Search results for "Breakdown"

Food composition and structure, in-mouth breakdown, oral physiology and sensory perception: example of dairy products

2018

During eating, the first food transformations occur in the mouth and constitute preliminary steps of a series of reactions leading to digestion. Food breakdown occurring in the mouth contributes to the bolus formation and to the release of the stimuli responsible for the global sensory perception. However food breakdown not only depends on food composition and structure but also on human oral physiology, which could explain the high inter-individual differences observed in sensory perception and liking. After a general introduction, the presentation will focus on examples related to dairy products. Dairy products offer a great variability in terms of composition and structure and their liki…

ChemInform Abstract: Electrical and Mechanical Breakdown of Anodic Films on Tungsten in Aqueous Electrolytes.

1988

Abstract Different types of breakdown are reported to occur during the galvanostatic growth of WO3 films in different aqueous electrolytes. Stresses inside the growing film cause the occurrence of cracks at a critical thickness which varies with the anodizing solution. The electrical breakdown is caused by avalanche ionization of the electronic current inside the film. The influence of the different experimental parameters on both the mechanical and the electrical breakdown voltages is discussed. For the electrical breakdown a model is proposed which explains the dependence of the sparking voltage on the electrolyte resistivity by assuming a double layer effect on the oxygen evolution react…

Poling dynamics of an EO active material using parallel-plate electrodes

2017

We describe the sample preparation and experimental setup for second harmonic generation measurement of electro-optical (EO) chromophore/polymer system at the time of contact-poling. Different types of spacers for avoiding electric breakdown due to avalanche multiplication are compared. Electric field threshold values for second harmonic generation are observed in all samples.

Large-area dielectric breakdown performance of polymer films

2015

In this study, large-area dielectric breakdown performances of various bi-axially oriented polypropylene (BOPP)-silica nanocomposite films are studied by utilizing the self-healing multi-breakdown method presented in the Part I of this publication. In particular, the effects of silica filler content, pre-mixing method, co-stabilizer content and film processing on the large-area breakdown performance are analyzed. Nanostructural and film cross-sectional analyses are correlated to the breakdown responses. The optimum silica filler content is found to reside at the low fill fraction level (~1 wt-%) and automatic pre-mixing of the raw materials and the optimization of the orientation temperatur…

Glucose, Lactate, and Ketone Body Utilization by Human Mammary Carcinomas in Vivo

1985

Uncontrolled growth, one of the fundamental properties of malignant tumors, requires a great supply of energy. This energy can be derived from the use of a variety of substrates. Besides glucose oxidation and glucose breakdown to lactic acid, the turnover of endogeneous substrates such as amino acids, free fatty acids and ketone bodies is well documented in vitro. However, under in vivo conditions, only glucose utilization has been investigated in detail, using tumor isotransplants in rodents. For human tumors, only scarce data is available, derived mainly from clinical observations rather than from systematic studies.

ChemInform Abstract: Electrical Breakdown and Pitting in Anodic Films on Tungsten in Halogen Ion-Containing Solutions.

1988

Abstract The systematic investigation of the anodic behaviour of W in halogen ion-containing solutions reveals noticeable differences in the presence of different anions. Strong generalized dissolution is observed in fluoride solutions, the oxide growth being hindered at low anodizing current densities. Sparking phenomena occur in the presence of Br− and I− anions as in nitrate and sulphate solutions. Only in Cl− containing solutions is the growth of the anodic films limited by the occurrence of pitting phenomena at a critical thickness of the oxide. The laws of dependence of the phenomenon on the experimental parameters and the influence of ferrous ions on the voltage at which pitting occu…

Measurements on electric breakdown in dielectric barriers between carbon nanotubes and electrodes

2009

Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles

2009

[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…

The Born–Oppenheimer equilibrium bond distance of GeO from millimetre- and submillimetre-wave spectra and quantum-chemical calculations

2014

The millimetre- and submillimetre-wave spectra of the five common isotopologues of (GeO)-O-16 in their electronic and vibrational ground state have been recorded in the spectral region 115-732GHz; for (GeO)-Ge-74-O-16, the rotational spectrum in the v = 1 state has been detected as well. Exploiting the high precision of the measurements, the Born-Oppenheimer breakdown parameter Delta(Ge)(01) could be determined from a Dunham analysis of the spectral data, whereas Delta(O)(01) was obtained from quantum-chemical calculations, because of the lack of high-precision measurements for the (GeO)-O-18 isotopologues. From the rotational equilibrium constant, the Born-Oppenheimer equilibrium distance …

Breakdown studies for high-gradient RF warm technology in: CLIC and hadron therapy linacs

2016

La presente tesis se centra en el estudio de las limitaciones, debidas principalmente a fenómenos de breakdowns, en el rendimiento de estructuras aceleradoras de radiofrecuencia (RF) de alto gradiente (HG) y de conductividad normal. La formación de arcos en vacío perturban los campos electromagnéticos de las cavidades, lo cual afecta en la calidad del haz de partículas acelerado. El proyecto de Compact Linear Collider (CLIC) estudia la viabilidad de un colisionador lineal electrón-positrón en la escala de energía centro de masa del TeV, y desarrolla las estructuras aceleradoras de última generación para alcanzar altos gradientes de 100 MV/m con una tasa máxima de fenómenos de breakdowns de …