo, Haixiang

2014-05-01

423

A device for concurrent, local/remote control of RS232-based devices by GSM/GPRS  

E-print Network

A device for concurrent, local/remote control of RS232-based devices by GSM/GPRS Eloi Ramon computer control and monitoring. In this paper we present a system to allow remote control by GSM-directional communications between a RS232 and the two other ports (RS232 and GSM/GPRS). Keywords -- GSM, GPRS, RS232, serial

Autònoma de Barcelona, Universitat

424

Dual-port serial arbiter with GSM modules for simultaneous local/remote control of RS232-  

E-print Network

Dual-port serial arbiter with GSM modules for simultaneous local/remote control of RS232- based a RS232 and the two other ports (RS232 and GSM). Index Terms-- GSM, RS232, serial port arbiter, SMS-485, Ethernet, USB, FireWire, Bluetooth, IEEE 802.11, GSM/GPRS, I2C, et cetera. These modules act totally

Autònoma de Barcelona, Universitat

425

Effects of common polymorphisms rs2910164 in miR-146a and rs3746444 in miR-499 on cancer susceptibility: a meta-analysis.  

PubMed

MicroRNAs (miRNAs) are a class of new non-coding RNA, which may play a more important role in the pathogenesis of human cancers. Rs2910164 in miR-146a and rs3746444 in miR-499 are shown to be associated with increased/decreased cancer risk. We performed a meta-analysis to systematically summarize the possible association. We retrieved the relevant articles from PubMed databases. Studies were selected using specific inclusion and exclusion criteria. ORs and 95% CIs were calculated to access the strength of association between microRNA polymorphism and cancer risk. All analyses were performed using the Stata software. Twenty-nine studies were included in this meta-analysis. There were not significant associations between miR-146a rs2910164 and miR-499 rs3746444 polymorphisms with overall cancer risk. In the subgroup analysis by ethnicity, significantly affected cancer risks were found among Asians for both rs2910164 (GC vs. GG: OR = 0.89, 95% CI = 0.82-0.96; CC vs. GG: OR = 0.80, 95% CI = 0.66-0.97; GC + CC vs. GG: OR = 0.86, 95% CI = 0.76-0.97; C vs. G: OR = 0.91, 95% CI = 0.82-1.00) and rs3746444 (GG + AG vs. AA: OR = 1.21, 95% CI = 1.00-1.46). In the tumor type subgroup analysis, rs2910164 C allele decreased the risk of hepatocellular carcinoma (C vs. G: OR = 0.89, 95% CI = 0.80-1.00) and cervical squamous cell carcinoma (C vs. G: OR = 0.72, 95% CI = 0.62-0.84). The rs2910164 in miR-146a and the rs3746444 in miR-499 are likely to be associated with cancer risk. PMID:23292097

Yin, Zhihua; Yan, Lei; Cui, Zhigang; Li, Xuelian; Ren, Yangwu; Zhou, Baosen

2013-04-01

426

Characterization of two unusual RS1 gene deletions segregating in Danish retinoschisis families.  

PubMed

Over 100 distinct retinoschisis gene (RS1) mutations, of which approximately 10% are single exon deletions, have been described to date. In this paper we have characterized in detail two dissimilar RS1 gene deletions which are accountable for RS in one-third of Danish patients. First, a 136 kb deletion, spanning from the 5' region of the RS1 gene to intron 3, was identified. Unexpectedly this large deletion abolishes exons of three adjacent genes: serine-threonine phosphatase gene (PPEF-1)/serine-threonine protein phosphatase gene (PP7), retinoschisis gene (RS1), and serine-threonine kinase gene (STK9). We demonstrate that the RS1 and STK9 genes are partly overlapping and the sequences of the PP7 and PPEF-1 genes are identical. This is the first study which reports of retinoschisis patients who also suffer from deletions in genes adjacent to RS1. The 136 kb deletion is also the first gross deletion of the retinoschisis gene deleting three exons. It results from a recombination between two repetitive sequences of the Alu family, one in 5' region of the RS1 gene and the other in RS1 intron 3. The second alteration, the actual Danish RS founder mutation, is a 4.4 kb noncontiguous two-part deletion composed of two deleted 1.5 and 2.9 kb segments, separated by an intact 1.2 kb segment. It extends from the 5' flanking region of the retinoschisis gene to RS intron 1. RS1 gene deletions of this type have not been identified previously. Despite these two unique deletions, which either lead to severely defective transcription or total absence of the retinoschisin and PPEF-1 protein, all the patients have a typical retinoschisis phenotype. PMID:11013441

Huopaniemi, L; Tyynismaa, H; Rantala, A; Rosenberg, T; Alitalo, T

2000-10-01

427

MPI-LAPI: An Efficient Implementation of MPI for IBM RS\\/6000 SP Systems  

Microsoft Academic Search

The IBM RS\\/6000 SP system is one of the most cost-effective commercially available highperformance machines. IBM RS\\/6000 SP systems support the Message Passing Interfacestandard (MPI) and LAPI. LAPI is a low level, reliable and efficient one sided communicationAPI library, implemented on IBM RS\\/6000 SP systems. This paper explains howthe high performance of the LAPI library has been exploited in order

Mohammad Banikazemi; Rama K. Govindaraju; Robert Blackmore; Dhabaleswar K. Panda

2001-01-01

428

Complete genome sequence of a filamentous bacteriophage, RS611, that infects the phytopathogen Ralstonia solanacearum.  

PubMed

Filamentous bacteriophage RS611 (?RS611), which infects the phytopathogen Ralstonia solanacearum, had a circular single-stranded DNA genome that was characterized as an Ff-type phage belonging to the family Inoviridae. The ?RS611 genome was composed of 6386 bases with a G + C content of 62.1 % and contained 11 putative open reading frames. The ?RS611 genome showed high similarity to those of Ralstonia phages RSS0 and RSS1. However, approximately 900-nucleotide deletions were found in the region corresponding to open reading frames 10 and 11 of ?RSS0 and ?RSS1. PMID:25559667

Van, Truong Thi Bich; Yoshida, Shohei; Miki, Kaito; Kondo, Akihiro; Kamei, Kaeko

2015-03-01

429

Stars equilibrium  

NSDL National Science Digital Library

What causes the fusion reaction in a star's core? This activity page, part of an interactive laboratory series for grades 8-12, introduces students to processes inside a star. Students read about the equilibrium process in a star, in which outward gas pressure equals inward gravitational pressure. Then, an interactive lab activity offers students the opportunity to predict temperature, pressure, and gravity changes that occur during equilibrium. The chemical reactions of the fusion process are presented, and more specific detailed reactions are available in a pop-up box. Student practice quizzes about the equilibrium process and pressure and gravity interactions inside the star are included, as are answers. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2003-01-01

430

The Low-Temperature Crystal Structure of RS-Camphor  

NASA Astrophysics Data System (ADS)

The crystal structure of the low-temperature phase of RS-camphor (1,7,7-trimethylbicyclo[2.2.1]heptan-2-one, C 10H 16O) has been solved at 100 K by high-resolution powder X-ray diffraction using synchrotron radiation. The structure is orthorhombic, space group Cmcm, with a=6.8341(2) Å, b=11.6584(3) Å, c=11.5000(3) Å, and Z=4. The structure has four-fold disorder of the molecules. Left-handed and right-handed molecules are situated on the same crystallographic site, with an additional two-fold rotational disorder of the molecules. The structure was obtained from a combination of auto indexing, direct methods, and a grid search of molecular orientations.

