• Journal of the Korean Home Economics Association
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• v.44 no.7 s.221
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• pp.63-72
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• 2006

The purpose of this study was to survey the wearing practices and problems in the working uniform for volunteer fire brigade members and then to develop its design with a improved movement adaptability, physical suitability, ease for equipment accommodation, functionality, convenience and fit. Based on the questionnaire, we have made a testing uniform for volunteer fire brigade members first. Through a subjective analysis for functionality and apparence, we suggested a final design. The final design includes the following elements: 1. It was a two-piece style composed of a jumper and trousers with the upper garments pulled out. Raglan sleeves were used to increase arm's movement scope. Pleats and velcro tapes were attached along the base hem of sleeves to prevent heat transmission. 2. Various types of pockets were attached to secure enough space for keeping things. 3. In trousers, spare space was given at the buttock area with rubber string inserted only at selected part of side lines, and knee pads were attached to prevent wearing out.

• Korean Journal of Materials Research
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• v.17 no.8
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• pp.437-441
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• 2007

Preparation and morphology control of $TiO_2$ nano powders for gas sensor applications are investigated. $TiO_2$ nanopowders with rutile and anatase structures were prepared by controlling the pH value of a precursor solution without any heat treatment. The mean particle size of $TiO_2$ powders were below 10nm. The prepared $TiO_2$ nano powders were hydrothermal treated by NaOH solution. The sample was washed in HCl solution. As a result and $TiO_2$ nanotubes were formed. The lengths of $TiO_2$ nanotube were $1{\mu}m$ and the diameters were 10nm. Crystal structure and microstructure of $TiO_2$ nanotube were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). As-prepared $TiO_2$ nanotube powders have several advantages of nano particle size and high surface area and could be a prominent candidate for nano-sensors. The sensitivity of $TiO_2$ nanotube sensor was measured for toluene and NO in this study.

• Korean Journal of Materials Research
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• v.23 no.7
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• pp.359-365
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• 2013

We investigated the nanostructural, chemical and optical properties of nc-Si:H films according to deposition conditions. Plasma enhanced chemical vapor deposition(PECVD) techniques were used to produce nc-Si:H thin films. The hydrogen dilution ratio in the precursors, [$SiH_4/H_2$], was fixed at 0.03; the substrate temperature was varied from room temperature to $600^{\circ}C$. By raising the substrates temperature up to $400^{\circ}C$, the nanocrystalite size was increased from ~2 to ~7 nm and the Si crystal volume fraction was varied from ~9 to ~45% to reach their maximum values. In high-resolution transmission electron microscopy(HRTEM) images, Si nanocrystallites were observed and the crystallite size appeared to correspond to the crystal size values obtained by X-ray diffraction(XRD) and Raman Spectroscopy. The intensity of high-resolution electron energy loss spectroscopy(EELS) peaks at ~99.9 eV(Si $L_{2,3}$ edge) was sensitively varied depending on the formation of Si nanocrystallites in the films. With increasing substrate temperatures, from room temperature to $600^{\circ}C$, the optical band gap of the nc-Si:H films was decreased from 2.4 to 1.9 eV, and the relative fraction of Si-H bonds in the films was increased from 19.9 to 32.9%. The variation in the nanostructural as well as chemical features of the films with substrate temperature appears to be well related to the results of the differential scanning calorimeter measurements, in which heat-absorption started at a substrate temperature of $180^{\circ}C$ and the maximum peak was observed at ${\sim}370^{\circ}C$.

• Corrosion Science and Technology
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• v.11 no.3
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• pp.96-102
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• 2012

Outer diameter stress corrosion cracking (ODSCC) has occurred for Alloy 600 (Ni 75 wt%, Cr 15 wt%, Fe 10 wt%) as a heat exchanger tube of the steam generator (SG) in nuclear power plants (NPP) during long term operation. Among many causes for SCC, lead (Pb) is known to be one of the most deleterious species in the secondary system. In the present work, the oxide formed on Alloy 600 was characterized as a function of the PbO content in 0.1 M NaOH at $315^{\circ}C$ by using an electrochemical impedance spectroscopy (EIS), a transmission electron microscopy (TEM), equipped with an energy dispersive x-ray spectroscopy (EDS). The oxide property was analyzed in view of SCC susceptibility.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.635-640
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• 2016

