Materials Literature
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In this report a neutron protein crystallography station (PCS) is described that has been built at Los Alamos National Laboratory for the study of proteins using the wavelength-resolved Laue technique. This user facility is the first of its kind to be built at a spallation neutron source and the first to use the wavel…
The self-diffusion coefficient D and the viscosity η of low molecular weight polystyrene (1.9 × 10 3 g/mol) have been measured from T g + 3 °C to T g + 160 °C. Forward recoil spectrometry (FReS) and pulsed-gradient spin-echo NMR methods were combined to determine D values covering more than 10 orders of magnitude. Ove…
The recursive description of stacking in layered crystals, originally developed by Treacy et al. [ Proc. R. Soc. London Ser. A (1991), 433 , 499–520] and implemented in the DIFFaX code, is enclosed in a non-linear least-squares minimization routine and combined with additional models (of specimen-related broadening an…
An atomic pair distribution function (PDF) neutron powder diffraction round-robin experiment was performed on six diffractometers at three spallation sources. Instrument-specific effects on the real-space PDF were investigated, such as finite measurement range, the instrument resolution and the asymmetric shape of dif…
Alumina/poly(methyl methacrylate) (PMMA) nanocomposites were synthesized using 38 and 17 nm alumina nanoparticles. At an optimum weight fraction, the resulting nanocomposites display a room-temperature brittle-to-ductile transition in uniaxial tension with an increase in the strain-to-failure that averages 40% strain…
The electrochromic properties of electrodeposited poly(1,4-bis(2-[3‘,4‘-ethylenedioxy]thienyl)-2-methoxy-5-2‘ ‘-ethylhexyloxybenzene) (P(BEDOT-MEHB)), a material for polymer electrochromic displays, are reported in detail. While the polymer is transparent in the fully oxidized state, two absorption bands obtained in t…
The magnetic and transport properties of Dy 1− x Sm x Mn 6 Ge 6 ( x = 0.2–1.0) have been investigated using x-ray diffraction (XRD) and magnetization measurements. Analysis of the XRD patterns indicates that the samples with x ⩽ 0.4 mainly consist of the HfFe 6 Ge 6 -type phase and the samples with 0.6 ⩽ x ⩽ 1.0 mainl…
<div class="htmlview paragraph">Considering the benefits associated with use of Gasoline doped with Ethanol, viz, cleaner environment, energy security, boost to agrarian economy, opening of new avenues of employment in rural sector, Government of India mandated the use of 5% Ethanol blended Gasoline (henceforth…
Microphase separation in crosslinked diblock copolymers is investigated with a time-dependent Ginzburg–Landau model. Upon separation, polymers originally crosslinked in the homogeneous phase elongate parallel to the composition gradient. We take into account this elastic coupling as well as the random stress caused by…
The emission and excitation spectra of CaS:Pb thin films have been obtained at 10 K together with the emission decay curves. The CaS:Pb samples were prepared with the variation of the concentration and the spatial uniformity of active Pb 2+ ions within the CaS host matrix using atomic layer deposition (ALD) and tetrae…
Abstract The structure and physicomechanical properties of nylon 6 (N‐6) modified with polyethylene oxide–polyisoprene–polyethylene oxide (PEO‐PI‐PEO) copolymers via activated anionic polymerization have been investigated by using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), thermograv…
The effect of annealing on magnetic and transport properties in La 0.5 Sr 0.5 CoO 3−δ thin films is studied. The samples were prepared by annealing amorphous films at different temperatures. With increase in annealing temperature, the resistivity decreases, and the Curie temperature ( T c ) and negative magnetoresista…
The local atomic order of an amorphous Ga50Se50 alloy produced by mechanical alloying (MA) was studied by the extended x-ray absorption fine structure (EXAFS) and x-ray diffraction (XRD) techniques and by reverse Monte Carlo (RMC) simulations of its total x-ray structure factor. The coordination numbers and interatomi…
The whisker of polyoxymethylene produced in the cationic polymerization process of trioxane is a single crystal of extended chain crystal morphology. Since it has a quite small size of several microns in radius and several tens of microns in length, the crystal structure analysis of POM whisker had been tried by using…
<div class="htmlview paragraph">Contrary to gasoline cars only few of the new diesel vehicles are equipped with exhaust gas after treatment devices. Diesel engine producers have managed so far to meet the emission limits by improving the engine and its control. The new emission standards are worldwide forcing pr…
The humidity-voltaic effect, i.e. generation of open-circuit voltage ( V oc ), in Au–porous silicon (PS) interface in humid atmosphere (up to 450 mV at 95% relative humidity) in dark and daylight illumination is discovered. The humidity-stimulated voltage generation is attributed to the splitting of water and hydrogen…
To gain more insight into the process of formation of adsorbed layers of diblock copolymers, ellipsometry was used to monitor in situ the thickness and adsorbed amount of a series of polystyrene- b -poly(2-vinylpyridine) diblock copolymers adsorbed on silicon from toluene. First, it is demonstrated that ellipsometry c…
Anionic phosphodiester surfactants, possessing either two fluorinated chains (F/F) or one hydrocarbon chain and one fluorinated chain (H/F), were synthesized and evaluated for solubility and self-assembly in liquid and supercritical carbon dioxide. Several surfactants, of both F/F and H/F types and having varied count…
Directly linked bisporphyrin, Zn(II)2 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-2-(10,15,20-tris(3,5-di-tert-butylphenyl)porphyrin-5-yl)porphyrin, was investigated on the basis of the magnetic property of its bis(pi-radical cation). A stable triplet state of the bis(pi-radical cation) of the bisporphyrin, which obeys…
Abstract Electrospinning is a process that employs a high static electrical potential to produce polymeric fibers of nanoscale diameter. The process has been utilized to achieve color change by electrospinning black polymer solutions to produce white fiber mats. When subsequently heated, the electrospun mats undergo a…