Mass Scaling of Permanent Magnet Line Cusp Plasma Leaks

Plasma leaks to permanent magnetic produced "full line cusps" are shown to depend on ion mass as (mj?). This result is consistent with hybrid gyroradius (i.e., geometric mean of ion and electron gyroradii) leaks but not with ion gyroradius leaks.     

On sets of Haar measure zero in abelian polish groups

It is shown that the concept of zero set for the Haar measure can be generalized to abelian Polish groups which are not necessarily locally compact. It turns out that these groups, in many respects, behave like locally compact groups. Suitably modified, many theorems from harmonic analysis carry over to this case. A few applications are given and some open problems are mentioned.     

Evaluation of blood lead levels in Danes for the period 1976–1987

Summary Blood lead was measured in 504 men and 548 women in 1976 living in the Glostrup area, Denmark. The subjects were first seen in 1976 at age 40, and in 1981, 5 years later as 45 years old. 451 men and 410 women were reexamined. Finally 151 men, at age 51 were included in this study. The median blood lead levels averaged 130 and 90 g/ l in 1976 and 90 and 60 g/l in 1981 in male and female, respectively. In 1987 the median blood lead level of the male subjects was 71 g/l.By use of quality control samples, long term storage control and statistical methods a decrease in the median blood lead level of 45% was estimated for the male subjects for the period 1976–1987, probably due to a parallel decline in atmospheric lead pollution and decrease of occupational lead exposure.

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Auswertung des Bleiblutspiegels von Dänen für die Zeit 1976–1987

     

Sur la norme des opérateurs de convolution

Sans résumé     

Application of background oriented schlieren for quantitative measurements of shock waves from explosions

This paper describes application of a background oriented schlieren technique in order to obtain quantitative measurements of shock waves from explosions by processing high speed digital video recordings. The technique is illustrated by an analysis of two explosions, a high explosive test and a hydrogen gas explosion test. The visualization of the shock front is utilized to calculate the shock Mach number, leading to a predicted shock front pressure. For high explosives the method agreed quite well with a standard curve for side-on shock pressures. In the case of the gas explosion test we can also show that the shock front is non-spherical. It should be possible to develop this technique to investigate external blast waves and external explosions from vented gas explosions in more details. This paper is based on work that was presented at the 21th International Colloquium on the Dynamics of Explosions and Reactive Systems, Poitiers, France, July 23–27, 2007.