30 results match your criteria: "Center for Fundamental and Advanced Technical Research[Affiliation]"

Article Synopsis
  • * Despite their advantages, magnetorheological fluids face challenges like increased friction torque and leakage of carrier liquid when used in rotating seals.
  • * A novel approach involves using extremely bidisperse MR suspensions with micrometer-sized iron particles in a ferrofluid, which not only increases magnetization but also alters flow properties, leading to an innovative sealing mechanism that significantly boosts performance with minimal additives.
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The liquid-vapor phase separation is investigated via lattice Boltzmann simulations in three dimensions. After expressing length and time scales in reduced physical units, we combined data from several large simulations (on 512^{3} nodes) with different values of viscosity, surface tension, and temperature, to obtain a single curve of rescaled length l[over ̂] as a function of rescaled time t[over ̂]. We find evidence of the existence of kinetic and inertial regimes with growth exponents α_{d}=1/2 and α_{i}=2/3 over several time decades, with a crossover from α_{d} to α_{i} at t[over ̂]≃1.

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The present study reports the successful synthesis of biocompatible magnetic iron oxide nanoparticles (MNPs) by an ecofriendly single step method, using two ethanolic extracts based on leaves of L. and L. The effect of both green raw materials as reducing and capping agents was taken into account for the development of MNPs, as well as the reaction synthesis temperature (25 °C and 80 °C).

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Ofloxacin Removal from Aqueous Media by Means of Magnetoactive Electrospun Fibrous Adsorbents.

Nanomaterials (Basel)

October 2022

Department of Mechanical and Manufacturing Engineering, School of Engineering, University of Cyprus, Nicosia 1678, Cyprus.

Functionalized electrospun polymer microfibrous membranes were fabricated by electrospinning and further surface-functionalized with magnetic iron oxide (FeO) nanoparticles to yield magnetoactive nanocomposite fibrous adsorbents. The latter were characterized in respect to their morphology, mechanical properties and magnetic properties while they were further evaluated as substrates for removing Ofloxacin (OFL) from synthetic aqueous media and secondary urban wastewater (UWW) under varying physicochemical parameters, including the concentration of the pharmaceutical pollutant, the solution pH and the membranes' magnetic content. The magnetic-functionalized fibrous adsorbents demonstrated significantly enhanced adsorption efficacy in comparison to their non-functionalized fibrous analogues while their magnetic properties enabled their magnetic recovery and regeneration.

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Enhancement of the Catalytic Performance and Operational Stability of Sol-Gel-Entrapped Cellulase by Tailoring the Matrix Structure and Properties.

Gels

October 2022

Biocatalysis Group, Department of Applied Chemistry and Engineering of Organic and Natural Compounds, Faculty of Industrial Chemistry and Environmental Engineering, Politehnica University Timisoara, Carol Telbisz 6, 300001 Timisoara, Romania.

Commercial cellulase Cellic CTec2 was immobilized by the entrapment technique in sol-gel matrices, and sol-gel entrapment with deposition onto magnetic nanoparticles, using binary or ternary systems of silane precursors with alkyl- or aryl-trimethoxysilanes, at different molar ratios. Appropriate tailoring of the sol-gel matrix allowed for the enhancement of the catalytic efficiency of the cellulase biocatalyst, which was then evaluated in the hydrolysis reaction of Avicel microcrystalline cellulose. A correlation between the catalytic activity with the properties of the sol-gel matrix of the nanobiocatalysts was observed using several characterization methods: scanning electron microscopy (SEM), fluorescence microscopy (FM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA/DTA).

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Iron oxide nanoparticles were synthesized starting from two aqueous extracts based on L. leaf and stems, employing a simplest, eco-friendliness and low toxicity method-green synthesis. The nanoparticles were characterized by powder X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), X-ray fluorescence analysis (XRF), thermal analysis (TG/DSC), and scanning electron microscopy (SEM).

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Ferrofluids and bio-ferrofluids: looking back and stepping forward.

Nanoscale

March 2022

Romanian Academy - Timisoara Branch, Center for Fundamental and Advanced Technical Research, Laboratory of Magnetic Fluids, Mihai Viteazu Ave. 24, 300223 Timisoara, Romania.

Ferrofluids investigated along for about five decades are ultrastable colloidal suspensions of magnetic nanoparticles, which manifest simultaneously fluid and magnetic properties. Their magnetically controllable and tunable feature proved to be from the beginning an extremely fertile ground for a wide range of engineering applications. More recently, biocompatible ferrofluids attracted huge interest and produced a considerable increase of the applicative potential in nanomedicine, biotechnology and environmental protection.

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Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast agents, detection tags for in vitro biosensing, and mediators of heating in magnetic hyperthermia.

