A 57-year-old female patient underwent combined off-pump coronary artery bypass grafting and abdominal aortic aneurysm replacement. Anesthesia was maintained with propofol, fentanyl, and thoracic epidural anesthesia. Propofol doses were adjusted to maintain bispectral index (BIS) between 40-60. Despite the remarkable hemodynamic changes, BIS remained stable at about 50 during the surgery. The average dose of propofol was 3.3 mg.kg-1.hr-1. The patient awoke an hour after the surgery and was extubated 1.5 hours thereafter. This case report suggests that BIS is a useful index to determine the depth of anesthesia during surgeries which induce marked hemodynamic changes.
Abstract We investigated the effectiveness of poling processes for Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 single crystals (SCs) produced using a continuous feeding Bridgman method, which is known to produce a high property uniformity. The four studied poling processes are: (I) standard direct current poling (STD-DCP); (II) low-voltage field-cooling DCP (LV-FCP); (III) high-voltage field-cooling DCP (HV-FCP); and (IV) mid-temperature alternating current poling (MT-ACP). The highest free dielectric constant ( ε 33 T / ε 0 ) and piezoelectric constant ( d 33 ) were obtained by MT-ACP ( ε 33 T / ε 0 = 11 000, d 33 = 3000 pC/N), followed by LV-FCP ( ε 33 T / ε 0 = 7500, d 33 = 2400 pC/N), HV-FCP ( ε 33 T / ε 0 = 6250, d 33 = 1850 pC/N), and STD-DCP ( ε 33 T / ε 0 = 6200, d 33 = 1800 pC/N). The LV-FCP SC showed a 21% and 33% increase in ε 33 T / ε 0 and d 33 compared to that of the STD-DCP SC; however, this was not as much as the 77% and 67% improvement of the MT-ACP SC. These results provide guidance for SC transducers.
Lead-free piezoelectric sodium potassium niobate ((K,Na)NbO3; KNN) ceramics with various grain sizes were prepared by hot isostatic pressing (HIP) and post-annealing. Their dielectric and electromechanical properties were then investigated. The average grain sizes of the ceramics were controlled by changing the post-annealing temperature. KNN ceramics obtained by HIP at 800°C without post-annealing with an average grain size of 0.34 μm exhibited a dielectric constant of 149, field-induced strain of 0.006% under 20kV/cm, and the piezoelectric d33 coefficient of 40pC/N by d33 meter measurement.
(Pb, La)TiO 3 (PLT, La/Ti=0.17) thin films were prepared by multiple cathode rf-magnetron sputtering. The electrical properties of these films were investigated. The PLT thin films deposited on Pt/MgO substrates exhibited higher crystallinity and better ferroelectric properties, compared to the films deposited on Pt/SiO 2 /Si substrates. The hysteresis loops of the PLT films on RuO 2 /Ru/SiO 2 /Si or RuO 2 /Ru/MgO were narrow compared to that of film deposited on platinum electrodes. The dielectric constant of PLT films deposited at 540° C decreased with decreasing film thickness. Existence of a Pb-deficient layer near the film/substrate interface was observed by X-ray photoemission spectroscopy (XPS) analysis. By lowering the substrate temperature to 515° C, Pb re-evaporation from the substrate decreased, and ferroelectric properties were improved. By controlling the Pb/Ti incident ratio, thin films with different Pb contents of the interface layer were formed. With an increase in the Pb content near the film/substrate interface, the fatigue resistance increased.
Various approaches to achieve digital optical processing have been proposed[1]-[3]. In order to achieve general processing, it is necessary to execute various kinds of logic operations. Moreover, individual processors must be connected each other. Few processors, however, have been previously reported with data representation suitable for cascade connection. Most of the processors proposed so far require pre-coding process, which makes hardwares complicated. If optical output signals from a processor are to be used as optical input signals for a next stage processor, pre-coding process is not necessary, which results in the realization of cascade connectable processing systems.
