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Nipoti R.,CNR Institute for Microelectronics and Microsystems | Nath A.,George Mason University | Rao M.V.,George Mason University | Hallen A.,KTH Royal Institute of Technology | And 2 more authors.
Applied Physics Express | Year: 2011

A microwave heating technique has been used for the electrical activation of Al+ ions implanted in semi-insulating 4H-SiC. Annealing temperatures in the range of 2000-2100 °C and annealing time of 30 s have been used. The implanted Al concentration has been varied from 5 × 10 19 to 8 × 1020 cm-3. A minimum resistivity of 2 × 10-2 σcm and about 70% electrical activation of the implanted Al have been measured at room temperature for an implanted Al concentration of 8 × 1020 cm-3 and microwave annealing at 2100 °C for 30 s. © 2011 The Japan Society of Applied Physics.

Kancleris Z.,LT Technologies | Slekas G.,LT Technologies | Matulis A.,Institute for Research in Fundamental Sciences
IEEE Transactions on Antennas and Propagation | Year: 2013

The technique for implementation of two-dimensional electron gas (2DEG) sheet in a finite-difference time-domain (FDTD) scheme is proposed. The modified electromagnetic field update equations are derived differing from the standard Yee equations by the tangential components of the electric field in the 2DEG plane. The reliability of the proposed technique is checked applying it to the simple problem - the electromagnetic wave reflection dependence on the surface conductivity of 2DEG sheet overcovering wholly cross-section of the rectangular waveguide, and comparing the obtained results with the available analytical solution. © 1963-2012 IEEE.

Puiso J.,Kaunas University of Technology | Jonkuviene D.,Kaunas University of Technology | Macioniene I.,Kaunas University of Technology | Salomskiene J.,Kaunas University of Technology | And 2 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2014

In this study lingonberry and cranberry juices were used for silver nanoparticle synthesis. The berry juices were characterized by total phenolics, total anthocyanins and benzoic acid content, respectively 1.9-2.7. mg/ml, 55.2-83.4. mg/l and 590.8-889.2. mg/l. The synthesis of silver nanoparticles was performed at room temperature assisting in solutions irradiated by ultraviolet for 30. min. Ultraviolet-visible (UV-vis) spectroscopy and microscopy confirmed the formation of nanoparticles as well as the dark red color of colloid of silver samples showed the formation of stable nanoparticles. Broad localized surface plasmon resonance (LSPR) peaks in UV-vis spectra indicated the formation of polydispersive silver nanoparticles and LSPR was observed at 485. nm and 520. nm for the silver nanoparticles synthesis using lingonberry and cranberry juices, respectively. The antimicrobial activity of silver nanoparticles was determined against the reference strains of microorganisms that could be found in food products: Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 13076, Listeria monocytogenes ATCC 19111, Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and foodborne B. cereus producing and non-producing enterotoxins. Silver nanoparticles showed a broad spectrum of antimicrobial activity and were most active against S. aureus ATCC 25923, B. subtilis ATCC 6633 and B. cereus ATCC 11778 reference cultures, and less active against C. albicans ATCC 10231 and foodborne B. cereus. It can be concluded that lingonberry and cranberry juices could be used as bioreductants for silver ions. © 2014 Elsevier B.V.

Bockute K.,Kaunas University of Technology | Laukaitis G.,Kaunas University of Technology | Milcius D.,LT Technologies
Surface and Coatings Technology | Year: 2013

Lanthanum niobium oxide thin films were prepared using electron beam physical vapour deposition (EB-PVD). The composition, crystal structure, morphology and optical properties of the films formed were studied. The results indicated that La2O3 and Nb2O5 have different deposition rates, i.e., the stoichiometry of the elements in the thin films is different to the initial evaporated powder. The stoichiometry of 1 La:1 Nb was achieved when the molar ratio of the initial oxides was 1.3 La2O3:1 Nb2O5. The thin films formed were amorphous in all samples, and the molar mixing ratio of the La2O3 and Nb2O5 powders did not have an influence on the crystallinity of the thin films formed in our experiments. Swanepoel's method was used for the optical parameter calculations. It was found that the refractive indexes were dependent on the quantity of lanthanum in the thin films and had a tendency to decrease with an increasing amount of lanthanum. The calculated optical band gaps were from 3.69 to 3.9eV. © 2012 Elsevier B.V..

