Silviu Gurlui

Universitatea Alexandru Ioan Cuza din Iasi · Faculty Of Physics

Nowadays, trace metal contamination within urban atmospheres is a significant and concerning global issue. In the present study, two synanthropic bird species, namely, the feral pigeon (Columba livia f. domestica) and the rook (Corvus frugilegus), were employed as bioindicators to assess the atmospheric trace metal pollution in Iasi City, Romania....

Crystalline silver thin layers were obtained using high-energy pulsed laser ablation without the heating of the deposition substrate. The fluid Plateau–Rayleigh (PRI), Rayleigh–Taylor (RTI), and Richtmyer–Meshkov (RMI) instabilities, as well as the crown splash induced during the pulsed laser deposition (PLD) in the high energy regime, resulting in...

Crystalline silver thin layers were obtained by high-energy pulsed laser ablation without heating of the deposition substrate. The fluid Plateau-Rayleigh (PRI), Rayleigh – Taylor (RTI) and Richtmyer – Meshkov (RMI) instabilities, as well as crown splash induced during pulsed laser deposition (PLD) in high energy regime, resulting in ring and pearl...

This work studies the technological preparation conditions, morphology, structural characteristics and elemental composition, and optical and photoluminescent properties of GaSe single crystals and Eu-doped β–Ga2O3 nanoformations on ε–GaSe:Eu single crystal substrate, obtained by heat treatment at 750–900 °C, with a duration from 30 min to 12 h, in...

On the 23rd of September 2022, a small intensive aquaculture unit populated with rainbow trout (Oncorhynchus mykiss) reported increased mortality in adults and juvenile fish. The unit comprised 12 enclosed concrete basins with a capacity of ten cubic meters of water, populated with 150 kg of fish each. Fish were subjected to a clinical examination...

Dual-pulsed (DPL) laser deposition using oyster shells as targets was studied in order to find out if this method can replace the use of high-power pulsed lasers. Aspects related to changes in the morphological structure of the thin layer but also to the chemical composition of the obtained thin layer were analyzed and compared with the target as w...

Influences of landfills on the surrounding waters have been studied in the neighbourhood of an urban area. Analytical and spectroscopic methods were used to investigate the waters of a canal situated in the neighbourhood of the landfill. Dangerous chemical compounds have been identified in the water as pollutants resulting from the physico-chemical...

This work addresses the global sustainable development concerns by investigating the enhancement of piezo-photocatalytic efficiency in bismuth ferrite-based thin films synthesized using reactive high-power impulse magnetron sputtering. The influence of substrate type and Cr addition on structural, optical and ferroelectric properties of bismuth fer...

GaSxSe1−x solid solutions are layered semiconductors with a band gap between 2.0 and 2.6 eV. Their single crystals are formed by planar packings of S/Se-Ga-Ga-S/Se type, with weak polarization bonds between them, which allows obtaining, by splitting, plan-parallel lamellae with atomically smooth surfaces. By heat treatment in a normal or water vapo...

TiO2–SiO2 nanocomposite thin films have gained the attention of the scientific community due to their unique physical and chemical properties. In this paper, we report on the fabrication and characterization of a TiO2–SiO2 nanocomposite disk-shaped target. The target was used for the deposition of TiO2–SiO2 nanocomposite thin films on fluorine-dope...

The study in this paper was carried out as a result of the observation of pollution phenomena and foaming effects associated with anthropogenic activities, including street cleaning activity. The processes of dust binding used in order to reduce PM10 and PM 2.5 pollution has been proven to be inefficient, and even contributing to pollution with par...

Bismuth ferrite based thin films were grown by RF magnetron sputtering under different experimental conditions. The effects of substrate temperature, Ar:O2 mass flow ratio and gas mixture pressure on the films’ microstructure, phase evolution, optic, ferroelectric and magnetic properties were systematically investigated. The structural analysis res...

The study in this paper presents a new material that was produced as a thin film by the Pulsed Laser Deposition technique (PLD) using a 532 nm wavelength and 150 mJ/pulse laser beam on the hemp stalk as target. The analyses performed by spectroscopic techniques (Fourier Transform Infrared Spectroscopy—FTIR, Laser Induced Fluorescence Spectroscopy—L...

The addition of rare earth elements the ferrites can lead to significant changes in structural, magnetic and electric properties of bulk materials and also of thin films deposited by pulsed laser deposition. The present study relies on the analysis of the laser induced plasma of three sets of cobalt ferrite targets doped with various concentrations...

In this work, optical, including photoluminescence and photosensitivity, characteristics of micrometer-sized flexible n (p)–InSe/In2O3 heterojunctions, obtained by heat treatment of single-crystalline InSe plates doped with (0.5 at.%) Cd (Sn), in a water-vapor- and oxygen-enriched atmosphere, are investigated. The Raman spectrum of In2O3 layers on...