Mora, Asiloé J.; Fitch, Andrew N.

1997-11-01

431

CNC TORNA TEZGAHINDA AISI 304 ÇEL?KLER?N ??LENEMES?NDE OPT?MUM YÜZEY PÜRÜZLÜLÜ?ÜNÜ SA?LAYACAK KESME PARAMETRELER?N?N TESP?T?  

Microsoft Academic Search

The purpose of this study, is to determine optimum machinability parametres required to obtain ideal surface roughness for AISI 304 austenitic stainless steel processed on the CNC lathe. Changes made in the composition of stainless steels so as to provide the mechanical and chemical properties desired according to the fields of application affect also their machining. Surface quality changes according

Özgür TEKASLAN; Nedim GERGER; Kara Harp Okulu

432

Creating .DXF files from ProE (Wildfire 5.0) for use with ESPRIT CNC Software College of Engineering students and staff should be aware that ProE (Wildfire x.x) is available through the  

E-print Network

1 Creating .DXF files from ProE (Wildfire 5.0) for use with ESPRIT CNC Software College of Engineering students and staff should be aware that ProE (Wildfire x.x) is available through the CITES with older versions of ProE (Wildfire 4.0) are available upon request. Step 1. Verify that you have set

Thomas, Brian G.

433

Classifying stars  

NSDL National Science Digital Library

You will be able to describe the H-R diagram and explain how astronomers use it. The most important characteristics for classifying stars are: a) Color b) Temperature c) Size d) Composition e) Brightness The classification scheme that we currently use is the H-R diagram which is in the Earth Science Reference Tables (ESRT). The H-R diagram groups stars by surface temperature compared to their luminosity. 1)Today you will be reading a short tutorial ...

Mr. B

2007-11-10

434

Tycho's Star  

Microsoft Academic Search

A supernova remnant in Cassiopeia, 7.7° north of alpha Cas, which suddenly appeared as a brilliant naked-eye star in November 1572 and reached a maximum apparent magnitude of -3.5. Until its disappearance 16 months later, it was extensively studied by the Danish astronomer Tycho Brahe (1546-1601), who described its early appearance as follows: `Initially, the new star was brighter than

P. Murdin

2000-01-01

435

Tycho's Star  

NASA Astrophysics Data System (ADS)

A supernova remnant in Cassiopeia, 7.7° north of ? Cas, which suddenly appeared as a brilliant naked-eye star in November 1572 and reached a maximum apparent magnitude of -3.5. Until its disappearance 16 months later, it was extensively studied by the Danish astronomer Tycho Brahe (1546-1601), who described its early appearance as follows: `Initially, the new star was brighter than any other fixe...

Murdin, P.

2000-11-01

436

Lack of Association between miRNA-146a rs2910164 and miRNA-499 rs3746444 Gene Polymorphisms and Susceptibility to Pulmonary Tuberculosis.  

PubMed

Single-nucleotide polymorphisms (SNPs) in miRNAsmay alter its expression levels or processing and contribute to susceptibility to a wide range of diseases. Our study aimed to evaluate the possible association between miRNA-146a rs2910164 and miRNA-499 rs3746444 polymorphisms and susceptibility to pulmonary tuberculosis (PTB) in a sample of Iranian population. This case- control study was performed on 202 PTB patients and 204 healthy individuals. Genotyping was performed using tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). The results indicated that neither miRNA-499 rs3746444 nor miRNA-146a rs2910164 are associated with the risk of PTB in a sample of Iranian population. Larger studies with different ethnicities are required to validate our findings. PMID:25815281

Naderi, Mohammad; Hashemi, Mohammad; Khorgami, Parisa; Koshki, Maliheh; Ebrahimi, Mahboubeh; Amininia, Shadi; Sharifi-Mood, Batool; Taheri, Mohsen

2015-01-01

437

Lack of Association between miRNA-146a rs2910164 and miRNA-499 rs3746444 Gene Polymorphisms and Susceptibility to Pulmonary Tuberculosis  

PubMed Central

Single-nucleotide polymorphisms (SNPs) in miRNAsmay alter its expression levels or processing and contribute to susceptibility to a wide range of diseases. Our study aimed to evaluate the possible association between miRNA-146a rs2910164 and miRNA-499 rs3746444 polymorphisms and susceptibility to pulmonary tuberculosis (PTB) in a sample of Iranian population. This case- control study was performed on 202 PTB patients and 204 healthy individuals. Genotyping was performed using tetra amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR). The results indicated that neither miRNA-499 rs3746444 nor miRNA-146a rs2910164 are associated with the risk of PTB in a sample of Iranian population. Larger studies with different ethnicities are required to validate our findings.

Naderi, Mohammad; Hashemi, Mohammad; Khorgami, Parisa; Koshki, Maliheh; Ebrahimi, Mahboubeh; Amininia, Shadi; Sharifi-Mood, Batool; Taheri, Mohsen

2015-01-01

438

Star clusters  

NASA Astrophysics Data System (ADS)

Star clusters are observed in almost every galaxy. In this thesis we address several fundamental problems concerning the formation, evolution and disruption of star clusters. From observations of (young) star clusters in the interacting galaxy M51, we found that clusters are formed in complexes of stars and star clusters. These complexes share similar properties with giant molecular clouds, from which they are formed. Many (70%) of the young clusters will not survive the fist 10 Myr, due to the removal of left over gas. We study the evolution of clusters that have survived this first 10 Myr, to become bound star clusters that have cleared their primordial gas content. We determined the life time of such star clusters in M51 and the solar neighbourhood and compare these values, including existing values from literature, to the results of N-body simulations. These simulations consider realistic star clusters, with a stellar initial mass function, stellar evolution, accurate treatments of binaries and the tidal field of the host galaxy. We found that the observed disruption times of clusters in the solar neighbourhood and M51 are shorter than predicted by the simulations by a factor of 5 and 10, respectively. We studied the effect of additional perturbations by spiral arm crossings and encounters with giant molecular clouds with N-body simulations. We found that the mass loss due to these external perturbations, combined with the mass loss due to stellar evolution and the galactic tidal field can explain the observed disruption times. The star clusters in the solar neighbourhood have much lower masses than the young clusters observed in merging and interacting galaxies. We show that this can be largely explained by size-of-sample effects, that is, when more star clusters are observed, the chance of finding a more massive one is higher. However, we showed that there can exist a physical maximum to the cluster mass, which should be observable in the cluster luminosity function. We found this observational signature in the luminosity function of clusters in M51. A comparison to a cluster population model, that was developed for this thesis research, suggests that the maximum cluster mass in M51 is 5x10^5 solar masses. In the merging Antennae galaxies a similar luminosity function was observed. However, the maximum mass is four times higher there, suggesting that the maximum mass depends on galactic environment.