Ramanaviciene A.,Vilnius University | Ramanaviciene A.,State Research Institute | Virzonis D.,Kaunas University of Technology | Virzonis D.,LT Technologies | And 2 more authors.
Analyst | Year: 2010

An affinity sensor based on a capacitive micromachined ultrasound transducer (cMUT) is reported by this Communication. The cMUT micromembrane arrays modified with adsorbed bovine leukemia virus protein gp51 were applied as a biological recognition part. The cMUT-based sensor is shown to be sensitive to the antibodies against bovine leukemia virus protein gp51 (anti-gp51). Two different concentrations of anti-gp51-containing samples and one blank sample without anti-gp51 were tested. The sensitivity of cMUT-based immunosensor is comparable with the sensitivity of a quartz microbalance-based immunosensor. The cMUT array provides a multi-channel system for the measurement of analytical signal. Moreover, two different characteristics - the resonance frequency shift (Δf) and the shift of the real part of the electromechanical impedance (ΔRe) - could have been evaluated simultaneously. Both analytical signals are informative and can be applied for the estimation of immune complex formation. We found the performance of such a system being potentially superior over some other immunosensing techniques. It is more rapid than electrochemical techniques and provides two different informative parameters. © 2010 The Royal Society of Chemistry.

Trusovas R.,LT Technologies | Ratautas K.,LT Technologies | Raciukaitis G.,LT Technologies | Barkauskas J.,Vilnius University | And 3 more authors.
Carbon | Year: 2013

Reduction of graphite oxide (GO) to graphene induced by picosecond pulsed laser irradiation has been studied by Raman spectroscopy, scanning electron microscopy together with modeling of temperature dynamics in the materials. Dependence of the D, G, and 2D Raman band parameters on the laser pulse energy and the irradiation dose was evaluated. The exponential decline of the full width at half maximum of the Raman lines with increasing product of the pulse energy and irradiation dose was observed indicating ordering in the film and reduction in the number of graphene layers during the laser treatment. The minimum concentration of structural defects and the largest relative intensity of the 2D peak were found for the 50 mW mean laser power and the 30 mm/s scanning speed. Modeling of temperature dynamics revealed that the temperature of the GO film irradiated with a single laser pulse at a fluence of 0.04 J/cm2 (50 mW) increased up to 1400 °C for a few nanoseconds, which was sufficient for the effective reduction of GO to graphene with successive laser pulses. © 2012 Elsevier Ltd. All rights reserved.

Indrisiunas S.,LT Technologies | Voisiat B.,LT Technologies | Gedvilas M.,LT Technologies | Raciukaitis G.,LT Technologies
Journal of Micromechanics and Microengineering | Year: 2013

Interference of several identical laser beams allows for the fabrication of periodical structures over large areas. We present two complementary techniques for the patterning of thin films using the laser beam interference and direct ablation of material. The first one is based on precise control of the laser fluence relative to the ablation threshold of the film. Additional means for pattern management are provided by separate control of the intensity and phase of the interfering laser beams. Interference of four or six laser beams permits fabrication of periodical arrays of circular holes. Flexibility and sensitivity to the process parameters of the method beyond of simple hole arrays are shown for the thin Cr film ablation. Another versatile means for pattern generation in the films is the scanning of the periodic laser beam distribution over a workpiece in a sub-period area. By translation of the sample in small steps between laser shots, the structures with their shape independent of the interfering beam intensity distribution can be fabricated by overlapping the ablated holes. Slit- and cross-shaped periodical structures were fabricated using direct structuring with interfering nanosecond and femtosecond pulses. The thin-film structures fabricated by both techniques can be used as spectrally-selective elements for terahertz and infrared radiation. © 2013 IOP Publishing Ltd.

LT Technologies | Date: 2015-02-03

There is provided a method of implementing carrier aggregation on a first transceiver. The method comprises receiving and decoding, during a first subframe, channel quality information from user equipment and transferring, before the expiry of a second subframe immediately following the first subframe, the decoded channel quality information over a direct physical link to a second transceiver, for use in decoding further channel quality information from the user equipment.

LT Technologies | Date: 2014-02-17

In a surgical instrument with a shaft part (1), to which a slide (3) is assigned, wherein shaft part (1) and slide (3) are releasably connected to each other, a detent element (14) is intended to protrude from the shaft part (1) and/or from the slide and, as the slide (3) slides along the shaft part (1), the detent element (14) enters a recess (13) of the slide (3) and/or of the shaft part.

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