scholarly journals Variability of newly identified B-type stars observed by Kepler

2021 ◽  
Vol 503 (4) ◽  
pp. 5894-5928
Author(s):  
Wojciech Szewczuk ◽  
Przemysław Walczak ◽  
Jadwiga Daszyńska-Daszkiewicz

ABSTRACT Recent re-determination of stellar atmospheric parameters for a sample of stars observed during the Kepler mission allowed to enlarge the number of Kepler B-type stars. We present the detailed frequency analysis for all these objects. All stars exhibit pulsational variability with maximum amplitudes at frequencies corresponding to high-order g modes. Peaks that could be identified with low-order p/g modes are also extracted for a few stars. We identified some patters in the oscillation spectra that can be associated with the period spacings that can results from the asymptotic nature of the detected pulsational modes. We also tentatively confront the observed oscillation characteristics with predictions from linear non-adiabatic computations of stellar pulsations. For high-order g modes the traditional approximation was employed to include the effects of rotation on the frequency values and mode instability.

Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.


Author(s):  
Ingrid Kästel ◽  
Giles de Quincey ◽  
Jörg Neugebauer ◽  
Robert Sader ◽  
Peter Gehrke

Abstract Background There is disagreement about the optimal torque for tightening smartpegs for resonance frequency analysis (RFA). Subjective finger pressure during hand tightening could affect the reliability of the resulting values. The aim of the current study was therefore to assess whether or not the insertion torque of a smartpeg magnetic device influences the implant stability quotient (ISQ) value during RFA. Methods Thirty self-tapping screw implants (XiVE S, Dentsply Sirona Implants, Bensheim, Germany) with a diameter of 3.8 mm and a length of 11 mm were inserted in three cow ribs with a bone quality of D1. The RFA value of each implant was measured (Ostell, FA W&H Dentalwerk, Bürmoos, Austria) in two orthogonal directions (mesial and buccal) after tightening the corresponding smartpeg type 45 with a mechanically defined value of 5 Ncm (Meg Torq device, Megagen, Daegu, South Korea) (test). Additionally, 4 different examiners measured the RFA after hand tightening the smartpegs, and the results were compared (control). Insertion torque values were determined by measuring the unscrew torque of hand seated smartpegs (Tohnichi Manufacturing Co. Ltd, Tokyo, Japan). Results The ISQ values varied from 2 to 11 Ncm by hand tightening and from 2 to 6 Ncm by machine tightening. The comparison of hand and machine tightening of smartpegs displayed only minor differences in the mean ISQ values with low standard deviations (mesial 79.76 ± 2,11, buccal 77.98 ± 2,) and no statistical difference (mesial p = 0,343 and buccal p = 0,890). Conclusions Manual tightening of smartpeg transducers allows for an objective and reliable determination of ISQ values during RFA.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
M. Marchetti ◽  
M. Moutton ◽  
S. Ludwig ◽  
L. Ibos ◽  
V. Feuillet ◽  
...  

Thermal mapping has been implemented since the late eighties to establish the susceptibility of road networks to ice occurrence with measurements from a radiometer and some atmospheric parameters. They are usually done before dawn during wintertime when the road energy is dissipated. The objective of this study was to establish if an infrared camera could improve the determination of ice road susceptibility, to build a new winter risk index, to improve the measurements rate, and to analyze its consistency with seasons and infrastructures environment. Data analysis obtained from the conventional approved radiometer sensing technique and the infrared camera has shown great similarities. A comparison was made with promising perspectives. The measurement rate to analyse a given road network could be increased by a factor two.


2000 ◽  
Vol 62 (2) ◽  
Author(s):  
Lora Nugent-Glandorf ◽  
Michael Scheer ◽  
M. Krishnamurthy ◽  
Jennifer W. Odom ◽  
Stephen R. Leone

1992 ◽  
Vol 92 (3) ◽  
pp. 1564-1568 ◽  
Author(s):  
Hiroyuki Hachiya ◽  
Shigeo Ohtsuki ◽  
Motonao Tanaka ◽  
Floyd Dunn

2008 ◽  
Vol 49 (2) ◽  
pp. 336-345 ◽  
Author(s):  
F.J. Batlles ◽  
J.L. Bosch ◽  
J. Tovar-Pescador ◽  
M. Martínez-Durbán ◽  
R. Ortega ◽  
...  

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