Gieles, M.

2006-10-01

439

Common variant rs7597774 in ADD2 is associated with dilated cardiomyopathy in Chinese Han population  

PubMed Central

Two polymorphisms, rs7597774 and rs1739843 in ADD2 and HSPB7 respectively, were found to be associated with dilated cardiomyopathy (DCM) in European cohorts but the results were not validated in the Chinese Han population. We aimed to test the association of the two variants with DCM in a cohort of Chinese Han population. DCM (399) and control (1384) individuals were identified from the GeneID database in China, and DNA was isolated from peripheral blood lymphocytes for genotyping. Alleles were amplified by PCR, and amplicons harboring polymorphisms rs1739843 and rs7597774 were directly genotyped using high-resolution melting analysis. Statistical analysis was subsequently performed to evaluate the association of the variants with DCM. Allelic analysis demonstrated that rs7597774 was significantly related to DCM (P -adj = 0.0157), and an increased risk of DCM was specifically associated with the minor allele A (OR = 1.582). High-grade cardiac dysfunction (NYHA III/IV) was a clinical parameter significantly associated with the rs7597774 genotypes AA + AC relative to genotype CC (P = 0.021). Furthermore, DCM patients with the rs7597774 genotype AA tended to undergo more invasive medical interventions than those with the genotype CC (P = 0.008). No association was detected between rs1739843 and DCM under any allelic (P -adj = 0.407, OR = 0.920) or genotypic model. In the Chinese Han population, rs7597774 but not rs1739843 was found to be associated with DCM. This study is the first to demonstrate that underlying genotypes of rs7597774 may assist in assessing the heart functional status of DCM patients and also in the prediction of the benefit of particular therapies for these patients. PMID:25785112

Chen, Fei F; Xia, Yun L; Xu, Cheng Q; Li, Si S; Zhao, Yuan Y; Wang, Xiao J; Chen, Shan S; Gao, Lian J; Zhong, Yang; Tu, Xin; Wang, Qing; Yang, Yan Z

2015-01-01

440

Common variant rs7597774 in ADD2 is associated with dilated cardiomyopathy in Chinese Han population.  

PubMed

Two polymorphisms, rs7597774 and rs1739843 in ADD2 and HSPB7 respectively, were found to be associated with dilated cardiomyopathy (DCM) in European cohorts but the results were not validated in the Chinese Han population. We aimed to test the association of the two variants with DCM in a cohort of Chinese Han population. DCM (399) and control (1384) individuals were identified from the GeneID database in China, and DNA was isolated from peripheral blood lymphocytes for genotyping. Alleles were amplified by PCR, and amplicons harboring polymorphisms rs1739843 and rs7597774 were directly genotyped using high-resolution melting analysis. Statistical analysis was subsequently performed to evaluate the association of the variants with DCM. Allelic analysis demonstrated that rs7597774 was significantly related to DCM (P -adj = 0.0157), and an increased risk of DCM was specifically associated with the minor allele A (OR = 1.582). High-grade cardiac dysfunction (NYHA III/IV) was a clinical parameter significantly associated with the rs7597774 genotypes AA + AC relative to genotype CC (P = 0.021). Furthermore, DCM patients with the rs7597774 genotype AA tended to undergo more invasive medical interventions than those with the genotype CC (P = 0.008). No association was detected between rs1739843 and DCM under any allelic (P -adj = 0.407, OR = 0.920) or genotypic model. In the Chinese Han population, rs7597774 but not rs1739843 was found to be associated with DCM. This study is the first to demonstrate that underlying genotypes of rs7597774 may assist in assessing the heart functional status of DCM patients and also in the prediction of the benefit of particular therapies for these patients. PMID:25785112

Chen, Fei F; Xia, Yun L; Xu, Cheng Q; Li, Si S; Zhao, Yuan Y; Wang, Xiao J; Chen, Shan S; Gao, Lian J; Zhong, Yang; Tu, Xin; Wang, Qing; Yang, Yan Z

2015-01-01

441

Lack of Association of Two Common Polymorphisms rs2910164 and rs11614913 with Susceptibility to Hepatocellular Carcinoma: A Meta-Analysis  

Microsoft Academic Search

BackgroundSingle nucleotide polymorphisms (SNPs) in microRNA-coding genes may participate in the process of carcinogenesis by altering the expression of tumor-related microRNAs. It has been suggested that two common SNPs rs2910164 in miR-146a and rs11614913 in miR-196a2 are associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. In the present study, we performed a meta-analysis to

Zhongxia Wang; Yin Cao; Chunping Jiang; Guang Yang; Junhua Wu; Yitao Ding

2012-01-01

442

Association of the rs7903146 and rs12255372 polymorphisms in the TCF7L2 gene with type 2 diabetes in a population from northeastern Brazil.  

