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This paper proposes a simple and efficient method to develop a nanocomposite by depositing platinum (Pt) nanoparticles on a carbon nanotube (CNT) sheet, and experimentally verifies the applicability of the proposed nanocomposite as a reliable and sensitive carbon monoxide (CO) gas sensor that operates at room temperature. A Pt-CNT nanocomposite shows improved CO gas sensing properties compared with the pristine CNT sheet. Owing to its large surface area and high conductivity, a CNT sheet exhibits improved sensitivity and fast response and recovery times. Based on the Pt-CNT nanocomposite implemented by the proposed method, we fabricated a Pt-CNT sheet-based CO gas sensor operating at room temperature and experimentally verified its stable and reliable room temperature sensing properties and excellent structural flexibility.

Polycrystalline samples of RE 0.6Ca0.4Ba1.6Sr0.4Cu3O6 (RE = Nd, Gd, Dy, Y, Yb, Lu) without oxygen in the Cu(1)O chain have been prepared by the conventional solid-state reaction method. No superconductivity appears for larger RE = Nd, Gd, Dy, while superconductivity with T c ~50 K appears for smaller RE = Y, Yb, Lu. This is presumably because holes produced by the Ca-substitution for RE are more supplied to the conductive Cu(2)O2 plane than to Cu(1) as the lattice becomes small. The maximum T c = 53 K for RE = Lu is considerably lower than 90 K for REBa2Cu3O7. This may be due to the low hole-concentration in the Cu(2)O2 plane.

This paper presents a thermal convection-based sensor, which is fabricated using carbon nanotube (CNT) yarn. The key element in this device is the non-symmetrically distributed, heated air medium around the heater, particularly when it experiences acceleration and/or changes in inclination. Therefore, it can withstand much higher accelerations/inclination than conventional sensors that use a proof mass. However, a major challenge for the design of this type of sensor is the high heating power (in the order of tens of milliwatts) required to facilitate thermal convection in a sealed chamber. In order to reduce the high heating power, CNTs are investigated as materials for both the heater and the temperature sensors. Moreover, this paper discusses experiments that were performed by varying several parameters, such as the heating power, distance between the heater and temperature sensors, the gas medium used, and air pressure.