Materials Literature
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The present study investigated the in vitro mechanism and degradation rate of polyhydroxyoctanoate (PHO). Solution-cast PHO films were incubated in either water or isoosmotic phosphate-buffered saline (PBS) for periods ranging from 1 to 24 months. Physical characterization included weight loss, water absorption, pH ch…
The crystal structure of α-silicon nitride (Si 3 N 4 ) was refined by the Rietveld method using synchrotron radiation powder diffraction data (wavelength = 1.2 Å) collected at station BL-4B2 in the Photon Factory. A refinement procedure that adopted a new weight function, w = 1/Y_o^e ( Y o is the observed profile inte…
A variety of physico-chemical methods employ chemical denaturants to unfold proteins, and study different biophysical processes involved therein. Chemical denaturants are believed to induce unfolding by stabilizing the unfolded state of proteins over the folded state, either macroscopically or through specific interac…
The effect of the ac electric field on piezoelectric properties is investigated in lead zirconate-titanate (PZT) films of various compositions and thicknesses. Non-linear piezoelectric properties of PZT films are compared to those of bulk ceramics. It is shown that non-linearity is strongly suppressed in thin films of…
The influence of an asymmetric periodic grooved cell surface on the 2D static director configuration of a nematic liquid crystal has been investigated. The minimum in the Frank-Oseen free energy was solved numerically with the Rapini-Papoular form of the surface anchoring energy at the nematic-grating interface. Resul…
New ferrocenyloligosilylene aryl complexes have been synthesized, FcSi n Me 2 n C 6 H 5 ( n = 1−6) and FcSi 2 Me 4 {C 6 H 4 -X} (X = m -CF 3 . p -Cl, p -Br, p -OMe, p -NMe 2, p -CH C(CN) 2 ). The complexes have been evaluated with respect to their electrochemical redox and NLO hyperpolarizability properties. All compl…
The hyperfine parameters of iron atoms are studied in iron nanocrystallites prepared by different methods: ball milling of iron powder, partial crystallization of Fe-Zr-B-Cu amorphous ribbons, and vacuum evaporation of Fe-B polycrystalline multilayers. Careful analysis of the spectral contribution of the possible impu…
In actuator technology active or smart materials have opened up new horizons in terms of actuation simplicity, compactness, and miniaturization potential. One such material is the nickel-titanium shape memory alloy (NiTi SMA), which is gaining widespread use in a variety of applications. The numerous advantages of SMA…
Abstract A functionalized polyphosphazene, poly[ bis (carboxylatophenoxy)‐phosphazene], was blended with a structural polyurethane via reactive mixing of the polymer with diisocyante and diol prepolymers. The thermal stabilites of the resultant foams were analyzed by thermogravimetric analysis (TGA). The char yields a…
We analyze the properties of a Lennard-Jones system at the level of the potential energy landscape. After an exhaustive investigation of the topological features of the landscape of the systems, obtained by studying small size samples, we describe the dynamics of the systems in multidimensional configurational space b…
Case studies from three Wisconsin utilities found that polyphosphate blends used for corrosion control led to increased metal concentrations in the water. When polyphosphate blends are added to water systems under certain conditions, leaching of pipe metal into the water may be significantly increased rather than decr…
Force/displacement actuators with the high output power and time response can be fabricated from shape memory wires or ribbons. Typically Ni-Ti shape memory alloys are used as an active material in such actuators. They are driven by Joule heating and air convection cooling. In the present work, the time response of va…
The analysis of the equilibrium structure of a dendrimer of fourth generation by small-angle neutron scattering (SANS) is described. The analysis presented here is based on measurements of the SANS intensities at different contrasts ρ–ρm with ρ being the average scattering length density of the dissolved dendrimer and…
We investigate the role played by conservative forces in dissipative particle dynamics (DPD) simulation of single-component and binary fluids. We employ equations from kinetic theory for matching the coefficients of DPD interparticle force to the macroscopic properties of fluid such as: density, temperature, diffusion…
Three novel Zn(hfa) 2 ·2H 2 O·polyether adducts have been prepared through simple procedures with stoichiometric quantities of zinc hydroxide, Hhfa, and polyether. The products have been characterized by elemental analysis, X-ray single-crystal analysis, fast atom bombardment mass spectra, 1 H and 19 F NMR spectra, th…
Visible light-induced IR absorption in colloidal CdSe quantum dots is observed by step-scan FTIR spectroscopy. Size dependence and the effect of surface modification are investigated. The introduction of surface hole trap states enhances and prolongs the IR absorption in photoexcited quantum dots. Our measurements rev…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTStructure of Polymer Brushes under Shear Flow in a Good SolventS. M. Baker, G. S. Smith, D. L. Anastassopoulos, C. Toprakcioglu, A. A. Vradis, and D. G. BucknallView Author Information Harvey Mudd College, Claremont, California 9171…
The chemical diffusivity of undoped ${\mathrm{BaTiO}}_{3\ensuremath{-}\ensuremath{\delta}}$ which was measured in Song and Yoo [Solid St. Ionics 120, 141 (1999)] is analyzed on the basis of the defect structure proposed and Wagner's classic theory of chemical diffusion. It is confirmed that a maximum of isothermal che…
MarqX is a computer program for the modelling of powder diffraction data. It can be used for an unconstrained profile fitting (pattern decomposition, PD) or constrained modelling of the whole powder pattern (Pawley method, PM), for single- as well as multiple-phase samples. The program output includes: lattice paramet…
We present the electrical properties of polycrystalline samples Pr1—xSrxMnO3 (0 ≤ x ≤ 0.5). These properties are correlated to the ratio of the Mn3+/Mn4+ cations. The transport properties of the Pr1—xSrxMnO3 samples could be explained on the basis of double exchange mechanism between pairs of Mn3+ and Mn4+ cations, wi…