• Research in Community and Public Health Nursing
• /
• v.10 no.1
• /
• pp.32-43
• /
• 1999

This study is to classify subjectification and the perceived health of the elderly according to Q-methodology and to provide basic materials for health promotion of the elderly. In this study, 28 elderly people residing in Seoul classified 33 selected statements in to 9 standards. The material taken from this process resulted in 4 types by the analysis using a PC QUANL program. Case 1 thought that religion was important for their health. Case 2 were go-getters they thought they felt healthy at work. Case 3 took a serious view of their relationships with other people. Case 4 centered around the couple, and thought it important to live with their life's companion.

• Korean Journal of Materials Research
• /
• v.24 no.11
• /
• pp.573-577
• /
• 2014

The existing metal getters are invariably covered with thin oxide layers in air and the native oxide layer must be dissolved into the getter materials for activation. However, high temperature is needed for the activation, which leads to unavoidable deleterious effects on the devices. Therefore, to improve the device efficiency and gas-adsorption properties of the device, it is essential to synthesize the getter with a method that does not require a thermal activation temperature. In this study, getter material was synthesized using palladium oxide (PdOx) which can adsorb $H_2$ gas. To enhance the efficiency of the hydrogen and moisture absorption, a porous layer with a large specific area was fabricated by an etching process and used as supporting substrates. It was confirmed that the moisture-absorption performance of the $SiO_2/Si$ was characterized by water vapor volume with relative humidity. The gas-adsorption properties occurred in the absence of the activation process.

• The Korean Journal of Cytopathology
• /
• v.9 no.1
• /
• pp.69-78
• /
• 1998

There is a lot of difficulty in the diagnosis of follicular lesions of the thyroid by fine needle aspiration cytology(FNAC). The main purpose of this report is offering more guidance regarding the cytologic appearance to distinguish follicular neoplasm from nodular golfer and laying stress on the presence of mixed group. The histologic and cytologic findings of 23 follicular neoplasms and 13 nodular (adenomatous) getters were reviewed. Histologic specimens were classified into the microfollicular(MIF), mixed(MIX), and nodular getter(NG) groups. The comparison of histologic patterns with histologic diagnosis revealed that all the lesions with predominantly microfollicular, trabecular, or solid pattern were follicular carcinoma and all the lesions with predominantly macrofollicular pattern were nodular goiter. The distinguishing cytologic features for the MIF group were irregular cell arrangement in cell groups(100%, p=0.00001), absence of atrophic follicular cells(100%, p=0.0007), abundant microfollicles(100%, 0=0.002), pleomorphic nuclei(100%, p=0.002), not predominant syncytial smear pattern(100%, p=0.002), heterochromatin(100%, p=0.032), absence of macrofollicles(100%, p=0.038), scant colloid(100%, 0=0.04), clear back-ground(83%, p=0.00006), and uniform sized follicles(83%, p=0.014). And regular cell arrangement(honeycomb appearance) in cell groups(85%, p=0.0000), atrophic change of follicular cells(69%, p=0.0002), syncytial smear pattern(54%, p=0.000), monomorphic nuclei(85%, p=0.008), and hemorrhagic background(100%, p=0.027) were characteristic features of the NG group. Seventeen out of 36 cases(47%) were the MIX group composed of combined cytologic features of the MIF and NG groups. Therefore the frequent presence of the MIX group is considered to be main cause of the difficulty in the diagnosis of follicular lesions by FNAC. The mixed morphologic feature may support the hypothesis of a biologic 'continuum' between nodular goiter and follicular neoplasm of thyroid gland.

• Journal of the Korean Vacuum Society
• /
• v.14 no.1
• /
• pp.1-6
• /
• 2005

Getters are invariably covered with thin layers of oxides even in air. For the getter to function properly it is necessary to activate them by heating in vacuum during which the oxide layer is removed exposing clean surface. The so-called activation temperature is an important parameter along with gas sorption capacity since it determines the maximum temperature of a device in which a getter can be installed. Nevertheless, no standard method to measure activation temperature has been documented yet. In this study, a relatively simple method to measure the activation temperature based on the ultimate pressure measurement was suggested. The activation temperature of TiZrV alloy measured by the method was between 100℃～200℃.

