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There have been several extensive reviews of mandibular fractures, which have classified fractures according to their anatomical location. Our case is unusual, and to our knowledge there have been no previous reports of angle fractures solely below the inferior alveolar nerve and not involving the alveolar segment.

The electrophoretic mobilities of two β-blocker drugs, i.e., labetalol and atenolol, have been determined in a mixed solvent background electrolyte system containing sodium acetate+acetic acid as buffering agent and different volume fractions of water, methanol and ethanol using capillary electrophoresis. The produced data and three other sets collected from a recent work are employed to study the accuracy and prediction capability of a mathematical model to calculate the electrophoretic mobility with respect to the volume fractions of the solvents in the mixture. The results show that the proposed model is able to correlate/predict the mobility within an acceptable error range and it is possible to use the model in industry to achieve the optimum solvent composition for the buffer where using a ternary solvent system is required. The average percentage deviations (APDs) obtained for correlated and predicted data points are 0.71–2.48 and 1.72–4.39%, respectively. The accuracy of the proposed model is compared with that of a mixture response surface method and the results show that the proposed model is superior from both correlation and prediction points of view. The possibility of calculation of the mobility of chemically related drugs in water–methanol–ethanol mixtures using the proposed model is also shown and the produced prediction APD is ∼8%.

The electrophoretic mobilities of three beta-blocker drugs, practolol, timolol and propranolol, have been measured in electrolyte systems with mixed binary and ternary water-methanol-ethanol solvents with acetic acid/sodium acetate as buffer using capillary electrophoresis. The highest mobilities for the analytes studied have been observed in pure aqueous, the lowest values in ethanolic buffers. The measured electrophoretic mobilities have been used to evaluate the accuracy of a mathematical model based on a mixture response surface method that expresses the mobility as a function of the solvent composition. Mean percentage error (MPE) has been computed considering experimental and calculated mobilities as an accuracy criterion. The obtained MPE for practolol, timolol and propranolol in the binary mixtures are between 0.9 and 2.6%, in the ternary water-methanol-ethanol solvent system the MPE was about 2.7%. The MPE values resulting from the proposed equation lie within the experimental relative standard deviation values and can be considered as an acceptable error.

We investigate the coherent time regime in space- and time-resolved pump and probe experiments on a symmetrically strained InGaAs/GaAsP multiple quantum well. The spatial width of the transmission profiles shows a modulation which reflects the dynamics of an excitonic wave packet. This spatio–temporal beating originates from the combined action of various signal components which are detected simultaneously because of the collinearity of our experiment. The experimental results are in qualitative agreement with calculations obtained with a simplified model on the Hartree–Fock level.

The photoluminescence (PL) of InP strained-induced quantum dots in a GaInAs/GaAs quantum well is measured at low temperature (4.2 K) using near-field scanning optical microscopy. The PL originating from the first three confined levels of eight individual dots is mapped out over an area of 1.4×1.4 μm. The spatial resolution of the PL of the lowest energy level is found to be limited to about 0.5 μm. In contrast, the mapping of the PL of the higher excited state shows a much improved spatial resolution of the order of 150 nm which is the instrument resolution. This effect is understood in terms of Pauli-blocking of the dot level filling.

We report on low temperatures (4 K) in situ nanomanipulation of the confining potential of single strain-induced Ga0.9In0.1As quantum dots. This was achieved by scanning a metal coated tapered optical fiber tip over the self organized InP stressor islands that are responsible for the localized strain field in the GaInAs/GaAs quantum well. By scanning the tip with a shear force contact of the order of 1 nN, we thinned down the InP stressor islands in an unexpectedly reproducible and controlled way. The modification of the confining potential was directly monitored by measuring in situ the photoluminescence of each manipulated dot using a near-field scanning optical microscope.

