We give further results for Perron-Frobenius theory on the numericalrange of real matrices and some other results generalized from nonnegative matricesto real matrices. We indicate two techniques for establishing the main theorem ofPerron and Frobenius on the numerical range. In the rst method, we use acorresponding version of Wielandt's lemma. The second technique involves graphtheory.

In this study, the effects of various hydrophilic (HPMC and Carbopol 971) and plastic (Ethylcellulose and Eudragit RL100) polymers on the release profile of diltiazem HCl from matrix tablets were evaluated in-vitro. For this purpose, tablets containing 60 mg of diltiazem HCl along with various amounts of the aforementioned polymers were prepared using the wet granulation technique. Tablets prep...

solving a large sparse set of linear equations is of the problems widely seen in every numerical investigation in the entire range of engineering disciplines. employing a finite element approach in solving partial derivative equations, the resulting stiffness matrices would contain many zero-valued elements. moreover, storing all these sparse matrices in a computer memory would slower the compu...

In this study, the effects of various hydrophilic (HPMC and Carbopol 971) and plastic (Ethylcellulose and Eudragit RL100) polymers on the release profile of diltiazem HCl from matrix tablets were evaluated in-vitro. For this purpose, tablets containing 60 mg of diltiazem HCl along with various amounts of the aforementioned polymers were prepared using the wet granulation technique. Tablets prep...

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 $V^k(A)=sigma(A)$.