Alexandru Cocean

Universitatea Alexandru Ioan Cuza | UAIC · Department of Physics

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...

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...

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...

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...

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...

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...

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...

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...

Synthetic garments pose significant environmental and human risks, which are further increased by the presence of synthetic dyes. As synthetic fibers cannot be eliminated, steps need to be taken in order to improve their sustainability. The paper presents a sustainable and cleaner microwave (MW)-assisted process of dyeing acrylic knitted fabrics wi...

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...

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...

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...

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...