On the Progress Made in the Last Decade in the Determination of Stellar Motions in the Line of Sight

1900 ◽  
Vol 11 ◽  
pp. 373 ◽  
Author(s):  
H. C. Vogel
Keyword(s):  
Line Of Sight ◽  
Made In

scholarly journals I. On the rate of propagation of the luminous discharge of electricity through a rarefied gas

1891 ◽  
Vol 49 (296-301) ◽  
pp. 84-100 ◽  
Keyword(s):  
Electric Discharge ◽  
Discharge Tube ◽  
Rarefied Gas ◽  
Line Of Sight ◽  
Vacuum Tube ◽  
Large Velocity ◽  
Velocity Of Propagation ◽  
Made In

Though the determination of the velocity of propagation of the luminosity which accompanies the electric discharge through gases might well be expected to throw considerable light on the means by which the discharge is effected, as far as I can find, no attempts seem to have been made in this direction since Wheatstone, in 1835, observed the appearance presented in a rotating mirror of the discharge through a vacuum tube 6 feet long; he concluded from his observations that the velocity with which the flash went through the tube could not have been less than 2 x 10 7 . cm. per second. This very great velocity does not seem to be accompanied by a correspondingly large velocity of the luminous molecules, for von Jahn (Wiedemann’s ‘Annalen,’ vol. 8, 1879, p. 675) has shown that the lines of the spectrum of the gas in the discharge tube are not displaced by as much as 1/40 of the distance between the D lines when the line of sight is in the direction of the discharge tube. It follows from this, by Doppler’s principle, that the particles when emitting light are not travelling in the direction of the discharge at the rate of more than a mile a second, proving at any rate th at the luminosity does'not consist of a wind of luminous particles travelling with the velocity of the discharge.

The quantitative comparison of experimental and simulated diffraction contrast images

1995 ◽  
Vol 53 ◽  
pp. 102-103
Author(s):  
Stuart McKernan
Keyword(s):  
Image Processing ◽  
Personal Computer ◽  
Close Agreement ◽  
Quantitative Comparison ◽  
Image Simulation ◽  
Computing Power ◽  
Diffraction Contrast ◽  
Simulated Images ◽  
Made In

For many years the concept of quantitative diffraction contrast experiments might have consisted of the determination of dislocation Burgers vectors using a g.b = 0 criterion from several different 2-beam images. Since the advent of the personal computer revolution, the available computing power for performing image-processing and image-simulation calculations is enormous and ubiquitous. Several programs now exist to perform simulations of diffraction contrast images using various approximations. The most common approximations are the use of only 2-beams or a single systematic row to calculate the image contrast, or calculating the image using a column approximation. The increasing amount of literature showing comparisons of experimental and simulated images shows that it is possible to obtain very close agreement between the two images; although the choice of parameters used, and the assumptions made, in performing the calculation must be properly dealt with. The simulation of the images of defects in materials has, in many cases, therefore become a tractable problem.

Science of Ahangyol and Its Importance for Modern Scientific Thought

2019 ◽  
Vol 10 (5) ◽  
pp. 473-478
Author(s):  
Ahmad Gashamoglu ◽  
Keyword(s):  
Modern Science ◽  
Scientific Basis ◽  
New Paradigm ◽  
Islamic Philosophy ◽  
Scientific Thought ◽  
Religious Books ◽  
Strategic Approach ◽  
Scientific Potential ◽  
Made In

The Article briefly discusses the need for generation of the Science of Ahangyol, and this science’s scientific basis, object and subject, category system, scientific research methods and application options. Ahangyol is a universal science and may be useful in any sphere. It may assist in problem solving in peacemaking process and in many areas such as ecology, economics, politics, culture, management and etc. This science stipulates that any activity and any decision made in the life may only and solely be successful when they comply with harmony principles more, which are the principles of existence and activity of the world. A right strategic approach of the Eastern Philosophy and the Middle Age Islamic Philosophy and scientific thought has an important potential. This strategic approach creates opportunities to also consider irrational factors in addition to rational ones comprehensively in scientific researches. The modern scientific thought contributes to implementation of these opportunities. Ahangyol is a science of determination of ways to achieve harmony in any sphere and of creation of special methods to make progress in these ways through assistance of the modern science. Methods of the System Theory, Mathematics, IT, Astronomy, Physics, Biology, Sociology, Statistics and etc. are more extensively applied. Information is given on some of these methods. Moreover, the Science of Ahangyol, which is a new philosophical worldview and a new paradigm contributes to clarification of metaphysic views considerably and discovery of the scientific potential of religious books.

scholarly journals Determination of Environmental Factors for the Implementation of the Exploitability Index in Industrial Aggregate Mining Using Multi-Criteria Analysis

