Neural network controlled three-phase four-wire shunt active powerfilter

A three-phase four-wire shunt active power filter for harmonic mitigation and reactive power compensation in power systems supplying nonlinear loads is presented. Three adaptive linear neurons are used to tackle the desired three-phase filter current templates. Another feedforward three-layer neural network is adopted to control the output filter compensating currents online. This is accomplished by producing the appropriate switching patterns of the converter's legs IGBTs. Adequate tracking of the filter current references is obtained by this method. The active filter injects the current required to compensate for the harmonic and reactive components of the line currents, Simulation results of the proposed active filter indicate a remarkable improvement in the source current waveforms. This is reflected in the enhancement of the unified power quality index defined. Also, the filter has exhibited quite a high dynamic response for step variations in the load current, assuring its potential for real-time applications

Evidence for two-phase regions in BST thin films from capacitance-voltage data

The Curie-Weiss plots of reciprocal dielectric constant versus temperature, in Ba0.5Sr0.5TiO3 films grown onto SrRuO3 lower electrodes by pulsed-laser deposition, show two minima below film thicknesses of 280 nm. This double minima implies possible mixed phases in the thin films. A graphical plot of capacitance for decreasing dc voltage versus that of increasing dc voltage shows a well-defined triangular shape for both Pb(Zr0.4Ti0.6)O-3 and SrBi2Ta2O9 thin films. However, for a 175-nm-thick Ba0.5Sr0.5TiO3 thin film, the plot shows an overlapping of two triangles, suggesting mixed phases. This graphical method appears to be effective in detecting structural subtleties in ferroelectric capacitors.

Space and phase resolved plasma parameters in an industrial dual-frequency capacitively coupled radio-frequency discharge

The dynamics of high energetic electrons (>= 11.7 eV) in a modified industrial confined dual-frequency capacitively coupled RF discharge (Exelan, Lam Research Inc.), operated at 1.937 MHz and 27.118 MHz, is investigated by means of phase resolved optical emission spectroscopy. Operating in a He-O-2. plasma with small rare gas admixtures the emission is measured, with one-dimensional spatial resolution along the discharge axis. Both the low and high frequency RF cycle are resolved. The diagnostic is based on time dependent measurements of the population densities of specifically chosen excited rare gas states. A time dependent model, based on rate equations, describes the dynamics of the population densities of these levels. Based on this model and the comparison of the excitation of various rare gas states, with different excitation thresholds, time and space resolved electron temperature, propagation velocity and qualitative electron density as well as electron energy distribution functions are determined. This information leads to a better understanding of the dual-frequency sheath dynamics and shows, that separate control of ion energy and electron density is limited.

Phase and space resolved optical emission spectroscopic investigations of an inductively coupled RF plasma using an imaging acousto-optic spectrometer

A novel acousto-optic spectrometer (IfU Diagnostic Systems GmbH) for 2-dimensional (2D) optical emission spectroscopy with high spectral resolution has been developed. The spectrometer is based on acousto-optic tuneable filter technology with fast random wavelength access. Measurements for characterisation of the imaging quality, the spatial resolution, and the spectral resolution are presented. The applicability for 2D-space and phase resolved optical emission spectroscopy (2D-PROES) is shown. 2D-PROES has been applied to an inductively coupled plasma with radio frequency excitation at 13.56 MHz.

Prospects of phase resolved optical emission spectroscopy as a powerful diagnostic tool for RF-discharges

Phase resolved optical emission spectroscopy (PROES) bears considerable potential for diagnostics of RF discharges that give detailed insight of spatial and temporal variations of excitation processes. Based on phase and space resolved measurements of the population dynamics of excited states several diagnostic techniques have been developed. Results for a hydrogen capacitively coupled RF (CCRF) discharge are discussed as an example. The gas temperature, the degree of dissociation and the temporally and spatially resolved electron energy distribution function (EEDF) of energetic electrons (>12eV) are measured. Furthermore, the pulsed electron impact excitation during the field reversal phase, typical for hydrogen CCRF discharges, is exploited for measurements of atomic and molecular data like lifetimes of excited states, coefficients for radiationless collisional de-excitation (quenching coefficients), and cascading processes from higher electronic states.

