in this note we characterize polynomial numerical hulls of matrices $a in m_n$ such that$a^2$ is hermitian. also, we consider normal matrices $a in m_n$ whose $k^{th}$ power are semidefinite. for such matriceswe show that $v^k(a)=sigma(a)$.

Children living near a lead works and children of employees at the works were selected in order to analyse the lead content of their blood as the biological counterpart of a monitoring exercise for lead in the environment. The overall mean for the 262 children in the survey was 0.91 mumol/l and results were within the normal reference range of 0.3 to 1.8 for all except two children. The results...

In the title compound, C(16)H(12)O(2), the non-H atoms are coplanar with a mean r.m.s. deviation of 0.0260 (2) Å. The deviations of the bond angles from normal values at the indenyl junction C atom and the indenyl bridgehead C atom nearest the junction are imposed by the five-membered ring geometry. Due to conjugation, the single bond linking the two ring systems [1.455 (3) Å] is significantly ...

Analytical formulas are derived for the average intensity, the root-mean-square (rms) angular width, and the M2-factor of Laguerre-Gaussian correlated Schell-model (LGCSM) beam propagating in non-Kolmogorov turbulence. The influence of the beam and turbulence parameters on the LGCSM beam is numerically calculated. It is shown that the quality of the LGCSM beam can be improved by choo...

immunophenotyping of lymphocytes is very essential for evaluation of immune system. due  to  the  effect  of  environmental  factors  and  ethnical diversity on  immune  system, establishment of an internal normal range of lymphocyte subsets is a necessity for each population.  the  aim  of  this  study  was  to  determine  the  normal  range  of  t  and  b lymphocytes, and nk cells in normal i...

In the butterfly search technique, echoes from repeated firings of a transducer are resampled along a set of predetermined trajectories of constant velocities, called "butterfly lines," because of their intersection and crossing at a reference range. The slope of the trajectory on which the sampled signals satisfy a predetermined criterion appropriate for the type of signal in question, provide...