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High magnetization FeO/OA-FeCo/AlO nanocomposite magnetic clusters have been obtained using a modified oil-in-water miniemulsion method. These nanocomposite clusters dispersed in a ferrofluid carrier result in a magnetorheological fluid with improved characteristics. The magnetic clusters have a magnetic core consisting of a mixture of magnetite nanoparticles of about 6 nm average size, stabilized with oleic acid (FeO/OA) and FeCo/AlO particles of about 50 nm average size, compactly packed in the form of spherical clusters with a diameter distribution in the range 100-300 nm and a hydrophilic coating of sodium lauryl sulphate surfactant.

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Green Synthesis, Characterization, and Antibacterial Properties of Silver Nanoparticles Obtained by Using Diverse Varieties of Leaf Extracts.

Molecules

July 2021

Faculty of Food Engineering, Tourism and Environmental Protection, Institute for Research, Development and Innovation in Technical and Natural Sciences, Aurel Vlaicu University, 2 Elena Dragoi St., 310330 Arad, Romania.

L. (hemp) is a plant used in the textile industry and green building material industry, as well as for the phytoremediation of soil, medical treatments, and supplementary food products. The synergistic effect of terpenes, flavonoids, and cannabinoids in hemp extracts may mediate the biogenic synthesis of metal nanoparticles.

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Superparamagnetic electrospun microrods for magnetically-guided pulmonary drug delivery with magnetic heating.

Mater Sci Eng C Mater Biol Appl

July 2021

University of Cyprus, Department of Mechanical and Manufacturing Engineering, 75, Kallipoleos Avenue, P. O. Box 20537, 1678 Nicosia, Cyprus. Electronic address:

Controlled pulmonary drug delivery systems employing non-spherical particles as drug carriers attract considerable attention nowadays. Such anisotropic morphologies may travel deeper into the lung airways, thus enabling the efficient accumulation of therapeutic compounds at the point of interest and subsequently their sustained release. This study focuses on the fabrication of electrospun superparamagnetic polymer-based biodegradable microrods consisting of poly(l-lactide) (PLLA), polyethylene oxide (PEO) and oleic acid-coated magnetite nanoparticles (OA·FeO).

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Magnetic hydrogels composed of poly(vinyl alcohol) (PVA)/water-soluble tricarboxy cellulose (CO)/magnetic fluids (MFs) have been prepared by a freeze-thaw cycle technique. The system designed here combines the renewability and biocompatibility aspects of PVA and CO, as well as the magnetic properties of MFs, thereby offering special properties to the final product with potential applications in medicine. In the first step, the water-soluble CO is synthesized using a one-shot oxidation procedure and then the aqueous solutions of CO are mixed with PVA solutions and magnetic fluids in the absence of any additional cross-linking agent.

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Magnetic iron oxide nanoparticles are the most desired nanomaterials for biomedical applications due to their unique physiochemical properties. A facile single-step process for the preparation of a highly stable and biocompatible magnetic colloidal suspension based on citric-acid-coated magnetic iron oxide nanoparticles used as an effective heating source for the hyperthermia treatment of cancer cells is presented. The physicochemical analysis revealed that the magnetic colloidal suspension had a z-average diameter of 72.

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Iron oxide nanoparticles are the basic components of the most promising magnetoresponsive nanoparticle systems for medical (diagnosis and therapy) and bio-related applications. Multi-core iron oxide nanoparticles with a high magnetic moment and well-defined size, shape, and functional coating are designed to fulfill the specific requirements of various biomedical applications, such as contrast agents, heating mediators, drug targeting, or magnetic bioseparation. This review article summarizes recent results in manufacturing multi-core magnetic nanoparticle (MNP) systems emphasizing the synthesis procedures, starting from ferrofluids (with single-core MNPs) as primary materials in various assembly methods to obtain multi-core magnetic particles.

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Purpose: Breast cancer presents one of the highest rates of prevalence around the world. Despite this, the current breast cancer therapy is characterized by significant side effects and high risk of recurrence. The present work aimed to develop a new therapeutic strategy that may improve the current breast cancer therapy by developing a heat-sensitive liposomal nano-platform suitable to incorporate both anti-tumor betulinic acid (BA) compound and magnetic iron nanoparticles (MIONPs), in order to address both remote drug release and hyperthermia-inducing features.

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Engineered magnetoactive collagen hydrogels with tunable and predictable mechanical response.

Mater Sci Eng C Mater Biol Appl

September 2020

University of Cyprus, Department of Mechanical and Manufacturing Engineering, 75, Kallipoleos Avenue, P.O. Box 20537, 1678 Nicosia, CYPRUS. Electronic address:

In the present study, the synthesis of superparamagnetic collagen-based nanocomposite hydrogels with tunable swelling, mechanical and magnetic properties is reported. The fabrication strategy involved the preparation of pristine collagen type-I hydrogels followed by their immersion in highly stable aqueous solutions containing pre-formed double-layer oleic acid-coated hydrophilic magnetite nanoparticles (OA.OA.

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This study reports the development of a continuous flow process enabling the synthesis of very small iron oxide nanoparticles (VSION) intended for T-weighted magnetic resonance imaging (MRI). The influence of parameters, such as the concentration/nature of surfactants, temperature, pressure and the residence time on the thermal decomposition of iron(III) acetylacetonate in organic media was evaluated. As observed by transmission electron microscopy (TEM), the diameter of the resulting nanoparticle remains constant when modifying the residence time.

