A comparative study on structural,morphological and photocatalytic properties of anodically grown ZnO nanowires under varying parameters

Journal of Materials Science: Materials in Electronics - In this study, zinc oxide (ZnO) nanowires (NWs) were successfully produced on Zn plates through electrochemical anodization in potassium...     

Methacrylate-functionalized POSS influence on cross-linking and mechanical properties of styrene-butadiene rubber

Iranian Polymer Journal - The addition of methacrylate-functional polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles to styrene-butadiene rubber (SBR) composites was evaluated in terms of...     

Adaptive Q control for tapping-mode nanoscanning using a piezoactuated bimorph probe

A new approach, called adaptive Q control, for tapping-mode atomic force microscopy (AFM) is introduced and implemented on a homemade AFM setup utilizing a laser Doppler vibrometer and a piezoactuated bimorph probe. In standard Q control, the effective Q factor of the scanning probe is adjusted prior to the scanning depending on the application. However, there is a trade-off in setting the effective Q factor of an AFM probe. The Q factor is either increased to reduce the tapping forces or decreased to increase the maximum achievable scan speed. Realizing these two benefits simultaneously using standard Q control is not possible. In adaptive Q control, the Q factor of the probe is set to an initial value as in standard Q control, but then modified on the fly during scanning when necessary to achieve this goal. In this article, we present the basic theory behind adaptive Q control, the electronics enabling the online modification of the probe's effective Q factor, and the results of the experiments comparing three different methods: scanning (a) without Q control, (b) with standard Q control, and (c) with adaptive Q control. The results show that the performance of adaptive Q control is superior to the other two methods.     

Investigation of the Equivalence of National Dew-Point Temperature Realizations in the ?50?°C to +?20?°C Range

In the field of humidity quantities, the first CIPM key comparison, CCT-K6 is at its end. The corresponding European regional key comparison, EUROMET.T-K6, was completed in early 2008, about 4?years after the starting initial measurements in the project. In total, 24 NMIs from different countries took part in the comparison. This number includes 22 EURAMET countries, and Russia and South Africa. The comparison covered the dew-point temperature range from ?50?°C to +20?°C. It was carried out in three parallel loops, each with two chilled mirror hygrometers as transfer standards in each loop. The comparison scheme was designed to ensure high quality results with evenly spread workload for the participants. It is shown that the standard uncertainty due to the long-term instability was smaller than 0.008?°C in all loops. The standard uncertainties due to links between the loops were found to be smaller than 0.025?°C at ?50?°C and 0.010?°C elsewhere. Conclusions on the equivalence of the dew-point temperature standards are drawn on the basis of calculated bilateral degrees of equivalence and deviations from the EURAMET comparison reference values (ERV). Taking into account 16 different primary dew-point realizations and 8 secondary realizations, the results demonstrate the equivalence of a large number of laboratories at an uncertainty level that is better than achieved in other multilateral comparisons so far in the humidity field.     

Power‐law conductivity in polythiophene/copper(II) acetylacetonate composites

This paper reports the charge transport mechanism of polythiophene (PT) matrix composites having various concentrations of copper(II) acetylacetonate. Characterization and structural analyses of the samples were carried out via Fourier transform infrared spectroscopy, atomic absorption spectroscopy, differential scanning calorimetry, thermogravimetric analysis and scanning electron microscopy (SEM). The alternating current electrical properties were investigated as a function of temperature. The change of free energy of adsorption calculated from the Langmuir adsorption isotherm showed that metal ions were electrostatically adsorbed onto polymer chains. Significant morphological changes were observed from SEM images of PT depending on doping process which in turn affected the thermal degradation of PT. The charge transport mechanism determined from a power law showed that there was one frequency‐dependent conductivity region for PT, while there were two regions for the composites in contrast to studies reported in the literature. © 2013 Society of Chemical Industry     

The effects of Cu and Al on dry sliding wear properties of eutectic Sn-9Zn lead-free solder alloy

The present study investigates the influence of Cu and Al on microstructure and wear behavior of a eutectic Sn-9Zn solder alloy. The Sn-9Zn–X alloy was produced by adding various amounts of Cu and Al through investment casting method. The produced Sn-9Zn–X alloys were characterized by a scanning electron microscope, X-ray diffraction, and hardness measurements. In wear tests at 1 ms^?1 sliding speed, 10 N load and 5 different sliding distances (400–2000 m) were used. The results show that as the amount of Cu and Al increased within Sn-9Zn alloy, the hardness of the alloy increased as well. Depending on the increase in hardness of the alloys produced by investment casting, it was observed that weight loss decreased during wear tests. Furthermore, the same proportion of added Al alloys’ hardness and weight loss were observed to be higher than the added Cu alloys. Furthermore, the Cu-added alloy exhibited higher hardness and lower weight loss than the Al-added alloy did.     

Comprehensibility of universal healthcare symbols for wayfinding in healthcare facilities

Healthcare facilities are often complex and overwhelming for visitors, and wayfinding in healthcare facilities can be challenging. As there is an increasing number of global citizens who travel to seek medical care in another country, it is critical to make wayfinding easy for visitors who are not familiar with the language in a foreign country. Among many wayfinding aids, symbols are helpful for those visitors who have limited ability to understand written language. This study tested universal healthcare symbols in the United States, South Korea, and Turkey to compare the comprehension of symbols cross-country and identify predictors of the correct comprehension. To explore statistically significant relationships between symbol comprehension and countries, Pearson's Chi-square tests, logistic regression, and ANOVA were conducted. The test results showed that ten symbols among 14 tested have significant relationship with countries. Results of this study demonstrate that symbol comprehension can be varied significantly in different countries.     

Tungsten(VI) oxide supported rhodium(0) nanoparticles; highly efficient catalyst for H2 production from dimethylamine borane

It reports the preparation and characterization of tungsten(VI) oxide supported rhodium(0) nanoparticles (Rh⁰/WO₃ NPs) being used as catalysts in releasing H₂ from dimethylamine borane (DMAB). The reducible nature of WO₃ plays a significant role in the catalytic efficiency of rhodium(0) nanoparticles in the dehydrogenation of DMAB. The Rh⁰/WO₃ NPs were in-situ generated from the reduction of Rh²⁺ ions on the surface of WO₃ during the catalytic dehydrogenation of dimethylamine borane in toluene and isolated from the reaction solution after the dehydrogenation to be characterized by using SEM, TEM, XPS, ATR-IR and XRD. The results reveal the formation of Rh⁰ NPs with a mean particle size of 1.92 ± 0.34 nm dispersed on the surface of tungsten(VI) oxide. Rh⁰/WO₃ NPs are found to be very active catalyst releasing 1.0 equiv. H₂ per mole of dimethylamine borane under ambient conditions. Among the various WO₃ supported Rh⁰ NPs with different metal loadings, the sample with 0.1% wt. Rh provide the record catalytic activity (TOF = 2816 h^?1) which is one of the highest value ever reported for rhodium-based catalysts in H₂ generation from DMAB at 60.0 ± 0.5 °C. Rh⁰/WO₃ NPs were also reusable catalyst in dehydrogenation of DMAB retaining 55% of their initial catalytic activity in the 3rd run of the dehydrogenation reaction. Control experiments were performed at various catalyst concentrations and temperatures to investigate the kinetics of dehydrogenation and to calculate the activation parameters for the reaction.