Materials Literature
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We report the preparation methods and electro-optical characterization of polymer-dispersed liquid crystals with nanosized liquid crystal domains obtained by using a multifunctional monomer in a prepolymer mixture that is suitable for a fast photopolymerization process. The electric-field-induced optical phase shift h…
The thermal conductivity of ZnO with different particle sizes (micrometer, submicrometer, and nanometer) was measured using the laser flash technique. As the “green” samples were heated from room temperature to 600°C (and 1000°C) and then cooled down to room temperature, the thermal conductivity was measured in situ .…
The quinol-fumarate reductase (QFR) respiratory complex of Escherichia coli is a four-subunit integral-membrane complex that catalyzes the final step of anaerobic respiration when fumarate is the terminal electron acceptor. The membrane-soluble redox-active molecule menaquinol (MQH(2)) transfers electrons to QFR by bi…
The structure of low-temperature β-Ta 2 O 5 oxide has been studied by the method of Rietveld full-profile analysis. It is established that this oxide has an orthorhombic structure with lattice parameters a = 6.217 Å, b =3.677 Å, and c = 7.794 Å. The atomic coordinates and thermal parameters are also determined.
This is a companion work to our previous study on the pressureless sintering of boron carbide (B 4 C). The Vickers hardness and indentation fracture toughness of B 4 C compacts were measured after various sintering heat treatments. Increases in hardness and decreases in indentation fracture toughness as the grain size…
A method for the reliable fabrication of less than 200 nm thick, free-standing purified-SWNT films having large surface areas exceeding several cm2 is described. Films were characterized using a variety of optical, microscopic and spectroscopic methods. The procedure was also used to prepare thin films of as-prepared,…
ABSTRACT Thermal stability and kinetic parameters of commercial edible oils were investigated by non‐isothermal thermogravimetry/derivative thermogravimetry (TG/DTG). Kinetic parameters were calculated by integral and approximation methods. Results obtained indicated that these parameters were dependent on composition…
Fluorescence radiation trapping and nonradiative energy losses from the Nd 3+ 4 F 3/2 state are reported for two widely used commercial phosphate laser glasses (LHG‐8 and LG‐770). The effects of hydroxyl‐group, transition‐metal (Cu, Fe, V, Co, Ni, Cr, Mn, and Pt), and rare‐earth (Dy, Pr, Sm, and Ce) impurities on the…
Research in development of antimicrobial packaging applications for further processed meats has become more common with recent outbreaks of contamination of these products. In this present study, lauric acid (8%, wt/wt) and 2.5% pure nisin (4%, wt/wt) were incorporated singly and together into thermally compacted soy…
By in vitro evolution experiment, we have first succeeded in acquiring higher active mutants of a synthase that is a key enzyme essential for bacterial synthesis of biodegradable polyester, polyhydroxyalkanoate (PHA). Aeromonas caviae FA440 synthase, termed PhaC(Ac), was chosen as a good target for evolution, since it…
Abstract The addition of a coupling agent to silica-rubber compounds enhances the filler-matrix compatibility. Under certain mixing conditions the surface of the filler may be only partly activated, which may have an adverse effect on the properties in the final product. Some coupling agents may also act as sulfur don…
Air layers trapped within a clothing microenvironment contribute to the thermal insulation afforded by the ensemble. Any exchange of air between the external environment and these trapped air layers results in a change in the ensemble's thermal insulation and water vapor resistance characteristics. These effects are s…
A perspective is provided on corrosion inhibition by bacterial biofilms. Inhibition of general corrosion by biofilms has been reported for mild steel, copper, aluminum, and stainless steels. The mechanisms most frequently cited for the inhibition are formation of a diffusion barrier to corrosion products that stifles…
The morphogenesis, particle size, size distribution, and phase evolution of zinc oxide precipitated in the presence of water-soluble poly(ethylene oxide- block -methacrylic acid) (P(EO- b -MAA)) and poly(ethylene oxide- block -styrene sulfonic acid) (P(EO- b -SSH)) diblock copolymers is reported. Without a polymeric a…
Membrane osmometry is used to measure osmotic pressures of dilute solutions containing quasispherical CdSe nanocrystals covered with polymer brushes in toluene in the range 31−45 °C. Osmotic-pressure data, as a function of nanocrystal concentration, yield the molecular weight and the osmotic second virial coefficient…
The preparation, isolation, and characterization of several new peripherally functionalized monomeric porphyrins and metalloporphyrins and of porphyrin dimers are described. These dimers are obtained by linking with metal ions two monomeric porphyrins bearing at their periphery an enaminoketone chelate fully conjugate…
The crystal structures of alanine racemase bound with reaction intermediate analogs, N-(5'-phosphopyridoxyl)-L-alanine (PLP-L-Ala) and N-(5'-phosphopyridoxyl)-D-alanine (PLP-D-Ala), were determined at 2.0-A resolution with the crystallographic R factor of 17.2 for PLP-L-Ala and 16.9 for PLP-D-Ala complexes. They were…
Two series of rigid and flexible polyurethane foams were prepared with two types of silica fillers. The density of the flexible foams was 60 kg/m 3 and that of rigid 30 kg/m3. The fillers were micro-silica of the average particle size of 1.5 mm and nano-silica of the average particle size of 12 nm. The concentration o…
BACKGROUND AND AIM OF THE STUDY: Contemporary tissue valves are non-viable, and unable to grow, repair or remodel. It was postulated that tissue-engineered heart valves (TEHV) fabricated from autologous cells and a biodegradable scaffold could yield a dynamic progression of cell phenotype and extracellular matrix (ECM…
The growth and dissolution of calcium oxalate monohydrate (COM) were investigated by real-time in situ atomic force microscopy (AFM). The (100) surfaces of COM crystals were sufficiently rough that direct AFM imaging of terrace growth and step motion was not feasible. In undersaturated aqueous solutions, however, COM…