scholarly journals Declination Angle Gage for Tilt Measurement Sensors

2012 ◽  
Vol 48 ◽  
pp. 549-556 ◽  
Author(s):  
Miroslav Pastor ◽  
Tatiana Kelemenová ◽  
Michal Kelemen ◽  
Ľubica Miková ◽  
Rastislav Baláž
Keyword(s):  
Declination Angle ◽  
Angle Gage

scholarly journals Semiautomatic sun shots with the WIDIF DIflux

2017 ◽  
Vol 6 (2) ◽  
pp. 257-261
Author(s):  
Jean L. Rasson ◽  
Olivier Hendrickx ◽  
Jean-Luc Marin
Keyword(s):  
Gps Receiver ◽  
Magnetic Declination ◽  
Declination Angle ◽  
Magnetic North

Abstract. The determination of magnetic declination angle entails finding two directions: geographic north and magnetic north. This paper deals with the former. The known way to do it by using the sun's calculable orientation in the sky is improved by using a device based on a WIDIF DIflux theodolite and split photocells positioned on its telescope ocular. Given the WIDIF accurate timing and location provided by the onboard GPS receiver, an astronomical computation can be effected to accurately and quickly determine the sun's azimuth and an auxiliary mark's azimuth. The precise sun's crossing of the split photocell, amplified by the telescope's magnification, allows azimuth accuracies of a few seconds of arc.

Design of an Embedded Solar Tracking System Based on GPS and Astronomical Equations

2014 ◽  
Vol 9 (1) ◽  
pp. 12-30 ◽  
Author(s):  
Fawzi M. Al-Naima ◽  
Ramzy S. Ali ◽  
Ahmed J. Abid
Keyword(s):  
Tracking System ◽  
High Accuracy ◽  
The Sun ◽  
Solar Tracking ◽  
Declination Angle ◽  
Cost Efficient ◽  
Equation Of Time

This article presents the design of a reliable, accurate, and easy to install solar dual axis tracking system. The system utilizes the GPS for fixing the time, date and location in terms of longitude and latitude. Approximations having high accuracy of the astronomical equations to represent the declination angle and the equation of time are selected to determine the sun locations needed by the designed tracking system in any chosen location on earth. The proposed system is standalone, accurate, durable, reliable, and cost efficient. Annual energy assessments of the system are also given.

DECLINATION ANGLE AND ITS ROLE IN SELECTING SURGICAL TELESCOPES

1999 ◽  
Vol 130 (7) ◽  
pp. 1096-1100 ◽  
Author(s):  
LANCE M. RUCKER ◽  
CRAIG BEATTIE ◽  
CATHY MCGREGOR ◽  
SUSANNE SUNELL ◽  
YUTAKA ITO
Keyword(s):  
Declination Angle

scholarly journals Statistical analysis of radar observed F region irregularities from three longitudinal sectors

2013 ◽  
Vol 31 (12) ◽  
pp. 2137-2146 ◽  
Author(s):  
R. Y. C. Cueva ◽  
E. R. de Paula ◽  
A. E. Kherani
Keyword(s):  
Onset Time ◽  
Solar Flux ◽  
Christmas Island ◽  
F Region ◽  
Incoherent Scatter Radars ◽  
Declination Angle ◽  
Spread F ◽  
Occurrence Characteristics ◽  
Using Data

Abstract. Equatorial Spread F (ESF) is a manifestation of ionospheric interchange instabilities in the nighttime equatorial F region. These instabilities generate plasma density irregularities with scale sizes ranging from centimetres to thousands of kilometres. The irregularities can be detected from a variety of instruments such as digisonde, coherent and incoherent scatter radars, in situ space probes, and airglow photometers. In the present study, occurrence statistics of the ESF, based on various parameters are presented using data obtained from the VHF radars located at three longitudinally separated equatorial stations: Christmas Island (2° N, 202.6° E, 2.9° N dip latitude), São Luís (2.59° S, 315.8° E, 0.5° S dip latitude) and Jicamarca (12° S, 283.1° E, 0.6° N dip latitude). The ESF parameters presented here are the onset altitude, onset time (onset refers to first appearance of signal in the radar field of view) of the bottom-type and plume, and the peak altitude of the plume. Recent studies have used these parameters to classify the spread F occurrence characteristics. The present study reveals novel features namely, the dependence of ESF parameters on the seasonal, solar flux, declination angle and longitudinal dependence from the three radar sites. In addition, we also present an empirical model to determine the nature of these ESF parameters as a function of the solar flux which may enable us to forecast (with 30 min to 1 h tolerance) the plume occurrence at any longitude located in between São Luís and Christmas Island.

