Search results for "reduction"
showing 10 items of 2058 documents
Vibrational Properties of CuO and Cu4O3 from First-Principles Calculations, and Raman and Infrared Spectroscopy
2012
International audience; A combined experimental and theoretical study is reported on the vibrational properties of tenorite CuO and paramelaconite Cu4O3. The optically active modes have been measured by Raman scattering and infrared absorption spectroscopy. First-principles calculations have been carried out with the LDA+U approach to account for strong electron correlation in the copper oxides. The vibrational properties have been computed ab initio using the so-called direct method. Excellent agreement is found between the measured Raman and infrared peak positions and the calculated phonon frequencies at the Brillouin zone center, which allows the assignment of all prominent peaks of the…
Praktyczne zarządzanie energią w przedsiębiorstwie
2016
Zarządzanie energią w przedsiębiorstwie może być skutecznym narzędziem do zmniejszenia zapotrzebowania energii pierwotnej oraz końcowej przedsiębiorstwa, a tym samym poprawy konkurencyjności firmy. Niniejsza praca przedstawia przykłady zarządzania energią zastosowane w przedsiębiorstwach oraz efekty przeprowadzonych audytów energetycznych wskazujących na poprawę efektywności energetycznej. W pracy zestawiono z jednej strony niektóre wymagania normy PN-EN ISO 50001:2011,kupiające się na przeglądzie energetycznym i monitorowaniu zużycia energii oraz wymagania Ustawy o efektywności energetycznej z 20 maja 2016 wymagającej przeprowadzenia audytu energetycznego przedsiębiorstwa, a drugiej strony…
Modelling spatial and spectral systematic noise patterns on CHRIS/PROBA hyperspectral data
2006
In addition to typical random noise, remote sensing hyperspectral images are generally affected by non-periodic partially deterministic disturbance patterns due to the image formation process and characterized by a high degree of spatial and spectral coherence. This paper presents a new technique that faces the problem of removing the spatial coherent noise known as vertical stripping (VS) usually found in images acquired by push-broom sensors, in particular for the Compact High Resolution Imaging Spectrometer (CHRIS). The correction is based on the hypothesis that the vertical disturbance presents higher spatial frequencies than the surface radiance. The proposed method introduces a way to…
Correction of systematic spatial noise in push-broom hyperspectral sensors: application to CHRIS/PROBA images
2008
Hyperspectral remote sensing images are affected by different types of noise. In addition to typical random noise, nonperiodic partially deterministic disturbance patterns generally appear in the data. These patterns, which are intrinsic to the image formation process, are characterized by a high degree of spatial and spectral coherence. We present a new technique that faces the problem of removing the spatially coherent noise known as vertical striping, usually found in images acquired by push-broom sensors. The developed methodology is tested on data acquired by the Compact High Resolution Imaging Spectrometer (CHRIS) onboard the Project for On-board Autonomy (PROBA) orbital platform, whi…
Diffusion equations with negentropy applied to denoise mammographic images.
2006
Mammography is a radiographic technique used for the detection of breast lesions. The analysis of the digital image normally requires a previous application of filters as a preprocessing step to reduce the noise level of the image, while preserving important details to carry out a suitable diagnostic. In the literature, there are a large amount of denoising techniques applied to different medical images. In this work we have studied the performance of a diffusive filter with a stopping condition based on the statistical concept of negentropy, applied to denoise mammographic images. The negentropy has been succesfully prove with other denoising methods as independent component analysis by th…
Immediate and flapless implant insertion and provisionalization using autogenous bone grafts in the esthetic zone: 5-year results.
2017
Objectives As the 2-year results for immediately inserted and provisionalized implants have been reported, it remained an open issue, whether the initially high success rates and the esthetic outcome remain stable for longer observation periods. Therefore, this prospective study examines the 5-year hard and soft tissue changes at implants placed in the anterior maxilla. Material and methods Meanwhile, 37 microthreaded implants were placed in 21 patients into extraction sockets with and without facial bone deficiencies by a flapless approach. Facial gaps and bony defects were grafted with autogenous bone chips. The implants were immediately provisionalized. The primary outcome parameters wer…
Disulfide stress and its targets in acute pancreatitis
2014
Under physiological conditions, the balance between ROS production and removal properly maintains the intracellular redox-sensitive signaling as well as the appropriate status of protein thiols and disulfides. However, inflammation among other factors can modify this balance causing a rapid increase in intracellular ROS levels and hence thiol oxidation, eventually leading to oxidative stress. In the case of acute pancreatitis, both redox signaling and oxidative stress seem to contribute to the progression of the severe form of the disease. In this review we will focus on the reversible oxidation of protein cysteines during the course of acute pancreatitis. We describe disulfide stress in an…
A new cell for the study of in situ chemical reactions using X-ray absorption spectroscopy
2005
An in situ cell for reductive and oxidative treatments at different temperatures that allows the possibility of recording data as a function of temperature has been designed and constructed for X-ray absorption experiments at the GILDA beamline BM08 of ESRF. The cell is linked to a mass quadrupole spectrometer providing control of the reaction gases and monitoring of the products. The apparatus allows measurements to be performed both in transmission and fluorescence geometry. The cell was tested by studying the CO oxidation reaction promoted by a Pt/ceria-zirconia-supported catalyst. The CO(2) yield is correlated with the structural results confirming the existence of a strong metal-suppor…
Assessing the efficiency of wastewater treatment plants in an uncertain context: a DEA with tolerances approach
2012
Abstract As the number of wastewater treatment plants (WWTPs) has increased, the economics associated with their management have become more relevant. The efficiency assessment is therefore a useful tool for cost reduction. For this purpose, Data Envelopment Analysis (DEA) is a highly suitable technique, since it is a holistic approach that aggregates performance indicators into a single index. However, one of the most common criticisms of DEA models is that information on uncertainty estimates is not provided. To overcome this limitation, we assess efficiency by using a DEA model with statistical tolerances for both inputs and outputs. This model is applied to a sample of Spanish WWTPs. Th…
Kinetics of the lipoperoxyl radical-scavenging activity of indicaxanthin in solution and unilamellar liposomes
2007
Abstract The reaction of the phytochemical indicaxanthin with lipoperoxyl radicals generated in methyl linoleate methanol solution by 2,20-azobis(2,4-dimethylvaleronitrile), and in aqueous soybean phosphatidylcholine unilamellar liposomes by 2,20-azobis(2- amidinopropane)hydrochloride, was studied. The molecule acts as a chain-terminating lipoperoxyl radical scavenger in solution, with a calculated inhibition constant of 3.63 £ 105M21 s21, and a stoichiometric factor approaching 2. Indicaxanthin incorporated in liposomes prevented lipid oxidation, inducing clear-cut lag periods and decrease of the propagation rate. Both effects were concentration-dependent, but not linearly related to the p…