PubMed

Approximately 200 million people suffer from type 2 diabetes (T2D) worldwide, and the rapid increase in the prevalence of this disease is likely a result of multiple environmental factors, such as increased food intake and decreased physical activity in genetically predisposed individuals. Different population studies have demonstrated a strong association of two polymorphic variations in the TCF7L2 gene, the noncoding single nucleotide polymorphisms (SNPs) rs7903146 (C/T) and rs12255372 (G/T), with T2D. Herein, we analyzed the association of these SNPs with T2D in a population from northeastern Brazil. Our results showed that the genotype and allele frequencies in TCF7L2 rs7903146 and rs12255372 were similar in the patient and control groups (P > 0.05). In addition, the allele frequencies were not significantly associated with T2D risk [rs7903146: odds ratio (OR) = 0.95, 95% confidence interval (CI) = 0.52-1.76, P = 1.00, and rs12255372: OR = 1.38, 95%CI = 0.72-2.62, P = 0.41]. These data suggest that the TCF7L2 SNPs rs7903146 and rs12255372 may not significantly contribute to T2D susceptibility in this population. However, our results may reflect the small number of subjects. Alternatively, these results may be attributable to specific ethnic effects, as most of the previously reported associations were demonstrated with predominantly European populations. To reach a definitive conclusion on the role of such gene variants for T2D in mixed populations, additional efforts are necessary to replicate this study with larger populations from areas with more ethnic heterogeneity. PMID:25299103

Barros, C M A R; Araujo-Neto, A P; Lopes, T R; Barros, M A L; Motta, F J N; Canalle, R; Nunes, L C C; Rey, J A; Burbano, R R; Lima-Barros, M A; Yoshioka, F K N; Pinto, G R

2014-01-01

443

Genetic variant in the BCL11A (rs1427407), but not HBS1-MYB (rs6934903) loci associate with fetal hemoglobin levels in Indian sickle cell disease patients.  

PubMed

India along with Nigeria and DRC contribute to 57% of the world sickle cell anemia population. The annual number of newborns in India with SCA was estimated at 44,000 in 2010. Even with this high prevalence there is minimal information about genetic factors that influence the disease course in Indian patients. The current study was conducted on 240 patients with SCD and 60 with sickle cell trait, to determine the association of genetic variants at the BCL11A (rs1427407) and HBS1-MYB (rs6934903) loci with fetal hemoglobin levels (HbF). Both these loci have been implicated with influencing HbF levels, a powerful modulator of the clinical and hematologic features of SCD. Our results indicate the BCL11A rs1427407 G>T variant to be significantly associated with HbF levels {19.12±6.61 (GG), 20.27±6.92 (GT) and 24.83±2.92 (TT) respectively} contributing to ~23% of the trait variance. Interestingly no association of the HBS1L-MYB rs6934903 with the HbF levels was seen. The present study indicates the BCL11A (rs1427407) but not HMIP (rs6934903) to be associated with elevated HbF levels in Indian patient. Further interrogation of additional variants at both the loci; as also a GWAS which may help uncover new loci controlling HbF levels. PMID:25457385

Bhanushali, Aparna A; Patra, P K; Nair, D; Verma, H; Das, B R

2015-01-01

444

Synergistic epistasis of paraoxonase 1 (rs662 and rs85460) and apolipoprotein E4 genes in pathogenesis of Alzheimer's disease and vascular dementia.  

PubMed

Genetic polymorphism and epistasis play a role in etiopathogenesis of Alzheimer's disease (AD) and vascular dementia (VaD). In this case-control study, a total of 241 patients were included in the study to see the effect of paraoxonase 1 (PON1; rs662 and rs85460) and apolipoprotein E (ApoE) genes in altering the odds of having AD and VaD along with serum PON and lipid profile. The presence of at least 1 variant allele of rs662, but not rs85460, increased the risk of having AD by 1.8-fold (95% confidence interval [CI]: 0.97-3.40) and VaD by 3.09-fold (95% CI: 1.4-6.9). The interaction between PON1 genes (rs662 and rs85460) and ApoE genes showed synergistic epistasis in altering the odds of significantly having both AD and VaD. On the other hand, low serum level of high-density lipoprotein and low level of serum PON activity were found associated significantly (P ? .001 in both cases) only in patients with VaD as compared to healthy control. PMID:24965284

Alam, Rizwan; Tripathi, Manjari; Mansoori, Nasim; Parveen, Shama; Luthra, Kalpana; Lakshmy, Ramakrishnan; Sharma, Subhadra; Arulselvi, Subramanian; Mukhopadhyay, Asok K

2014-12-01

445

Nanostructured lipid carrier surface modified with Eudragit RS 100 and its potential ophthalmic functions  

PubMed Central

This study was carried out to evaluate the ocular performance of a cationic Eudragit (EDU) RS 100-coated nanostructured lipid carrier (NLC). The genistein encapsulated NLC (GEN-NLC) was produced using the melt-emulsification technique followed by surface absorption of EDU RS 100. The EDU RS 100 increased the surface zeta potential from ?7.46 mV to +13.60 mV, by uniformly forming a spherical coating outside the NLC surface, as shown by transmission electron microscopy images. The EDU RS 100 on the NLC surface effectively improved the NLC stability by inhibiting particle size growth. The obtained EDU RS 100-GEN-NLC showed extended precorneal clearance and a 1.22-fold increase in AUC (area under the curve) compared with the bare NLC in a Gamma scintigraphic evaluation. The EDU RS 100 modification also significantly increased corneal penetration producing a 3.3-fold increase in apparent permeability coefficients (Papp) compared with references. Draize and cytotoxicity testing confirmed that the developed EDU RS 100-GEN-NLC was nonirritant to ocular tissues and nontoxic to corneal cells. These results indicate that the NLC surface modified by EDU RS 100 significantly improves the NLC properties and exhibits many advantages for ocular use. PMID:25246787

Zhang, Wenji; Li, Xuedong; Ye, Tiantian; Chen, Fen; Yu, Shihui; Chen, Jianting; Yang, Xinggang; Yang, Na; Zhang, Jinsong; Liu, Jinlu; Pan, Weisan; Kong, Jun

2014-01-01

446

Association between BDNF-rs6265 and obesity in the Boston Puerto Rican Health Study  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study is to examine a functional variant (rs6265) in the BDNF gene interacting with dietary intake modulate obesity traits in the Boston Puerto Rican Health Study population. BDNF rs6265 was genotyped in 1147 Puerto Ricans (aged 45-75 years), and examined for association with o...

447

Nanostructured lipid carrier surface modified with Eudragit RS 100 and its potential ophthalmic functions.  