High-power laser irradiation interaction with natural polymers in biocomposites and Laser-Induced Chitin Deacetylation (LICD) was studied in this work, in order to produce thin films consisting of chitosan composite. The new method can lead to a cutting-edge technology, as a response to the concern regarding the accumulation of “natural biological...

This research was aimed at investigating the Saharan dust cloud recorded on 11–12 May 2020, by AERONET AOD stations in Italy, Austria, Slovakia, Poland, Ukraine, and Romania and deter-mining whether it affected the area of the Republic of Moldova. During this period, the Chisinau AERONET monitoring site was not operational. The incentive for the in...

The aim of this in vitro study was to evaluate the effect of hydrochloric acid associated with the abrasive effect of toothbrushing on the surface condition of three flowable composite resins used for direct restoration. Seventy samples of each composite resin: Grandio Flow (VOCO, Germany)—group A, Filtek Ultimate Flow (3M-ESPE, MN, USA)—group B, G...

In this paper, several researches were undertaken related to a violent phenomenon, characterized by a sonic boom, felt on an area of at least 500 km2, shortly followed by the fall of rock fragments that were then recovered from the ground. These presented different appearance characteristics from those of the materials and rocks specific to the res...

Abstract Study of physico – chemical phenomena and processes that may occur during laser ablation, plasma plume expansion from target to support and finally deposition on special supports was performed on a nonhomogeneous target. The target is made of silver with impurities of iron and nickel. Experimental study was assisted and completed by COMSOL...

In the study presented in this paper, the results obtained by producing nanocomposites consisting of a silver citrate thin layer deposited on hemp fiber surfaces are analyzed. Using the pulsed laser deposition (PLD) method applied to a silver target with impurities of nickel and iron, the formation of the silver citrate film is performed in various...

In this paper, we report on the effect of titanium dioxide (TiO2) target sintering temperature on the morphological and optical properties of amorphous titanium dioxide thin films synthesized by pulsed laser deposition (PLD) on indium tin oxide (ITO) glass substrate and subsequently heat-treated in air at low temperature (150 °C). Three types of ta...

A new possible method to produce a transdermal patch is proposed in this paper. The study refers to the pulsed laser deposition method (PLD) applied on turmeric target in order to obtain thin layers. Under high power laser irradiation of 532 nm wavelength, thin films containing curcuminoids were obtained on different substrates such as glass and qu...

The paper presents a series of methods and techniques of investigation used in the valorisation of the special avifaunistic protection areas (SPA), which also integrate historical monuments, included in the list of sites of community importance (SCI) belonging to the Natura 2000 ecological network in Iasi county. One of the analysed aspects consist...

Effects of 532 nm and 320 mJ laser beam on aqueous solution of Reactive Blue 21 (RB21), a copper based on reactive dye, have been studied in both presence and absence of garnet gemstone with the aim to receive a proper coating of the hemp fibers contained in the yarns of a woven texture while reducing the dyeing time compared to the classic exhaust...

Urban air/environmental pollution as a major concern of contemporary civilization, substantially affecting the health of the residents, requires identification of both physico-chemical specificity and generating sources. Particle matter (PM) monitored in the atmosphere should be associated to their chemical composition that allows identification of...

In the herein paper, the possibility of obtaining spontaneous surface relief gratings (SSRGs) on azo-polymeric film surfaces, using a single laser beam of 1.13 mJ energy in pulse mode, was investigated. Chain rigidity is essential to have SSRG of reasonable quality so three azo modified polymers, with different main-chain rigidity, were considered:...

Experimental and theoretical investigations were performed on transient plasmas generated by ns-laser ablation on ten mineral samples. Space-and time-resolved optical emission spectroscopy and ICCD fast camera imaging were implemented to understand the kinetics of the ablated particles and how the samples physical properties can be reflected by tho...

Two different polyimide structures were synthesized by two-step polycondensation reaction in solution, in the first step using equimolar amounts of one of two aromatic diamine (DDM or MMDA) and one dianhydride (6HDA) in N,N-dimethylacetamide (DMAc) to obtain the poly(amic acids), followed in the second step by thermal imidization. In order to obtai...

Transient plasmas generated by ns - laser ablation of graphite in air have been investigated by complementary optical diagnosis techniques to study complex multiple structures generated in carbon laser produced plasmas (C-LPP) during the expansion phase. The overall emission was investigated by ICCD fast camera imaging and revealed the structuring...

