A method for reduction of number of actuators in Independent Modal Space Control

In this paper, a modified Independent Modal Space Control (IMSC) that relaxes the fundamental hardware requirement of IMSC is proposed for handling the vibration and attitude control problem of large, flexible structures. The method incorporates a new switching algorithm for dynamically selecting controlled modes and a novel design technique for determining the modal control force. The main advantage of the proposed method is that it minimizes the discontinuity of the modal control forces and assures the asymptotic stability of the closed-loop system. The simplicity and efficiency of the method is demonstrated through an example involving vibration control of a cantilevered beam. The system performance and stability of the proposed method is compared with previously published methods that also seek to reduce the number of actuators in IMSC.     

Enhancement of surface quality in ultrasonic machining of glass using a sacrificing coating

We present a new fabrication method that enables precision hole machining to be achieved by sacrificing the coating on the substrate in ultrasonic machining (USM). A hard wax coating is deposited on the glass substrate, and holes are precisely fabricated in the coated glass using USM. Finally, a wax coating is removed using a cleaning process. The wax coating protects the surface of the glass so that cracks are generated in the wax rather than on the surface. The surface accuracy of the glass substrate is evaluated at the hole entrance using the new tools in USM as a function of the thickness of the coating. The entrance diameters of the machined holes and the machining forces at the beginning of cutting are measured as a function of the thickness of the coating. The entrance cracks and out-of-roundness of the machined holes are generated in the sacrificed coating on the glass substrate; hence, the surface quality of the glass holes is enhanced in USM.     

An analysis of safety-critical digital systems for risk-informed design

This paper quantitatively presents the results of a case study which examines the fault tree analysis framework of the safety of digital systems. The case study is performed for the digital reactor protection system of nuclear power plants. The broader usage of digital equipment in nuclear power plants gives rise to the need for assessing safety and reliability because it plays an important role in proving the safety of a designed system in the nuclear industry. We quantitatively explain the relationship between the important characteristics of digital systems and the PSA result using mathematical expressions. We also demonstrate the effect of critical factors on the system safety by sensitivity study and the result which is quantified using the fault tree method shows that some factors remarkably affect the system safety. They are the common cause failure, the coverage of fault tolerant mechanisms and software failure probability.     

Epoxy/BaTiO/sub 3/ composite films and pastes for high dielectric constant and low-tolerance embedded capacitors fabrication in organic substrates

Epoxy/BaTiO/sub 3/ composite embedded capacitor films (ECFs) were newly designed for high dielectric constant and low-tolerance (less than /spl plusmn/5%) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of a specially formulated epoxy resin and latent curing agent, and in terms of a coating process, a comma roll coating method is used for uniform film thickness in large area. The dielectric constant of ECF in high frequency range (0.5/spl sim/3 GHz) is measured using the cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. The dielectric constant is calculated by observing the frequencies of the resonant cavity modes. Calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of the epoxy matrix. The dielectric relaxation of barium titanate (BaTiO/sub 3/: BT) powder is not observed within measured frequency. An alternative material for embedded capacitor fabrication is epoxy/BaTiO/sub 3/ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming a capacitor partially in the desired part. However, the screen printing makes surface irregularities during mask peel-off. Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, a dielectric layer with improved thickness uniformity is successfully demonstrated. Using epoxy/BaTiO/sub 3/ composite ECP, a dielectric constant of 63 and specific capacitance of 5.1 nF/cm/sup 2/ were achieved.     

Induction of apoptosis in HeLa cells by ethanolic extract of Corallina pilulifera

Marine organisms are rich sources of new, biologically active compounds. Seaweeds have traditionally been used as food, but have also been used as folk medicine, particularly by coastal peoples. Recently, much attention has been paid to the anticancer activity of seaweed. Thus, we have screened organic extracts of seaweeds for their anticancer activity against human cell lines, and selected Corallina pilulifera as a candidate for use in treatment. The ethanolic extracts of Corallina pilulifera (EECP) showed cytotoxic activity against human cervical adenocarcinoma cell line, HeLa. The IC₅₀ of EECP against the HeLa cells was 250 μg/ml. Treatment of HeLa cells with various concentrations of EECP resulted in growth inhibition and induction of apoptosis in a dose-dependent manner. In Western blot analysis, apoptosis in the HeLa cells was associated with the release of cytochrome C from mitochondria into the cytosol, activation of caspase-3 and caspase-8, and proteolytic cleavage of PARP (poly (ADP-ribose) polymerase). These results strongly suggest that EECP may be a potential candidate in the field of anticancer drug discovery.     

Catalytic fluorination of HCFC-133a (1,1,1-trifluoro-2-chloroethane)

Catalytic fluorination of HCFC-133a was performed over metal oxide catalysts. Chromium oxide showed the best catalytic activity among several metal oxides tested. An increase in the crystallinity with decreased surface area resulted in a decrease of catalytic activity for the fluorination reaction. Active phase of chromia is Cr-O-F-OH having a proper ratio of O/F and a high hydroxyl content. The hydroxyl content on the catalyst is strongly dependent on support material. The selectivity to HFC-134a is independent of the O/F ratio on the Cr surface.     

多维非线性sobolev型发展方程(组)的初边值问题

本文主要研究了如下的初边值问题其中Ω∈R~n是一有界开集,其边界Ω充分光滑。进一步证明了这个问题整体解的存在唯一及t→ ∞时解的渐近性质。     

One-bath dyeing of poly(ethylene terephthalate)/cotton blends with alkali-clearable azo disperse dyes containing a fluorosulphonyl group

Monoazo disperse dyes containing a fluorosulphonyl group, based on 4-amino-4'-fluorosulphonylazobenzene derivatives, were dyed on poly(ethylene terephthalate)/cotton blends and their dyeing and fastness properties investigated. A one-bath dyeing method was used, as these dyes can be alkali cleared in the same bath. In particular, the cross-staining of cotton was studied in order to assess their suitability for the one-bath dyeing of poly(ethylene terephthalate)/cotton blends.     

Fabrication of 50-nm gate SOI n-MOSFETs using novel plasma-doping technique

A plasma-doping technique for fabricating nanoscale silicon-on-insulator (SOI) MOSFETs has been investigated. The source/drain (S/D) extensions of the tri-gate structure SOI n-MOSFETs were formed by using an elevated temperature plasma-doping method. Even though the activation annealing after plasma doping was excluded to minimize the diffusion of dopants, which resulted in a laterally abrupt S/D junction, we obtained a low sheet resistance of 920 /spl Omega///spl square/ by the elevated temperature plasma doping of 527 /spl deg/C. A tri-gate structure silicon-on-insulator n-MOSFET with a gate length of 50 nm was successfully fabricated and revealed suppressed short-channel effects.