PubMed

This study was carried out to evaluate the ocular performance of a cationic Eudragit (EDU) RS 100-coated nanostructured lipid carrier (NLC). The genistein encapsulated NLC (GEN-NLC) was produced using the melt-emulsification technique followed by surface absorption of EDU RS 100. The EDU RS 100 increased the surface zeta potential from -7.46 mV to +13.60 mV, by uniformly forming a spherical coating outside the NLC surface, as shown by transmission electron microscopy images. The EDU RS 100 on the NLC surface effectively improved the NLC stability by inhibiting particle size growth. The obtained EDU RS 100-GEN-NLC showed extended precorneal clearance and a 1.22-fold increase in AUC (area under the curve) compared with the bare NLC in a Gamma scintigraphic evaluation. The EDU RS 100 modification also significantly increased corneal penetration producing a 3.3-fold increase in apparent permeability coefficients (Papp) compared with references. Draize and cytotoxicity testing confirmed that the developed EDU RS 100-GEN-NLC was nonirritant to ocular tissues and nontoxic to corneal cells. These results indicate that the NLC surface modified by EDU RS 100 significantly improves the NLC properties and exhibits many advantages for ocular use. PMID:25246787

Zhang, Wenji; Li, Xuedong; Ye, Tiantian; Chen, Fen; Yu, Shihui; Chen, Jianting; Yang, Xinggang; Yang, Na; Zhang, Jinsong; Liu, Jinlu; Pan, Weisan; Kong, Jun

2014-01-01

448

Fusion Engineering and Design 38 (1997) 115137 ARIES-RS divertor system selection and analysis  

E-print Network

Fusion Engineering and Design 38 (1997) 115­137 ARIES-RS divertor system selection and analysis C analysis, fabrication methods and vacuum system design are presented. An innovative design using adjustable by the control of impurities and helium ash removal. For the ARIES-RS design, a double- null divertor

449

The application of dyadic wavelet in the RS building image edge detection  

Microsoft Academic Search

In the edge detection of RS building image, the useful detail losing and the spurious edge often appear. To solve the problem, we used the dyadic wavelet to detect the edge of surface features by combining the edge detecting with the multi-resolution analyzing of the wavelet transform. Via the dyadic wavelet decomposing, we obtained the RS building image of a

Qin Qiming; Wang Wenjun; Chen Sijin

2004-01-01

450

Architectural vs. delivered performance of the IBM RS\\/6000 and the Astronautics ZS-1  

Microsoft Academic Search

The paper presents a comparative performance evaluation of two novel superscalar architectures, the IBM RS\\/6000 and the Astronautics ZS-1. The machine architectures are presented to lay the groundwork for discussing performance issues, with a RISC architecture, the Decstation 3100, serving as a baseline architecture. Important qualitative observations are made to highlight similarities between the RS\\/6000 and the ZS-1. Performance measurements

William Mangione-Smith; Santosh G. Abraham; Edward S. Davidson

1991-01-01

451

AFRL-IF-RS-TR-2006-89 Final Technical Report  

E-print Network

AFRL-IF-RS-TR-2006-89 Final Technical Report March 2006 SEMANTIC WEB TECHNOLOGIES FOR MOBILE nations. AFRL-IF-RS-TR-2006-89 has been reviewed and is approved for publication. APPROVED: /s/ MARK Agency AFRL/IFSB 3701 North Fairfax Drive 525 Brooks Road Arlington Virginia 22203-1714 Rome New York

Sadeh, Norman M.

452

AFRL-IF-RS-TR-2006-250 Final Technical Report  

E-print Network

AFRL-IF-RS-TR-2006-250 Final Technical Report July 2006 INTEGRATION OF AUDIT DATA ANALYSIS). At NTIS it will be releasable to the general public, including foreign nations. AFRL-IF-RS-TR-2006-250 has Laboratory/IFGA 525 Brooks Rd Rome New York 13441-4505 11. SPONSORING/MONITORING AGENCY REPORT NUMBER AFRL

Noel, Steven

453

AFRL-IF-RS-TR-2004-100 Final Technical Report  

E-print Network

AFRL-IF-RS-TR-2004-100 Final Technical Report April 2004 SCALABLE PROTECTION AGAINST DDOS AND WORM). At NTIS it will be releasable to the general public, including foreign nations. AFRL-IF-RS-TR-2004-100 has AGENCY NAME(S) AND ADDRESS(ES) Defense Advanced Research Projects Agency AFRL/IFGA 3701 North Fairfax

Park, Kihong

454

FUNGOS LIQUENIZADOS EM FORÓFITOS DE MATA CILIAR, NO PARQUE ESTADUAL DO ESPINILHO, BARRA DO QUARAÍ, RS  

Microsoft Academic Search

LICHENIZED FUNGI IN PHOROPHYTES FROM THE CILIAR FOREST OF THE ESPINILHO STATE PARK, BARRA DO QUARAI, RS. Located at the Campanha region, far south west of RS, the Espinilho State Park is a vegetable disjunction from Chaquenha Province, characterized by a vegetable formation like the savanna type, with very typical flower and physiognomic features and a pseudo formation in the

Izabel MOTA; Gleici Meri FERNANDES; Francisco R. GALVANI

455

Clinical Features: Patients with Robinow syndrome (RS) [OMIM #268310] have characteristic facial features, growth  

E-print Network

recessive Robinow syndrome--Mutations in the ROR2 [OMIM #602337] gene have been identified in patients recessive RS (RRS) appear to be more severely affected than those believed to have autosomal dominant RS autosomal recessive Robinow syndrome. Brachydactyly, type B1--Heterozygous mutations of the ROR2 [OMIM

Ober, Carole

456

A non-LTE spectral analysis of the 3He and 4He isotopes in the HgMn star ? Cancri  

NASA Astrophysics Data System (ADS)

Aims: We present a pilot study on non-local thermodynamic equilibrium (NLTE) line-formation computations for the isotopes 3He and 4He in the mercury-manganese star ? Cancri. The impact of NLTE effects on the determination of isotopic abundances and the vertical stratification of helium in the atmosphere is investigated. Methods: Modern NLTE line-formation computations were employed to analyse a high-resolution and high signal-to-noise ratio ESO-VLT/UVES spectrum of ? Cnc. The atmospheric parameters were determined from fitting the hydrogen Balmer lines and the spectral energy distribution. Multiple He i lines were investigated, including He i ?4921 Å and ?6678 Å, which show the widest isotopic splits. Results: Half of the observed He i lines in the spectrum of ? Cnc show significant NLTE strengthening, the effects are strongest in the red lines He i?5875 Å and He i?6678 Å. NLTE abundances from individual He i lines are up to a factor of ~3 lower than LTE values. Helium is found to be stratified in the atmosphere of ? Cnc. While the LTE analysis indicates a step-like profile of the helium abundance, a gradual decrease with height is indicated by the NLTE analysis. A 3He/4He ratio of ~0.25-0.30 is found. With the available data it cannot be decided whether the two isotopes follow the same stratification profile, or not. Conclusions: This work implies that NLTE effects may be ubiquitous in the atmospheres of HgMn stars and may have a significant impact on abundance determinations and the interpretation of the vertical abundance stratification of elements. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 076.B-0055(A).Figures 3 and 4 are available in electronic form at http://www.aanda.org

Maza, Natalia L.; Nieva, María-Fernanda; Przybilla, Norbert

2014-12-01

457

The ARIES-RS power core -- Recent development in Li/V designs  

SciTech Connect

The ARIES-RS fusion power plant design study is based on reversed-shear (RS) physics with a Li/V (lithium breeder and vanadium structure) blanket. The reversed-shear discharge has been documented in many large tokamak experiments. The plasma in the RS mode has a high beta, low current, and low current drive requirements. Therefore, it is an attractive physics regime for a fusion power plant. The blanket system based on a Li/V has high temperature operating capability, good tritium breeding, excellent high heat flux removal capability, long structural life time, low activation, low after heat and good safety characteristics. For these reasons, the ARIES-RS reactor study selected Li/V as the reference blanket. The combination of attractive physics and attractive blanket engineering is expected to result in a superior power plant design. This paper summarizes the power core design of the ARIES-RS power plant study.

