Safety of the Las Vegas left-turn display

This paper provides a safety evaluation of a special protected/permitted left turn signal control (Las Vegas LT Display) that has been implemented in the urbanized area of Las Vegas, Nevada. The Las Vegas LT Display eliminates the yellow trap condition for leading approach in lead/lag operation. It provides protected only left turns during certain times of day by suppressing the permitted green ball and yellow ball displays. Before and after studies were conducted using the crash data from 10 intersections. Results from the analyses indicated that no obvious safety concerns due to use of the special display.     

Effects of process parameters on tungsten boride production from WO3 by self propagating high temperature synthesis

In the present study, the production parameters of tungsten boride compounds by self-propagating high-temperature synthesis (SHS) method and following leaching process were investigated. In the SHS stage, the products consisting of tungsten borides, magnesium oxide, magnesium borate, and also minor compounds were obtained by using different initial molar ratios of WO₃, Mg and B₂O₃ as starting materials. In the leaching step, Mg containing byproducts, i.e. MgO and Mg₃B₂O₆, existed in the selected SHS product synthesized at 1:8:2.5 initial molar ratio of WO₃:Mg:B₂O₃ were leached out by using aqueous HCl solution to obtain clean tungsten boride compounds at different experimental parameters which are time, acid concentration and temperature. The acid leaching experiments of the SHS product showed that optimum leaching conditions could be achieved by using 5.8 M HCl at 1/10 S/L ratio and the temperature of 80 °C for 60 min.     

The application of seasonal latent variable in forecasting electricity demand as an alternative method

In this study, we used ARIMA, seasonal ARIMA (SARIMA) and alternatively the regression model with seasonal latent variable in forecasting electricity demand by using data that belongs to “Kayseri and Vicinity Electricity Joint-Stock Company” over the 1997:1–2005:12 periods. This study tries to examine the advantages of forecasting with ARIMA, SARIMA methods and with the model has seasonal latent variable to each other. The results support that ARIMA and SARIMA models are unsuccessful in forecasting electricity demand. The regression model with seasonal latent variable used in this study gives more successful results than ARIMA and SARIMA models because also this model can consider seasonal fluctuations and structural breaks.     

Enhanced proton transport properties of Nafion via functionalized halloysite nanotubes

The introduction of naturally occurring fibrillary structured halloysite clays (HNTs) into the Nafion matrix resulted in an enhanced proton conductivity and a reduced activation energy for proton transport. To assess the effect of the various states of the HNTs as a membrane additive, the σ_H⁺ of the composite membranes (Nafion/HNTs, Nafion/HNTs-NH₂, Nafion/HNTs-SO₃H) was measured at 30 °C and 80 °C and at different levels of relative humidity (%RH). An overall improvement of the σ_H⁺ of the Nafion was observed in the presence of the nanotubular additives (HNTs or HNTs-NH₂) which can be attributed to the high specific surface area accommodating hydrophilic functional groups and therefore contributing to the water retention/management in the composite membrane. However, the Nafion/HNT-SO₃H composites are distinguished in terms of enhanced performance in σ_H⁺ which persist in the whole range of % RH levels and noted that the σ_H⁺ values are almost 2 times higher than native Nafion in the low humidity region (30%–50%) and at 80 °C. In agreement with the σ_H⁺ enhancement, the activation energy is lower than that of native Nafion indicating that the proton transport is facilitated in the presence of -SO₃H modified HNTs, probably due to an improved connectivity and arrangement of ionic conducting domains.     

Activity and stability enhancement of α-amylase treated with sub- and supercritical carbon dioxide

Various physical, chemical and genetic approaches have been applied in order to enhance enzyme stability and activity. In this study, the aim was to investigate the capability of sub- and supercritical carbon dioxide to alter the stability and activity of α-amylase as an alternative technique. The effects of operational parameters such as pressure (50-300 bar), temperature (28-80 °C), CO? flow (2-10 g min?1) and time (60-180 min) were evaluated in regard to the activity and stability of fungal based α-amylase from Aspergillus oryzea. The activity of untreated enzyme was determined as 17,726 μmol/ml/min. While both sub- and supercritical conditions enhanced the activity, the increase in flow rate had an adverse effect and the activity was decreased by 28.9% at a flow rate of 10 g min?1 under supercritical conditions. Nuclear magnetic resonance (NMR) spectra of untreated enzyme and treated samples exhibiting the lowest and the highest activities were almost identical except for the chemical shifts observed at the lowest activity sample from 4.0 to 4.4 ppm which were assigned to protons of hydrogen-bonded groups. Optimum conditions were determined as 240 bar, 41 °C, 4 g min?1 CO? flow and 150 min of process duration yielding 67.7% (29,728 μmol/ml/min) higher activity than the untreated enzyme providing fundamental basis for enzymatic applications.     

An ethanol electrooxidation study on carbon-supported Pt-Ru nanoparticles for direct ethanol fuel cells

Carbon supported Pt-Ru catalysts were prepared at varying Pt:Ru ratios by polyol method. The crystallite sizes of these catalysts were determined by X-ray diffraction technique. The specific surface areas of these catalysts were also defined by Brunauer–Emmett–Teller technique. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy measurements were conducted on these carbon supported Pt-Ru catalysts to investigate the effect of ruthenium on the ethanol electrooxidation kinetics. Results indicated that Pt-Ru (25:1) catalyst showed the best ethanol electrooxidation activity. In conclusion, ethanol electrooxidation mechanism was proposed.     

Slow, fast and flash pyrolysis of rapeseed

Pyrolysis experiments have been conducted on a sample of rapeseed to determine particularly the effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rate on the pyrolysis product yields and their chemical compositions. The maximum oil yield of 73% was obtained at the final pyrolysis temperature of 550–600 °C, particle size range of +0.6–1.25 mm, and sweep gas flow rate of 100 cm³min⁻¹ (N₂) at flash pyrolysis conditions in tubular transport reactor. Chromatographic and spectroscopic studies on the pyrolytic oil showed that the oil obtained from rapeseed can be used as a renewable fuel and chemical feedstock.     

Polyphenol oxidase properties,anti-urease,and anti-acetylcholinesterase activity of Diospyros lotus L. (Plum Persimmon)

Diospyros lotus fruit polyphenol oxidase was purified using affinity chromatography, resulting in a 15-fold enrichment in specific activity. The purified enzyme, having 16.5 kDa molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, exhibited the highest activity toward 4-methylcatechol. Maximum diphenolase activity was reached at pH 7.0 and 60°C in the presence of 4-methylcatechol. K_m and V_max values were calculated as 3.8 mM and 1250 U/mg protein, respectively. Ascorbic acid was a promising inhibitor with an IC₅₀ value of 0.121 µM. The activity of the purified enzyme was stimulated by Fe²⁺, Sr²⁺, Zn²⁺, and K⁺ and deeply inhibited by Hg²⁺, at 1 mM final concentration. Aqueous extract of Diospyros lotus L. fruit showed strong substantial urease and acetylcholinesterase inhibition, with IC₅₀ values of 1.55 ± 0.05 and 16.75 ± 0.11 mg/mL, respectively.