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Your search keyword '"Iordache, Iuliana"' showing total 38 results
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38 results on '"Iordache, Iuliana"'

3. A polyaniline/platinum coated fiber optic surface plasmon resonance sensor for picomolar detection of 4-nitrophenol.

Author

UCL - SST/IMCN/BSMA - Bio and soft matter, Antohe, Iulia, Iordache, Iuliana, Antohe, Vlad-Andrei, Socol, Gabriel, UCL - SST/IMCN/BSMA - Bio and soft matter, Antohe, Iulia, Iordache, Iuliana, Antohe, Vlad-Andrei, and Socol, Gabriel

Abstract

The paper reports for the first time an innovative polyaniline (PANI)/platinum (Pt)-coated fiber optic-surface plasmon resonance (FO-SPR) sensor used for highly-sensitive 4-nitrophenol (4-NP) pollutant detection. The Pt thin film was coated over an unclad core of an optical fiber (FO) using a DC magnetron sputtering technique, while the 4-NP responsive PANI layer was synthetized using a cost-effective electroless polymerization method. The presence of the electrolessly-grown PANI on the Pt-coated FO was observed by field-emission scanning electron microscopy and subsequently evidenced by energy dispersive X-ray analysis. These FO-SPR sensors with a demonstrated bulk sensitivity of 1515 nm/RIU were then employed for 4-NP sensing, exhibiting an excellent limit-of-detection (LOD) in the low picomolar range (0.34 pM). The proposed sensor's configuration has many other advantages, such as low-cost production, small size, immunity to electromagnetic interferences, remote sensing capability, and moreover, can be operated as a "stand-alone device", making it thus well-suited for applications such as "on-site" screening of extremely low-level trace pollutants.

Published
2021

4. Abeles method revisited

Author

Logofatu, Petre C., Apostol, Dan, Damian, Victor, Iordache, Iuliana M., Bojan, Mihaela M., and Muller, Raluca

Subjects
Refractive index -- Analysis, Astronomy, Physics
Abstract

The Abeles method is a classical method for determining the refractive index of dielectric thin films. In this paper we examine the main features of the method in a formal manner, using closed-form equations, and we show that the method is ambiguous in certain yet unreported situations. OCIS codes: 310.6860, 120.4530.

Published
2006

8. Determination of the magnetic moment and geometrical dimensions of the magnetotactic bacteria using an optical scattering method.

Author

Logofătu, Petre Cătălin, Ardelean, Ioan, Apostol, Dan, Iordache, Iuliana, Bojan, Mihaela, Moisescu, Cristina, and IoniŢă, Bogdan

Subjects
MAGNETIC fields, FIELD theory (Physics), PROKARYOTES, BACTERIA, OPTICS
Abstract

We adapted an experimental technique for characterizing the magnetotactic bacteria and simplified it by transferring the burden to literal and numerical computation, which is an advantageous tradeoff. In a magnetic field the bacteria tend to orient their magnetic axes along the direction of the magnetic field, resulting in an anisotropic distribution of the orientation and, consequently, a significant change of the directional distribution of the scattering efficiency of light. We made a simple experimental arrangement for measuring the scattering efficiency of light by the bacteria in certain directions for various values of an external magnetic field applied to the bacteria. We inferred from the fitting of the experimental to the theoretical data the most probable values for the magnetic moment and the dimensions of the magnetotactic bacteria. In the experiments a wild-type Magnetospirillum gryphiswaldense strain was used. [ABSTRACT FROM AUTHOR]

Published
2008
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9. Titanium oxide – reduced graphene oxide – silver composite layers synthesized by laser technique: Wetting and electrical properties

Author

Ministry of Education and Research (Romania), Ministerio de Economía y Competitividad (España), Gyorgy, Eniko, Pérez del Pino, Ángel, Datcu, Angela, Duta, Liviu, Logofatu, Constantin, Iordache, Iuliana, Duta, Anca, Ministry of Education and Research (Romania), Ministerio de Economía y Competitividad (España), Gyorgy, Eniko, Pérez del Pino, Ángel, Datcu, Angela, Duta, Liviu, Logofatu, Constantin, Iordache, Iuliana, and Duta, Anca

Abstract

Electrically conductive and highly hydrophobic surface layers are attractive for many practical applications. In this work the functional, wetting and electrical properties of titanium dioxide (TiO2), TiO2/silver (Ag), and TiO2/reduced graphene oxide (rGO)/Ag nanocomposite coatings layers are reported. The functional properties of the layers were correlated with their chemical composition and bonding states between the constituent elements, determined in turn by the synthesis and immobilization process parameters. The nanocomposite coatings were obtained by matrix assisted pulsed laser evaporation, a laser-based environmental friendly thin film deposition technique. The synthesized ternary TiO2/rGO/Ag coatings has optimum performances, highly hydrophobic character and low electrical resistance, attributed to the presence of Ag nanoparticles and to the reduction of the oxygen containing functional groups of the GO platelets during laser irradiation and transfer processes leading to the formation of graphene-like material.