Sze, D.K.; Billone, M.C.; Hua, T.Q. [and others

1997-04-01

458

The Semiregular Variable Star Observing Program at Grinnell College  

NASA Astrophysics Data System (ADS)

A large body of photometric and spectroscopic data on 38 semiregular variable stars has been acquired at the Grant O. Gale Observatory of Grinnell College since 1984. This includes V and B band photoelectric photometry, CCD spectroscopic monitoring, and a large set of spectra for RS Cygni. The stars in the program were selected because they had a history of “quiescent episodes” in their pulsations that might be explained as mode switches. Time-dependent Fourier analysis has been applied to the photometric data to reveal the dominant frequency components represented in the light curves and to investigate how the strengths of those components vary - sometimes quite abruptly - over time. The spectroscopic monitoring of the entire set of stars is an ongoing project. The 413 RS Cygni spectra have been used to explore the variation of spectral features with phase. The conspicuous dip near the peak of the RS Cygni light curve does not appear to be associated with obvious variations in the strengths of spectral features.

Cadmus, Robert R.

2014-06-01

459

SWIRE Stars  

NASA Astrophysics Data System (ADS)

We propose IRS lo-res spectroscopy of 21 carefully selected stars from the SWIRE survey which show excess emission above the expected photospheric levels at 24um. This program differs from many extensive Spitzer stellar surveys, such as the FEPS legacy program and the MIPS GTO VLS survey in that the targets are not preselected. We hope through this approach to start to: 1) characterize the galactic population of stars with excesses at 24um; 2) to discover and identify rare transitional objects, such as protoplanetary nebulae; and 3) to test the inferences drawn from the targeted surveys. We will augment the Spitzer spectroscopy with 6.5 hrs. of visible spectroscopy from NOAO designed to permit classification of the stars. The type of program we undertake here exploits the unique discovery potential of the Spitzer mission.

Werner, Michael; Morales, Farisa; Padgett, Deborah; Stauffer, John

2006-05-01

460

Massive stars  

NASA Astrophysics Data System (ADS)

We describe the present state of massive star research seen from the viewpoint of stellar evolution, with special emphasis on close binaries. Statistics of massive close binaries are reasonably complete for the Solar neighbourhood. We defend the thesis that within our knowledge, many scientific results where the effects of binaries are not included, have an academic value, but may be far from reality. In chapter I, we summarize general observations of massive stars where we focus on the HR diagram, stellar wind mass loss rates, the stellar surface chemistry, rotation, circumstellar environments, supernovae. Close binaries can not be studied separately from single stars and vice versa. First, the evolution of single stars is discussed (chapter I). We refer to new calculations with updated stellar wind mass loss rate formalisms and conclusions are proposed resulting from a comparison with representative observations. Massive binaries are considered in chapter II. Basic processes are briefly described, i.e. the Roche lobe overflow and mass transfer, the common envelope process, the spiral-in process in binaries with extreme mass ratio, the effects of mass accretion and the merging process, the implications of the (asymmetric) supernova explosion of one of the components on the orbital parameters of the binary. Evolutionary computations of interacting close binaries are discussed and general conclusions are drawn. The enormous amount of observational data of massive binaries is summarized. We separately consider the non-evolved and evolved systems. The latter class includes the semi-detached and contact binaries, the WR binaries, the X-ray binaries, the runaways, the single and binary pulsars. A general comparison between theoretical evolution and observations is combined with a discussion of specially interesting binaries: the evolved binaries HD 163181, HD 12323, HD 14633, HD 193516, HD 25638, HD 209481, ? Per and silon Sgr; the WR+OB binary V444 Cyg; the high mass X-ray binaries Vela X-1, Wray 977, Cyg X-1; the low mass X-ray binaries Her X-1 and those with a black hole candidate; the runaway ? Pup, the WR+compact companion candidates Cyg X-3, HD 50896 and HD 197406. We finally propose an overall evolutionary model of massive close binaries as a function of primary mass, mass ratio and orbital period. Chapter III deals with massive star population synthesis with a realistic population of binaries. We discuss the massive close binary frequency, mass ratio and period distribution, the observations that allow to constrain possible asymmetries during the supernova explosion of a massive star. We focuss on the comparison between observed star numbers (as a function of metallicity) and theoretically predicted numbers of stellar populations in regions of continuous star formation and in starburst regions. Special attention is given to the O-type star/WR star/red supergiant star population, the pulsar and binary pulsar population, the supernova rates.

Vanbeveren, D.; De Loore, C.; Van Rensbergen, W.

461

The enigmatic star EZ Pegasi - A mystery solved?  

NASA Technical Reports Server (NTRS)

EZ Peg, a ninth-magnitude G star that has been classified by various authors as an irregular variable, a U Gem system, and a contact binary, is shown to have all the spectroscopic and photometric characteristics of an active-chromosphere RS CVn binary. It is suggested that the reported outburst of 1943, when the spectrum appeared to be that of a B star, never occurred. The strong Ca II H and K reversals, viewed with low spectral resolution, caused the photospheric Ca II absorption to appear abnormally weak, mimicking a much earlier spectral type.

Howell, S. B.; Bopp, B. W.

1985-01-01

462

A study of X-ray flares - II. RS CVn-type binaries  

NASA Astrophysics Data System (ADS)

We present an analysis of seven flares detected from five RS CVn-type binaries (UZ Lib, ? Gem, ? And, V711 Tau and EI Eri) observed with XMM-Newton observatory. The quiescent state X-ray luminosities in the energy band of 0.3-10.0 keV of these stars were found to be 1030.7-30.9 erg s-1. The exponential decay time in all the sample of flares range from ˜1 to 8 h. The luminosity at peak of the flares in the energy band of 0.3-10.0 keV was found to be in the range of 1030.8-1031.8 erg s-1. The great sensitivity of the XMM-European Photon Imaging Camera instrument allowed us to perform time resolved spectral analysis during the flares and also in the subsequent quiescent phases. The derived metal abundances of coronal plasma were found to vary during the flares observed from ? Gem, V771 Tau and EI Eri. In these flares elemental abundances found to be enhanced by factors of ˜1.3-1.5 to the quiescent states. In most of the flares, the peak temperature was found to be more than 100 MK, whereas emission measure increased by factors of 1.5-5.5. Significant sustained heating was present in the majority of flares. The loop lengths (L) derived for flaring structure were found to be in the order of 1010-11 cm and are smaller than the stellar radii (R?), i.e. L/R?? 1. The flare from ? Gem showed a high and variable absorption column density during the flare.

