Large magnetoresistance at room-temperature in semiconducting polymer sandwich devices

We report on the discovery of a large, room temperature magnetoresistance (MR) effect in polyfluorene sandwich devices in weak magnetic fields. We characterize this effect and discuss its dependence on voltage, temperature, film thickness, electrode materials, and (unintentional) impurity concentration. We usually observed negative MR, but positive MR can also be achieved under high applied electric fields. The MR effect reaches up to 10% at fields of 10mT at room temperature. The effect shows only a weak temperature dependence and is independent of the sign and direction of the magnetic field. We find that the effect is related to the hole current in the devices.Comment: 3 pages, 4 figure

Strategy revision opportunities and collusion

This paper studies whether and how strategy revision opportunities affect levels of collusion in indefinitely repeated two-player games. Consistent with standard theory, we find that such opportunities do not affect strategy choices, or collusion levels, if the game is of strategic substitutes. In games of strategic complements, by contrast, revision opportunities lead to more collusion. We discuss alternative explanations for this result

2014 IEEE 20TH INTERNATIONAL SYMPOSIUM FOR DESIGN AND TECHNOLOGY IN ELECTRONIC PACKAGING (SIITME)

This paper aims to perform the numerical analysis and to investigate thermal characteristics of the LED backlight TFT TV according to thermal design parameters. Natural convective cooling of a LED array system used TFT TV is considered in this study. Numerical computations are carried out for horizontal and vertical orientations of the LED array. The effects of the PCB materials on the temperature distribution are discussed in detail. It is found that the maximum temperature of the LED packages significantly decreases by the horizontal orientation of the LED array in TFT based television. In addition, ceramic based PCB materials having high thermal conductivity such as A1N present better thermal performance than that of metal based PCB materials

Optical and microstructural properties of pure and Ru doped SnO2 semiconducting thin films

WOS: 000347510000015Pure and ruthenium (Ru) doped nanostructure SnO2 (Ru-SnO2) semiconductor films were prepared by sot-gel technique on glass substrates. The effect of Ru incorporation on microstructure and optical properties of SnO2 films was investigated. Crystalline structure, orientations, morphological, optical properties of the films were investigated by using XRD, SEM, AFM, VEECO profilometer, and UV spectrophotometer, respectively. The optical band gap, refractive index, extinction coefficient and dielectric constants were calculated by using transmittance and reflectance spectrum of the films. The obtained structural data indicated that all the films possess polycrystalline structure with tetragonal rutile SnO2 and Ru incorporation conducts to significant changes in the microstructure of the SnO2 films. In addition to these, the highest average optical transmittance value was obtained in the visible region for pure SnO2 film. It was found that optical band gap of film was decreased with the increase in Ru doping, and absorption edge shifted to higher wavelengths with incorporation of Ru.Scientific Research Project of Ege UniversityEge UniversityThis work has been partially supported by Scientific Research Project of Ege University. The author also wants to thank Dr. Mustafa Erol and Dr. Erdal Celik for their characterization support

Degradation of contaminated industrial waste water using sol-gel derived Ru-doped TiO2 photocatalyticfilms [Sol-jel ile elde edilen Ru katki{dotless}li{dotless} TiO2 fotokatalitik filmler kullani{dotless}larak endüstriyel-kirli sularin ayriştirilmasi]

In this study, Ru-TiO2 films were deposited on glass substrates with a sol-gel route for degradation of contaminated industrial water. A solution with the Ru/Ti molar ratio of 0.05 was prepared using ruthenium and titanium based precursors. Solution characterizations were made using a turbidimeter and pH meter. The gel films, prepared by the sol-gel drop casting method, were dried at 300°C for 10 minutes and subsequently heat-treated at 500°C for 5 minutes in air. After that, the oxide thin films were annealed at 600°C for 60 minutes in air. In order to evaluate the phase structure, microstructure, optical, and photocatalytic properties of the coatings, they were investigated using XRD, SEM, and UV/Vis spectrophotometer, respectively. The obtained phase was mostly anatase TiO2. Photo-oxidation experiments were performed to obtain the photocatalytic activity of the films on impure water using an UV light source. The absorption spectrum of the water samples taken from Cigli Industrial Plant and Gediz River in Izmir/Turkey showed that they have absorbance bands in the range of 300 nm and 500 nm. The Ru doped TiO2 films exhibited highly photocatalytic activity to decompose organic species in contaminated waters. The degradation percentage ratios were calculated as 75% and 62% for two different industrial water samples

The Comparison of the Novel Co-adsorbent Molecules' Effects on the DSSC's Efficiency

6th International Conference on Nanomaterials - Applications & Properties (NAP) -- SEP 14-19, 2016 -- Minist Educ & Sci Ukraine, Lviv, UKRAINEWOS: 000391877500018In this paper, the effect of co-adsorbed molecules used in Dye Sensitized Solar Cell (DSSC) on the performance parameters have been investigated. The aim of using these molecules is to prevent agglomeration during the soaking process of TiO2 covered electrodes. In order to understand the effect of the co-adsorbed molecules, typical DSSC devices with and without co-adsorbers were fabricated

Assessment of reaction between thorium and polyelectrolyte nano-thin film using Box–Behnken design

Sandwich type polyelectrolyte nano-thin films (PENTFs) were prepared by using polyallylamine hydrochloride and polyacrylic acid from layer-by-layer assembly process with spin coating system. Their nanostructures have been studied by scanning electron microscope, atomic force microscope, and attenuated total reflectance Fourier transform infrared spectroscopy. In order to understand the effects of the initial concentration of thorium, initial solution pH, temperature, and contact time on the reaction between thorium and PENTF, an experiment data set was designed according to Box–Behnken model. The analysis of variance calculations for regression model were carried out in 95% confidence level and were checked for fitting experimental data and predicted values. The correlation coefficient value (R2) obtained as 94% showed that there was a correlation between the predicted and the observed values. The optimum pH, temperature, initial concentration of thorium, and interaction time in studied ranges were found as 2.81, 35?, 160 mg·L-1, and 120 min, respectively. At these conditions thorium (IV) ions adsorption yield was obtained as 89 ± 2%. The Freundlich, Langmuir, and Dubinin–Radushkevich isotherms were used to investigate the characteristics of the process. These characteristics data imply that the Freundlich model fits better than the Langmuir model for the Th (IV) sorption onto PENTFs with KF and n values were found to be 20.6 mg·g-1 and 1.08 L·mg-1, respectively. The thermodynamic parameters were also computed as negative ?H value suggest that adsorption of Th (IV) is exothermic nature. The calculated negative and positive values of ?G indicate that the sorption process is favorable (energetically) while running below 40? and over this point the process status change to non-spontaneous, respectively. © 2017, © The Author(s) 2017

The powerboard design for the first AMOLED TV of Turkey [The powerboard design for the first AMOLED TV of Turkey]

2016 National Conference on Electrical, Electronics and Biomedical Engineering, ELECO 2016 -- 1 December 2016 through 3 December 2016 -- 126446In this study, the design of 600W power board for Vestel AMOLED TV that is prototyped firstly in Turkey, is presented. Furthermore, our study includes the properties of the circuit elements and integrated circuits that is used in board design. Additionally, Filter, Protection, Stand-By, Power Factor Correction (PFC), Resonant and Synchronous Rectifier Blocks of power board design are given. The reliability and performance tests of power board completed successfully in Ar-Ge test laboratories in the level of board and system and results are also discussed. The result of Reliability analysis gives nearly 8 ppm error ratio in terms of MIL STD 217F. © 2016 The Chamber of Turkish Electrical Engineers