Materials Literature
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The modulus spectroscopy of potassium lithium niobate (KLN) crystals was investigated in the frequency range from 100 Hz to 10 MHz and temperature range from 30°C to 600°C. The dielectric anomaly with a broad peak was observed around 430°C. The a c conductivity is frequency dependent at low temperatures such as σ=σ dc…
The solid solubility of the aliovalent dopants Fe 3+ and Nb 5+ in the BaBi 4 Ti 4 O 15 compound, a member of the family of Aurivillius bismuth‐based layer‐structure perovskites, has been studied using quantitative wavelength‐dispersive spectroscopic microanalysis (SEM/EPMA) in combination with X‐ray powder diffractome…
Stoichiometric In2S3 films were prepared by thermal evaporation technique onto clean glass substrates. According to X-ray investigations, the as-deposited films were in amorphous state. Both the ac conductivity and dielectric constants were measured in the frequency range 100 Hz−100 kHz at different temperatures. Diff…
The mesophase behaviour of the lanthanum(III) alkanoates [La(CxH2x+1COO)3] (x =3-19) has been investigated by hot-stage polarizing optical microscopy, differential scanning calorimetry and high-temperature X-ray diffraction. Lanthanum(III) butyrate monohydrate shows no mesomorphism, whereas for the remaining short cha…
Contaminants in cotton fibers cause yam regularity defects that alter their structure. The effect of these alterations on yarn strength is discussed with particular focus on seed coat fragments (SCF), one of the primary cotton contaminants from the fiber to the finished product. This paper presents the results of an e…
Optically transparent SrTi1−xSbxO3 (=0.05, 0.10, 0.15, and 0.20) thin films with transmittances higher than 85% in the visible region have been grown on SrTiO3 substrates by pulsed-laser deposition. Unless overdoped, the films possess a single-crystal phase and impurity conduction. The temperature dependence of the re…
Abstract Zeolites with hierarchical structure were prepared through layer-by-layer electrostatic assembly of zeolite nanocrystals on the diatom substrate. The thickness and composition of the zeolite coatings on the diatom could be readily tailored by varying the number of deposition cycles and the zeolite types used,…
A new design for a DRIFTS (diffuse reflectance infrared Fourier transform spectrometry) cell for in situ studies in heterogeneous catalysis is presented, which allows for improved reaction control (i.e., gas flow, temperature, minimized background conversion) and for precise kinetic measurements via on-line gas analys…
Microscopic examinations of concrete specimens can be compromised because improper and damaging techniques are utilized in preparing the samples. Unless great care is given to preparing specimens, it can be very difficult to know if a simple crack was originally present or created during the sample cutting. Extraction…
Acetate kinase catalyzes the magnesium-dependent transfer of the gamma-phosphate of ATP to acetate. The recently determined crystal structure of the Methanosarcina thermophila enzyme identifies it as a member of the sugar kinase/Hsc70/actin superfamily based on the fold and the presence of five putative nucleotide and…
The modern trend towards low electron energies in scanning electron microscopy (SEM), characterised by lowering the acceleration voltages in low-voltage SEM (LVSEM) or by utilising a retarding-field optical element in low-energy SEM (LESEM), makes the energy range where new contrasts appear accessible. This range is f…
The effect of phosphorus ions on the proton conductivity was examined for the sol–gel‐derived glasses. The porous glasses were prepared through hydrolysis of PO(OCH 3 ) 3 and Si(OC 2 H 5 ) 4 , in which the phosphorus ions consisted of the POH bonds and were dissolved into the silica matrix without any P‐O‐Si bond. The…
In a junction system which consists of ferromagnetic- (La1−xSrx)MnO3 and band insulating-SrTiO3, the double exchange ferromagnetism in the (La, Sr)MnO3 layer was controlled by light irradiation through photocarrier injection form SrTiO3. We investigated the dependence of hole doping level (Curie temperature) on the ph…
La 0.8 Sr 0.2 Cr 0.9 Ti 0.1 O 3 perovskite has been designed as an interconnect material in high‐temperature solid oxide fuel cells (SOFCs) because of its thermal expansion compatibility in both oxidizing and reducing atmospheres. La 0.8 Sr 0.2 Cr 0.9 Ti 0.1 O 3 shows a single phase with a hexagonal unit cell of a = 5…
The synthesis of calcium hexaboride (CaB 6 ) powder via the reaction of calcium carbonate (CaCO 3 ) with boron carbide (B 4 C) and carbon has been investigated systematically in the present study. The influences of heating temperature and holding time on the reaction products have been studied using X‐ray diffractomet…
Associations of diatom species were identified, in the Arroio Sampaio Basin, Rio Grande do Sul, Brazil, based on monthly samplings over a year along Arroio Sampaio and its main tributaries, using polyamide thread as an artificial substrate. The species groupings showed four different environments: medium-lower course…
Rather than a marriage of convenience, which implies a relationship that is non-rigorous and has a substantial degree of independence, we argue that as we move forward through the 21st Century, studies on the taxonomy and ecology of freshwater diatoms will, and by necessity must, be linked. This linkage will be forged…
Abstract There is increased technological interest to use blends of various dissimilar elastomers in applications for which service, material availability, or cost of a single elastomer do not provide the necessary processing, vulcanizate, or economic properties. Properties of polyblends are sensitive to variations in…
Polyurethane closed cell rigid foams have been widely used as insulants in the building and refrigeration industry and also for district heating pipes. It is the special combination of its excellent insulation performance and the mechanical stability due to the foaming process which makes this material very attractive…
The adhesive interphase formed between brass plated steel cord and sulfur crosslinked rubber is known to be a complex layer of metal oxides, sulfides, and rubber. Hostile aging of this system produces changes in the structure, morphology, thickness, and mechanical properties of this layer. In a previous publication it…