Vasile Lavric

Vasile Lavric
Polytechnic University of Bucharest | UPB · Department of Chemical and Biochemical Engineering

Professor

About

156
Publications
40,500
Reads
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1,079
Citations
Additional affiliations
October 2005 - September 2006
Vrije Universiteit Brussel
Position
  • Flame Characterization and NOx Reduction through RTD Analysis
April 2000 - September 2003
Vrije Universiteit Brussel
Position
  • Introduction of chemical pinch technology and applications in petrochemical industries
October 1995 - April 1996
University "Jean Monnet" - St. Etienne, France
Position
  • Twin Screw Extruders as Polymerization Reactors

Publications

Publications (156)
Article
Full-text available
Propolis, a complex bee product, is a source of numerous bioactive principles, beneficial for human health, therefore it is intensively studied. In the present work, extracts of propolis from Bihor Romanian County were studied to identify the relationship between the polyphenolic derivatives profile and their antioxidant and antimicrobial activity....
Article
Full-text available
Ultrasound (US) and Microwaves (MW) are effective methods for processes intensification. Their combined use in the same reactor can lead to remarkable results. Recently there has been a resurgence of interest in this field for new synthetic applications using reactors based upon existing technologies. We describe here a new type of apparatus in whi...
Article
In recent years, significant attention has been dedicated to converting biomass carbohydrates into alkyl levulinates (biofuel additives) in alcoholic media, in search of various cheap and active solid catalysts through relatively easy pathways and from non-dangerous precursors. The synthesis of methyl levulinate (ML) using a new Brønsted/Lewis acid...
Article
Full-text available
Gold nanoparticles (AuNPs) have attracted great interest in a variety of medical applications such as computed tomography (CT), nuclear imaging, therapy, photoacoustic, ultrasound, and magnetic resonance imaging (MRI). Due to their surface chemistry, structure properties, and biocompatibility, AuNPs are a key feature for targeted drug delivery and...
Article
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Polyunsaturated fatty acids (PUFA) have a preventive effect on high blood pressure. [...]
Article
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The use of synthetic pesticides creates problems due to their toxicity, low biodegradability, anduse of them in high amounts, which can damage crops and contaminate the environment. [...]
Article
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: We identified and quantified by LC-MS/MS 11 (quercetin, galangin, pinocembrin, kaempferol, vanillin, chrysin, gallic acid, p-coumaric acid, trans-ferulic acid, caffeic acid, and caffeic acid phenethyl ester) out of the 21 polyphenolic compounds we looked for in ethanolic (25% and 50%) and aqueous propolis extracts by comparison with standards and...
Article
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In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction paramete...
Article
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Recent advances and large-scale use of hybrid imaging modalities like PET-CT have led to the necessity of improving nano-drug carriers that can facilitate both functional and metabolic screening in nuclear medicine applications. In this study, we focused on the evaluation of four potential imaging nanoparticle structures labelled with the 68Ga posi...
Article
Calcium alginate (CaAlg) beads were prepared using ultrasound for use in the removal of lead from natural and wastewaters by ion exchange. Ultrasound was applied in a batch mode with an ultrasonic bath or in a flow mode using an ultrasonic clamp-on device. For comparison purposes the synthesis was performed in batch mode in the absence of the ultra...
Article
Nowadays, the concerns regarding cadmium pollution increased steadily, due to its serious damages to the environment and human health. Consequently, stringent limits have been set for this heavy metal ion both in industrial and drinking water. Numerous traditional and unconventional methods were applied to reach these limits. In this paper, two pho...
Article
Full-text available
Three equal mass fractions containing fine (d < 600 μm), medium (600 μm < d < 1.25 mm), and large (d > 1.25 mm) size propolis particles were subjected to extraction using demineralized water or 1:1 ethanol:water, at 150 rpm and 25̊ C, ensuring a 10:1 liquid:solid ratio. Extraction duration varied between 1 and 7 days. Aqueous and ethanolic extracts...
Article
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Alkyl esters of levulinic acid have significant potential as blend components in diesel formulations. [...]
Article
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This study was aimed to evaluate the growth conditions of Porphyridium purpureum and Nannochloropsis sp. microalgae for carbohydrates and lipids productivity increase. The cultivation experiments for both microalgae strains were done in triplicates using the artificial seawater (ASW) as culture media. The lipids were separated from the algal biomas...
