Search results for "Roth"
showing 10 items of 806 documents
CCDC 1997244: Experimental Crystal Structure Determination
2020
Related Article: Yuxing Zhang, Chaoqun Wang, Stefan Mecking, Zhongbao Jian|2020|Angew.Chem.,Int.Ed.|59|14296|doi:10.1002/anie.202004763
CCDC 1997246: Experimental Crystal Structure Determination
2020
Related Article: Yuxing Zhang, Chaoqun Wang, Stefan Mecking, Zhongbao Jian|2020|Angew.Chem.,Int.Ed.|59|14296|doi:10.1002/anie.202004763
Thermal inactivation kinetics of Bacillus stearothermophilus spores using a linear temperature program.
1999
A systematic study of the inactivation kinetics of Bacillus stearothermophilus spores was carried out in nonisothermic heating conditions using a linear temperature increase program and analyzing the experimental data by means of a one-step nonlinear regression. The D and z values estimated are close to those obtained in isothermic conditions and estimated by using a two-step model, first D values are calculated, and then in the second step a z value is deduced (D(121 degrees C) = 3.08 and 4.38 min, respectively, and z = 7 and 7.9 degrees C, respectively). No convergence problems were observed when using the one-step nonlinear regression proposed. The results indicated that the methodology …
Water and temperature contribution to the structuration of starch matrices in the presence of flavour
2015
The effect of hydrothermal treatments and flavours addition on starch structure and its physical properties were studied. Native wheat starch was treated at 2 different hydrations (water-starch ratios: 50/50 and 80/20 g w/w) and temperatures (65 and 85 °C) in the presence of flavours (ethyl hexanoate and 2-hexanone). The freshly prepared samples were subjected to DSC and flavour analysis. Flavour inclusion complex could not be detected by DSC, however the result of flavour analysis proved that there were flavours interactions with starch. Both ethyl hexanoate and 2-hexanone interacted with starch at similar rates. The highest flavour loss was found in the samples at high hydration and heate…
Water absorption and hydrothermal performance of PHBV/sisal biocomposites
2014
[EN] The performance of biocomposites of poly(hydroxybutyrate-co-valerate) (PHBV) and sisal fibre subjected to hydrothermal tests at different temperatures above the glass transition of PHBV (TH ¿ 26, 36 and 46 C) was evaluated in this study. The influences of both the fibre content and presence of coupling agent were focused. The water absorption capability and water diffusion rate were considered for a statistical factorial analysis. Afterwards, the physico-chemical properties of water-saturated biocomposites were assessed by Fourier-Transform Infrared Analysis, Size Exclusion Chromatography, Differential Scanning Calorimetry and Scanning Electron Microscopy. It was found that the water d…
Stabilization of ZSM-5 zeolite catalysts for steam catalytic cracking of naphtha for production of propene and ethene
2012
In order to increase ethene and propene, naphtha steam catalytic cracking has been considered. The cracking of C 5-C 12 n-alkanes with ZSM-5 has been studied in absence and in presence of steam and the influence of the operation variables was studied. Irreversible catalyst deactivation by dealumination also occurs in the reactor when the cracking is carried out in the presence of steam. To diminish steam deactivation, the influence of zeolite Si/Al framework and a postsynthesis treatment by phosphorous have been studied and optimized. Much more stable catalyst can be achieved that result in an increase in activity without penalty for production of ethene and propene.
Mono- and di-nuclear complexes of ortho-palladated and -platinated 4,4′-dimethylazobenzene with bis(diphenylphosphino)methane. More data on transphob…
2002
Abstract Complexes [Pd(κ2-R)(μ-Cl)]2 [κ2-R=κ2-C,N′-C6H3(NNC6H4Me-4′)-2-Me-5 (1)] and [Pd(κ1-R)Cl(κ1-dppm)(κ2-dppm)]TfO [dppm=bis(diphenylphosphino)methane (2)] have been used to prepare new palladium derivatives containing dppm. Thus, complex 1 reacts with one equivalent of dppm to afford [{Pd(κ2-R)Cl}2(μ-dppm)] (3) and with AgClO4 and dppm (1:2:2 molar ratios) to give [Pd(κ2-R)(κ2-dppm)]ClO4 (4·ClO4). The triflate salt of this complex (4·TfO) reacts with PPh3 to yield [Pd(κ1-R)(PPh3)(κ2-dppm)]TfO (5). Dinuclear complexes were obtained by reacting 2, (i) with [AuCl(PPh3)] or [AuCl(tht)] (tht=tetrahydrothiophene) (1:1, −60 °C) and (ii) with 1 (2:1) to give, respectively, [Pd(κ1-R)Cl(μ-dppm…
Mo-W-containing tetragonal tungsten bronzes through isomorphic substitution of molybdenum by tungsten
2010
Mixed metal oxides based in Mo(W)–Nb–V–Te with tetragonal tungsten bronze (TTB) structure have been synthesized by a hydrothermal method from aqueous solutions of the corresponding Keggin-type heteropolyacids and further heat-treatment in N2 at 700 ◦ C. The materials have been characterized by several physico-chemical techniques, i.e. XRD, Raman, FTIR, SEM-EDS, and TEM. This procedure allows controlling the chemical species to be distributed in the different interstices of the TTB skeleton, which is a key factor to regulate the catalytic properties of the final solid. In this sense, the isomorphic replacement of Mo by W results in lattice parameter and crystal morphology variation, although…
ChemInform Abstract: Catalytic Activity of Large-Pore High Si/Al Zeolites: Cracking of Heptane on H-Beta and Dealuminated HY Zeolites
1988
Abstract The catalytic activity, selectivity, catalyst decay, thermal and hydrothermal stability, and acidity of H-Beta and HY zeolites with Si Al ratios of 7.5 and 10, respectively, have been studied during cracking of n-heptane at 450 °C and atmospheric pressure. It has been found that the H-Beta zeolite is more active and decays more slowly than HY. H-Beta presents a higher steric hindrance for dibranched molecules and therefore its open structure should be smaller than that of HY. A lower hydrogen transfer activity and hydrothermal stability is observed for H-Beta in comparison with the corresponding HY.
Ritmo della forma e patosofia: l’espressione del vivente nella tradizione morfologica fra Rothacker e Weizsäcker
2014
In the tradition of twentieth-century morphological thinking, the concept of form constitutes the profound unity from which it is possible to articulate the relationship between subject and object and the expressive qualities of experience and reality. Erich Rothacker in his last book, pub- lished posthumously in 1966 and titled Zur Genealogie des menschlichen Bewusstseins, outlines a genesis of human consciousness in which the relationship with reality is structured expressively starting from sensory-motor images up to the conscience of the world (Weltbewusstsein) on the basis of a criterion of organic-expressive significance, while, even more markedly, Viktor von Weizsäcker concludes his …