Surface‐discharge electrode design methods for ACPDPs

Abstract— In order to lower development costs and to shorten development time, small panels, under 10‐in on the diagonal, are used for the experiments to improve the luminous efficiency of plasma‐display panels. However, it is difficult to show the same results as those of large panels, over 40 in. on the diagonal. In this paper, first, we show that the luminous efficiency and the voltage margin of mini‐panels are not obtained with large panels by using an actual 46‐in. PDP. The reason is that the resistance in the large panels is larger than that in the mini panels and the voltage drop in the large panels are larger than in mini‐panels. Therefore, we conclude that the bus electrode width and the transparent electrode width are important factors in the design of large PDPs. Next, we show the technique of designing large panels by using a database obtained from mini‐panels. The estimated cell‐design results show good agreement with an actual 46‐in. PDP in luminous efficiency and minimum sustain voltage. We show that a desired large PDP can be obtained by using the cell design proposed in the present paper.     

Simulation of a zero-dispersion filter monochromator for image-spectroscopic measurements

I propose a novel filter monochromator for image spectroscopic measurements. An aberration-corrected double monochromator that I reported on previously [Appl. Opt. 36, 7114-7118 (1997)] is modified for use in a zero-dispersion mode. An incident image on the entrance aperture is focused onto an imaging detector attached on the exit focal plane with a spectral bandwidth determined by the width of the intermediate slit. Unlike a conventional interference filter, the spectral bandwidth and its center wavelength are determined arbitrarily while both a low stray-light level and the sharp cutoff characteristics of the wavelength are maintained. To demonstrate the real capabilities, ray-tracing simulations are carried out. I also discuss the problem of wavelength purity in the spectroscopic image.     

Water mist formation in vapor-mist dielectrics and its effect

It has been proposed that vapor-mist dielectrics in which mixing liquid droplets such as tetrachloroethlene in a gas have the ability of increasing flashover, impulse voltage, and of suppressing partial discharge. Vapor-mist methods have been performed on other materials and the effect of the mist can also be obtained on benzene, hexane, and even water as general materials. Although these studies have been carried out, neither the discharge mechanism on vapor-mist nor the reason for the increase of the discharge voltage is understood fully because the mist is of various sizes. On the other hand, agglomeration of water molecules can be studied with the FR-IR method, and are classified into monomer, dimer, trimer (including polymer). Water gives mist stats which are significant in discussing effects. This paper describes states of water mist and their effect under nonuniform field with positive and negative polarities. Water mist in vapor exists as dimer and trimer, and their amount decreases with the reduction of temperature. These mists have no effect on discharge suppression. However, when the mists are formed by space charges, the inception voltage is increased by these mists in the negative polarity.     

Prediction of the capacity of a heat exchanger by a thermal network method: Modified effective specific heat model considering the influence of static pressure distributions of refrigerants

In this paper, we proposed a method to predict the capacity of a heat exchanger by considering static pressure distributions of refrigerants. The thermal network method was modified by adding an equivalent heat generation term into a heat balance equation that was connected with calculated 1D static pressure distributions of refrigerants. An experiment was performed with a heat exchanger having two rows and two passes to verify the accuracy of the proposed method. The result showed the error of the predicted capacity to be less than 1% for an evaporator and less than 2% for a condenser. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(5): 376–390, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10039     

Small polypoid lesions of the gallbladder: differential diagnosis and surgical indications by helical computed tomography

We report the case of a 16-year-old girl who experienced sudden cardiac arrest from ventricular fibrillation, complicating an arrhythmogenic right ventricular dysplasia, a rare heart muscle disorder, occurring typically in young adults, characterized by a fibrofatty replacement of the right ventricular myocardium. Symptomatic ventricular arrhythmias are frequent, and sudden death has been reported. In our case, diagnosis of arrhythmogenic dysplasia was based on the association of one major criterion and two minor criteria as suggested by the relevant task force. In contrast with most other reports, the chest ECG did not display the typical features. An automatic transvenous pectoral cardioverter-defibrillator was implanted. The authors emphasise that juvenile forms are more exposed to ventricular fibrillation and sudden cardiac death, and consequently require the early detection of the disease. Family cases have been described and the occurrence in one individual must lead to investigations in the relatives.     