The optimization of the pulsed laser deposition process was attempted here for the generation of hydroxyapatite thin films. The deposition process was monitored with an ICCD (Intensified Coupled Charged Device) fast gated camera and a high-resolution spectrometer. The global dynamics of the laser produced plasma showed a self-structuring into three...

The properties of pulsed laser deposited of Ni60Ti40 shape memory thin films generated in various deposition conditions were investigated. In-situ plasma monitoring was implemented by means of space-and time-resolved optical emission spectroscopy, and ICCD fast camera imaging. Structural and chemical analyses were performed on the thin films using...

Several surface investigation techniques, such as X-ray diffraction (XRD), EDX, and optical microscopy, were employed in order to describe the mineral contents in several geomaterials. Space and time resolved optical emission spectroscopy was implemented to analyze the plasma generated by the laser–geomaterial interaction. The values of the plasma...

Understanding the fundamental mechanisms behind industrial laser-based technologies represents one the cornerstones of the development and tailoring of new materials. With the thin-film deposition using laser ablation being one of the most important techniques for obtaining complex materials with controllable stoichiometry, there is a high request...

The influence of rare earth (RE = Dy, Gd, Yb) ion doping on the structural, magnetic and optical properties of cobalt ferrite thin films was studied. CoFe2-xRExO4 (x = 0.01; 0.03; 0.05; 0.1; 0.2; 0.3) films were obtained by pulsed laser deposition on silicon substrates. The X-ray diffraction and Raman spectroscopy results on the bulk materials, whi...

Ge-Sb-Te thin films were obtained by ns-, ps-, and fs-pulsed laser deposition (PLD) in various experimental conditions. The thickness of the samples was influenced by the Nd-YAG laser wavelength, fluence, target-to-substrate distance, and deposition time. The topography and chemical analysis results showed that the films deposited by ns-PLD reveale...

A new method to produce keratin thin films using Pulsed Laser Deposition (PLD) is studied herein in order to obtain composite materials with application for medical purposes while being investigated α-keratin physico-chemical behavior during compared procedures. The novelty of the method consists in using direct wool fibers and horn bulk as targets...

The aim of the study presented in this paper is to investigate and evaluate the water contamination during different episodes of pollution, with different symptoms that proved to be generated by the same contaminant source, the soot. FTIR investigation on diesel cars muffler-collected compound proved that the soot is a composite structure where agg...

We investigate the oscillatory regimes of the Langmuir probe current recorded for the electrical characterization of femtosecond laser-produced plasma. The influence of metallic target biasing, which can perturb the ambipolar electric field generated through the charge separation at early stages of the expansion, is also studied. Two distinct behav...

The aim of this study is to evaluate the role of the weather conditions and local climate on the temporal and spatial variability of particulate matters (PM 10) in Iași city which is facing major pollution problems in the recent years. Daily data from 4 monitoring stations of Environmental Protection Agency-Iași-for main weather parameters and part...

The formation and dynamics of Al and Ag–Ni–Fe plasmas were studied through ICCD imaging and space- and time-resolved optical emission spectroscopy techniques. The experiments were conducted in pulsed laser deposition configuration and the surface topography and chemical composition of the obtained thin films were analyzed. For both targets, a split...

The problem of plasma self-structuring during the pulse laser deposition of multicomponent materials is discussed from both theoretical and experimental perspectives. A non-differential mathematical model was used to build the set of equation to characterize a complex fluid, assimilated with the laser produced plasmas in the fractal paradigm. Numer...

Urban air quality has changed rapidly in recent years, that requiring new research focused on the effects of pollution, both on the environment and on human health, as well as on apparent changes in building surfaces, including historical ones. As is known, permanent exposure to the atmosphere in the urban environment causes degradation processes o...

A big amount of mineral dust from Sahara desert, about half of the total annual amount is lifted by the wind from arid surfaces and transported around the Europe every year. The physical and chemical properties of the mineral dust are needed for a better analysis of remote sensing observations and are of fundamental importance in understanding dust...

A big amount of mineral dust from Sahara desert, about half of the total annual amount are lifted by the wind from arid surfaces and transported around the Europe every year. The physical and chemical properties of the mineral dust are needed to better constrain remote sensing observations and are of fundamental importance for the understanding of...

Electric (d.c. conduction mechanism, the influence of environmental humidity, thermistor effect) and optical properties of new five substituted calixarene derivatives in thin films have been studied. The films behave as typical n-type polycrystalline semiconductors with activation energy of the electric conduction between 0.26 and 2.36 eV. In the h...

Ferrites are interesting magnetic materials with a wide applicability in current and emerging technologies. CoFe2O4 presents a high magnetostrictive response, important electrical resistivity, mechanical hardness and chemical stability making this material a suitable alternative for the development of sensors, actuators and magneto-optic devices. T...