Article
Full-text available
The conventional and microwave solvent extraction of active principles from vegetables is a mature experimental domain. Still, the mathematical modeling of microwaves (MWs) irradiation using either multimode or monomode MWs applicators should be improved. MWs irradiation intensifies extraction process since, due to its higher tangent loss, the vege...
Article
Glycerol acetals/ketals and their esters, produced from renewable raw materials, are highly valuable compounds, being used as oxygenated fuel additives and ecological solvents. A new method for obtaining glycerol acetal/ketal esters, difficult to synthesize using classical techniques, was developed. This method is based on the reversible reaction o...
Article
Silver is one of the eight precious metals, along with gold and the six platinum-group metals (PGM). Most of the silver is being obtained as a by-product of other metals mining and refining. Fine silver is produced in electrolytic processes, using silver anodes (electrolytic refining) or inert ones (electrowinning) and acidified silver nitrate elec...
Article
Bioethanol is the world's leader biofuel and it is produced by fermentation from glucose feedstocks. The fermentation rate is quite low and any method of increasing the reaction rate is welcome. The main goal of our research is to identify the domain for microwave Specific Absorption Ratio (SAR) which leads to an increase in fermentation rate of Sa...
Article
The waste resulted from fish processing industries are discarded into the environment around the world, causing environmental pollution. The main problem of fish oil extracted from waste is the high content in free fatty acids (FFA) which decrease the yield in fatty acids esters during transesterification reactions. Therefore, to correct the fish-o...
Article
Full-text available
A reactive extraction/back-extraction process was studied experimentally in a two-stage column. The mathematical model of the reactive extraction using a closed loop moving organic liquid membrane, based upon first principle equations, was derived as a set of Partial/Ordinary Differential Algebraic Equations (P/ ODAE). The mathematical model, reduc...
Article
The synthesis of TiO2 was studied in an original hydrothermal process that uses triethanolamine titanium complex Ti(TeoaH)2 as Ti precursor and triethanolamine (TeoaH3) as shape controller to obtain bipyramidal anatase nanoparticles. Backed-up by experimental evidence,i.e time profiles for Ti(IV) species concentrations together with crystal shape a...
Article
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The application of biopolymer-based sorbents in solving some environmental problems such as the removal and recovery of heavy metals from natural polluted water and wastewater has received lately a lot of attention due to their unique characteristics. The fundamental properties that recommend the usage of biopolymers-based sorbents for environmenta...
Article
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The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG), ¹⁸F-Fluoroestradiol (¹⁸F-FES), ¹⁸F-Fluorothymidine (¹⁸F-FLT), ¹⁸F-Fluoromisonidazole (¹⁸F-FMISO). Radiopharmaceuticals are radioactive preparations for medi...
Article
The mathematical modeling of the phenomena taking place during the electron beam flue gas treatment is a complex endeavor due to the different time scales of the processes occurring as accelerated electrons are bombarding the flue gas. The paper presents a complex kinetic model for these gas phase interactions, consisting of 1034 chemical reactions...
Article
Microwave assisted extraction is a powerful tool for natural compounds extraction from plants. The main goal of our research is to obtain a maximum extraction yield without affecting the chemical structure of the valuable natural compounds. In order to avoid the degradation of the latter, a special equipment has been developed. This equipment allow...
Article
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2-fluoro-2-deoxy-D-glucose (FDG) and 2-chloro-2-deoxy-D-glucose (ClDG) are chemical impurities found in the 2-[¹⁸F]fluoro-2-deoxy-D-glucose products (¹⁸F-FDG). The objective of this study was to find the best condition for the separation of FDG and ClDG, evaluating different columns under various operating conditions. Chromatographic parameters suc...
Book
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The book is presenting a collection of researches on important fields of biophysics for biomedical and environmental sciences. The chapters were presented in the frame of International Conference on Analytical and Nanoanalytical Methods for Biomedical and Environmental Sciences, IC-ANMBES 2016 which have been held in Braşov, June 29th – July 1st, 2...
Article
This research study deals with lead(II)/Pb2 + removal from aqueous solutions by calcium alginate (CA) and chitosan coated calcium alginate (CCCA) as adsorbents, in batch experiments. A simple synthesis method was used to prepare both adsorbent materials. CA and CCCA were characterized using infrared spectroscopy (FT-IR), scanning electron microscop...
Article
Full-text available
The development of a high performance liquid chromatography (HPLC) method for the determination of the radiochemical purity evaluation of [18F]NaF was described. HPLC analysis was performed with an Agilent system. Separation was achieved with a Carbopac PA1 column. The method was found to be precise, accurate and specific, assets recommending its u...