• Transactions of the Korean hydrogen and new energy society
• /
• v.7 no.2
• /
• pp.157-164
• /
• 1996

The AB5-type metal hydride electrodes using $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$(LM : Lanthaniumrich Mischmetal) alloy powders(${\leq}200$mesh) which were coated with 25wt% copper in an acidic bath were prepared with or without addition of 10wt% PTFE as a binder. Prior to electrochemical measurements, the electrodes were sintered at $40^{\circ}C$ for 1 and 2hrs in vacuum with Mm(mischmetal) and sponge type Ti getters. The properties such as maximum capacity, cycle life and mechanical strength of the negative electrode have been investigated. The surface analysis of the electrode was also obtained before and after charge-discharge cycling using scanning electron microscope(SEM). From the observations of electrochemical behavior, it was found that the sintered electrode shows a lower maximum discharge capacity compared with non-sintered electrode but it shows a better cycle life. For the both electrodes with or without addition of PTFE binder, the values of mechanical strength were obtained, and their values increased with increasing sintering time. However, there is little difference of discharge capacity for both electrodes.

• Applied Science and Convergence Technology
• /
• v.23 no.6
• /
• pp.309-316
• /
• 2014

A large particle accelerator requires an ultrahigh vacuum (UHV) system of average pressure under $1{\times}10^{-7}$ Pa for mitigating the impact of beam scattering from the residual gas molecules. The surface inside the beam ducts should be controlled with an extremely low thermal outgassing rate under $1{\times}10^{-9}Pa{\cdot}m^3/(s{\cdot}m^2)$ for the sake of the insufficient pumping speed. To fulfil the requirements, the aluminum alloys were adopted as the materials of the beam ducts for large accelerator that thanks to the good features of higher thermal conductivity, non-radioactivity, non-magnetism, precise machining capability, et al. To put the aluminum into the large accelerator vacuum systems, several key technologies have been developed will be introduced. The concepts contain the precise computer numerical control (CNC) machining process for the large aluminum ducts and parts in pure alcohol and in an oil-free environment, surface cleaning with ozonized water, stringent welding process control manually or automatically to form a large sector of aluminum ducts, ex-situ baking process to reach UHV and sealed for transportation and installation, UHV pumping with the sputtering ion pumps and the non-evaporable getters (NEG), et al. The developed UHV technologies have been applied to the 3 GeV Taiwan Photon Source (TPS) and revealed good results as the expectation. The problems of leakage encountered during the assembling were most associated with the vacuum baking which result in the consequent trouble shootings and more times of baking. Then the installation of the well-sealed UHV systems is recommended.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.27 no.3
• /
• pp.144-157
• /
• 2022

Noble gases, which are chemically inert and behave conservatively in marine environments, have been used as tracers of physical processes such as air-sea gas exchange, mixing of water masses, and distribution of glacial meltwater in the ocean. For precise measurements of Ne, Ar, and Kr, we developed a mass spectrometric system consisting of a quadrupole mass spectrometer (QMS), a high vacuum preparation line, an activated charcoal cryogenic trap (ACC), and a set of isotope standard gases. The high vacuum line consists of three sections: (1) a sample extraction section that extracts the dissolved gases in the sample and mixes them with the standard gases, (2) a gas preparation section that removes reactive gases using getters and separates the noble gases according to their evaporation points with the ACC, and (3) a gas analysis section that measures concentrations of each noble gas. The ACC attached to the gas preparation section markedly lowered the partial pressures of Ar and CO₂ in the QMS, which resulted in a reduced uncertainty of Ne isotope analysis. The isotope standard gases were prepared by mixing ²²Ne, ³⁶Ar, and ⁸⁶Kr. The amounts of each element in the mixed standard gases were determined by the reverse isotope dilution method with repeated measurements of the atmosphere. The analytical system achieved precisions for Ne, Ar, and Kr concentrations of 0.7%, 0.7%, and 0.4%, respectively. The accuracies confirmed by the analyses of air-equilibrated water were 0.5%, 1.0%, and 1.7% for Ne, Ar, and Kr, respectively.

