Approaches to atomistic triple-line properties from first-principles

Different approaches to study wetting and adhesion by applying density-functional theory (DFT) methods are highlighted. The ab initio thermodynamics method is used to demonstrate the link between the calculated work of separation and the work of adhesion and wetting angles from sessile-drop measurements. An approach to extend DFT calculations to the case of large-scale interfaces relevant for wetting systems is also discussed.     

Interactions of oxidized lipids with protein. Part XVI. Interactions of oxidized ethyl linoleate with collagen

The reaction of ethyl linoleate with collagen proceeded at 60 degrees C following the first order kinetics but during the hydroperoxide decomposition the rate constant of the first order decomposition was substantially lower than that of the second order decomposition. Contrary to cellulose, collagen catalyzed the hydroperoxide decomposition. The amount of total oxidation products rose rapidly at the stage of rapid hydroperoxide formation, and slowly afterwards. The browning reaction was fasted in the stage of maximum hydroperoxide content, and both ether-insoluble and ether-soluble pigments were formed, the latter low in nitrogen. The amount of lipid oligomers increased mainly in the reaction stage following the hydroperoxide maximum. Soluble collagen was converted into insoluble forms by the reaction with oxidized lipids. Basic amino acids were blocked by reaction with oxidized lipids but the bonds formed became resistant to acid hydrolysis only in the stage following the hydroperoxide maximum. Changes of sensory profiles could be explained by reactions of flavour-active carbonylic oxidation products with protein.     

Integrated Inductors Modeling for Library Development and Layout Generation

In this work we propose a modification to the conventional lumped equivalent circuit model for integrated inductors. Also the widely used parametric model is modified. The proposed models expand the frequency range where the integrated inductor behavior is accurately predicted. They are useful in developing automatic tools to assist the designers in selecting and automatically laying-out integrated inductors [1]. This work is based on measurements from integrated inductors fabricated in a standard silicon process.     

Discerning nonstationarity from nonlinearity in seizure-free and preseizure EEG recordings from epilepsy patients

A number of recent studies indicate that nonlinear electroencephalogram (EEG) analyses allow to define a state predictive of an impending epileptic seizure. In this paper, we combine a method for detecting nonlinear determinism with a novel test for stationarity to characterize EEG recordings from both the seizure-free interval and the preseizure phase. We discuss differences between these periods, particularly an increased occurrence of stationary, nonlinear segments prior to seizures. These differences seem most prominent for recording sites within the seizure-generating area and for EEG segments less than one minute's length.     

Special Important Aspects of the Thomson Effect

A comprehensive study of the mechanisms of heating and cooling originating from an electrical current in semiconductor devices is reported. The variation in temperature associated with the Peltier effect is not related to the presence of heat sources and sinks if the heat flux is correctly determined. The Thomson effect is commonly regarded as a heat source/sink proportional to the Thomson coefficient, which is added to the Joule heating. In the present work, we will show that this formulation of the Thomson effect is not sufficiently clear. When the heat flux is correctly defined, the Thomson heat source/sink is proportional to the Seebeck coefficient. In the conditions in which the Peltier effect takes place, the temperature gradient is created, and, consequently, the Thomson effect will occur naturally.     

Thermal Effects of Microwave Energy in Agricultural Soil Radiation

The thermal treatment by millimeter waves for the soil disinfection can be one possible alternative to chemical treatments. This physical method is based on incrementing the soil temperature and its pathogens irradiating with high frequency electromagnetic waves. So the previous knowledge of the temperature distribution in the irradiated soil is essential for achieving an effective bad microorganism and weed seeds elimination. This report analyse the heating kinetic and spatial distribution of the maximum temperatures reached by the soil. It is presented a mathematic model about how are distributed the reached temperatures in the depth of the irradiated soil. This model concludes that when an orchard soil is irradiated superficially by microwaves, the microwaves have a big attenuation due to the soil dielectric properties and the water located in the pores of the most superficial layer. This fact causes a shield effect blocking the waves penetration in few centimetres. The heating by radiation is reduced to the superficial layer. The heating propagation in the depth is occurred by conduction following the Fourier equations.     

Compositional, structural, optical and electrical characterization of CulnTe2 grown by the tellurization of stoichiometric Cu and in in the liquid phase

A new method to grow single crystals with stoichiometry close to 1:1:2 of CuInTe₂, an important member of the Cu-III-VI₂ family of semiconductors is described. This consists of tellurization in the liquid phase of stoichiometric Cu and In and later solidification under directional freezing. It is found from energy dispersive spectroscopy that the ingots obtained with the evaporation temperature (T_t) of Te at 590 and 635°C were very close to the ideal stoichiometry 1:1:2. Samples of all ingots obtained with T_t between 530 and 690°C, as studied by x-ray and differential thermal analysis, were of single phase having chalcopyrite structure and p-type conductivity. Optical and electrical characterization of different ingots were made. The acceptor ionization energy E_A and the density of states effective mass m _p ^* of the holes are estimated from the temperature dependence of the hole concentration p in samples of different ingots. m _p ^* = (0.78 ± 0.02) m_e agrees quite well with the reported value. From a combined analysis of the variation of E_A with p^1/3 and the knowledge of molecularity and valence stoichiometry of each sample, it is established that the shallow acceptor level observed in different samples with E_A (0) ⋍ 30 meV is due to V_In.     

Copper-induced changes in the properties of arsenic chalcogenides

The influence of the presence of Cu in the amount between 1% and 6% in arsenic chalcogenide glasses is examined through a study of the electronic energy levels by means of x-ray photoelectron and x-ray emission spectroscopy, through an investigation of the low-energy tunneling systems by means of phonon echoes at 0.37 K, and through an examination of the photodarkening and the photoinduced dichroism caused by polarized Ar⁺ laser irradiation. Possible links between the various effects are examined. The Cu atoms become an integral part of the amorphous lattice structure and strongly influence the photodarkening, but they do not have a significant effect on the tunneling systems or the dichroism. It is concluded that the tunneling levels and the dichroism involve only local configurations, while the photodarkening involves larger-scale areas of the lattice. Fiz. Tekh. Poluprovodn. 32, 976–981 (August 1998)     

Transient negative photocurrent and out-of-well dipole kinetics in novel piezoelectric InGaAs/GaAs MQW pin diodes

In 111B InGaAs/GaAs pin structures with a multiple quantum well (MQW) embedded region, the average internal field in the active MQW region can be tailored to obtain device configurations with a negative average field (NAF), opposite to the built-in field. In 111 NAF diodes, carriers photogenerated at the wells become trapped early at the potential minima located at the ends of the active region thus creating an electric dipole. In this work, in 111 NAF devices with a 0.17 In mole fraction layers, by using time-resolved photocurrent and a novel optical-pump electrical-probe techniques, we report the presence of a negative transient photocurrent, a direct quantitative evidence of such dipole formation, and we present measurements of its extinction kinetics at room temperature.