Subtalar Distraction Bone Block Fusion: An Assessment of Outcome

1997 ◽  
Vol 18 (12) ◽  
pp. 785-791 ◽  
Author(s):  
Paul A. Bednarz ◽  
Timothy C. Beals ◽  
Arthur Manoli
Keyword(s):  
Scale Score ◽  
Bone Block ◽  
Os Calcis ◽  
Time Work ◽  
Declination Angle ◽  
Change In The Mean ◽  
Part Time ◽  
The Mean ◽  
Os Calcis Fractures ◽  
American Orthopaedic

Twenty-nine feet in 28 patients who underwent subtalar distraction bone block fusion for the treatment of subtalar deformities associated with symptomatic arthrosis were evaluated. All patients were assessed with the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score. Eighteen men and 10 women with a mean age of 44 years were evaluated. The mean follow-up was 33 months. Subtalar arthrosis was secondary to trauma in 27 of 29 feet (93%) with os calcis fractures in 19, subtalar dislocations in 5, and talus fractures in 3. Eighteen of the 28 patients (64%) returned to either full- or part-time work. The change in the mean AOFAS Ankle-Hindfoot Scale score from 25 preoperatively to 75 postoperatively was statistically significant ( P < 0.0001). The radiographic analysis of the pre- and postoperative standing lateral radiographs showed an average increase of 8 mm in hindfoot height, 9° in lateral talocalcaneal angle, and 11° in lateral talar declination angle that were statistically significant ( P < 0.0001). All patients but one (96%) were satisfied. Complications included four nonunions, two varus malunions, one metatarsal stress fracture, and one medial plantar nerve paresthesia. Each nonunion occurred in patients who smoked.

Etalonnage de cales étalons angulaires par la méthode de zéro

1981 ◽  
Vol 59 (7) ◽  
pp. 871-875
Author(s):  
Gratien Bouillon ◽  
Gilles Tremblay ◽  
Claude Delisle
Keyword(s):  
High Precision ◽  
Balance Method ◽  
Rotary Table ◽  
Dimensional Metrology ◽  
Angle Gage ◽  
Surface Plate

A method used to calibrate a set of reference angle gage blocks is described. Only the equipment usually found in a dimensional metrology laboratory is used, such as autocollimators and a surface plate. Contrary to some other well-known methods, supplementary sets of angle gage blocks, a high precision dividing head or a rotary table are not needed. To benefit from the sensitivity and repeatability of the autocollimators, while eliminating their errors of accuracy, a null-balance method has been used.[Journal translation]

scholarly journals Spline-Based Formulas for the Determination of Equation of Time and Declination Angle

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Fawzi Al-Naima ◽  
Bilal Abdul Majeed
Keyword(s):  
Spline Interpolation ◽  
Absolute Error ◽  
Cubic Spline ◽  
Analytical Evaluation ◽  
Maximum Absolute Error ◽  
Cubic Spline Interpolation ◽  
Approximation Formulas ◽  
Declination Angle ◽  
Equation Of Time

This paper presents new approximation formulas for the determination of the equation of time and declination angle. The proposed approach is based on the cubic spline interpolation techniques defined for sixteen or twenty chosen knots over the whole year. The results obtained by the proposed formulas for both equation of time and declination angle show marked improvements in terms of speed and sum of squared errors and maximum absolute error over the whole year in comparison with other five existing methods for analytical evaluation of equation of time and two existing methods for analytical evaluation of declination angle.

scholarly journals Impact of Preparation of Titanium Alloys on Their Abrasive Water Jet Machining

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7768
Author(s):  
Adam Štefek ◽  
Martin Tyč
Keyword(s):  
Titanium Alloys ◽  
Niti Alloy ◽  
Traverse Speed ◽  
Structural Features ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Abrasive Water Jet Machining ◽  
Declination Angle ◽  
The Impact ◽  
Awj Cutting

Several titanium alloys, i.e., grade 2 Ti, Ti6Al4V and NiTi alloy, prepared by selected deformation procedures were subjected to abrasive water jet (AWJ) cutting and subsequently analysed. The study describes samples’ preparations and respective material structures. The impact of deformation processing of the selected alloys on the declination angle during cutting, and the results of measurements of surface wall quality performed for the selected samples at the Department of Physics of Faculty of Electrical Engineering and Computer Science at VŠB–Technical University of Ostrava, are presented and discussed, as are also the influences of structural features of the processed titanium alloys on surface qualities of the investigated samples. The results showed that the highest resistance to AWJ machining exhibited the Ti6Al4V alloy prepared by forward extrusion. Its declination angle (recalculated to the thickness 10 mm to compare all the studied samples) was 12.33° at the traverse speed of 100 mm/min, pumping pressure of 380 MPa, and abrasive mass flow rate of 250 g/min.

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