The title compound, C14H13BrO3 [systematic name: rac-(9S,10R)-9-bromo-10-hy-droxy-8,8-dimethyl-9,10-di-hydro-2H,8H-pyrano[2,3-f]chromen-2-one], is a substituted pyran-ocoumarin, obtained by bromination of seselin [8,8-dimethyl-2H,8H-pyrano[2,3-f]chromen-2-one], which was isolated from the Indian herb Trachyspermum stictocarpum (Aajmod). The pyrano ring has a distorted half-chair conformation an...

The hydrated title salt, [Cd2Cl2(C10H8N2)4](C9H5N4O)2·0.81H2O, was obtained from the hydro-thermal reaction between 2,2'-bi-pyridine, cadmium(II) chloride and potassium 1,1,3,3-tetra-cyano-2-eth-oxy-propenide. The binuclear cation lies across a centre of inversion in the space group P21/c, with the other components in general positions. The cation has approximate, but non-crystallographic 2/m s...

This paper presents a control architecture designed to accommodate a selection of modern control algorithms on a full-scale rotary-wing, unmanned aerial vehicle. The architecture integrates a visual landing system, two path planners, a flight envelope protection algorithm, and two low-level flight controllers that were developed independently by six agencies in academia and industry. A newly de...

Details of a heat pump assisted solar water heating system, is briefly described. Refrigerants compromising of Fluorocarbons and Chlorofluorocarbons have been generally used as the working fluid. But due to its ozone depletion effect and high Global warming potential, they have been replaced by synthetic refrigerants such as R22, R134 etc. The heat pump utilizing such refrigerants has shown to ...

The title compounds, C16H15N5OS, (I), and C12H12FN5OS, (II), are [(di-amino-pyrimidine)-sulfan-yl]acetamide derivatives. In (I), the pyrimidine ring is inclined to the naphthalene ring system by 55.5 (1)°, while in (II), the pyrimidine ring is inclined to the benzene ring by 58.93 (8)°. In (II), there is an intra-molecular N-H⋯N hydrogen bond and a short C-H⋯O contact. In the crystals of (I) an...

This paper presents an analytical evaluation of isobutane (R600a), propane (R290), R134a, R22, R410A, and R32 in a vapor compression system used for comfort cooling applications. The evaluation method was based on a system simulation model that was complimented with an evolutionary computation module for the optimization of refrigerant circuitries in the evaporator and condenser. The evaluation...