1′′-Benzyl-1′-methyl-4′-(naphthalen-1-yl)naphthalene-2-spiro-3′-pyrrolidine-2′-spiro-3′′-indoline-1,2′′-dione

In the title compound, C38H32N2O2, the pyrrolidine ring adopts an envelope conformation, whereas the cyclo­hexa­none ring in the tetra­hydro­naphthalene fused-ring system adopts a half-chair conformation. The benzyl ring is oriented at an angle of 67.1 (1)° with respect to the naphthyl ring system. Four intra­molecular C—H⋯O close contacts and C—H⋯π inter­action are observed. In the crystal, mol­ecules associate via C—H⋯O hydrogen bonds, forming a C(12) chain motif along the ac plane

Methyl 4-(4-chloro­phen­yl)-3,3a,4,4a,5,12c-hexa­hydro-2-thia­naphtho­[1′,2′:3,2]furo[5,4-b]pyrrolizine-4a-carboxyl­ate

In the title compound, C25H22ClNO3S, both the pyrrolidinyl and thia­zolyl rings adopt envelope conformations whereas the dihydro­pyran ring adopts a half-chair conformation. The chloro­phenyl and naphthalenyl ring systems are oriented at a dihedral angle of 59.7 (1)°. The crystal packing is stabilized by an intra­molecular C—H⋯N hydrogen bond and weak inter­molecular C—H⋯π inter­actions

1′,1′′-Dimethyl-4′-(naphthalen-1-yl)-1,2,3,4-tetra­hydro­naphthalene-2-spiro-3′-pyrrolidine-2′-spiro-3′′-indoline-1,2′′-dione

In the title compound, C32H28N2O2, the pyrrolidine ring adopts an envelope conformation, whereas the cyclo­hexa­none ring in the tetra­hydro­naphthalene fused-ring system adopts a half-chair conformation. The oxindole ring system is oriented at an angle of 48.2 (1)° with respect to the naphthyl ring system. An intra­molecular C—H⋯O close contact is observed. In the crystal, mol­ecules associate via two C—H⋯O hydrogen bonds, forming R 2 2(14) and R 2 2(10) dimers

Methyl 3-[(1H-benzimidazol-1-yl)meth­yl]-1-methyl-4-(4-methyl­phen­yl)-2′-oxopyrrolidine-2-spiro-3′-1-benzimidazole-3-carboxyl­ate

In the title compound, C29H28N4O3, the pyrrolidine ring adopts a twist conformation whereas the oxindole and benzimidazole residues are approximately planar with maximum deviations of 0.159 (1) and 0.011 (1) Å, respectively. The oxindole residue is almost perpendicular to the benzimidazole residue, making a dihedral angle of 89.2 (1)°. The methyl-substituted benzene ring is oriented at angles of 47.7 (1) and 71.0 (1)°, respectively, with respect to the oxindole and benzimidazole residues. An intra­molecular C—H⋯O hydrogen bond is observed. In the crystal, mol­ecules associate via N—H⋯N hydrogen bonds, forming R 2 2(9) dimers

1′-Methyl-4′-(1-naphth­yl)-1′′,2′′,3′′,4′′-tetra­hydro­indane-2-spiro-2′-pyrrolidine-3′-spiro-2′′-naphthalene-1,3,1′′-trione

In the title compound, C32H25NO3, the pyrrolidine ring adopts an envelope conformation, whereas the cyclo­hexa­none ring in the tetra­hydro­naphthalene fused-ring system adopts a half-chair conformation. The indanedione unit is oriented at an angle of 58.9 (1)° with respect to the naphthyl ring system. Three intra­molecular C—H⋯O close contacts and an intra­molecular C—H⋯π inter­action are observed. In the crystal, mol­ecules associate via C—H⋯O hydrogen bonds, forming a helical chain with a C(10) motif along the b axis

Methyl 2-(2,2,4-trimethyl-6-tosyl­perhydro-1,3-dioxino[5,4-c]pyridin-5-yl)acetate

