Theoretical Considerations on Transition Metals Sulphides Precipitation in Alloyed Steels

2020 ◽  
Vol 55 (1) ◽  
pp. 94-102
Author(s):  
Islam Moussaoui ◽  
Abdelmalek Roula ◽  
Mirsalim M. Asadov ◽  
Kamel Boudeghdegh
Author(s):  
R.W. Carpenter

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.


2006 ◽  
Vol 19 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Myriam Juda ◽  
Mirjam Münch ◽  
Anna Wirz-Justice ◽  
Martha Merrow ◽  
Till Roenneberg

Abstract: Among many other changes, older age is characterized by advanced sleep-wake cycles, changes in the amplitude of various circadian rhythms, as well as reduced entrainment to zeitgebers. These features reveal themselves through early morning awakenings, sleep difficulties at night, and a re-emergence of daytime napping. This review summarizes the observations concerning the biological clock and sleep in the elderly and discusses the documented and theoretical considerations behind these age-related behavioral changes, especially with respect to circadian biology.


1971 ◽  
Vol 32 (C1) ◽  
pp. C1-74-C1-75 ◽  
Author(s):  
K. ENDO ◽  
Y. FUJITA ◽  
R. KIMURA ◽  
T. OHOYAMA ◽  
M. TERADA

Sign in / Sign up

Export Citation Format

Share Document