Article
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This paper aims to present the contributions to the mathematical modeling of atmospheric pollutants' removal using the electron beam flue gas treatment (EBFGT), after an in-depth look at its current status and perspectives for future development. Despite having been demonstrated at industrial level, EBFGT s market penetration is still low. The bulk...
Article
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The objective of this study was testing the stability of the radiopharmaceutical [18F]NaF solution, stored at room temperature (15-25°C) at different time intervals. It was investigated the quality of this radiopharmaceutical substance in time under the influence of environmental factors and the influence of material composition of septum from airt...
Article
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18F-FDG is a glucose analog in which the hydroxyl group on the second carbon is substituted with 18F, being used as an indicator of glucose uptake and cell viability. The aim of this work was to synthesize the 18F-FDG and to validate the methodology for the assessment of its both radiochemical and chemical purities, according to the European Pharma...
Article
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The treatment of flue gases with high energy electron beams for the abatement of sulfur and nitrogen oxides has been developed as an alternative to the more traditional methods of treating atmospheric pollutants (i.e. wet gas desulfurization, selective catalytic reduction). This paper proposes a new mathematical model for the complex phenomena occu...
Article
The non-thermal plasma treatment of exhausts using electron beams is an innovative, highly effective process, which can simultaneously remove sulphur and nitrogen oxides as well as a variety of volatile organic compounds. The main objective of this paper is to introduce the plug flow approach to the modelling of the physico-chemical phenomena occur...
Article
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The interdependences between environment changes and cellular responses to external stimuli are still not fully understood. Accordingly, in many cases the influence of the individual cellular heterogeneity on the productivity of some metabolites at industrial scale cannot be justified. This study intends to highlight the response of a bacterial pop...
Article
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The dispersed-phase processes, such as heterogeneous polymerization and crystallization, are widely discussed contexts for application of the population balance. This technique allows, through its parameters, to quantify the changes in dispersed phase size. These coefficients are the rates of occurrence of dispersed phase size-hanging phenomena, wh...
Article
The removal of sulfur and nitrogen oxides from flue gases using high energy electron beams is based on the generation of excited molecules when the flue gas is bombarded by accelerated electrons. The excited molecules undergo ionization, dissociation and electron attachment to yield reactive species (ions, metastables, free radicals and electrons)...
Article
This work addresses the selective recovery of platinum group metals (PGMs) from aqueous streams, a critical issue within the recycling and metal refining industries aiming to lose zero of the value contained. Herein, selective PGM capture was investigated using three metal-capturing polymeric resins from different manufacturers: a special anion exc...
Article
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The existing relations used in averaging physical properties of suspensions do not address the special case of suspension polymerization, an exothermal, discontinuous, volume shrinking, dispersed phase process, difticult to describe. A previous work showed that each drop is characterized, in connection to its size, by a temperature and conversion p...
Chapter
This chapter begins with a short history of process design, and then presents a hierarchical approach to the main currents: heuristic approach, phenomena-driven design, conflict-based approach, case-based reasoning, driving force method and axiomatic design. The main similarities and differences between design and retrofit are emphasised. Process I...
Article
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A simple "first generation" multi-scale computational model of the formation of activated sludge flocs at micro-scale and reactor performance at macro-scale is proposed. The model couples mass balances for substrates and biomass at reactor scale with an individual-based approach for the floc morphology, shape and micro-colony development. Among the...
Conference Paper
Full-text available
The highly exothermal polymerization reaction needs an efficient cooling system in order to avoid thermal runaways. The thermal agent flowrate or inlet temperature may represent the manipulated variable (MV) that the controller should adjust according to a set of laws to achieve a suitable goal. The laws the controller observes determine the class...
Conference Paper
Full-text available
The electron beam technology has been developed successfully for the removal of sulphur and nitrogen oxides from flue gases and has recently been applied on an industrial scale. The flue gases contain also nitrogen, carbon dioxide, oxygen, water, and ammonia. As the sulphuric acid appears during the chemical processes generated by the beam interact...
Article
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This paper introduces a new approach in the field of industrial water/wastewater networks optimization by compiling the double objective optimization with the benefits of regeneration opportunities. The dual-objective optimization accounts for the most two important parameters of a water network: fresh water consumption and total cost (comprising o...