The dynamics of excitons interacting with a phonon bath following the generation by an ultrashort laser pulse can be subdivided into a coherent regime immediately after the excitation and the subsequent gradual transformation of coherent excitations into incoherent occupations. In the coherent regime the interaction with the phonon system modifies the dy namics of the highly phase sensitive interband transition amplitude, but does not immediately lead to a total loss of coherence. For a GaAs quantum-wire we compare a treatment of the coupled exciton phonon system on a quantum kinetic level with the results of Boltzmann dynamics demonstrating noticeable effects of the energy-time uncertainty on linear spectra. Furthermore, we discuss the influence of the Coulomb interaction during the exciton phonon scattering process and the resulting modifications of the spectra. The opposite limit of incoherent exciton dynamics is marked by redistribution processes between exciton occupation densities. Time and space resolved pump-probe experiments are compared with calculations based on the exciton Boltzmann equation in relaxation time approximation. These experiments are found to reflect the time evolution of the mean kinetic energy of the excitons. In particular for excitation above the band edge the diffusivities show a non-monotonic behavior reflecting the exciton formation process leading to large kinetic energies. To account for the gradual loss of coherence a theory is presented that deals consistently with the combined dynamics of coherent excitonic interband transitions and incoherent excitonic occupations. Of particular interest is the build-up of exciton densities with non-vanishing center-of-mass motion. Numerical results are presented for a quantum well system demonstrating that the loss of coherence is typically much faster than the thermalization, whereby both time scales crucially depend on the well width. Furthermore it is found that the build-up of incoherent exciton densities with finite center-of-mass motion is noticeably accelerated by a transfer process involving only coherent interband transitions.

We present results of the optically excited dynamics in semiconductor quantum wells on short length and time scales. Nonlinear optical experiments are performed with high temporal and high spatial resolution. To interpret the experimental findings calculations are performed on different approximation levels. Two different time regimes are investigated: In the incoherent time regime we study the dynamics of heating, cooling, and the formation of excitons by measuring the temporal behavior of the lateral expansion rate of locally created electron-hole pairs or excitons. A monomolecular exciton formation process is found. The experimental results in this regime are well reproduced by the Boltzmann equation for incoherent exciton densities with phenomenological scattering rates. In addition rye have performed a microscopic density matrix analysis for the heating scenario where we have modeled explicitly the initial transformation of coherent excitations into incoherent exciton densities. It is found that the heating due to scattering with acoustic phonons gives reasonable agreement with the observed rates. In the coherent time regime a spatio-temporal beating is observerd. This unexpected non-monotonic modulation of the spatial width arises from excitonic wave-packets which modulate the detected lateral profile of the optical nonlinearity in a characteristic way. It is explained by the superposition of various signal components which are detected simultaneously due to the collinearity of our experiment. This effect is illustrated by calculations using a simplified model on the Hartree-Fock level.

In spatially and temporally resolved pump and probe experiments we observe a spatial beating which reflects the coherent dynamics of an excitonic wave packet.

A selfconsistent modeling of discharges obviously aims at a full description without requiring prior knowledge or diagnostic determination of any parameter beyond those actually chosen by an operator in the laboratory, i.e. beyond gas type and pressure, geometry and material of discharge tube, electric field frequency and voltage setting of power supply (for simplicity assumed to possess negligible internal resistance). This setting of power supply can be considered here in the case of surface wave (SW) sustained discharges as equivalent to the knowledge of electric field strength right at the beginning of the discharge column. The electric field strength and its spatial structure throughout the discharge is expected to be provided by the model as well as value and spatial structure of electron density. Actually simultaneous determination and (nonlinear) interdependence of electron density and electric field strength is a particular feature of truly selfconsistent modeling. This implies to go beyond the well known Schottky approximation for the electric field strength which may provide simple estimates, but is degenerate in the electron density and requires prior knowledge of its value. A model on the basis of ion and electron fluid equations can be condensed to two equations: the electron energy and the electron particle balance equation. The former connects electron temperature and electric field intensity (nonlocally in case of sufficient heat conductivity). The latter, balancing diffusion losses and ionization, should contain nonlinear contributions such as stepwise ionization or at high density recombination in order to avoid the above mentioned degeneracy in electron density. For selfconsistency these two equations of discharge physics have to be augmented by two equations of electrodynamical character: by the proper SW dispersion relation and wave power equation connecting Poynting flux with power transfer to the plasma. Here SW sustained discharges are chosen, which possess well defined electrodynamic boundary

Using a near-field optical antenna effect, we measure the homogeneous line shape of the surface-plasmon resonance in single gold nanoparticles. The surface-plasmon dephasing times extracted from the near-field spectra of the individual particles vary around 8 fs. This mean value agrees with calculations based on Mie theory, which neglect surface effects. Deviations of individual particles from this value are interpreted as being due to variations in the local nanoenvironment. We also observe double-peaked line shapes caused by electromagnetic coupling between close-lying particles.

