scholarly journals Determination of Yarn Diameter and Relevant Applications in Various Theoretical and Practical Problems

2021 ◽  
Vol 28 (122) ◽  
pp. 134-148
Author(s):  
GÜNGÖR BAŞER
Keyword(s):  
2020 ◽  
Vol 68 (3) ◽  
pp. 10-14
Author(s):  
Miodrag Đorđević ◽  
Viktorija Stanković ◽  
Ana Ilić

Yarn length in a loop is one of the most important technological parameters in knitwear structure analysis. Therefore, determination of the accurate values of yarn length in a loop is of great importance in knitwear structure parameters projection. This paper presents comparative results of the determination of yarn length in a loop based on the loop row height, loop row width and calculated yarn diameter, as well as determination of loop length based on machine technological parameters taking into account needle pace, platinum and needle diameter, platinum and needle curved radius, span angle of yarn with needle and platinum and projected cooling depths. The results obtained show various values of yarn length in a loop.


2016 ◽  
Vol 24 (2(116)) ◽  
pp. 29-36 ◽  
Author(s):  
Aleš Hladnik ◽  
Alenka Pavko-Čuden ◽  
Syamak Farajikhah ◽  
Syamak Farajikhah

1976 ◽  
Vol 46 (8) ◽  
pp. 545-562 ◽  
Author(s):  
Bohuslav Neckář

Part I: Theoretical Model The equilibrium of the yarn element is defined on the basis of a cylindrical model of yarn formation. The fibrous system is considered a continuum. The stress-strain relationship is solved for the element of this fibrous continuum. A mathematical model is proposed which is based on the idea of effective elastic bonds including nonlinearity and finite strains. Through substitution of this model in a differential equation of equilibrium, a differential equation is found which can be solved numerically. Also, the effect of fiber migration is taken partly into consideration. A method of calculation is deduced for the course of the radial fiber packing density. Part II: Application A new method of experimental determination of the course of the fiber packing density is described. The method is based on mathematical evaluation of tracer fibers from photographs produced on the OMEST Tester. A modified evaluation of experimentally determined yarn diameters is proposed. Results obtained with carded cotton yarns are specified. The theoretical model is processed numerically. The input parameters of the numerical solution are discussed. Theoretical results are compared with the results of the fiber packing density and yarn diameter measurements. The findings are discussed from the viewpoint of the physical aspects of the internal mechanics of yarn.


1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.


1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.


1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).


1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.


2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.


1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.


1979 ◽  
Vol 44 ◽  
pp. 349-355
Author(s):  
R.W. Milkey

The focus of discussion in Working Group 3 was on the Thermodynamic Properties as determined spectroscopically, including the observational techniques and the theoretical modeling of physical processes responsible for the emission spectrum. Recent advances in observational techniques and theoretical concepts make this discussion particularly timely. It is wise to remember that the determination of thermodynamic parameters is not an end in itself and that these are interesting chiefly for what they can tell us about the energetics and mass transport in prominences.


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