Pandey, J. C.; Singh, K. P.

2012-01-01

463

Astronomy & Astrophysics manuscript no. jetquellen c ESO 2012 February 10, 2012  

E-print Network

-star feedback. The Carina Nebula complex (hereafter CNC) is located at a moderate and very well in the CNC. At the same time, the com- paratively small distance to the CNC guarantees that we still can

Kersting, Roland

464

Energy Star  

E-print Network

ENERGY STAR ENERGY TARGETS ESL-KT-12-10-08 CATEE 2012: Clean Air Through Energy Efficiency Conference, Galveston, TX, October 9-11, 2012 POP QUIZ!!!! What is EUI?? Energy Use Intensity Do you know the EUI and any of the buildings you designed... Efficiency Conference, Galveston, TX, October 9-11, 2012 The CFLs in an ENERGY STAR qualified light fixture only need to be changed once every 8 years on average, compared with an annual ladder-climb for incandescent light bulbs. 6 CONSIDERING TIME...

Reihl, K.; Tullos, A.

2012-01-01

465

Cool stars, stellar systems, and the sun; Proceedings of the 6th Cambridge Workshop, Seattle, WA, Sept. 18-21, 1989  

NASA Technical Reports Server (NTRS)

The present conference on cool stars, stellar systems, and the sun encompasses stellar chromospheres and coronae, binary stars, the stellar evolution of contracting stars and red giants, stellar evolution abundances of the elements, mass loss and envelopes, and stellar pulsation. Specific issues addressed include theories regarding the acoustic and magnetic heating of stellar chromospheres and coronae, stellar granulation, wave heating in magnetic flux tubes, observations of the solar Ca-II lines, longitudinal-transverse magnetic tube waves in the solar atmosphere, radio emission from rapidly rotating cool giant stars, and spot temperatures and area coverages on active dwarf stars. Also addressed are the optical and UV spectra of RS-CVn stars, emission lines from T-Tauri stars, the spectroscopy of HR1614 group stars, red giants in external galaxies, the rotation of evolved stars, the transition from red giant to planetary nebula, and radiative transfer in the dynamic atmospheres of variable stars.

Wallerstein, George (editor)

1990-01-01

466

Performance Characterization of RaPToRS Systems  

NASA Astrophysics Data System (ADS)

The Rapid Pneumatic Transport of Radioactive Samples (RaPToRS) system can quickly and efficiently move radioactive materials from their activation site to a counting station. Facilities such as the NIF and LLE are considering these systems while NRL is currently using one. The system is essentially a 10 cm diameter pneumatic tube with a cylindrical sample carrier. The performance of the system depends on many factors, including the mass of the carrier, length of the tube, angle and difference in height of the tube's endpoints, the carrier's physical design, and the number, type, and distribution of blowers attached to the tube. These factors have been systematically examined to develop the fastest and most reliable system. The most significant factors are the mass and the vertical travel of the carrier. When the carrier mass is low, moving air supports the carrier in the tube, resulting in low friction. The terminal velocity ranges from 13.5 to 2.5 m/s for masses varying from 1 kg to 3 kg. Using a single 1100 W blower, the initial force exerted on the carrier was 11.3 N.

Shibata, K.; Krieger, M.; Fallica, J.; Henchen, R.; Pogozelski, E.; Padalino, S.

2011-11-01

467

Assessment of Leptin Gene Polymorphism rs2060713 in Psoriasis Vulgaris  

PubMed Central

Psoriasis is a lifelong disorder characterized by approximately 8-fold reduction of the duration of normal skin keratinocyte cell cycle and 2-fold increase of the number of dividing cells. Multiple genes, several environmental factors, and immune system alterations are involved in the pathogenesis of psoriasis. Hyperleptinemia is associated with psoriasis and leptin acts as an angiogenic factor. Angiogenetic processes precede the epidermal hyperplasia in psoriasis, indicating possible involvement of leptin in the pathogenesis of psoriasis. Leptin gene polymorphisms and their association with psoriasis have been given very little attention. We present a study of the rs2060713C/T genetic polymorphism in the pathogenesis of psoriasis vulgaris in 263 vulgaris patients and 252 unrelated matched healthy controls. No statistically significant differences were observed between patients and controls. A statistically nonsignificant trend was observed in males with the early onset type of psoriasis (11.1% C/T in patients versus 5.6% in controls) and in females with the late onset type of the disease (12.8% C/T in patients versus 3.3% in controls). Still, there is no hard evidence on correlation of psoriasis vulgaris with this polymorphism. Possible association with specific forms of the disease and either gender needs further investigation in larger studies. PMID:24600521

Karpouzis, Anthony; Tripsianis, Gregory

2014-01-01

468

Early Super Soft Source spectra in RS Oph  

E-print Network

Recent Swift X-ray monitoring campaigns of novae have revealed extreme levels of variability during the early super-soft-source (SSS) phase. The first time this was observed was during the 2006 outburst of the recurrent nova RS Oph which was also extensively covered by grating observations with XMM-Newton and Chandra. I focus here on an XMM-Newton observation taken on day 26.1, just before Swift confirmed the start of the SSS phase, and a Chandra observation taken on day 39.7. The first observation probes the evolution of the shock emission produced by the collision of the nova ejecta with the stellar wind of the companion. The second observation contains bright SSS emission longwards of 15A while at short wavelengths, the shock component can be seen to have hardly changed. On top of the SSS continuum, additional emission lines are clearly seen, and I show that they are much stronger than those seen on day 26.1, indicating line pumping caused by the SSS emission. The lightcurve on day 39.7 is highly variable ...

Ness, Jan-Uwe

2015-01-01

469

Hyperspectal RS image classification based on kernel methods  

NASA Astrophysics Data System (ADS)

Hyperspectral RS technology organically combines the radiation information and the space information. The spectrum information, which the hyperspectral image enriches, can be better to carry on the ground target classification, compare with panchromatic remote sensing image and multispectral remote sensing image. As support vector machine was applied to many fields successfully recent years, using kernel methods, the classic linear methods can cope with the nonlinear problem, which was called the 3rd revolution of pattern analysis algorithms. This paper introduced two classifying methods for hyperspectral image based on kernel function, Support Vector Machine and Kernel Fisher Discriminant Analysis, and studied the selection of kernel function and its parameters as well as multi-class decomposition. We use radial basic function kernel, one against one or one against rest decomposition methods to construct multi-class classifier, and optimize parameter selection using cross-validating grid search to build an effective and robust kernel classifier. It is verified that, through the OMIS and AVIRIS image classifying experiments, comparing with common image classifying methods, kernel classifying method can avoid Hughes phenomenon, thus improve the classifying accuracy.

