New Raman spectrometer using a digital micromirror device and a photomultiplier tube detector for rapid on-line industrial analysis. Part II: Choice of analytical methods

In this paper, the performances of four improved analytical methods (backward stepwise selection of peak intensities, sum of characteristic peaks of a component, moving window partial least squares, and genetic algorithms) using wavelength selection for the analysis of xylene mixtures by Raman spectroscopy are tested for further use on the new "digital micromirror device associated with a photomultiplier tube" Raman spectrometer. It is shown that the errors of prediction using only a few selected points (from 4 to 49 depending on the method) are almost the same as when using the whole spectral range (1050 points). Compared to the last two methods, the "backward stepwise selection of peak intensities" and "sum of characteristic peaks of a component" methods are robust under industrial conditions and appear to be well suited for chemical quantitative analysis with the new Raman spectrometer, which allows the measurements of the total intensity to be made simultaneously for a number of pre-selected frequencies. Results show that the errors of prediction can be near to or even lower than 2%.     

Uncertainties associated to measurements of inherent optical properties in natural waters

Monte Carlo simulations are used to explain and quantify the errors in inherent optical properties (IOPs) (absorption and attenuation coefficients) measured using the WET Labs AC-9 submarine spectrophotometer, and to assess correction algorithms. Simulated samples with a wide range of IOPs encountered in natural waters are examined. The relative errors on the measured absorption coefficient are in general lower than 25%, but reach up to 100% in highly scattering waters. Relative errors on attenuation and scattering coefficients are more stable, with an underestimation mainly driven by the volume scattering function. The errors in attenuation and scattering spectral shapes are small.     

Electro‐optical study of a ×1024 concentrator photovoltaic system

Concentrator photovoltaic (CPV) systems are one of the most promising technologies for future energy supply. Several studies reported the interest of using a Fresnel lens coupled with a secondary optical element in such a system. For high concentration factor, the optimization of the optical configuration plays a key role regarding electrical performances. On the other hand, the thermal management of the solar cell is also critical to ensure a better module efficiency. This paper presents a study of a ×1024 CPV system performances and a methodology for estimating the optical chain efficiency, the cell temperature impact and the alignment requirements. Module efficiencies were then measured as a function of the cell temperature and correlated to optical performances through current‐tension characterizations under real solar illumination conditions and the estimation of the power density received by the solar cell. The system yield was up to 27% for a cell temperature around 30 °C, confirming that high concentration ratio should be of great interest in the near future. A 1D model was also developed in order to quantify the possible improvements of this CPV system. Using a solar cell with an efficiency of 36.7% at ×600, we then demonstrated that the ×1024 CPV system could reach up to 30% in standard test conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

State estimation of discrete event systems for RUL prediction issue

This paper concerns Remaining Useful Life (RUL) estimation of discrete event systems. For that purpose, physics-based models with partially observed stochastic Petri nets are used to represent the system and its sensors. The advantage of the proposed modelling approach is to provide a realistic representation of the system, including the interaction between the normal behaviours and the failure processes. From the proposed modelling and collected measurements, timed trajectories, which are consistent with the observations, are obtained. Based on the event dates, our approach consists in evaluating the probabilities of the consistent behaviours using probabilistic models. State estimation is obtained as a consequence. The most probable future degradations, from the current state, are then considered and a method for fault prognosis is presented. Finally, the prognosis result is used to estimate the RUL as a time interval. A case study is proposed to show the applicability of the proposed method.     

blue-c Räumlich-immersive Projektions- und 3D Video-Portale für Telepräsenz. Teil 2: Kommunikation, Systemleistung und Anwendungen

Ohne Zusammenfassung     

Disruption of Six Novel Yeast Genes Reveals Three Genes Essential for Vegetative Growth and One Required for Growth at Low Temperature

We describe here the construction of six deletion mutants and their basic phenotypic analysis. Six open reading frames (ORFs) from chromosome X, YJR039w, YJR041c, YJR043c, YJR046w, YJR053w and YJR065c, were disrupted by deletion cassettes with long (LFH) or short (SFH) flanking regions homologous to the target locus. The LFH deletion cassette was made by introducing into the kanMX4 marker module two polymerase chain reaction (PCR) fragments several hundred base pairs (bp) in size homologous to the promoter and terminator regions of a given ORF. The SFH gene disruption construct was obtained by PCR amplification of the kanMX4 marker with primers providing homology to the target gene. The region of homology to mediate homologous recombination was about 70 bp. Sporulation and tetrad analysis revealed that ORFs YJR041c, YJR046w and YJR065c are essential genes. Complementation tests by corresponding cognate gene clones confirmed this observation. The non-growing haploid segregants were observed under the microscope. The yjr041cΔ haploid cells gave rise to microcolonies comprising about 20 to 50 cells. Most yjr046wΔ cells were blocked after one or two cell cycles with heterogeneous bud sizes. The yjr065cΔ cells displayed an unbudded spore or were arrested before completion of the first cell division cycle with a bud of variable size. The deduced protein of ORF YJR065c, that we named Act4, belongs to the Arp3 family of actin-related proteins. Three other ORFs, YJR039w, YJR043c and YJR053w are non-essential genes. The yjr043cΔ cells hardly grew at 15°C, indicating that this gene is required for growth at low temperature. Complementation tests confirmed that the disruption of YJR043c is responsible for this growth defect. In addition, the mating efficiency of yjr043cΔ and yjr053wΔ cells appear to be moderately a ffected. © 1997 John Wiley & Sons, Ltd.     

Comparison of the influence of corneo-scleral and scleral lenses on ocular surface and tear film metrics in a presbyopic population

Purpose

To assess and compare the effect of the corneo-scleral lenses (C-ScL) and scleral lenses (ScL) on tear film parameters and central corneal thickness (CCT) in healthy presbyopic subjects.

Gradient-based controllers for timed continuous Petri nets

This paper is about control design for timed continuous Petri nets that are described as piecewise affine systems. In this context, the marking vector is considered as the state space vector, weighted marking of place subsets are defined as the model outputs and the model inputs correspond to multiplicative control actions that slow down the firing rate of some controllable transitions. Structural and functional sensitivity of the outputs with respect to the inputs are discussed in terms of Petri nets. Then, gradient-based controllers (GBC) are developed in order to adapt the control actions of the controllable transitions according to desired trajectories of the outputs.