Browsing by Subject "Angle measurement"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Open Access A comparative study of map building techniques by processing sonar arc-maps(2005) Kurt, Arda; Barshan, BillurIn this study, four signal processing schemes regarding sonar sensor based map-building applications were compared. The newly proposed method, Directional Maximum is found to be successful in terms of reducing the innate angular ambiguity of the sonar sensors. With respect to several works presented earlier in the same field and specifically map-building related studies, the new method is successful both in terms of mean absolute error and computational cost.Item Open Access Electric field effects on optical properties of semiconductor nanorods(2009-05) Gurinovich L. I.; Lutich, A. A.; Stupak, A. P.; Prislopskii, S. Va.; Artemyev, M. V.; Rusakov, E. K.; Demir, Hilmi VolkanWe studied electric field effects on optical properties of CdSe/ZnS nanorods integrated in thin films sandwiched between transparent electrodes. It was demonstrated that P-polarized component of the photoluminescence of CdSelZnS nanorods is quenched stronger by external electric field than the S-polarized component. Quantum dots are more sensitive to external electric field than the nanorods. A mechanism of external electric field influence on the luminescence spectrum of semiconductor nanorods is discussed.Item Open Access In vitro biocompatibility of plasma-aided surface-modified 316L stainless steel for intracoronary stents(Institute of Physics Publishing, 2010) Bayram, C.; Mizrak, A.K.; Aktürk, S.; Kurşaklioǧlu H.; Iyisoy, A.; Ifran, A.; Denkbaş, E.B.316L-type stainless steel is a raw material mostly used for manufacturing metallic coronary stents. The purpose of this study was to examine the chemical, wettability, cytotoxic and haemocompatibility properties of 316L stainless steel stents which were modified by plasma polymerization. Six different polymeric compounds, polyethylene glycol, 2-hydroxyethyl methacrylate, ethylenediamine, acrylic acid, hexamethyldisilane and hexamethyldisiloxane, were used in a radio frequency glow discharge plasma polymerization system. As a model antiproliferative drug, mitomycin-C was chosen for covalent coupling onto the stent surface. Modified SS 316L stents were characterized by water contact angle measurements (goniometer) and x-ray photoelectron spectroscopy. C1s binding energies showed a good correlation with the literature. Haemocompatibility tests of coated SS 316L stents showed significant latency (t-test, p < 0.05) with respect to SS 316L and control groups in each test. © 2010 IOP Publishing Ltd.Item Open Access Resonant excitation of surface plasmons in one-dimensional metallic grating structures at microwave frequencies(Institute of Physics Publishing, 2005) Akarca-Biyikli, S. S.; Bulu, I.; Özbay, EkmelGrating-coupling phenomena between surface plasmons and electromagnetic waves were studied in the microwave spectrum using metallic gratings. Transmission measurements were carried out to observe the transmitted radiation around the surface plasmon resonance frequencies. Grating structures with subwavelength apertures were designed for transmission experiments. Measurements were made in the microwave spectrum of 10-37.5 GHz, corresponding to a wavelength region of 8-30 mm. The A1 samples had a grating periodicity of 16 mm. A 2 mm wide subwavelength slit was opened for transmission samples. Samples with one/double-sided gratings displayed remarkably enhanced transmission and directivity with respect to the reference sample without gratings. The experimental results agreed well with theoretical simulations. ∼50% transmission at 20.7 mm, ∼25-fold enhancement, and ±4° angular divergence were achieved with a ∼λ/10 aperture.