Yang, Guopeng; Liu, Hangye; Yu, Xuchu

2007-11-01

470

Periodicities of Radio Flares in RS CVn and Algol Binaries  

NASA Astrophysics Data System (ADS)

Periodicities of radio flaring activity from the Algol systems beta Per and delta Lib and the RS CVn systems V711 Tau and UX Ari were determined from a continuous 5-year survey. The radio continuum fluxes at 2.3 GHz and 8.3 GHz were monitored with the NRAO--Green Bank Interferometer for 2096 days from 1995 January to 2000 October. The maximum detected flare strengths at 8.3 GHz were 1.17 Jy for beta Per 0.034 Jy for delta Lib 1.44 Jy for V711 Tau and 0.82 Jy for UX Ari. Power Spectrum Analysis and Phase Dispersion Minimization were used to determine the periodicity of flaring activity in each binary. The strongest periodicities found were 48.9 days for beta Per 120.7 days for V711 Tau and 141.4 days for UX Ari. No significant periodicities were found for delta Lib. The continuous survey has demonstrated that there are active and quiescent flaring cycles in V711 Tau and beta Per.

Richards, M. T.; Waltman, E. B.; Ghigo, F. D.; Richards, D. St. P.

2004-01-01

471

Two component X-ray emission from RS CVn binaries  

NASA Astrophysics Data System (ADS)

A summary of results from the solid state spectrometer on the Einstein Observatory for 7 RS CVn binaries is presented. The spectra of all require two emission components, evidenced by line emission characteristic of plasma at 4 to 8 x 10 to the 6th power and bremsstrahlung characteristic of 20 to 100 x 10 to the 6th power K. The data are interpreted in terms of magnetic coronal loops similar to those seen on the Sun, although with different characteristic parameters. The emission regions could be defined by separate magnetic structures. For pressure less than approximately 10 dynes/sq cm the low temperature plasma would be confined within the stellar radii, while the high temperature plasma would, for the synchronous close binaries, fill the binary orbits. However, for loop pressures exceeding 100 dynes/sq cm, the high temperature components would also be confined to within the stellar radii, in loops covering only small fractions of the stellar surfaces. While the radio properties and the occurrence of X-ray flares suggest the larger emission regions, the observations of time variations leave the ambiguity unresolved.

Swank, J. H.; White, N. E.; Holt, S. S.; Becker, R. H.

1980-11-01

472

The rs1024611 Regulatory Region Polymorphism Is Associated with CCL2 Allelic Expression Imbalance  

PubMed Central

CC chemokine ligand 2 (CCL2) is the most potent monocyte chemoattractant and inter-individual differences in its expression level have been associated with genetic variants mapping to the cis-regulatory regions of the gene. An A to G polymorphism in the CCL2 enhancer region at position –2578 (rs1024611; A>G), was found in most studies to be associated with higher serum CCL2 levels and increased susceptibility to a variety of diseases such as HIV-1 associated neurological disorders, tuberculosis, and atherosclerosis. However, the precise mechanism by which rs1024611influences CCL2 expression is not known. To address this knowledge gap, we tested the hypothesis that rs1024611G polymorphism is associated with allelic expression imbalance (AEI) of CCL2. We used haplotype analysis and identified a transcribed SNP in the 3?UTR (rs13900; C>T) can serve as a proxy for the rs1024611 and demonstrated that the rs1024611G allele displayed a perfect linkage disequilibrium with rs13900T allele. Allele-specific transcript quantification in lipopolysaccharide treated PBMCs obtained from heterozygous donors showed that rs13900T allele were expressed at higher levels when compared to rs13900C allele in all the donors examined suggesting that CCL2 is subjected to AEI and that that the allele containing rs1024611G is preferentially transcribed. We also found that AEI of CCL2 is a stable trait and could be detected in newly synthesized RNA. In contrast to these in vivo findings, in vitro assays with haplotype-specific reporter constructs indicated that the haplotype bearing rs1024611G had a lower or similar transcriptional activity when compared to the haplotype containing rs1024611A. This discordance between the in vivo and in vitro expression studies suggests that the CCL2 regulatory region polymorphisms may be functioning in a complex and context-dependent manner. In summary, our studies provide strong functional evidence and a rational explanation for the phenotypic effects of the CCL2 rs1024611G allele. PMID:23166687

Pham, Minh-Hieu T.; Bonello, Gregory B.; Castiblanco, John; Le, Tuan; Sigala, Jose; He, Weijing; Mummidi, Srinivas

2012-01-01

473

The star sky atlas  

Microsoft Academic Search

This atlas consists of 20 star charts together with a stellar catalogue. A booklet with explanations to the star sky atlas and to the stellar catalogue is included. The charts of the atlas contain stars to visual magnitude 6.5. The total number of stars is ?8,500. The star charts also contain star clusters, nebulae and galaxies. The atlas is referred

V. K. Abalakin

1991-01-01

474

Seeing Stars  

Microsoft Academic Search

Seeing Stars is written for astronomers, regardless of the depth of their theoretical knowledge, who are taking their first steps in observational astronomy. Chris Kitchin and Bob Forrest - both professional astronomers - take a conducted tour of the night sky and suggest suitable observing programmes for everyone from beginners to experts. How is this book different? We are all

Chris Kitchin; Robert W. Forrest

1998-01-01

475

Star Power  

SciTech Connect

The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

None

2014-10-17

476

STAR Highlights  

E-print Network

We report selected results from STAR collaboration at RHIC, focusing on jet-hadron and jet-like correlations, quarkonium suppression and collectivity, di-electron spectrum in both p+p and Au+Au, and higher moments of net-protons as well as azimuthal anisotropy from RHIC Beam Energy Scan program.

Hiroshi Masui; for the STAR Collaboration

2011-06-29

477

Star Power  

ScienceCinema

The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

None

2014-11-18

478

Star quality.  

PubMed

Around 150 wards are participating in the voluntary Star Wards scheme to provide mental health inpatients with more activities with therapeutic value. Suggested activities range from a library, to horse riding Internet access and comedy. Service users are particularly keen to have more exercise, which can be a challenge in inpatient settings. PMID:17970387

Dent, Emma