The self-cleaning of the atmosphere under humidity conditions is observed due to the change in emission intensity when chemical traces are investigated with DARLIOES – the advanced LIDAR based on space- and time-resolved RAMAN and breakdown spectroscopy in conditions of consistent humidity of atmosphere. The determination was performed during the n...

DARLIOES - the advanced LIDAR is based on space- and time-resolved RAMAN and breakdown spectroscopy, to investigate chemical and toxic compounds, their kinetics and physical properties at high temporal (2 ns) and spatial (1 cm) resolution. The high spatial and temporal resolution are needed to resolve a large variety of chemical troposphere compoun...

The Langmuir probe is used to characterize the plasma produced by fs-laser ablation from pure metallic targets. Time dependence of the probe current and the total collected charge is discussed in terms of a shifted Maxwell–Boltzmann distribution function, and from probe characteristics the plasma temperature and average charge state are calculated....

The spectroscopic and photochemical properties of polyurethane coumarine (PUC) in solid state were investigated at room temperature under once-photon excitation. One photon induced photocycloaddition of PUC was investigated and the AFM and spectroscopic FTIR analysis confirmed dimer formation. The AFM analysis shows that the fotodimerization proces...

Despite the industrial decline, air pollution continues to be a major issue in Romanian cities. As in many other urban areas, in Iasi city the traffic is one of the main sources of air pollution which has a high environmental impact, also exposing population's health to a high risk. The study focuses on the small scale examining the spatial and tem...

The spectroscopic and photochemical properties of polyurethane coumarin (PUC) in dimethyl sulf-oxide (DMSO), thetra hydro furan (THF), dimethyl formamide (DMF) and film state were investigated at room tempe rature unde r one photon excitation. The re sults show that unde r irradiation of λ> 310 nm photodimerization process are increased and under U...

The spectroscopic and photochemical properties of polyurethane coumarine (PUC) in dimethyl sulf-oxide (DMSO), thetra hydro furan (THF), dimethyl formamide (DMF) and film state were investigated at room temperature under one photon excitation. Photodimer products were formed via UV irradiation. Syn headto-head and syn head-To-Tail photodimers were f...

According to the scientific literature, the pollution phenomenon is strongly related by the urban activity from the last decades, with direct effects on the state of conservation of the stone constructions also. This paper presents a preliminary study on the colorimetric evolution of the lithic surfaces exposed under strongly traffic influence from...

In the current context of climate and environmental changes, knowledge on the degradation and deterioration of the geomaterials mechanisms existing in the structure of both buildings and historical monuments becomes a priority due to the influence of atmospheric pollutants on apparent lithic surfaces. The aim of the paper is to highlight the impact...

Optical emission spectroscopy and Langmuir probes were used to diagnose complex space-charge structures that appear inside and around a spherical grid with orifice applying a negative voltage below a critical value to it. Measurements (through the orifice) delivered the axial profiles of plasma potential, electron temperature and density, and of th...

We present a short overview of studies performed in our research groups over the last decade on the characterization of transient plasma plumes generated by laser ablation in various temporal regimes, from nanosecond to femtosecond. New results are also presented along with this overview, both being placed in the context of similar studies performe...

Langmuir probe measurements were performed on transient plasmas generated by femtosecond laser ablation of several metallic targets (Al, Cu, Mn, Ni, In, Te, W). The analysis of current-voltage characteristics at various delays after the laser pulse gave access to the temporal evolution of ion density, electron temperature and plasma potential. The...

This paper reports preliminary results concerning thermal effects induced by urban/industrial air pollutants deposited on a limestone rock when heated by pulsed laser in the cleaning process. The process of laser cleaning treatment of the crust is simulated using COMSOL Multiphysics 4.4, finite element analysis software. Scanning Electron Microscop...

Various differentiable physical models are frequently used to describe the dynamics of laser-produced plasma plumes (e.g., kinetic models, two-fluid models, etc.). Given the complexity of all the phenomena involved in the laser-matter interactions, it is required to introduce the laser ablationplasma dynamic variable dependencies both on the space-...

In this paper, thin films behavior obtained by Pulsed Laser Deposition (PLD) have been analyzed by means COMSOL Multiphysics, taking into account various experimental parameters: laser fluence, laser pulse width, laser wavelength, the temperature achieved during ablation, the target material type, the temperature of the support, the distance betwee...

The present paper presents experimental data on the evolution of polychromy and the aesthetics of a number of indigenous carbonate rocks originating from the Paun–Repedea area in Iasi, which were treated with the aim of hydrophobization and consolidation with water-solvated emulsions, Nanopro-C and Nano-Seal, all commercially available products. Th...