Abstract: Phosphate free, Er/Yb co-doped borosilicate glass compositions and optical devices made from said compositions are disclosed; said compositions comprising, for 100 parts by weight of: 60 to 70 parts by weight SiO2 or SiO2+GeO2 with SiO2 always being greater than 40 parts by weight, 8 to 12 parts by weight of B2O3, 10 to 25 parts by weight M2O wherein M2O is an alkali metal oxide, 0 to 3 parts by weight of BaO, 0.1 to 5 parts by weight Er2O3, and from 0.1 to 12 parts by weight of Yb2O3 and from 0 to less than 5 parts by weight F; and within which, the boron atoms are of tetrahedral spatial coordination.

Abstract: The invention concerns a substance of diester type, i.e. an organic compound with three benzene nuclei joined by --COO-- groups, exhibiting at least one mesomorphic phase of smectic type.The substance of the invention answers to the formula: ##STR1## where R.sub.1 is an alkyl or alkoxy radical and R.sub.2 an alkyl. In the case where R.sub.1 is an octyl and R.sub.2 a pentyl there is a dielectric isotropy frequency of 30 kHz, i.e. a frequency where the dielectric anistropy changes sign.Application to field-effect display devices with dual-frequency memory.

Abstract: The invention relates to an organic compound having an enantiotropic or monotropic mesomorphous phase.

Abstract: A family of diphenylic esters are disclosed, which, within certain temperature ranges exhibit mesomorphic phases, either smectic or nematic, having the general formula: ##STR1## where R.sub.1 is C.sub.n H.sub.2n+1 O or C.sub.n H.sub.2n+1 in which n is an integer of from 1 to 10,R.sub.2 is C.sub.m H.sub.2m+1 in which m is an integer of from 1 to 10, andX is Br or CN.

Abstract: A family of organic compounds having at least one mesomorphic phase of nematic type and, in respect of some compounds, one or more smetic phases. The liquid crystals according to the invention satisfy general formula: ##STR1## in which R.sub.1 is an alkyl or alkoxy group having n carbon atoms (n being an integer of 1 to 10) X designates the bromine or the cyano group, Y is a methyl group.

Abstract: A pyridine derivative having the formula 1,3-dihydro-3-(3',4',5'-trimethoxy-styryl)-6-methyl-7-hydroxy-furo-[3,4,c] pyridine and therapeutically acceptable salts thereof are disclosed. Also disclosed is a process for the preparation of the compound. The compounds are therapeutically useful for a stabilizing effect on the red blood corpuscles and as selective diuretics.

Abstract: New derivatives of pyrimidine are disclosed. The disclosed compounds are substituted piperazinyl derivatives of pyrimidine and the pharmaceutically acceptable salts thereof. The compounds show therapeutic value especially in the area of atheromas.

Abstract: A liquid crystal composition with high negative dielectric anisotropy, which is capable of exhibiting a high dynamic light scattering effect and of inducing similar characteristics into mixtures of the liquid crystal and another nematic liquid crystal and which derives an advantage from a larger mesomorphic temperature range, which comprises at least one compound of the formula: ##STR1## wherein R represents NO.sub.2, bromine or cyano; R.sub.1 is an alkyl or alkoxy group and R.sub.2 is an alkyl group.