The title compound, C20H29NO6S, crystallizes with two mol­ecules in the asymmetric unit, with similar conformations. The dioxane and pyridine rings adopt twist conformations in both mol­ecules. The packing is stabilized by inter­molecular C—H⋯O hydrogen bonds

1-Vinyl-1H-indole-3-carbaldehyde

In the title compound, C11H9NO, the C and O atoms of the attached carbaldehyde group deviate by just 0.052 (2) and 0.076 (1) Å, respectively, from the mean plane of the indole ring system. In addition to van der Waals forces, the mol­ecular packing is stabilized by C—H⋯O hydrogen bonds, which form a C(7) chain motif, and π–π inter­actions (centroid–centroid distance 3.637 Å) between the pyrrole and benzene rings of the indole ring system

A High Speed Networked Signal Processing Platform for Multi-element Radio Telescopes

A new architecture is presented for a Networked Signal Processing System (NSPS) suitable for handling the real-time signal processing of multi-element radio telescopes. In this system, a multi-element radio telescope is viewed as an application of a multi-sensor, data fusion problem which can be decomposed into a general set of computing and network components for which a practical and scalable architecture is enabled by current technology. The need for such a system arose in the context of an ongoing program for reconfiguring the Ooty Radio Telescope (ORT) as a programmable 264-element array, which will enable several new observing capabilities for large scale surveys on this mature telescope. For this application, it is necessary to manage, route and combine large volumes of data whose real-time collation requires large I/O bandwidths to be sustained. Since these are general requirements of many multi-sensor fusion applications, we first describe the basic architecture of the NSPS in terms of a Fusion Tree before elaborating on its application for the ORT. The paper addresses issues relating to high speed distributed data acquisition, Field Programmable Gate Array (FPGA) based peer-to-peer networks supporting significant on-the fly processing while routing, and providing a last mile interface to a typical commodity network like Gigabit Ethernet. The system is fundamentally a pair of two co-operative networks, among which one is part of a commodity high performance computer cluster and the other is based on Commercial-Off The-Shelf (COTS) technology with support from software/firmware components in the public domain.Comment: 19 pages, 4 eps figures, To be published in Experimental Astronomy (Springer

3′-[Hy­droxy(4-oxo-4H-chromen-3-yl)meth­yl]-2-oxospiro­[indoline-3,2′-pyrrolidine]-3′-carbonitrile

In the title compound, C23H19N3O4, the pyran ring adopts a half-chair conformation, while the pyrrolidine (with a C atom as the flap atom) and the five-membered ring in the indoline (with a C atom as the flap atom) ring system adopt slight envelope conformations. The pyrrolidine ring makes dihedral angles of 83.3 (1) and 60.4 (1)° with the mean plane through all non-H atoms of the indoline and chromene ring systems, respectively. In the crystal, mol­ecules are connected by two unique N—H⋯O and O—H⋯O hydrogen-bonding inter­actions, which form centrosymmetric patterns described by graph-set motifs R 2 2(18) and R 2 2(14). These two motifs combine to form a hydrogen-bonded chain which propagates in the a-axis direction. The crystal structure is also stablized by C—H⋯O inter­actions and by aromatic π–π stacking inter­actions between the pyran and benzene rings of neighbouring mol­ecules [centroid–centroid distance = 3.755 (1) Å and slippage = 1.371 (2) Å]

Methyl 4-phenyl-1,2,3,3a,4,4a,5,12c-octa­hydronaphtho[1′,2′:3,2]furo[5,4-b]pyrrolizine-4a-carboxyl­ate

In the title compound, C26H25NO3, both pyrrolidine rings adopt envelope conformations, whereas the dihydro­pyran ring adopts a half-chair conformation. The phenyl ring is oriented at an angle of 27.9 (1)° with respect to the naphthalene ring system. An intra­molecular C—H⋯O hydrogen bond is observed. The crystal packing is stabilized by weak inter­molecular C—H⋯π inter­actions