Determination of ejection velocity of rock fragments during rock burst in consideration of damage

2005 ◽  
Vol 12 (5) ◽  
pp. 618-622 ◽  
Author(s):  
Yu-jun Zuo ◽  
Xi-bing Li ◽  
Zi-long Zhou
Keyword(s):  
Rock Burst ◽  
Ejection Velocity ◽  
Rock Fragments

Fabric Description of Archaeological Ceramics

2016 ◽  
pp. 199-216 ◽  
Author(s):  
Ian Whitbread
Keyword(s):  
Quantitative Data ◽  
Raw Materials ◽  
Thin Sections ◽  
Archaeological Ceramics ◽  
Qualitative And Quantitative ◽  
Rock Fragments ◽  
Construction Methods ◽  
Hand Specimen ◽  
Technological Analysis

Fabric description is fundamental to the characterization, technological analysis and provenance determination of archaeological ceramics. It encompasses description of the arrangement, size, shape, frequency and composition of ceramic material constituents. These properties are used to identify the raw materials, their processing, vessel construction methods, and firing conditions. The process of description should, so far as possible, be an objective record of observed fabric properties that is independent of interpretations concerning technology and provenance. Fabric descriptions are made of ceramics in hand specimen and of samples prepared as thin sections for examination under a polarizing microscope. Rapid evaluation of fabric properties in the field is achieved by studying hand specimens using a magnifying glass or stereomicroscope. Laboratory-based analysis of thin sections provides more accurate and comprehensive identification of fabric properties, especially mineral and rock fragments in coarse fabrics, in terms of qualitative and quantitative data.

Determination of specific heat capacity on rock fragments

Geothermics ◽  
2001 ◽  
Vol 30 (1) ◽  
pp. 93-110 ◽  
Author(s):  
Ueli Schärli ◽  
Ladislaus Rybach
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Rock Fragments

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

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.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

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.

International determination of the total motion of the pole

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

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).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

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.

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