Published
2016

15. Magnetic liquid surface behaviour to external stimulus

Author

Damian, V., primary, Logofatu, P. C., additional, Apostol, D., additional, Vekas, L., additional, Bica, Doina, additional, Damian, A., additional, Garoi, F., additional, Iordache, Iuliana, additional, Sima, A., additional, and Bojan, Mihaela, additional

Published
2007
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17. Static Fourier transform lambdameter

Author

Apostol, Dan, primary, Sima, Adrian, additional, Logofătu, Petre C., additional, Garoi, Florin, additional, Damian, Victor, additional, Nascov, Victor, additional, and Iordache, Iuliana, additional

Published
2007
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18. Fourier transform digital holography

Author

Apostol, Dan, primary, Sima, Adrian, additional, Logofătu, Petre C., additional, Garoi, Florin, additional, Damian, Victor, additional, Nascov, Victor, additional, and Iordache, Iuliana, additional

Published
2007
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22. Optical encoder measurement technology

Author

Iordache, Iuliana, primary, Bojan, Mihaela, additional, Apostol, D., additional, Damian, V., additional, Garoi, F., additional, Logofatu, P. C., additional, Muller, Raluca, additional, and Savu, B., additional

Published
2007
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26. 2D Multiple Beam Interference Lithography

Author

Apostol, A.D., primary, Damian, V., additional, Garoi, F., additional, Iordache, Iuliana, additional, Logofatu, P.C., additional, Nascov, V., additional, Sima, A., additional, Cristea, B. Dana, additional, and Muller, Raluca, additional

Published
2006
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37. Annealing study of two-dimensional patterned Ge nanostructures via nanosphere lithography.

Author

Ulmeanu, Magdalena, Iordache, Iuliana, Filipescu, Mihaela, Craciun, Valentin, Pinzaru, Simona, and Hörner, Andreas

Abstract

Experimental studies on patterning hexagonal Ge nanostructures have been conducted on Si substrates through deposition of Ge with colloidal particles as a mask. The deposited Ge thin film possesses, according to the X-ray diffraction measurements, in plane texture, being epitaxial and aligned with the (111) Si substrate. The size distribution of the patterned Ge nanostructures is narrow, as indicated by the atomic force microscopy and scanning electron microscopy measurements. We have obtained Ge nanostructures with lateral dimension of 490 nm (height 12 nm), 200 nm (height 6 nm) and 82 nm (height 6 nm) by using different sizes of polystyrene spheres. We have performed in depth studies of the Ge nanostructures' behavior due to thermal and rapid thermal post-annealing processes. FT micro-Raman spectroscopy shows that there is no Si intermixing during the annealing process. In order to quantify the changes in the height and lateral dimension, we have performed atomic force microscopy and white light interferometry analysis. The changes in shape and the decrease in the area of a cross-section of Ge nanostructure will be discussed in respect to similar results shown in the literature for Ge thin films during the annealing process. [ABSTRACT FROM AUTHOR]

Published
2011
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38. High accuracy laser based machine vision for calibration of linear encoders and dial instruments

Author

Iordache, Iuliana, Schiopu, Paul, Apostol, Dan, and Damian, Victor

Abstract

A laser interferometer, a vision system, and 1-D precision translation stage are used to develop a high precision measuring station with a working range of 12 mm. The object inspected by the laser-and-vision system is moved using a linear translation stage (LUMINOS INDUSTRIES I1000 - 1-Axis Stage) so that the camera can take images of the feature points of the object at two (or more) different positions. Meanwhile, the displacement of the table is measured using a laser interferometer. Putting these two feature points successively in focus the distance between them can be evaluated and adding the displacement measured by the laser interferometer, the real distance between these two feature points is obtained. The developed 1-D laser-and-vision measuring system is used to measure the geometric size (pitch) of grating type linear encoders or industrial line scales. Software counts automatically the number of lines and the laser interferometer produces the corresponding length. For dial instruments the vision machine observes the coincidence of the moving needle with divisions representing (sub) units of length. The displacements measured by laser interferometer are compared with dial indicator and the measuring errors are observed.

Published
2010
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