Materials Literature
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The activation of molecular oxygen on the surface of cerium oxide and the reactivities of surface oxygen species with methane and ethane were studied by means of in situ confocal microprobe Raman spectroscopy in the temperature range 298–1023 K. The results showed that O22-, O2- and O2δ- (0<δ<1) adspecies formed on th…
Addition of the bis(β-diketone) ligand L [L = 1,3-bis(3-phenyl-3-oxopropanoyl)benzene] to a suitable source of M III ions (M = Ti, V, Mn, Fe) in a L:M = 3:2 ratio gives the dinuclear products [M 2 L 3 ], which have a triple-helical structure.
▪ Abstract Casting of molten metals against a spinning wheel substrate is considered. Issues of fluid mechanics divide between steady and unsteady behavior (stability). The previous work on steady casting is hung on a framework provided by the long-puddle model of planar flow casting. Heat and fluid flow interact only…
Protein adsorption and complement activation were studied on thin evaporated films of titanium (Ti). The surfaces were cleaned in either a radio frequency (RF) plasma unit, or washed sequentially in trichloroethylene, acetone, ethanol, and water. Both methods resulted in hydrophilic surface with low carbon contaminati…
This paper presents a new expression of the vector magnetic properties under alternating and rotating flux conditions. The expression is defined by an improved reluctivity tensor based on measured results. Moreover, the expression is more accurate than conventional expressions about the approximation of magnetic prope…
A method was developed for construction of stability diagrams for metals in the presence of realistically modeled aqueous solutions. The method was based on a comprehensive thermodynamic model that combines the Helgeson-Kirkham-Flowers (HKF) equation of state for standard-state properties with a solution nonideality m…
MurB catalyzes the second committed step in the synthesis of peptidoglycan, a key component of the bacterial cell wall. The crystal structures of both a S229A mutant and wild-type MurB in the presence of the substrate enolpyruvyl-UDP-N-acetylglucosamine were solved and refined at 1.8 A resolution. The single point mut…
Abstract Samples of isotactic polypropylene(PP) were subjected to stress‐relaxation experiments after simple tensile tests at four strain rates and at different levels of temperature. The relaxation moduli were determined in the range of temperature between 20 and 80°C with a relaxation period of 1200s duration. The a…
The relations between fabric compression and friction are examined. It is found that the higher the fabric compression, the larger is the difference between the static- and kinetic-friction forces. The influence of some experimental variables such as normal load, area, and time of contact on frictional properties is a…
A detailed study of the layered manganite La 1+ x Sr 2- x Mn 2 O 7 has been performed, establishing that within the composition range 0.1 ≤ x ≤ 0.45 the phases crystallize in the I 4/ mmm space group. The evolution of structural parameters with x in this composition range has been followed using a novel application of…
The state of the art in proton conducting polymers is described and the interest in the use of sulfonamide groups to prepare a series of such polymers is stressed. The most relevant aspects of the chemical and physical characteristics of sulfamide are reviewed. Its history is briefly presented. A detailed description…
In this paper the active control of beam deflection through heating and cooling of Shape Memory Alloy (SMA) wires is examined. A phenomenological constitutive law for SMA wires is coupled with beam theory to provide predictions of beam shape upon temperature change in the SMA actuator. Both the linear and nonlinear be…
The hyperpolarizability β of an ionic species, 1-anilinonaphthalene-8-sulfonic acid ammonium salt (ANS), was determined in various solvents by the Hyper-Rayleigh scattering (HRS) technique. Increase in the solvent polarity led to a decrease in the hyperpolarizability; i.e. β=37.4±2.5×10 -30 esu in p-dioxane and β=10.3…
The effects of different nitrogen and carbon sources on cell growth, pH, and exopolysaccharide (EPS) and poly-(beta)-hydroxybutyrate (PHB) production by two strains of Rhizobium meliloti (M5N1 and Su47) are reported. Differences in the behavior of glucose- and fructose-grown cells were shown, in particular with the M5…
Three series of hydrogen bonded adducts have been formed between 4-alkoxy-4′-stilbazoles and the nitrophenols 4-nitrophenol, 3-nitrophenol and 2,4-dinitrophenol. Each series is mesomorphic displaying both nematic and smectic A phases, in sharp contrast to the behaviour of the individual components. The binary phase be…
Under the influence of extreme contact pressure and high factional heating, the real contact areas of diamond films may undergo phase transformation and gradual wear during long-duration dry sliding contacts. The wear debris particles that accumulate at the contact interface can then dominate the long-term sliding fri…
Abstract Constant pressure constant temperature molecular dynamics method is employed to investigate the atomistic scale dynamics of a model Bisphenol A polycarbonate in the vicinity of its glass transition temperature. First, the glass transition temperature and the thermal expansion coefficients of the polymer are p…
Abstract Whether crystalline or amorphous sp 3 ‐bonded carbon nitrides containing substantial amounts of nitrogen can be synthesized remains an open question. Various deposition techniques and high pressure syntheses to 40 GPa have not been successful thus far. The use of appropriately designed molecular or solid‐stat…
Diatom seasonal succession and interannual variability were studied using laminated sediments from Saanich Inlet, British Columbia, for the years 1900–1991. Frozen sediment cores allowed fine-scale sampling of laminae for each year. Thus, three ‘seasons’ for each year were identified based on species composition. Thal…
Inorganic–organic hybrids containing various inorganic components have been successfully synthesized from silanol-terminated poly(dimethylsiloxane) (PDMS) and three different inorganic sources, Al(OBu s ) 3 , Ti(OEt) 4 and Ta(OEt) 5 , by using a sol–gel process. Inorganic components as well as the process conditions w…