2021 ◽  
Vol 10 (4) ◽  
pp. 196
Author(s):  
Julio Manuel de Luis-Ruiz ◽  
Benito Ramiro Salas-Menocal ◽  
Gema Fernández-Maroto ◽  
Rubén Pérez-Álvarez ◽  
Raúl Pereda-García
Keyword(s):  
Environmental Factors ◽  
Environmental Factor ◽  
Human Life ◽  
Accurate Estimation ◽  
Analytic Hierarchy ◽  
Main Components ◽  
Hierarchy Process ◽  
Made In

The quality of human life is linked to the exploitation of mining resources. The Exploitability Index (EI) assesses the actual possibilities to enable a mine according to several factors. The environment is one of the most constraining ones, but its analysis is made in a shallow way. This research is focused on its determination, according to a new preliminary methodology that sets the main components of the environmental impact related to the development of an exploitation of industrial minerals and its weighting according to the Analytic Hierarchy Process (AHP). It is applied to the case of the ophitic outcrops in Cantabria (Spain). Twelve components are proposed and weighted with the AHP and an algorithm that allows for assigning a normalized value for the environmental factor to each deposit. Geographic Information Systems (GISs) are applied, allowing us to map a large number of components of the environmental factors. This provides a much more accurate estimation of the environmental factor, with respect to reality, and improves the traditional methodology in a substantial way. It can be established as a methodology for mining spaces planning, but it is suitable for other contexts, and it raises developing the environmental analysis before selecting the outcrop to be exploited.

scholarly journals Characterization of Degenerate Configurations in Attitude Determination of Three-Vehicle Heterogeneous Formations

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4631
Author(s):  
Pedro Cruz ◽  
Pedro Batista
Keyword(s):  
Unique Solution ◽  
Multiple Solutions ◽  
Attitude Determination ◽  
Line Of Sight ◽  
Number Of Solutions ◽  
Relative Line ◽  
Heterogeneous Formations ◽  
Heterogeneous Formation

The existence of multiple solutions to an attitude determination problem impacts the design of estimation schemes, potentially increasing the errors by a significant value. It is therefore essential to identify such cases in any attitude problem. In this paper, the cases where multiple attitudes satisfy all constraints of a three-vehicle heterogeneous formation are identified. In the formation considered herein, the vehicles measure inertial references and relative line-of-sight vectors. Nonetheless, the line of sight between two elements of the formation is restricted, and these elements are denoted as deputies. The attitude determination problem is characterized relative to the number of solutions associated with each configuration of the formation. There are degenerate and ambiguous configurations that result in infinite or exactly two solutions, respectively. Otherwise, the problem has a unique solution. The degenerate configurations require some collinearity between independent measurements, whereas the ambiguous configurations result from symmetries in the formation measurements. The conditions which define all such configurations are determined in this work. Furthermore, the ambiguous subset of configurations is geometrically interpreted resorting to the planes defined by specific measurements. This subset is also shown to be a zero-measure subset of all possible configurations. Finally, a maneuver is simulated to illustrate and validate the conclusions. As a result of this analysis, it is concluded that, in general, the problem has one attitude solution. Nonetheless, there are configurations with two or infinite solutions, which are identified in this work.

Determination of Underwater Plate Dynamics Using Laser Beams

1974 ◽  
Vol 96 (3) ◽  
pp. 722-728
Author(s):  
Rudolph E. Croteau ◽  
Herman E. Sheets
Keyword(s):  
Near Field ◽  
Surface Displacement ◽  
Coupled System ◽  
Green Laser ◽  
Testing Facility ◽  
Acoustic Testing ◽  
Propeller Blades ◽  
The Relationship ◽  
Made In

Underwater plate vibration and its associated noise are of interest for the analysis of ship structures, propeller blades, and other areas of underwater acoustics. In order to analyze the relationship between a plate vibrating underwater and the acoustic pressure in the near-field, optical interferometric holography, using a blue-green laser beam, was used to determine surface displacement for the vibrating plate, which was excited through a fluid-coupled system. Acoustic measurements of the same source were made in a water tower concurrently with the holography and later at a precision acoustic testing facility. This method permits prediction of underwater plate modal frequencies and shapes with high accuracy.