• Electrical & Electronic Materials
• /
• v.12 no.7
• /
• pp.7-11
• /
• 1999

Fully sealed field emission display in size of 4.5 inch has been fabricated using single-wall carbon nanotubes-organic vehicle com-posite. The fabricated display were fully scalable at low temperature below 415$^{\circ}C$ and CNTs were vertically aligned using paste squeeze and surface rubbing techniques. The turn-on fields of 1V/${\mu}{\textrm}{m}$ and field emis-sion current of 1.5mA at 3V/${\mu}{\textrm}{m}$ (J=90${\mu}{\textrm}{m}$/$\textrm{cm}^2$)were observed. Brightness of 1800cd/$m^2$ at 3.7V/${\mu}{\textrm}{m}$ was observed on the entire area of 4.5-inch panel from the green phosphor-ITO glass. The fluctuation of the current was found to be about 7% over a 4.5-inch cath-ode area. This reliable result enables us to produce large area full-color flat panel dis-play in the near future. Carbon nanotubes (CNTs) have attracted much attention because of their unique elec-trical properties and their potential applica-tions [1, 2]. Large aspect ratio of CNTs together with high chemical stability. ther-mal conductivity, and high mechanical strength are advantageous for applications to the field emitter [3]. Several results have been reported on the field emissions from multi-walled nanotubes (MWNTs) and single-walled nanotubes (SWNTs) grown from arc discharge [4, 5]. De Heer et al. have reported the field emission from nan-otubes aligned by the suspension-filtering method. This approach is too difficult to be fully adopted in integration process. Recently, there have been efforts to make applications to field emission devices using nanotubes. Saito et al. demonstrated a car-bon nanotube-based lamp, which was oper-ated at high voltage (10KV) [8]. Aproto-type diode structure was tested by the size of 100mm $\times$ 10mm in vacuum chamber [9]. the difficulties arise from the arrangement of vertically aligned nanotubes after the growth. Recently vertically aligned carbon nanotubes have been synthesized using plasma-enhanced chemical vapor deposition(CVD) [6, 7]. Yet, control of a large area synthesis is still not easily accessible with such approaches. Here we report integra-tion processes of fully sealed 4.5-inch CNT-field emission displays (FEDs). Low turn-on voltage with high brightness, and stabili-ty clearly demonstrate the potential applica-bility of carbon nanotubes to full color dis-plays in near future. For flat panel display in a large area, car-bon nanotubes-based field emitters were fabricated by using nanotubes-organic vehi-cles. The purified SWNTs, which were syn-thesized by dc arc discharge, were dispersed in iso propyl alcohol, and then mixed with on organic binder. The paste of well-dis-persed carbon nanotubes was squeezed onto the metal-patterned sodalime glass throuhg the metal mesh of 20${\mu}{\textrm}{m}$ in size and subse-quently heat-treated in order to remove the organic binder. The insulating spacers in thickness of 200${\mu}{\textrm}{m}$ are inserted between the lower and upper glasses. The Y\ulcornerO\ulcornerS:Eu, ZnS:Cu, Al, and ZnS:Ag, Cl, phosphors are electrically deposited on the upper glass for red, green, and blue colors, respectively. The typical sizes of each phosphor are 2~3 micron. The assembled structure was sealed in an atmosphere of highly purified Ar gas by means of a glass frit. The display plate was evacuated down to the pressure level of 1$\times$10\ulcorner Torr. Three non-evaporable getters of Ti-Zr-V-Fe were activated during the final heat-exhausting procedure. Finally, the active area of 4.5-inch panel with fully sealed carbon nanotubes was pro-duced. Emission currents were character-ized by the DC-mode and pulse-modulating mode at the voltage up to 800 volts. The brightness of field emission was measured by the Luminance calorimeter (BM-7, Topcon).