A review of recent work in sub-nanometre displacement measurement using optical and X–ray interferometry

2002 ◽  
Vol 360 (1794) ◽  
pp. 953-968 ◽  
Author(s):  
G. N. Peggs ◽  
A. Yacoot
Keyword(s):  
Recent Work ◽  
Displacement Measurement ◽  
X Ray

Differential displacement measurement using scanning x-ray beams

1998 ◽  
Vol 69 (2) ◽  
pp. 452-456 ◽  
Author(s):  
Howard A. Canistraro ◽  
Eric H. Jordan ◽  
Douglas M. Pease
Keyword(s):  
Displacement Measurement ◽  
X Ray

Some Recent Work in Low Energy X-Ray and Electron Analysis

1969 ◽  
pp. 480-495 ◽  
Author(s):  
Burton L. Henke ◽  
Robert E. Lent
Keyword(s):  
Recent Work ◽  
Low Energy ◽  
X Ray

scholarly journals Non-axisymmetric Instabilities in Shocked Accretion Flows

2003 ◽  
Vol 214 ◽  
pp. 95-96
Author(s):  
Wei-Min Gu ◽  
Thierry Foglizzo
Keyword(s):  
Black Hole ◽  
Numerical Integration ◽  
Recent Work ◽  
Growth Rates ◽  
Linearized Equations ◽  
X Ray ◽  
Accretion Flows ◽  
The Stability ◽  
X Ray Binaries ◽  
Axisymmetric Perturbations

We investigate the stability of shocked inviscid isothermal accretion flows onto a black hole. Of the two possible shock positions, the outer one is known to be stable to axisymmetric perturbations, while the inner one is unstable. Our recent work, however, shows that the outer shock is generally linearly unstable to non-axisymmetric perturbations. Eigenmodes and growth rates are obtained by numerical integration of the linearized equations. These results offer new perspectives to interpret the variability of X-ray binaries.

scholarly journals Torque Reversals in Disk Accreting Pulsars

1998 ◽  
Vol 15 (2) ◽  
pp. 250-253
Author(s):  
Jianke Li ◽  
Dayal T. Wickramasinghe
Keyword(s):  
Neutron Star ◽  
Binary System ◽  
Recent Work ◽  
Time Scale ◽  
Accretion Rate ◽  
Future Studies ◽  
X Ray ◽  
The Past ◽  
X Ray Binaries ◽  
Coherent Picture

AbstractX-ray binaries in which the accreting component is a neutron star commonly exhibit significant changes in their spin. In the system Cen X-3, a disk accreting binary system, the pulsar was observed to spin up at a rate ḟ = 8 × 10−13 Hz s−1 when averaged over the past twenty years, but significant fluctuations were observed above this mean. Recent BASTE observations have disclosed that these fluctuations are much larger than previously noted, and appeared to be a system characteristic. The change in the spin state from spin-up to spin-down or vice-versa occurs on a time scale that is much shorter than the instrument can resolve (≤1 d), but appears always to be a similar amplitude, and to occur stochastically. These observations have posed a problem for the conventional torque–mass accretion relation for accreting pulsars, because in this model the spin rate is closely related to the accretion rate, and the latter needs to be finely tuned and to change abruptly to explain the observations. Here we review recent work in this direction and present a coherent picture that explains these observations. We also draw attention to some outstanding problems for future studies.

Some topical issues in research on short-pulse laser-produced plasmas

1980 ◽  
Vol 298 (1439) ◽  
pp. 351-364 ◽  
Keyword(s):  
Recent Work ◽  
Pulse Laser ◽  
Short Pulse ◽  
Fast Time ◽  
Physical Processes ◽  
Time Resolved ◽  
X Ray ◽  
Short Pulse Laser ◽  
Laser Facility ◽  
Interaction Phenomena

A brief review is presented of the main physical processes in laser-produced plasmas. This is followed by illustrations taken from recent work at the S.R.C. Central Laser Facility of the use of X-ray and visible streak cameras for fast time resolved measurements of implosion and interaction phenomena in laser-produced plasmas.

scholarly journals The secondary cathode rays expelled from metals by molybdenum K α radiations

1935 ◽  
Vol 149 (868) ◽  
pp. 587-595 ◽  
Keyword(s):  
Magnetic Field ◽  
Recent Work ◽  
Photoelectric Effect ◽  
Specific Charge ◽  
Secondary Electrons ◽  
X Ray ◽  
A Value ◽  
The Mean ◽  
The Absolute ◽  
Gold Platinum

