Search results for "Decomposition"
showing 10 items of 766 documents
Paramagnetic Mono- and Polyhydrides of the Transition Metals
2001
Publisher Summary This chapter reviews the methods used for the synthesis or generation of paramagnetic hydride complexes. It subsequently surveys the known classes of stable open-shell hydride complexes. The chapter also reveals the fundamental properties of the M–H bond in open-shell compounds and finally examines the various established decomposition modes. The classical picture of the terminal M–H bond is that where the hydrogen atom is orbital and combines with an appropriate metal-fragment hybrid orbital to generate the bonding and antibonding combinations. The chapter also elaborates the paramagnetic hydride complexes, which are thermally sensitive compounds and are unstable toward a…
ANOVA-MOP: ANOVA Decomposition for Multiobjective Optimization
2018
Real-world optimization problems may involve a number of computationally expensive functions with a large number of input variables. Metamodel-based optimization methods can reduce the computational costs of evaluating expensive functions, but this does not reduce the dimension of the search domain nor mitigate the curse of dimensionality effects. The dimension of the search domain can be reduced by functional anova decomposition involving Sobol' sensitivity indices. This approach allows one to rank decision variables according to their impact on the objective function values. On the basis of the sparsity of effects principle, typically only a small number of decision variables significantl…
The impact of baking on chlorinated paraffins: Characterization of C10–C17 chlorinated paraffins in oven-baked pastry products and unprocessed pastry…
2019
Abstract This study presents an HPLC–ESI–Q–TOF method for simultaneous quantification of short-chain chlorinated paraffins (SCCPs, C10–13) and an additional characterization of medium-chain chlorinated paraffins (MCCPs, C14–17) in oven-baked pastry products (n = 38) and unprocessed pastry dough material (n = 15). Almost 2 times higher SCCP levels were found in the dough material. ΣSCCP concentrations in products ranged from 0.3 ng g−1 to 23.0 ng g−1 (mean: 6.3 ng g−1), while the results for dough ranged from 5.8 ng g−1 to 22.8 ng g−1 (mean: 12.9 ng g−1). Regardless of the sample matrix, the most abundant CP homologue groups were hepta- and octa-chlorinated undecanes and dodecanes. The avera…
Die Umsetzung von L-Äpfelsäure durchSaccharomyces cerevisiae bei der Gärung
1970
Yeasts of the genusSaccharomyces are able to decompose L-malic acid partially, during and after fermentation, whereby ethanol and carbon dioxide are the end products. The decarboxylation of malic acid by yeast can be achieved with resting cells and cell free extracts.
The Structure and the Stereochemistry of Atractyliretin
1986
The nor-kaurane diterpene Atractyliretin was obtained by acid hydrolysis of Atractyloside, a toxic substance isolated from ATRACTYLIS GUMMIFERA L (Compositae). On the basis of spectral (IR, (1)H-NMR, (13)C-NMR and MS) analysis and chemical degradation its structure and stereochemistry was identified as 4.
Interdiffusion in blends of polystyrene and polymethylstyrene studied by light scattering after temperature jumps across the phase boundary
1992
Abstract We describe a simple light scattering set-up for measuring interdiffusion coefficients D in polymer blends by generating spinodal decomposition and subsequent dissolution after temperature jumps across the phase boundary. In blends of polystyrene and polymethylstyrene (random copolymer of 60% m-methylstyrene and 40% p-methylstyrene) D values were obtained between 10−11 and 10−15 cm2s−1 at temperatures up to 50 K above the upper critical solution temperature. The results are discussed in relation to tracer diffusion in the same system.
Characterization and Decomposition of the Natural van der Waals SnSb2Te4 under Compression
2020
[EN] High pressure X-ray diffraction, Raman scattering, and electrical measurements, together with theoretical calculations, which include the analysis of the topological electron density and electronic localization function, evidence the presence of an isostructural phase transition around 2 GPa, a Fermi resonance around 3.5 GPa, and a pressure-induced decomposition of SnSb2Te4 into the high-pressure phases of its parent binary compounds (alpha-Sb2Te3 and SnTe) above 7 GPa. The internal polyhedral compressibility, the behavior of the Raman-active modes, the electrical behavior, and the nature of its different bonds under compression have been discussed and compared with their parent binary…
Mechanisms for the Dynamics of Phase Transformations
1984
An introductory review of the dynamics of (first- order) phase transitions is given. Concepts describing the initial stages of the transition, such as nucleation, spinodal decomposition (in the case of unmixing) are introduced, and their validity is critically discussed. The theoretical results are compared to recent computer simulations and pertinent experiments. Then the scaling concepts describing the late stages of domain growth are discussed, and open problems are outlined.
High Pressure Raman, Optical Absorption, and Resistivity Study of SrCrO4
2018
We studied the electronic and vibrational properties of monazite-type SrCrO4 under compression. The study extended the pressure range of previous studies from 26 to 58 GPa. The existence of two previously reported phase transitions was confirmed at 9 and 14 GPa, and two new phase transitions were found at 35 and 48 GPa. These transitions involve several changes in the vibrational and transport properties with the new high-pressure phases having a conductivity lower than that of the previously known phases. No evidence of chemical decomposition or metallization of SrCrO4 was detected. A tentative explanation for the reported observations is discussed.
Concurrent molecular dynamics simulation of spinodal phase transition on transputer arrays
1990
Abstract We describe a concurrent implementation on cost-effective transputer arrays of a molecular dynamics program to efficiently simulate physical systems consisting of thousands of mobile particles with an interaction range much shorter than the system dimensions. This program, which uses a geometric decomposition strategy and includes a distributed dynamic load balancer, has been extensively tested by simulating the two-dimensional spinodal phase separation of a large Lennard-Jones system.