Search results for "tyre"
showing 10 items of 586 documents
Motherhood in the Context of Human Trafficking and Sexual Exploitation
2020
This book discusses motherhood of Nigerian and Romanian women in Italy and Romania, who are human trafficking victims for sexual purposes. It provides a broad gender approach to emerge on the phenomenon of human trafficking with an analytic perspective of all the social, cultural, legal and economic components that play an important role during all phases of motherhood. The book compares the motherhood of these two nationalities within a context of an illegal/legal status in the European territory. It reflects on the used terms of vulnerability, sexual exploitation, victim, resistance and resilience. This book enlightens scholars and students with a broad perspective on this complex phenome…
Reaktionskinetik der Polymerisationshemmung durch molekularen Sauerstoff
1957
Die Polymerisationshemmung geschieht bei Styrol nach demselben Mechanismus wie er kurzlich fur Methylmethacrylat berichtet wurde1. Wahrend der Inhibierungsperiode findet streng alternierende Copolymerisation zwischen molekularem Sauerstoff und dem monomeren Styrol statt. Die fur die Anlagerung von O2 an das Radikal RM · masgebende Konstante kMO2 ist etwa von der Grosenordnung 106–107, d. h. die Reaktionsfahigkeit des Sauerstoffs in dieser Reaktion entspricht der eines Radikals. Bruttogeschwindigkeit und kinetische Kettenlange wahrend der Inhibierungsperiode werden auf Grund des Reaktionsmechanismus berechnet und experimentell bestatigt. The inhibition mechanism in the polymerization of styr…
The calculation of the number-average degree of polymerization starting from intrinsic viscosity and overall rate
1962
The relation between the intrinsic viscosity [η] and the number-average degree of polymerization Pn is a function of the molecular weight distribution of the polymer. In a polymer in which the termination of polymer radicals occurs partly by combination of two growing chains, this molecular weight distribution depends on number and extent of additional reactions such as chain transfer; i.e., it is variable. Therefore Pn of such polymers cannot be obtained from intrinsic viscosity measurements by means of an equation of the type [η] = KPna. A new method is proposed which allows the evaluation of Pn in these cases, without necessity of osmotic (or related) measurements or fractionation. The v…
Synthesis and X-ray Crystal Structures of (C5HiPr4)Ln(BH4)2(THF)(Ln = Nd and Sm), Versatile Precursors for Polymerization Catalysts
2000
The new half metallocenes [(C5HiPr4)Ln(BH4)2(THF)] [Ln = Sm (1) and Nd (2)], and [(C5HiPr4)U(BH4)3] (3) have been synthesized. The crystal structures of 1 and 2 and of the metallocenes [(C5HiPr4)2Ln(BH4)] [Ln = Sm (4) and Nd (5)] have been determined. The substitution of the BH4 groups of 1 and 2 by a nitrogen-based ligand is possible. In the presence of butyllithium, these complexes show an activity in isoprene and styrene polymerization.
Lanthanide molecular oxohydroxides: Synthesis and characterisation of [Y4(μ4-O)(μ-OEt)2(μ,η2-AAA)2(η2-AAA)3]2(μ3-OH)4(μ3-OEt)2 (HAAA = allylacetatoac…
2007
International audience; The reaction between Y5O(OPri)13 and allylacetatoacetate or 2-(methacryloyloxy)ethyl acetatoacetate in 1:5 stoichiometry afforded octanuclear oxohydroxo species. Structural characterization was achieved for the allylacetatoacetate derivative homo and copolymerisation reactions with styrene were evaluated for doping of polystyrene. Hydoxo species, Y4(OH)2(AAA)10, where also obtained by reacting Y[N(SiMe3)]3 and HAAA.
Estimation of the size of liposomes by modified HDC
1991
Internal calibration in modified hydrodynamic chromatography has been realized by the approach of Prieve and Hoysan, i.e. the use of polystyrene monodisperse latexes to evaluate the equivalent capillary radius, R. The value obtained has been used to estimate the average sizes of a variety of liposome samples from egg yolk lecithin.
Stationary–mobile phase distribution coefficient for polystyrene standards
2002
The measured shifts of the retention volume V R of polystyrene (PS) towards lower values in benzene–methanol (Bz–MeOH), and towards higher values in butanone–heptane (But–Hep) are in agreement with our theoretical model, in which both MeOH and But are adsorbed on Lichrospher. This paved way for us to model the chromatographic stationary (s)-phase as MeOH and the mobile (m)-phase as Bz–MeOH, and to calculate the distribution coefficients for PS. For But–Hep, the s-phase has been modeled as But, and the m-phase as But–Hep. A linear relation for the experimental equilibrium distribution P sm of PS is shown between the s- and m- phases in Bz–MeOH and But–Hep vs. the logarithm of the molecular m…
Untersuchungen zu den orientierungs- und dichtefluktuationen in amorphen polymeren mit hilfe der lichtstreuung
1976
Es wurden mit einem Lichtstreuphotometer die Orientierungs- und Dichtefluktuationen in den amorphen Polymeren «Polycarbonat» (Poly(oxycarbonyloxy-1,4-phenylenisopropyliden-1,4-phenylen)) und Polystyrol in Abhangigkeit von der Temperatur untersucht. Ferner fuhrten wir erganzende Messungen an Oligomeren des Polystyrols und an der flussig-kristallinen Verbindung 4-Butyl-N-(p-methoxybenzyliden)anilin (MBBA) in der isotropen Phase durch. Aus der Hohe der depolarisierten Lichtstreuung ergab sich, das eine Orientierungskorrelation, wie sie fur einige Bundelmodelle vorgeschlagen wurde, nicht auftritt. Besonders detaillierte Aussagen konnten fur Polystyrol gemacht werden. Die depolarisierte Lichtstr…
Production de styrene par Penicillium camemberti Thom
1989
National audience; The Celluloïd taste observed in some mould-ripened cheeses is bound to the presence of styrene in these cheeses. The accumulation of this molecule was only detected on cultures of some strains of Penicillium camemberti. It seems to be bound to a deregulation of oxidative metabolism of tneee strains.; L'apparition du goût de Celluloïd dans les fromages à pâte molle à croûte fleurie est liée à la présence de styrène dans ces fromages. L'accumulation de cette molécule n'est observée que sur des cultures de souches particulières de Penicillium camemberti. Elle semble liée à un dérèglement du métabolisme oxydatif de ces souches.
How Low Can You Go? Low Densities of Poly(ethylene glycol) Surfactants Attract Stealth Proteins.
2018
It is now well-established that the surface chemistry and “stealth” surface functionalities such as poly(ethylene glycol) (PEG) chains of nanocarriers play an important role to decrease unspecific protein adsorption of opsonizing proteins, to increase the enrichment of specific stealth proteins, and to prolong the circulation times of the nanocarriers. At the same time, PEG chains are used to provide colloidal stability for the nanoparticles. However, it is not clear how the chain length and density influence the unspecific and specific protein adsorption keeping at the same time the stability of the nanoparticles in a biological environment. Therefore, this study aims at characterizing the…