Kretschmar has recently described a series of accurate measurements of the energies of the electrons expelled by molybdenum K α 1 radiations from targets of gold, platinum, silver and copper. He deduced his electron energies from deflections in an accurately known magnetic field, and it is obviously important to compare his results with those of similar recent work in which other primary radiations (copper and chromium K-rays) were used to excite secondary electrons from the same targets. Kretschmar applies his results to the deduction of a value for the specific charge, e / m 0 , of the electron. In doing this he has to assume a value for e / h , as well as values of X-ray wave-lengths. He eliminates part (not all) of the effect of uncertainty in the absolute values of the wave-lengths by using the X-ray (inverse photoelectric effect) value for e / h . He takes, in fact, e / h = 7·2796 × 10 16 e. s. u. erg -1 sec -1 —the mean of the values given by Duane, Palmer and Yeh and by Feder. He then deduces, as the mean result of his own deflection experiments, 1·757 × 10 7 e. m. u. gm -1 as the most probable value of e / m 0 .

scholarly journals Pressure and the water relations of proteins I—isoelectric gelatin gels

1934 ◽  
Vol 147 (861) ◽  
pp. 382-395 ◽  
Keyword(s):  
Recent Work ◽  
Water Relations ◽  
Vapour Pressure ◽  
Bound Water ◽  
Protein Molecule ◽  
Volume Changes ◽  
X Ray ◽  
Gelatin Gels ◽  
Water Of Hydration

Recent work on the structure of fibre proteins, as deduced form X-ray analysis, suggests that the bound water of hydration of proteins cannot be regarded as being simply a complete shell of water around the protein molecule or micelle. It seems much more probable that the water is localized around definite points and in a recent paper one of us has suggested two possible mechanisms of hydration. Katz, Svedberg, Rosenbaum§ and other have followed the thermal, vapour pressure and volume changes when a dried protein takes up water. Their work also suggests that the linkages or orientating forces holding water to the protein are not uniform in strength. More recent work on the freezing of gelatin gels which is discussed later in this paper has confirmed this and given figures for the amounts of water held by the gelatin at different activities of the water.

scholarly journals Advective Disks

1997 ◽  
Vol 163 ◽  
pp. 75-89 ◽  
Author(s):  
R. Narayan
Keyword(s):  
Black Holes ◽  
Recent Work ◽  
Galactic Nuclei ◽  
Critical Value ◽  
Event Horizons ◽  
X Ray ◽  
Accretion Flows ◽  
Accretion Rates ◽  
X Ray Binaries ◽  
Spectral States

AbstractRecent work on advection-dominated accretion flows (ADAFs) is reviewed. The article concentrates on an optically thin branch of ADAFs which is present at mass accretion rates below a critical value ~ (10−2– 10−1) the Eddington rate. Models based on this branch have been quite successful at explaining a number of low-luminosity X-ray binaries and galactic nuclei, and some brighter systems. Some progress has also been made toward understanding the various spectral states of accreting black holes. It is argued that ADAFs may provide one of the best techniques for demonstrating the reality of event horizons in black holes.

scholarly journals Review of X-ray Spectroscopy from Laser-Produced Plasmas

1988 ◽  
Vol 102 ◽  
pp. 145-152
Author(s):  
R.L. Kauffman
Keyword(s):  
Recent Work ◽  
Diagnostic Tool ◽  
Recent Progress ◽  
High Density ◽  
X Ray ◽  
Isoelectronic Series ◽  
Laser Plasmas

AbstractRecent progress in x-ray spectroscopy from laser plasmas is reviewed. Advances in the use of K-shell spectra as a diagnostic tool is discussed. Much activity in understanding complex spectra especially from Ne I and Ni I isoelectronic series have been made. Much of the progress has been due to observation of amplification from Δn=0 transitions from these configurations. The spectroscopy will be discussed and examples of spectra of the amplified lines will be shown. Finally, recent work on using x-ray spectroscopy to diagnose high density implosions will be discussed.

Whitlockite from Sebdou, Oran, Algeria

1947 ◽  
Vol 28 (196) ◽  
pp. 29-30 ◽  
Author(s):  
F. A. Bannister
Keyword(s):  
Recent Work ◽  
Late Jurassic ◽  
British Museum ◽  
Density Data ◽  
X Ray ◽  
Geological Maps ◽  
Geological Formations

During the course of recent work on minyulite (KAl2(PO4)2 (OH,F).4H2O) X-ray, optical, and density data were obtained for several hydrous K-Al phosphate minerals. These included one specimen of a soft white compact mineral labelled by P. Pallary as minervite from Sebdou, Orau, Algeria, which was presented in 1940 to the Trustees of the British Museum by Major M. Connolly. Minervite was originally described and analysed in 1895 by A. Carnot from Minerva grotto, Fauzan, dép. Hérault, France. In the same year Carnot also described the same species from Tour-Combes grotto, Misserghin, Oran. Sebdou is some 80 miles SSW. of Oran and geological maps show there a patch of Pliocene on late Jurassic. No doubts were entertained that the specimen under discussion belonged to the same species as minervite from Misserghin, since the geological formations of both localities are closely related.

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