A planar microstrip ring resonator structure on alumina was developed using the commercial FEM software COMSOL. Design parameters were evaluated, eventually leading to an optimized design of a miniaturized microwave gas sensor. The sensor was covered with a zeolite film. The device was successfully operated at around 8.5 GHz at room temperature as a humidity sensor. In the next step, an additio...

The small radiant heaters that burn hydrocarbon fuels propane, butane, methane/natural gas and liquid hydrocarbon fuels are used widely because of their simple design, their portability, and the ready availability of fuels. The open flame heater presents obvious disadvantages as follows. An upset heater is a grave fire risk where the surroundings are flammable and this restricts usage in, for e...

In this work we present a high performance micro gas chromatograph column with a novel two dimensional axial heating technique for faster and more precise temperature programming, resulting in an improved separation performance. Three different axial resistive heater designs were simulated theoretically on a 3.0 m × 300 μm × 50 μm column for the highest temperature gradient on a 22 by 22 μm col...

carbon monoxide (co) poisoning is still a health problem all over the world. informing users about symptoms and suggesting annual inspection of co producing devices will result in co poisoning reduction. the goal of this study was to evaluate awareness about co poisoning symptoms and its prevention ways in iranian population. in this study, a total of 700 patients' family members attended imam ...

Iron oxide (Fe₂O₃) nanopowder was prepared by a precipitation method and then mixed with different proportions of carbon nanotubes. The composite materials were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. A fabricated heater-type gas sensor was compared with a pure Fe₂O₃ gas sensor under the influence of acetone. The effec...

We have measured diffusion thermopower in a two-dimensional electron gas at low temperature (T=40 mK) in the field range 0 < B < 3.4 T, by employing the current heating technique. A Hall bar device is designed for this purpose, which contains two crossing Hall bars, one for the measurement and the other used as a heater, and is equipped with a metallic front gate to control the resistivity of t...

A tin dioxide (SnO2) sensor was fabricated by inkjet printing onto polyimide foil. Gold electrodes and heater were printed on each side of the substrate. A SnO2 based ink was developed by sol-gel method and jetted onto the electrodes. A final annealing at 400°C compatible with the polymeric transducers allowed to synthetize the SnO2 sensing film. Electrical measurements were carried out to char...