Materials Literature
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We present a review of recent advances in the study of many-body effects in magnetic nanoparticles. Considering classical spins on a lattice coupled by the exchange interaction in the presence of the bulk and surface anisotropy, we investigate the effects of finite size, free boundaries, and surface anisotropy on the…
The performance of fiber reinforced thermoplastic composites strongly depends on solid fiber-matrix adhesion to allow stress transfer between the phases. Fiber surface modification with coupling agents is generally needed to induce bond formation between the fiber and the polymer. This study investigated the effects o…
The emergence of the blue phases I and II that are thought to exist in highly chiral systems has been found in chiral nematic liquid crystals ${(N}^{*}$ LCs) when they are doped with achiral bent-core liquid crystals (banana mesogens). The same effect was also observed by adding racemic 4-(1-methylheptyl oxycarbonyl)p…
We argue that a single-band itinerant electron model with short-range interactions, proposed by Karchev et al. (cond-mat/9911489) and investigated further by Jackiewicz et al. (cond-mat/0302449), cannot describe the coexistence of superconducting and ferromagnetic order.
We present model calculations for the Landauer conductance of tunnel junctions. The tunneling of free electrons through a rectangular potential barrier is considered. The conductance of a finite number of barriers was calculated using a transfer matrix method. The periodic arrangement of the same barriers was describe…
We have studied the volume collapse of LaMnO$_3$ at the Jahn- Teller (JT) transition temperature T$_{JT}$=750 K which has recently been found in high temperature powder x- ray and neutron diffraction experiments. We construct a model Hamiltonian involving the pseudospin of Mn$^{3+}$ e$_g$ states, the staggered JT dist…
We consider, theoretically and experimentally, the effects of structural disorder, quantum and thermal fluctuations in the magnetic and transport properties of certain ferromagnetic alloys.We study the particular case of UCu2Si(2-x)Ge(x). The low temperature resistivity, rho(T,x), exhibits Fermi liquid (FL) behavior a…
It is shown for the first time, that room temperature Ultrasonic Defect Manipulation (UDM) can significantly reduce the concentration of radiation defects in high resistivity silicon. Secondary Ion Mass Spectroscopy revealed that oxygen- and hydrogen- related chemical reactions in silicon are likely to occur under UDM…
95, 97Mo NMR experiments have been performed on a series of Sr2FeMoO6 and electron-doped Sr2-xLaxFeMoO6 ceramics. Detailed analysis of the NMR spectra from pristine Sr2FeMoO6 conclusively shows that the Mo hyperfine field is mainly due to atomic Mo magnetic moments. No contribution of transferred hyperfine field has b…
Li 3 N is a potential H 2 storage material due to its high theoretical H 2 capacity (10.4 wt %). A critical potential issue regarding this N-based storage material is the generation of NH 3, which consumes some H 2 and also constitutes a poison for the downstream processes. In this Letter, by using the temperature-pro…
The degradation and the tissue response evoked by poly(1,3-trimethylene carbonate) [poly(TMC)] and copolymers of TMC with either 52 mol % D,L-lactide (DLLA) or 89 mol % epsilon-caprolactone (CL) were evaluated in vivo by subcutaneous implantation of polymer films in rats for periods up to one year. Poly(TMC) specimens…
A palladium-nanoparticle-cored G-3 dendrimer, characterized by TEM, TGA, absorption, and IR spectroscopies, has approximately 300 Pd atoms in the metallic core and an average diameter of 2.0 nm, to which are attached fourteen G-3 dendrons. Nearly 90% of the metal nanoparticle surface is unpassivated and available for…
A novel end-on azide-bridged homospin 1D chain, Co(bt)(N3)2 (1) (bt = 2,2'-bithiazoline), is constructed by sharing edges of Co(II) distorted octahedrons to form a helix, which shows magnetic hysteresis with steps and slow relaxation below 5-6 K, typical of single-chain magnet behavior.
Nanofibrous materials, by virtue of their morphological similarities to natural extracellular matrix, have been considered as candidate scaffolds for cell delivery in tissue-engineering applications. In this study, we have evaluated a novel, three-dimensional, nanofibrous poly(epsilon-caprolactone) (PCL) scaffold comp…
CO2 molecule chemisorbs selectively on the zigzag tube edge without an activation barrier, whereas it physisorbs on the armchair edge of nanotubes. In addition, carbon nanotubes can be etched by an adsorbed oxygen atom of CO2 molecule. From our results, we suggest a selective etching mechanism for tuning the chirality…
Erbium ions incorporated into amorphous hydrogenated silicon suboxides $(a\ensuremath{-}{\mathrm{SiO}}_{x}:\mathrm{H})$ allow to overcome the disadvantages of ${\mathrm{Er}}^{3+}$ in $c\ensuremath{-}\mathrm{Si}$ such as the limited solubility, the strong quenching of the luminescence at room temperature, and the need…
Exposure to gamma ray irradiation is a frequent, clean, and superior method used to prevent bacterial contamination of sterilized biomedical end products. However, the potential damage induced by gamma ray irradiation of collagen is of concern because of the decay of bioactivity, which correlates with considerable str…
Abstract A series of hyperbranched poly(arylene ether phosphine oxide)s (HB PAEPOs) were prepared via an A 2 + B 3 polymerization scheme with tris(4‐fluorophenyl)phosphine oxide as B 3 , and a variety of bisphenols as A 2 . The effects of the reactivity of the A 2 monomer, the A:B ratio, the addition mode, the solvent…
Abstract We describe non‐radiative energy‐transfer experiments to measure the rates of polymer interdiffusion in P(MMA‐ co ‐BA) latex films formed in the presence of poly(vinyl alcohol) (PVOH). PVOH had relatively little effect on the initial efficiency of energy transfer, even when the amount of PVOH was large enough…
The TetL antiporter from the Bacillus subtilis inner membrane is a tetracycline-divalent cation efflux protein that is energized by the electrochemical proton gradient across the membrane. In this study, we expressed tetL in Escherichia coli and investigated the oligomeric state of TetL in the membrane and in detergen…