A Phase I and Pharmacokinetic Study of OSI-7904L, a Liposomal Thymidylate Synthase Inhibitor in Combination with Oxaliplatin in Patients with Advanced Colorectal Cancer.

OSI-7904L is a liposomal formulation of a potent thymidylate synthase (TS) inhibitor. This phase I study evaluated the safety, tolerability and pharmacokinetics (PK) of OSI-7904L administered in combination with oxaliplatin every 21 days in patients with advanced colorectal carcinoma. METHOD: A 3+3 study design was utilized at predefined dose levels. Polymorphisms in the TS enhancer region and XPD enzyme were investigated as potential predictors of efficacy and toxicity. RESULTS: Fourteen patients received 76 cycles of treatment. At the highest dose level (OSI-7904L 9 mg/m(2), oxaliplatin 130 mg/m(2)) investigated, one of nine patients experienced dose-limiting toxicity of grade 3 oral mucositis with cycle 1 and five further patients required dose reductions. The toxicity profile of stomatitis, diarrhea, nausea, fatigue, sensory neuropathy and skin rash was consistent with that expected for a TS inhibitor/oxaliplatin combination regimen. PK analysis showed high interpatient variability with no detectable interaction between OSI-7904L and oxaliplatin. Partial radiological responses were documented in two patients. CONCLUSIONS: The recommended regimen for further investigation is OSI-7904L 9 mg/m(2) and oxaliplatin 130 mg/m(2).

A phase Ib trial of Docetaxel, Carboplatin and Erlotinib in ovarian, fallopian tube and primary peritoneal cancers.

The safety and maximum tolerated dose (MTD) of erlotinib with docetaxel/carboplatin were assessed in patients with ovarian cancer. Chemonaive patients received intravenous docetaxel (75 mg m(-2)) and carboplatin (area under the curve 5) on day 1 of a 3-week cycle, and oral erlotinib at 50 (cohort 1), 100 (cohort 2a) or 75 mg day(-1) (cohort 2b) for up to six cycles. Dose-limiting toxicities were determined in cycle 1. Forty-five patients (median age 59 years) received treatment. Dose-limiting toxicities occurred in 1/5/5 patients (cohorts 1/2a/2b). The MTD of erlotinib in this regimen was determined to be 75 mg day(-1) (cohort 2b; the erlotinib dose was escalated to 100 mg day(-1) in 11 out of 19 patients from cycle 2 onwards). Neutropaenia was the predominant grade 3/4 haematological toxicity (85/100/95% respectively). Common non-haematological toxicities were diarrhoea, fatigue, nausea and rash. There were five complete and seven partial responses in 23 evaluable patients (52% response rate). Docetaxel/carboplatin had no measurable effect on erlotinib pharmacokinetics. In subsequent single-agent maintenance, erlotinib was given at 100-150 mg day(-1), with manageable toxicity, until tumour progression. Further investigation of erlotinib in epithelial ovarian carcinoma may be warranted, particularly as maintenance therapy

A computational model for the cooling phase of injection moulding

This paper discusses the approaches and techniques used to build a realistic numerical model to analyse the cooling phase of the injection moulding process. The procedures employed to select an appropriate mesh and the boundary and initial conditions for the problem are discussed and justified. The final model is validated using direct comparisons with experimental results generated in an earlier study. The model is shown to be a useful tool for further studies aimed at optimising the cooling phase of the injection moulding process. Using the numerical model provides additional information relating to changes in conditions throughout the process, which otherwise could not be deduced or assessed experimentally. These results, and other benefits related to the use of the model, are also discussed in the paper. © 2007 Elsevier B.V. All rights reserved.