A PAIR OF SPECTACLES

Coloured Spectacles

The Tensor Degree of a Pair of Finite Groups

In this paper, we study the tensor commutativity degree of pair of finite groups. Erdos introduced the relative commutativity degree and studied its properties. Then, Mr. Niroomand introduced the tensor relative commutativity degree, calculated tensor relative degree for some groups, and studied its properties. Also, he explained its relation with relative commutativity degree. In this paper, w...

The structure of a pair of nilpotent Lie algebras

Assume that $(N,L)$, is a pair of finite dimensional nilpotent Lie algebras, in which $L$ is non-abelian and $N$ is an ideal in $L$ and also $mathcal{M}(N,L)$ is the Schur multiplier of the pair $(N,L)$. Motivated by characterization of the pairs $(N,L)$ of finite dimensional nilpotent Lie algebras by their Schur multipliers (Arabyani, et al. 2014) we prove some properties of a pair of nilpoten...

British Standards for Spectacles.

EARLIER articles have reviewed parts of the work of the British Standards Institution in the field of standardization of spectacles (Brit. J. Ophthal., 1956, 40, 611; 1959, 43, 509), but the publication of B.S. 3521, completing the series of Standards relating to spectacles, provides the opportunity for a general survey. The nine British Standards fall into two categories with some overlap. The...

Origin of spectacles in India.

The European records of the origin of spectacles are very controversial. The suggestion that spectacles were first invented during the I 3th century in Italy by an unknown layman of Pisa is not convincing, because there are also references to spectacles in Hindu literature at about the same time. In the life of Vyasaraya (1446-1539), written in Sanskrit by his contemporary, the poet Somnath, th...