Magnetostrictive actuator is fabricated with powder nano bonding method instead of sputtering method. Fabrication process and experimental measurement method for magneto-mechanical characteristics is proposed. For the design of highly flexible magnetostrictive actuator, TbDyFe nano powder bonding with Teflon substrate is adopted. The fabrication process for Teflon substrate and nano powder bonding is suggested and magnetostrictive behaviors are investigated. Variable magnetic field is applied to measure the magnetostrictive characteristics and magnetostriction is measured with different waves and different magnitude of magnetic field.
In this study, TbDyFe thin films with the thickness of 1000 Å are fabricated by DC magnetron sputtering. TbDyFe thin films are prepared by DC magnetron sputtering method. The pressure of Ar gas below 1.33 kPa and DC input power of 200 W are used for the sputtering conditions. During sputtering process the substrate holder is heated up to 150 ℃. The thin films are deposited to a thickness of 1000 Å on polyimide substrate with a thickness of 2 μm. The fabricated microstructures are observed by X-ray diffraction (XRD) and the film thickness is measured. Magnetostrictions are determined from the curvature of the thin films which are measured by the optical cantilever method. The experimental results are discussed with numerical data.
Diesel engines show better thermal efficiency and fuel consumption, but diesel engines typically generate more NOx emissions because of lean-burn conditions. Therefore, it is necessary to reduce the emissions of diesel engines either by efficiently controlling combustion or by employing exhaust gas after-treatment systems. In this study several problems we're observed in a SCR system and Engine control system. The analysis result, new technology SCR is suitable for the vehicle with low temperature operating condition. Through this analysis we can find out more effective repair factors from the various fault in SCR component.
Emission regulation by Europe and the U.S. on air pollutants from diesel automobiles which include particulate matter and nitrogen oxides are becoming stricter than ever.
The SCR uses Urea, which is NH3 diluted by water, and chemically reacts with emission gases reducing over 90% of the NOx created.
In this study several problems were observed in a SCR system and Engine control system.
Through this analysis we can find out more effective repair factors from the various fault in SCR component.
This study suggested comprehensive structural characterization methods for the commercial blue light emitting diodes(LEDs). By using the Z-contrast intensity profile of Cs-corrected high-angle annular dark field scanning transmission electron microscope(HAADF-STEM) images from a commercial lateral GaN-based blue light emitting diode, we obtained important structural information on the epilayer structure of the LED, which would have beendifficult to obtain by conventional analysis. This method was simple but very powerful to obtain structural and chemical information on epi-structures in a nanometer-scale resolution. One of the examples was that we could determine whether the barrier in the multi-quantum well(MQW) was GaN or InGaN. Plan-view TEM observations were performed from the commercial blue LED to characterize the threading dislocations(TDs) and the related V-pit defects. Each TD observed in the region with the total LED epilayer structure including the MQW showed V-pit defects for almost of TDs independent of the TD types: edge-, screw-, mixed TDs. The total TD density from the region with the total LED epilayer structure including the MQW was about 3.6 × 108 cm−2 with a relative ratio of Edge- : Screw- :Mixed-TD portion as 80%: 7%: 13%. However, in the mesa etched region without the MQW total TD density was about 2.5 × 108 cm−2 with a relative ratio of Edge- : Screw- :Mixed TD portion of 86%: 5%: 9 %. The higher TD density in the total LED epilayer structure implied new generation of TDs mostly from the MQW region.