Materials Literature
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PURPOSE: To compare T(1) values of blood and myocardium at 1.5T and 3T before and after administration of Gd-DTPA-BMA in normal volunteers, and to evaluate the distribution of contrast media between myocardium and blood during steady state. MATERIALS AND METHODS: Ten normal subjects were imaged with either 0.1 mmol/kg…
ZnO is a wide band gap, naturally n-type semiconductor with great promise for optoelectronic applications; the main obstacle yet to be overcome is p-type doping. Nitrogen, the most promising candidate currently being pursued as a dopant, has been predicted to preferentially incorporate into the ZnO lattice in the form…
A new scenario of the mechanism of intriguing ferromagnetic properties in Mn-doped magnetic semiconductor (Ga,Mn)As is examined in detail. We find that magnetic features seen in zero-field cooled and field cooled magnetizations are not interpreted with a single domain model [Phys. Rev. Lett. 95, 217204 (2005)], and th…
Extreme pressure strongly affects the superconducting properties of "simple" elemental metals, such as Li, K, and Al. Pressure induces superconductivity in Li (as high as 17 K) while suppressing it in Al. We report first-principles investigations of the superconducting properties of dense Li, K, and Al based on a rece…
We synthesized Cu-In sulfide heterostructured nanocrystals from the thermal decomposition of a mixture of Cu-oleate and In-oleate complexes in dodecanethiol. By varying the reaction temperature and time, we were able to synthesize Cu-In sulfide nanocrystals with acorn, bottle, and larva shapes.
Molecular self-assembly offers new routes for the fabrication of novel materials at the nano-scale. Peptide-based nanostructures represent nano-objects of particular interest, as they are biocompatible, can be easily synthesized in large amounts, can be decorated with functional elements and can be used in various bio…
The low-energy electronic structure of icosahedral fullerenes is studied within the field-theory model. In the field model, the pentagonal rings in the fullerene are simulated by two kinds of gauge fields. The first one, non-abelian field, follows from so-called K spin rotation invariance for the spinor field while th…
Merrifield's Variational Ansatz is extended so as to cover the case of two electronic bands mixed by an Einstein phonon. The Hamiltonian is composed of the local and kinetic (hopping) energies in the absence of vibrations, the vibrational energy, and a mixing band-off-diagonal part linear in the electron-phonon coupli…
We present classical density functional theory calculations of the free-energy landscape for fluids below their triple point as a function of density and crystallinity. We find that, both for a model globular protein and for a simple atomic fluid modeled with a Lennard-Jones interaction, it is free-energetically easie…
Magnetization and high resolution neutron powder diffraction measurements on the magnetic shape memory compound Ni 2 Mn 1.44 Sn 0.56 have confirmed that it is ferromagnetic below 319 K and undergoes a structural phase transition which takes place at T M = 221 K on cooling and 239 K on warming. The high temperature pha…
A theory for the anomalous vibrational and thermal properties of disordered solids based on the model assumption of randomly fluctuating transverse elastic constants is presented. Mean-field expressions for the vibrational density of states and the energy diffusivity are derived with field-theoretical techniques. As i…
A novel method for the electrospinning of multiple polymer jets into nanofibres is presented. In this work, 20 wt% nylon 6 solution was electrified and pushed by air pressure through the walls of a porous polyethylene tube. Multiple jets formed on the porous surface and electrospun into nanoscale fibres. The length we…
The early stage aggregation kinetics of bare and alginate-coated hematite nanoparticles are acquired through time-resolved dynamic light scattering (DLS). Varying concentrations of monovalent (NaCl) and divalent (MgCl2 and CaCl2) electrolytes are employed to induce aggregation. In the presence of NaCl and MgCl2, the a…
Atomic substitution in alloys can efficiently scatter phonons, thereby reducing the thermal conductivity in crystalline solids to the "alloy limit." Using In0.53Ga0.47As containing ErAs nanoparticles, we demonstrate thermal conductivity reduction by almost a factor of 2 below the alloy limit and a corresponding increa…
Nanomaterials are engineered structures with at least one dimension of 100 nanometers or less. These materials are increasingly being used for commercial purposes such as fillers, opacifiers, catalysts, semiconductors, cosmetics, microelectronics, and drug carriers. Materials in this size range may approach the length…
Abstract Alternativ zur Schmelztauch‐ bzw. elektrogalvanischen Verzinkung von Stählen bieten sich Gasphasenabscheidungen (PVD) wegen ihrer Flexibilität bezüglich Legierungszusammensetzung und Umweltverträglichkeit an. Dabei muss ein PVD‐beschichteter Stahl mindestens die gleiche Korrosionsbeständigkeit besitzen wie di…
In the present work, oxidation of fibre grade polypropylene granules in the melt phase using oxygen gas has been performed. Then, virgin polypropylene granules were mixed with up to 10% by weight of oxidised granules and multifilament yarns from the blends were spun by a pilot-plant melt spinning machine. The characte…
We propose a new experimental approach that enables to evaluate the chemical and positional availability of soil potassium (K) to pot-grown plants. The proposed approach makes use of the inherent differences between the removal of soil K by plants and by chemical methods, and comprises the following procedures: 1) pre…
In this work, lattice vibrations in BaTi 4 O 9 ceramic were investigated using far-infrared spectra (FIRS), which were transformed by Kramers–Kronig relations into the real and imaginary parts of permittivity spectra. Curve fitting of reflectance spectra shows that 32 vibration modes were observed, among which transve…
A new mold flux has been developed to favour cuspidine crystallisation at the upper level of the mold. This reduces the local heat flux and allows an even solidification of the slab shell, thus preventing any occurrence of longitudinal cracks. Pilot tests have established that the new flux make it possible to cast hyp…