The main structural unit of the title compoud, C(21)H(18)O(6), is a fused three-ring group consisting of coumarin and tetra-hydro-pyrane ring systems. Two C atoms of the tetra-hydro-pyran ring are displaced by 0.295 (3) and -0.360 (2) Å from the mean plane of coumarin ring. The dihedral angle between the phenyl and coumarin rings is 73.94 (3)°. Inter-molecular O-H⋯O hydrogen bonds are present i...

In the title compound, C(24)H(21)ClN(4)O(2)S, the two adjacent spiro junctions link an almost planar (r.m.s. deviation = 0.017 Å) 2-oxindole ring, a hexa-hydro-1H-pyrrolizine ring and a tetra-hydro-imidazo[2,1-b]thia-zole ring. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds occur, generating an R(2) (2)(16) loop.

In the title Schiff base, C(18)H(22)N(4)O, the hexa-hydro-pyrimidinyl ring adopts a chair conformation. The dihedral angle between the aromatic rings of the 4-(2-phenyl-diazen-yl)phenol unit is 15.7 (1)°. There is an intra-molecular O-H⋯N hydrogen bond between the hydroxyl group and an N atom of the hexa-hydro-pyimidinyl unit. Inter-molecular N-H⋯O and N-H⋯N hydrogen bonds give rise to a layer ...

In the title compound, C(27)H(25)NO(4), the tetra-hydro-pyridine ring adopts a half-chair conformation. The three phenyl rings form dihedral angles of 66.33 (7), 87.36 (8) and 36.90 (7)° with the least-squares plane through the tetra-hydro-pyridine ring. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond, generating an S(6) motif.

In the title compound, C23H20ClN3O, each of the cyclo-hexene and 1,4-di-hydro-pyridine rings of the 1,4,5,6,7,8-hexa-hydro-quinoline ring system adopts a twisted-boat conformation. The dihedral angle between the two benzene rings is 11.52 (7)°. In the crystal, mol-ecules are linked through a pair of amino-nitrile N-H⋯N hydrogen bonds, forming inversion dimers. These assemble into a three-dimens...

The natural resources of Himalayas in terms of hydro power generation are not only crucial for the Himalayan states of India, but very important for the whole country. These states seem to be keen in exploiting their vast hydro electricity potential for net revenue earning. However, due to weak geological conditions and steep slopes these rivers carry a huge quantity of sediment with them. The ...

Automatic generation control in electric power system design is a major concern nowadays due to its rising size, varying structure, integration of renewable-energy sources and distributed generators to meet the growing demand. In this paper, automatic generation control of an interconnected four area hydro thermal system examined. Each area equipped with reheat turbine for thermal system and hy...

This paper presents a study of various researches which were come out in last few decades on hydro thermal scheduling problems. As we know that the Operation of mix both hydro and thermal plants is far more complex and is of much more importance in a modern power system. The aim of the hydrothermal scheduling problem is to optimize the electricity production and minimized the cost of power. Thi...

The title compound, C14H12BrNO4, has two chiral C atoms. The C atom next to the O atom in the di-hydro-furan ring has an S configuration, while the adjacent chiral C atom has an R configuration. The cyclo-hex-2-enone and di-hydro-furan rings both adopt envelope conformations, with the flap atoms (middle CH2 in cyclo-hex-2-enone and NO2-substituted C in di-hydro-furan) lying 0.612 (3) and 0.295 ...

In the anion of the title hydrated mol-ecular salt, C4H8N3O(+)·C12H9N4O7 (-)·H2O [systematic name: 2-amino-1-methyl-4-oxo-4,5-di-hydro-1H-imidazol-3-ium 5-(2,4-di-nitro-phen-yl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidin-4-olate monohydrate], the 2,4-di-nitro-phenyl ring is inclined to the mean plane of the pyrimidine ring [r.m.s. deviation = 0.37 Å] by 43.24 (8)°. The five-membered r...