Materials Literature
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Pyrochlore dielectric materials such as (Bi$_{1.5}$Zn$_{0.5}$)(Nb$_{1.5}$Zn$_{0.5}$)O$_7$ (BZN) have generated interest because they combine high dielectric constants with small dielectric loss tangents and yet are cubic at all temperatures. The recent low-temperature preparation and structural characterization of Bi$…
The formation of regular precipitate stripes in the wake of moving chemical reaction-diffusion fronts is investigated. Experiments on the $NaOH+CuCl_2$ reaction in PVA hydrogel yield stripes parallel or slightly oblique to the front that supplies the precursor of the precipitate. The pattern formation was modeled by p…
We present time-dependent dielectric loss data for various glass formers below the glass temperature. The observed aging dynamics is described using a modified Kohlrausch-Williams-Watts law taking into account the variation of the relaxation time during aging. It leads to values for the aging relaxation time and stret…
The present investigation describes the synthesis and characterization of novel biodegradable nanoparticles based on chitosan for biomedical applications. Natural di- and tricarboxylic acids were used for intramolecular cross-linking of the chitosan linear chains. The condensation reaction of carboxylic groups and pen…
The effect of nanofiber surface coatings on the cell's proliferation behavior was studied. Individually collagen-coated poly(epsilon-caprolactone) (PCL) nanofibers (i.e., Collagen-r-PCL in the form of a core-shell structure) were prepared by a coaxial electrospinning technique. A roughly collagen-coated PCL nanofibrou…
We have observed experimentally that the thermal conductance of a 2.76-microm-long individual suspended single-wall carbon nanotube (SWCNT) was very close to the calculated ballistic thermal conductance of a 1-nm-diameter SWCNT without showing signatures of phonon-phonon Umklapp scattering for temperatures between 110…
We investigate spin-dependent interband tunnelling in a ferromagnetic (Ga,Mn)As/ GaAs Zener diode. The ferromagnetic pn-junction is fabricated with a Mn-doped p-type GaAs layer on top of a nonmagnetic n-type GaAs substrate. When both sides of the junction are heavily doped, a large magnetic-field–dependent tunnelling…
Der neue Westernstar: Eine sehr empfindliche Fluoreszenzsonde für die alkalische Phosphatase (ALP) wurde ausgehend von einem Fluoresceinderivat entwickelt und erwies sich als geeignet für den Einsatz in der Westernblot-Analyse. Die Sonde 1 fluoresziert nicht, wird aber in Gegenwart von ALP zum grün fluoreszierenden De…
Crystals of SrY 2 O 4 (space group Pnam ) were examined by high‐temperature powder X‐ray diffractometry to determine the changes in unit‐cell dimensions with temperature. The individual cell dimensions linearly increased with increasing temperature up to 1473 K. The expansion coefficients (K −1 ) were 1.263(8) × 10 −5…
The thermal diffusivities D th of mullite single crystals with about 2/1‐composition parallel to the crystallographic a, b, and c axes (i.e., parallel to [100], [010], and [001]) and of monophase, dense mullite ceramics were measured between room temperature and 1200°C using the laser flash method. The semi‐transparen…
MalY from Escherichia coli is a bifunctional dimeric PLP (pyridoxal 5'-phosphate) enzyme acting as a beta-cystathionase and as a repressor of the maltose system. The spectroscopic and molecular properties of the holoenzyme, in the untreated and NaBH4-treated forms, and of the apoenzyme have been elucidated. A systemat…
Highly grain‐oriented lead metaniobate (PbNb 2 O 6 ; PN) ceramics were prepared by a layered manufacturing (LM) process. This process has enabled us to obtain a net‐shaped piezoelectric ceramic component with grain orientation of f ∼89%, and improvement in electromechanical properties. The LM feedstock (filament) incl…
The solubilities of 16α,17α-epoxyprogesterone in methanol, ethanol, acetone, ethyl acetate, acetic acid, and 1,4-dioxane were measured using an isothermal method from 283 K to 323 K. A laser monitoring observation technique was used to determine the dissolution of the solid phase in a solid + liquid mixture. The solub…
Good slip resistant tread patterns of outer-sole of military boot are vital to minimize the risk or severity of slip in combat and physical training situations. A series of non-linear, three-dimensional finite element analyses of footwear and ground interaction based upon the Drucker-Prager elastic-perfectly plastic m…
In this paper, the synthesis and micro/nanoscopic characterizations of polymer-clay nanocomposites are briefly introduced. Dynamic response for mode-I crack tip in polymer-clay nanocomposite is studied by combining high speed photography with optical caustic method. A series of caustic spots surrounding the crack tip…
Abstract The reaction of [{Ir(cod)(μ‐Cl)} 2 ] and K 2 CO 3 or of [{Ir(cod)(μ‐OMe)} 2 ] alone with the non‐natural tetrapyrrole 2,2′‐bidipyrrin (H 2 BDP) yields, depending on the stoichiometry, the mononuclear complex [Ir(cod)(HBDP)] or the homodinuclear complex [{Ir(cod)} 2 (BDP)]. Both complexes react readily with ca…
Abstract The effect of hydration on the dielectric constant and loss factor tan δ of viscose hydrocellulose, hydroxypropyl cellulose, and dextran was studied in a wide range of temperatures and frequencies. The results obtained reveal that (1) whereas hydration shows little effect on the variation with temperature of…
Remarkable hydrolytic stability in the range pH 7.0–8.0 is exhibited by the zwitterionic λ5Si-silicate 1, which can even be prepared in water and forms a stable hydrate 1⋅H2O. The synthetic route to 1 and the structure of the zwitterion in the crystal (O red; N blue; Si green; C gray) are shown in the picture.
Abstract This article deals with the effect of the kneading temperature on the crystallization of a matrix polymer and the viscoelasticity of a bamboo‐fiber‐reinforced biodegradable polymer composite. Upon the investigation of poly(butylene succinate) after melt mixing, spherulite generation was observed with polarize…
Abstract The copper complex [CuCl 2 (TzHy)] has been synthesized and its crystal structure determined. The coordination complex contains polymeric [CuCl 2 (TzHy)] n chains in which the units are linked by μ‐chloro bridges. The chains run along the crystallographic c axis. The geometry around the copper(II) is best des…