Improvements in finite-element simulation for stamping and application to the forming of laser-welded blanks

During stamping-die design, the formability in sheet-metal forming process has been evaluated by the geometrical functions in ‘Die-Face CAD’, which has been developed and improved by Toyota Motor Corporation. When evaluation by these functions is difficult, formability has been estimated by performing experiments using test dies in which the forming defects are similar to those in the actual process.

A numerical method has been developed in order to substitute numerical analysis for experiments using test dies for the accurate prediction of defects in sheet-metal forming. The elastic-plastic FEM with the commercial code ‘JNIKE3D’ has been improved in the areas of: (1) the material constitutive equation; (2) the consideration of the pressure distribution on the blank-holder; and (3) the evaluation of breakage initiation. Using the improved method, the square-cup drawing process and the hemming process have been analyzed. Numerical results for strain, breakage initiation, and hemming deflection were in good agreement with experimental results. The formability of laser-welded blanks and the most efficient process to form them were evaluated also using the improved method.     

Input system for part model in CAD from coloured hand-written illustration with use of ITV

An input system for CAD is developed to construct a part model within a computer from a hand-written sketch. The sketch is drawn based on the technical illustration method. The shape of the input part is constructed by the combination of cuboids and cylinders at present. A coloured illustration is adopted for the ease of the shape recognition and for the input of the technological information.

The illustration is fed into the computer via a black and white ITV. Colours are identified referring to the brightness of the input image. The constitutive bodies, the geometric element with the technological information and the content of the technological information are recognized through image processing such as noise filtering, thinning of the contours, detection of lines and so on. The input system outputs a set of commands to the modelling system. The integrated part model which includes not only the geometrical information but also the technological information of the part is constructed by the connected modelling system CIMS/MODE.

The combination of the input system and the modelling system can support the designer to construct the detailed part model within the computer effectively. It is expected to extend the ability of the input system to identify general hand-written illustrations so that the input method will be more practical and useful.     

Printed Low Velocity Delay Lines for Cathode Readout of Proportional Chambers

A new type of flat delay line was developed which has a low propagation velocity and very good delay to rise time ratio. It can be constructed by printed circuit techniques without crossovers. The magnetic loops of a shifted periodic structure yield high inductance per unit length. Geometric scaling factors are shown. This line, forming the cathode plane of a proportional chamber, allows simultaneously, a satisfactory induced signal and the readout of the second coordinate by time delay without disturbing the electric field configuration around the anode. Optimization of position resolution vs. noise is discussed. Experimental results are shown. Other properties of such delay lines are discussed.     

The dependence of structure and conductivity in three-dimensional phosphate ionic conductors on composition

Two series of solid solutions, Na _x Ca_(1−x)/2Zr₂(PO₄)₃ (NCZP(x), 0⩽x⩽1) and Na _x Nb_1-x Zr_1+x (PO₄)₃(NNZP(x), 0⩽x⩽1), were synthesized. They were examined by powder X-ray diffraction, infra-red (i.r.) absorption and Raman scattering. Ionic conductivities of graphite coated samples were measured. A complete series of solid solutions was formed for NCZP(x), while a second phase was found forx<0.1 for NNZP(x). The i.r. and Raman spectra of their solid solutions consistently showed the formation of PO₄ tetrahedra with different geometries. The composition dependence of conductivity is interpreted on the basis of a structural change around Na⁺.     

Measured resonance characteristics of a 2-ghz-fundamental quartz resonator

I fabricated an inverted-mesa AT-cut quartz resonator in which the thickness of the vibrating area was adjusted to 0.6 /spl mu/m by wet etching, and I demonstrated the excitation of a fundamental thickness vibration of 2.074 GHz. This main mode was inductive, and Q was 1037. However, all inharmonic modes were capacitive.