Article
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Soluble microbial products (SMP) have been long time considered the major cause of membrane fouling when membrane bioreactors (MBR) are used for wastewater treatment. As a result, the formation and degradation of SMP have been incorporated in the conventional ASM models for a better prediction of MBR performance. This paper studies the impact of SM...
Article
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The present work describes a simple method for the analysis of iosthiocyanates from mustard in cruciferous vegetables.
Article
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There is a vast literature available concerning suspension polymerization studies, the corresponding drop size distribution and the tuning of the associated PID controller. However, to the best of the authors' knowledge, there is no study that shows how the functioning of the controller is affected by the drop size distribution, on one hand, and by...
Article
Isothiocyanates (ITC) derived from plants of the order Brassicales are known for their antibacterial, anti-inflammatory or anticarcinogenic potential. Although only the free ITC exert bioactivity, quantification in vivo is almost exclusively performed on total ITC/metabolite content. We therefore investigated in a pilot study the amount of free ITC...
Article
Full-text available
A feedforward multilayer back-propagation artificial neural network (ANN) model was proposed to predict the extraction yields and rates of the bioactive constituents from three medicinal plants: Stevia rebaudiana Bert. leaves(SR), Cynara scolymus leaves (CS) and Arctium lappa roots (AL). The nature of bioactive constituents, the power expressed by...
Article
Pareto optimization approach was used in searching for the particular successions of topologies and operating conditions for a semicontinuous water network (batch with respect to the raw materials) that minimize both the freshwater consumption and the investment and operating costs. The semicontinuous wastewater network (SWN) formed of N water-usin...
Article
Full-text available
The objective of this work was to optimize the operating parameters of a system used for biological wastewater treatment. The system consists of two reactors (one anoxic and one aerobic), a separator, a recirculation line and a purge line. In order to satisfy the effluent requirements for environmental discharge (e.g. the EU Directive 91/271/ECC) a...
Conference Paper
Full-text available
Polymers are nowadays used in a multitude of applications, many of the latter being in close relationship with the polymer molecular mass distribution (PMMD), which could be affected by the way the polymer was obtained: bulk, solution, emulsion or suspension. The polymers produced in heterogeneous processes strongly depend not only on the polymeriz...
Article
Full-text available
The aim of this study was to increase extraction rate, yield and quality of products, associating microwave field with extraction of plant's active compounds such as flavonoids and phenolic acids from Cynara scolymus (CS) leaves. Compared to classical hot extraction methods (CE), microwave extraction (MAE) provides higher purities in active compoun...
Article
Full-text available
Many studies currently address the reduction of freshwater consumption at industrial level, under complex operating and topologic conditions (multiple contaminants, integrated water networks, etc.), while using single or multiple objectives. The present study offers insights on a Pareto approach used to optimize a semi-continuous water network hand...
Chapter
A multi-scale computational model was created for the formation of activated sludge floc structure. The model couples mass balances for substrates and biomass at reactor scale with an individual-based approach for the floc morphology, shape and micro-colony development. Among the novel model processes included are the group attachment of micro-floc...
Article
The dual-objective optimization of an integrated water/wastewater network (IWWN) is addressed by targeting for minimum fresh water consumption at the same time with operating costs reduction. An IWWN is a recycle system composed of two oriented graphs, the first encoding the water-using units (WUs) and the second, the treatment units (TUs). Althoug...
Article
Full-text available
A series of continuous- and sequencing-batch reactor experiments were performed to assess the growth dynamics of Escherichia coli strain K12-MG1655 in chemostat systems. Previous mathematical predictions and early experimental results had shown that confined oscillatory dynamics ensue in bioreactor populations, which relates to "group birth and dea...
Article
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The influence of cycloheximide and recirculation ratio upon system performance and microbial viability was studied in two continuous lab-scale wastewater treatment systems. Each system consists of an aerobic bioreactor, a settler, a sludge recycling line, and a sludge wastage line (purge). The addition of cycloheximide, which is a eukaryotic inhibi...
Article
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In this paper we first optimized the operating parameters of a submerged membrane bioreactor for wastewater treatment using a dual-objective function: the global conversion of ammonia plus ammonium nitrogen and the weighted productivity of the system. Given the dichotomy of these two objectives, a Pareto front was obtained and the results analyzed....
Article
Full-text available
Submerged membrane bioreactors (SMBR) are hybrid systems that couple a bio-logical reactor, where the biodegradable substrates are consumed by the active biomass, and a membrane module, which prevents the solids to pass into the effluent, replacing the classical separation and recirculation unit. An improved version of an available mathematical mod...