To preserve urban vegetation land cover quality and mitigate its degradation is an important task for urban planning and
environmental management of Bucharest metropolitan area in Romania. Since vegetation land cover dynamics directly
affect the urban landscape characteristics and air quality, remote sensing represents an effective tool for vegetation land
cover quality assessment at regional scale. In particular, the use of satellite-based vegetation indices, like the NDVI
(Normalized Difference Vegetation Index), can provide important information when evaluating Urban Vegetation Cover
Quality (UVCQ) patterns in urban areas, which represents one of the most sensitive landscape components to urban
environmental degradation. This paper proposes an approach for the regional-scale assessment of UVCQ by means of an
NDVI-based (functional) indicator using freely available time series MODIS Terra/Aqua (Moderate Resolution Imaging
Spectroradiometer) satellite data. As a case study, Bucharest metropolitan area landscape experiencing climate and
anthropogenic changes, increasing human pressure and high vulnerability to degradation was chosen. As UVCQ
indicator, the NDVI-based vegetation cover classification was produced by means of unsupervised multivariate statistical
techniques and compared with spatio-temporal changes during 2002-2012 period, statistical indicators, and field data
related to land cover management observed in the study area. Results demonstrate that the obtained remotely sensed
vegetation land cover characterization can be effectively considered as a proxy of the UVCQ status of the examined area.
Due to the large availability over time and low cost of satellite images, the proposed approach can be applied to wider
urban/periurban regions, to monitor vegetation quality and indirectly control vegetation land degradation.
The aim of the paper is to analyze the fluorescence characteristics of the neritic water on the Romanian Black Sea coast
under anthropogenic influences. A fluorescence LIDAR, based on excimer (308 nm) and a dye laser (367, 460 nm) was
used in order to map the Dissolved Organic Matter (DOM) and chlorophyll variations in a marine area. Onboard ship
campaign was performed during spring time to evidence the algal blooming. Physicochemical parameters of water and
chlorophyll concentration were determined also by laboratory measurements of collected samples. The organic
compounds and phytoplankton were characterized based on Laser Induced Fluorescence (LIF) and Raman scattering.
Highly polluted areas were noted and mapped along the ship trajectory.
The paper presents preliminary laboratory results in an investigation by laser induce fluorescence of the
environmental effects on the seawater. The aim of the paper was to analyze the fluorescence of the polluted water in the
south area of the Romanian Black Sea coast. The characteristics of the spectral fluorescence of water (intensity, shape,
bands) were analysed in connection with the extraction area and pollutants type. The fluorescence spectra are compared
with those of natural seawater samples measured at different laser excitation wavelengths (266 nm, 355 nm and 532 nm).
Fluorescence spectra of DOM (Dissolved Organic Matter), oil products (OP) and phytoplankton were characterized in
correlation with the band of the water Raman scattering and by their specific fluorescence decay. Seawater physicochemical
parameters and chlorophyll concentration were taking into account in seawater pollution analysis.
Spectroscopic diagnostics, using intensified high speed CCD camera, was applied to study the arc dynamics in low voltage circuit breakers, in vacuum and in air. Time-resolved emission spectroscopy of the vacuum arc plasma, generated during electrode separation, provided information about the interruption process. The investigations were focused on the partial unsuccessful interruption around current zero. Absorption spectroscopy, in a peculiar setup, was used in order to determine the metallic atoms densities in the interelectrode space of a low voltage circuit breaker, working in ambient air.
The photoluminescence (PL) decay measurements were performed on porous silicon films. It was observed that the two components of PL, one of them fast (ns) and the other slow (microsecond(s) or ms sometimes) have different contributions to PL signal, depending on the wavelength of the excitation light. The slow component of PL was in details investigated. Time decay cures for different excitation (337.1 nm, 470 nm, and 550 nm) and emission (550, 650, 700, 800 and 860 nm) wavelengths and also for different excitation intensities were taken. All decay curves were fitted with a stretched exponential. The slow component of PL was proposed to be attributed to the radiative recombination on surfaces.
The influence of the thermal annealing on the optical properties of the porous silicon films was revealed by photoluminescence (PL) and spectroellipsometric measurements. As result of 200 degree(s)C annealing small changes of the dielectric functions could be understood by desorption process of some molecules from Si skeleton surface. Strong changes of PL and dielectric function spectra after the thermal annealing at high temperatures (up to 800 degree(s)C) were explained by the change of the passivation from hydrogen to oxygen and then the beginning of the oxidation process. This oxidation process produces the disappearance of the PL slow component, an important enhancement of PL (2-3 orders of magnitude) and a shift of maximum position to higher energies, corresponding to the thinning of the nanocrystallites from the Si skeleton.
The thin titanium nitride films deposited on glass in a planar d.c. magnetron configuration have been optically investigated. The influence of the nitrogen partial pressure, substrate bias and film thickness as deposition parameters on the transmission (Vis) and the reflectance (Vis, FIR) spectra of the samples was studied. The analysis of surface properties of TiN films was also made by spectroscopic ellipsometry for different deposition conditions. The data were compared with the similar spectrum of a gold evaporated film.