James R. McElhanon

2-{(E)-[1-(2-Hydroxy­ethyl)-3,3-dimethyl-3H-indol-1-ium-2-yl]vin­yl}-6-hydroxy­meth­yl-4-nitro­phenolate dihydrate

The title merocyanine-type molecule, C21H22N2O5·2H2O, crystallizes in a zwitterionic form and has an E configuration at the styryl C=C bond. The styryl part of the molecule and the indolium ring are slightly twisted and form a dihedral angle of 13.4 (1)°. The 1.274 (3) Å C—O bond length in the phenolate fragment is the longest among similar molecules. Hydrogen bonds between solvent water molecules, two hydroxyl groups and the phenolate O atom dictate the packing arrangement of molecules in the crystal and join the molecules into a two-dimensional polymeric network which propagates parallel to (001). Four water molecules and four hydroxy groups form a centrosymmetric homodromic cyclic motif of O—H⋯O hydrogen bonds. Another cyclic centrosymmetric motif is generated by four water molecules and two phenolate O atoms.

N‐(4‐Hydro­xy­phenyl)male­imide

In the title compound, C10H7NO3, the malamute ring is rotated by 52.75 (5)° with respect to the phenyl ring. There is a weak O—H⋯O intermolecular hydrogen bond between the hydroxyl group and one of the malamute O atoms, with an O⋯O distance of 2.820 (2) A.

Interrogating adhesion using fiber Bragg grating sensing technology

The assurance of the integrity of adhesive bonding at substrate interfaces is paramount to the longevity and sustainability of encapsulated components. Unfortunately, it is often difficult to non-destructively evaluate these materials to determine the adequacy of bonding after manufacturing and then later in service. A particularly difficult problem in this regard is the reliable detection/monitoring of regions of weak bonding that may result from poor adhesion or poor cohesive strength, or degradation in service. One promising and perhaps less explored avenue we have recently begun to investigate for this purpose centers on the use of (chirped) fiber Bragg grating sensing technology. In this scenario, a grating is patterned into a fiber optic such that a (broadband) spectral reflectance is observed. The sensor is highly sensitive to local and uniform changes across the length of the grating. Initial efforts to evaluate this approach for measuring adhesive bonding defects at substrate interfaces are discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Evaluation of the Performance of O-rings Made with Different Elastomeric Polymers in Simulated Geothermal Environments at 300°C

Notice: This manuscript has been authored by an employee of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH 10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the United States Government purposes.

Biological detection and tagging using tailorable, reactive, highly fluorescent chemosensors.

This program was focused on the development of a fluorogenic chemosensor family that could tuned for reaction with electrophilic (e.g. chemical species, toxins) and nucleophilic (e.g. proteins and other biological molecules) species. Our chemosensor approach utilized the fluorescent properties of well-known berberine-type alkaloids. In situ chemosensor reaction with a target species transformed two out-of-plane, weakly conjugated, short-wavelength chromophores into one rigid, planar, conjugated, chromophore with strong long wavelength fluorescence (530-560 nm,) and large Stokes shift (100-180 nm). The chemosensor was activated with an isourea group which allowed for reaction with carboxylic acid moieties found in amino acids.