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The preparation procedure of zero magnetic remanence superparamagnetic white paper by means of three-layer membrane configuration (sandwiched structure) is presented. The cellulose acetate fibrous membranes were prepared by electrospinning. The middle membrane layer was magnetically loaded by impregnation with an aqueous ferrofluid of 8 nm magnetic iron oxide nanoparticles colloidally stabilized with a double layer of oleic acid.

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Magnetic immunochromatographic test for histamine detection in wine.

Anal Bioanal Chem

October 2019

Department of Physical and Analytical Chemistry, University of Oviedo, c/ Julián Clavería 8, 33006, Oviedo, Spain.

Histamine, a biogenic amine, is abundant in fermented foods and beverages, notably wine. A high intake of this monoamine may produce adverse reactions in humans, which may be severe in individuals with a reduced capacity to catabolise extrinsic histamine. Thus, control of histamine concentration during wine production and before distribution is advisable.

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Corner-transport-upwind lattice Boltzmann model for bubble cavitation.

Phys Rev E

February 2018

Istituto Applicazioni Calcolo, CNR, Via Amendola 122/D, 70126 Bari, Italy.

Aiming to study the bubble cavitation problem in quiescent and sheared liquids, a third-order isothermal lattice Boltzmann model that describes a two-dimensional (2D) fluid obeying the van der Waals equation of state, is introduced. The evolution equations for the distribution functions in this off-lattice model with 16 velocities are solved using the corner-transport-upwind (CTU) numerical scheme on large square lattices (up to 6144×6144 nodes). The numerical viscosity and the regularization of the model are discussed for first- and second-order CTU schemes finding that the latter choice allows to obtain a very accurate phase diagram of a nonideal fluid.

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The preparation of superparamagnetic composites obtained by CaCO mineralization from supersaturate aqueous solutions is presented. The preparation was conducted in the presence of oleic acid stabilized magnetite nanoparticles as a water-based magnetic fluid and insoluble templates as gel-like cross-linked polymeric beads. The presence of the magnetic particles in the composites provides a facile way for external manipulation using a permanent magnet, thus allowing the separation and extraction of magnetically modified materials.

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Shape changes of bioprinted tissue constructs simulated by the Lattice Boltzmann method.

Comput Biol Med

March 2016

Center for Modeling Biological Systems and Data Analysis, Department of Functional Sciences, Victor Babes University of Medicine and Pharmacy Timisoara, Piata Eftimie Murgu No. 2-4, 300041 Timisoara, Romania; Department of Physics & Astronomy, University of Missouri, Columbia, MO 65211, U.S.A.. Electronic address:

Tissue engineers seek to build living tissue constructs for replacing or repairing damaged tissues. Computational methods foster tissue engineering by pointing out dominant mechanisms involved in shaping multicellular systems. Here we apply the Lattice Boltzmann (LB) method to study the fusion of multicellular constructs.

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Magnetic iron oxide nanoparticles: Recent trends in design and synthesis of magnetoresponsive nanosystems.

Biochem Biophys Res Commun

December 2015

Romanian Academy-Timisoara Branch, Center for Fundamental and Advanced Technical Research, Lab. Magnetic Fluids, 24 M. Viteazu Ave., RO-300223 Timisoara, Romania. Electronic address:

Recent developments in nanotechnology and application of magnetic nanoparticles, in particular in magnetic iron oxide nanosystems, offer exciting possibilities for nanomedicine. Facile and precise synthesis procedures, high magnetic response, tunable morphologies and multiple bio-functionalities of single- and multi-core magnetic particles designed for nanomedicine applications are thoroughly appraised. This review focuses on the structural and magnetic characterization of the cores, the synthesis of single- and multicore iron oxide NPs, especially the design of the latter, as well as their protection, stabilization and functionalization by desired coating in order to protect against the corrosion of core, to prevent non-specific protein adsorption and particle aggregation in biological media, and to provide binding sites for targeting and therapeutic agents.

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An experimental study of magnetic colloidal particles cluster formation induced by an external electric field in a ferrofluid based on transformer oil is presented. Using frequency domain isothermal dielectric spectroscopy, we study the influence of a test cell electrode separation distance on a low-frequency relaxation process. We consider the relaxation process to be associated with an electric double layer polarization taking place on the particle surface.

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The Gauss-Laguerre quadrature method is used on the Cartesian semiaxes in the momentum space to construct a family of lattice Boltzmann models. When all quadrature orders Qx, Qy, Qz equal N+1, the Laguerre lattice Boltzmann model LLB(Qx,Qy,Qz) exactly recovers all moments up to order N of the Maxwell-Boltzmann equilibrium distribution function f(eq), calculated over any Cartesian octant of the three-dimensional momentum space. Results of Couette flow simulations at Kn=0.

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