Temperature Dependence

In this study, hydrogen sensing properties of nanoporous Pd films based on Anodic Aluminium Oxide (AAO) templates grown on a silicon substrate have been investigated at various temperatures (25–100°C) and hydrogen concentrations (100–1000 ppm) to determine the temperature-sensitivity relationship. For this purpose, a hexagonally shaped AAO template of approximately 50 nm in diameter and 700 nm in length with 80 nm interpore distances was fabricated using two-step anodization of an Al film deposited on an n-type (100) oriented oxidized Si substrate. Then, the nanoporous surface of the AAO template was used as a substrate for supporting a nanoporous Pd film of an approximately thickness of 60 nm. The morphologies of the AAO template and Pd film coated on the AAO template were studied mainly by Scanning Electron Microscopy (SEM). Hydrogen sensing properties of the nanoporous Pd film were measured using a resistance transient method. It was found that the sensor response of the nanoporous Pd films on the AAO template was better than the traditional Pd thin film sensors, the sensitivity of the sensor was approximately 1.8% for 1000 ppm H2, and the detection limit was lower than 100 ppm at room temperature. The highest sensitivity was measured at room temperature.

This work shows the experimental data of excess properties at several temperatures and the vapor–liquid equilibria (VLE) obtained for four binary systems of alkyl methanoates (methyl to butyl) with decane, all measured at constant pressure of 101.32kPa. The isobaric VLE data were thermodynamically consistent according to the Fredenslund test and did not present an azeotrope. The experimental data of HmE

Four highly crystalline, cobalt-containing microporous aluminophosphates (CoAPO-5, CoAPO-11, CoAPO-44, and CoAPO-46) have been investigated by using liquid He X- and/or Q-band electron spin resonance(ESR) spectroscopy in order to investigate the coordination of high-spin cobalt before and after calcination. The ESR spectra of the four zeolite structures are characterized by an axial signal with an effective g^ ≈ 5.80-5.44 and gII

We present the results of an experiment performed at PSI to investigate muon catalyzed fusion in pure deuterium gas of 5% density (LHD) at temperatures ranging from 28 K to 350 K. Using a new high pressure ionization chamber the reactions dd→ n+ 3 He and ...

Room temperature internal friction (Q sup-1) values of the 0.00002-0.00003 range were achieved with lunar rock 70215,85 by thorough outgassing procedures in ultrahigh vacuum. Results are presented on the temperature dependence of Q-1 as measured in the range 25 C to 600 C along with some data on the change in Q-1 with pressure in ultrahigh vacuum. The temperature dependence shows the existence of an internal friction peak at around 200 C followed at high temperatures by an extensive region with flat Q-1 (approximately 0.001); the work at ultrahigh vacuum shows decreases in the internal friction with decreases in ambient pressure even in the range 10 to the -8 to 10 to the -10 power torr.

Information about the times of thermal breakthrough and subsequent rates of thermal drawdown in enhanced geothermal systems (EGS) is necessary for reservoir management, designing fracture stimulation and well drilling programs, and forecasting economic return. Thermal breakthrough in heterogeneous porous media can be estimated using conservative tracers and assumptions about heat transfer rates; however, tracers that undergo temperature-dependent changes can provide more detailed information about the thermal profile along the flow path through the reservoir. To be effectively applied, the thermal reaction rates of such temperature sensitive traces must be well characterized for the range of conditions that exist in geothermal systems. Reactive tracers proposed in the literature include benzoic and