We study the damping of the surface-plasmon resonance in gold nanoparticles that is caused by high-intensity optical excitation of the electron gas. Femtosecond pump-probe experiments are performed on gold nanoparticles embedded in dielectric matrices. Optical excitation of single-electron interband transitions leads to a pronounced broadening of the surface-plasmon line, which reflects the excitation-induced damping of the collective electron oscillation. The time evolution of the damping rate follows that of the electron temperature, showing that the damping rate is strongly influenced by transient variations in the electronic scattering rate. The dependence of the damping rate on the excitation energy shows evidence for fast relaxation of the optically generated d-band holes. In addition, cw transmission experiments performed with a scanning near-field optical microscope (SNOM) on single gold nanoparticles give access to the homogeneous line width of the surface plasmon.

Summary form only given.The near-field transmission spectra for a series of individual Au particles were taken. We find that the homogeneous linewidths and the spectral positions of the surface plasmon (SP) resonance vary slightly from particle to particle and thus are not always reproducible by application of Mie theory using bulk values for the dielectric function of Au. Surface scattering events and possibly also quantum size effects might contribute to the SP lineshape opening up the exciting possibility of sensoring the nano-environment of a single Au particle.

High quality quantum dots have been fabricated by using self-organized InP islands as stressors. The tensile strain due the islands creates local potential minima in an InGaAs/GaAs quantum well under the islands, and confines both electrons and holes into these minima. The ground state emission from the dots is redshifted by up to 105 meV from the quantum well emission due to this lateral confinement potential, and clearly resolved emission peaks are observed from the excited states. From the time-resolved photoluminescence measurements an interlevel relaxation time of 0.6 ns between the first excited state and the ground state and a radiative lifetime of 0.9 ns for the quantum dot ground state are obtained. Photoluminescence up-conversion measurements show subpicosecond onset of the dot luminescence at high excitation densities, suggesting that Coulomb scattering is responsible for the fast capture process. A large Zeeman splitting of the higher angular momentum states is observed in a magnetic field perpendicular to the sample surface.

Stressor-induced InxGa1-xAs quantum dot structures of high structural quality allow a detailed experimental investigation of carrier relaxation between distinct zero-dimensional quantized states. Time-resolved photoluminescence studies combined with appropriate model calculations show that state filling effects, Coulomb scattering, and acoustic phonon scattering determine the relaxation scenario in a way characteristic for a zero-dimensional electronic system. These investigations allow a quantitative estimation of the inter-dot-level relaxation rates mediated by (i) Coulomb scattering and (ii) acoustic phonon scattering.

Ultrafast laser spectroscopy has been used extensively to study carrier relaxation phenomena in semiconductors and semiconductor nanostructures. Accordingly, several physical issues of the carrier thermalization and recombination scenario after optical excitation are well understood. This is particularly true for many III-V quantum well structures. However, there is a basic problem when using light-matter interaction to study carrier relaxation in crystals. As a consequence of (i) the conservation law for the total momentum and (ii) the vanishing momentum of visible light as compared to the extension of the Brillouin-zone only electron-hole (e-h) pair transitions with vanishing total wavevector (K→=0) can be excited and detected, provided no other quasi-particle carrying momentum is involved in the optical transition.

We perform time-resolved photoluminescence experiments to study carrier relaxation in strain-induced (GaIn)As quantum dots. A sub-picosecond onset of the photoluminescence from the lowest quantum-dot transition after optical excitation of higher-energetic barrier states is observed, which shows that carrier capture into the quantum-dot ground state can be extremely fast at high carrier densities. The recombination lifetime of the lowest quantum-dot transition and the interlevel relaxation time are extracted from the photoluminescence decay.