The heterocyclic core of the title compound, C(10)H(17)NO(5), adopts a chair conformation with its three C substituents positioned equatorially. In the crystal, inter-molecular O-H⋯N hydrogen bonds between neighbouring mol-ecules lead to chains along b. These chains are connected by hydro-phobic inter-actions, forming infinite layers and N-H⋯O=C contacts between mol-ecules of adjacent layers gi...

The title compound, C17H12N4O3, a pyrido-pyrrolo-pyrimidine derivative, is almost planar. The nitro-benzene ring is inclined to the mean plane of the 8,9-di-hydro-pyrido[2,3-d]pyrrolo-[1,2-a]pyrimidin-5(7H)-one moiety (r.m.s. deviation = 0.023 Å) by 6.8 (1)°. In the crystal, mol-ecules are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming layers parallel to (101).

In the crystal of the title salt, C6H9N2O2S(+)·ClO4 (-), the components are linked by N-H⋯O hydrogen bonds, forming a three-dimensional network. The cations are connected along a and b axes, leading to linear and zigzag C(3) and C(8) chain motifs, respectively. A cation-anion inter-action along the c axis leads to a C 2 (2)(12) chain motif. R 3 (3)(18) and R 3 (3)(20) ring motifs are observed a...

The title compound, C14H13N3O5 (HMNP), was synthesized by the simple condensation of p-nitro-phenyl-hydrazine with de-hydro-acetic acid (DHA) in a 1:1 molar ratio in ethanol. HMNP has been characterized by using FT-IR, 1H and 13C NMR and UV-Vis spectroscopic and single-crystal X-ray diffraction techniques. The crystal packing reveals strong hydrogen bonds between the NH group and the carbonyl O...

The title compound, 9-[(2R,4S,5R)-4-hy-droxy-5-(hy-droxy-meth-yl)tetra-hydro-furan-2-yl]-2-{[(2R,4S,5R)-4-meth-oxy-5-(meth-oxy-meth-yl)tetra-hydro-furan-2-yl]amino}-1H-purin-6(9H)-one, C17H25N5O7, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit. In the crystal, the guanosine moieties of mol-ecules A and B are linked by N-H⋯N and O-H⋯N hydrogen-bonding inter-actions...

The title compound, C(6)H(7)N(2)O(2) (+)·Br(-), is isomorphous with 2-nitro-anilinium chloride and contains an characteristic intra-molecular N-H⋯O hydrogen bond, forming an S(6) motif. Inter-molecular N-H⋯Br hydrogen bonds occur in the crystal structure. Two zigzag chains of C(2) (1)(4) motifs extend along the b-axis direction. These primary chain motifs inter-sect like a double helix structur...

The spirally arranged stems of the spikemoss Selaginella lepidophylla, an ancient resurrection plant, compactly curl into a nest-ball shape upon dehydration. Due to its spiral phyllotaxy, older outer stems on the plant interlace and envelope the younger inner stems forming the plant centre. Stem curling is a morphological mechanism that limits photoinhibitory and thermal damages the plant might...

Abstract The presented paper provides a modelling strategy for roll forming of high strength AA7075 aluminum tube. Roll allows the cost-effective production large quantities long profiles. Forming brings challenges like springback and poor formability due to low Young’s modulus, ductility yield strength. processes with aluminum, such as alloy, therefore require detailed process design. Three di...

Explosive forming is one of the unconventional techniques in which, most commonly, the water is used as the pressure transmission medium. One of the newest methods in explosive forming is gas detonation forming which uses a normal shock wave derived of gas detonation, to form sheet metals. For this purpose a detonation is developed from the reaction of H2+O2 mixture in a long cylindrical detona...

The present paper demonstrates a proof-of-concept by introducing variable guide vane system in the draft tube of high-head Francis model turbine. aim is to examine hydraulic performance turbine while mitigating pressure pulsations tube. vanes can rotate about an axis up ±45°. mitigation studies were performed at lower- and upper-part loads. was examined all operating ranges within head. There s...