A Progress Report on the Quest to Establish a Cybersickness Dose Value

2002 ◽  
Vol 46 (26) ◽  
pp. 2119-2123 ◽  
Author(s):  
Wei Chen ◽  
S.L. Yuen ◽  
R.H.Y. So
Keyword(s):  
Linear Relationship ◽  
Motion Sickness ◽  
Progress Report ◽  
Simulation Studies ◽  
Current Effort ◽  
British Standard ◽  
The Past ◽  
Frequency Weighting ◽  
Made In

This paper summarizes the progress made in the quest to establish a Cybersickness Dose Value (CSDV). The Motion Sickness Dose Value (MSDV), reported in the British Standard BS6841, has been used to predict the severity of seasickness since 1987. In 1999, the authors of this paper proposed a CSDV formulation with a structure similar to that of the MSDV (So, 1999). Since then, several experiments and simulation studies have been conducted to modify and develop the proposed CSDV formula. In particular, progress has been made in (i) the methods to measure CSDV, (ii) the determination of a frequency weighting curve to equalize the non-linear relationship between the navigation velocity and levels of cybersickness, and (iii) the detailed formulation of CSDV. This paper summarizes the past progress and reports on the current effort in developing a CSDV.

Downtime Analysis Techniques for Complex Offshore and Dredging Operations

2004 ◽  
Author(s):  
Remmelt J. van der Wal ◽  
Gerrit de Boer
Keyword(s):  
Wind Waves ◽  
Weather Forecast ◽  
Offshore Structures ◽  
Operational Mode ◽  
Offshore Structure ◽  
Hydrodynamic Models ◽  
Time Step ◽  
Made In

Offshore operations in open seas may be seriously affected by the weather. This can lead to a downtime during these operations. The question whether an offshore structure or dredger is able to operate in wind, waves and current is defined as “workability”. In recent decades improvements have been made in the hydrodynamic modelling of offshore structures and dredgers. However, the coupling of these hydrodynamic models with methods to analyse the actual workability for a given offshore operation is less developed. The present paper focuses on techniques to determine the workability (or downtime) in an accurate manner. Two different methods of determining the downtime are described in the paper. The first method is widely used in the industry: prediction of downtime on basis of wave scatter diagrams. The second method is less common but results in a much more reliable downtime estimate: determination of the ‘job duration’ on basis of scenario simulations. The analysis using wave scatter diagrams is simple: the downtime is expressed as a percentage of the time (occurrences) that a certain operation can not be carried out. This method can also be used for a combination of operations however using this approach does not take into account critical events. This can lead to a significant underprediction of the downtime. For the determination of the downtime on basis of scenario simulations long term seastate time records are used. By checking for each subsequent time step which operational mode is applicable and if this mode can be carried out the workability is determined. Past events and weather forecast are taken into account. The two different methods are compared and discussed for a simplified offloading operation from a Catenary Anchor Leg Mooring (CALM) buoy. The differences between the methods will be presented and recommendations for further applications are given.

A SIMPLE RAPID METHOD FOR DETERMINATION OF SPECIFIC GRAVITY OF SMALL SAMPLES OF URINE

PEDIATRICS ◽  
1959 ◽  
Vol 24 (5) ◽  
pp. 814-818
Author(s):  
Allen S. Goldman
Keyword(s):  
Specific Gravity ◽  
Present Report ◽  
Total Sample ◽  
Mineral Oil ◽  
Small Samples ◽  
Gradient System ◽  
Small Opening ◽  
Flotation Method ◽  
Made In

THE THERAPY of infants with disturbances in fluid balance is greatly assisted by knowledge of the specific gravity of the urine. Frequently only a few milliliters can be collected at any one time, while a minimum sample of 25 ml is necessary for use of the smallest urinometers currently available. The existing methods of determining specific gravity of one drop of urine are somewhat laborious, and require expensive equipment and the services of a relatively skilled technician. The present report describes a method which is rapid and simple and requires only a few drops of urine in its use. It is similar in principle to the determination of specific gravity of blood by the copper-sulfate method. For use with urine, mixtures are employed of two relatively nonvolatile liquids, immiscible with water, and with specific gravities nearly equally above and below the range in urine. The specific gravity of urine is determined by allowing one drop to fall into each of a series of tubes containing a mixture of the two liqquids made up to various specific gravities ranging from 1.005 to 1.030 (Fig. 1). That mixture in which the drop of urine comes most nearly to remaining still (neither rising nor falling after coming to rest) approximates the specific gravity of the urine. The total sample needed is only a few drops, which can be quite small if a dropper with a small opening (2 mm) is used. The determination takes a few minutes. A year's supply of the mixtures can be made in one afternoon and costs less than $6.00. MATERIALS The two solutions used were selected from the flotation method of Kirk, using a density gradient system. These are Liquid 1, dibutyl-n-phthalate (Eastman), specific gravity 1.04820°; and Liquid 2, kerosene, specific gravity 0.8220°. (Similar results were obtained by substituting California mineral oil, specific gravity 0.842-0.88420°, for kerosene.)

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