Lactobacillus acidophilus n.v. Er2 317/402 strain Narine is known as a health beneficial functional probiotic culture and supplementary source of nutrition for newborns. In this study, in vitro antimicrobial activities of Narine-lyophilized (Narine-L), Narine-heat treated (Narine-HT), and Narine crude cell-free extract (Narine-CCFE) were evaluated against pathogen Cronobacter sakazakii (C. sakazakii) in agar as well as in a reconstituted powdered infant formula (RPIF) model. Inhibition zones of 30 mg Narine-L and Narine-HT were both 150 U, whereas inhibition zone of 30 mg Narine-CCFE was 200 U. Narine-L (1 g) and Narine-HT (1 g) were added to 10 mL of artificially contaminated RPIF, respectively, containing 100 μL of C. sakazakii (1.62×10⁸ colony forming unit (CFU)/mL). After treatment with Narine-L and Narine-HT for 3 h and 6 h at 37℃, less than ≤107 CFU/mL of C. sakazakii was detected in RPIF. Without Narine-L and Narine-HT treatment, the population of C. sakazakii increased up to 5.36×10⁹ CFU/mL after 6 h. Examination by transmission electron microscopy confirmed C. sakazakii cells were damaged by Narine-CCFE. Thus, employing Narine culture as a natural and safe bio-preservative may protect infants from C. sakazakii.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.155-161
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• 1999

The land reclamation area of Saemangeum(Kunsan) is located between 126$^{\circ}$10' E~126$^{\circ}$50' E and 35$^{\circ}$35' N~356$^{\circ}$05'N at the western coast of the Korean peninsula. The are many small islands including extensive areas of semi-diurnally flooded and dewatered tidal flats. The reclamation area of Saemangeum has a range of 5.6m spring tide and the maximum tidal current speed is about 1.41m s-1 in ordinary spring tide. Most of the sediments deposited on the tidal flats are transported from the Geum river, the Manjyung river and The Dongjin river. The soil in this area consists of silty sand with the depth of 10m to 30m . The wind in winter is strong from the direction of northwest. In the past twenty years, land reclamation projects for agricutural purpose or industrial cocmplex have been mostly implemented along the western coast of Korea. Saemangeum coastal area is being constructed the33km sea dike and 40, 100ha reclamation area. The purpose of this study is to find the residual circulations in four seasons after the dike construction by a robust diagnostic and prognostic numerical model. Heat flux at the sea surface in January ,May , August , October was asopted on the basis on the daily inflow of solar radiation at the earth surface, assuming an average atomospheric transmission and no clouds , as a function of latitude and time of year(George L.P.J.E William, 1990). The discharge from the Geum , the Mankyung and the Dongjin rivers was adopted on the basis of experience formula of river flow in January , May ,August, October (The M. of C.Korea, 1993) . Water temperature and salinity along the open boundaries are obtained from the results of field observation s.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.614-622
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• 1999

Recent studies have implicated that more rostral components of the trigeminal spinal nucleus including subnucleus oralis (Vo) in orofacial nociceptive mechanisms. Since there is only limited electrophysiological evidence, the present study was initiated to characterize the receptive field and response properties of malls nociceptive neurons in chloralose/urethan-anesthetized rats. Single neuronal activity was recorded in right subnucleus oralis, and types of nociceptive neurons classified wide dynamic range (WDR), NS (nociceptive specific) and deep nociceptive (D) and the mechanoreceptive field (RF) and response properties were determined. A total of 34 nociceptive neurons could be subdivided into 17WDR neurons, 12NS neurons and 5D neurons. Vo nociceptive neurons had RF involving maxillary and/or mandibular divisions mainly located in the intraoral and/or perioral regions. Majority of Vo nociceptive neurons showed spontaneous activity less than 1Hz. The NS and D neurons activated only by heavy pressure and/or pinch stimuli had high mechanical thresholds compared to WDR neurons activated also by tactile stimuli. Vo nociceptive neurons showed a progressive increase of response to the graded mechanical stimuli. 39% of Vo nociceptive neurons received C-fiber electrical input as well as A-fiber electrical input from their RF, and 45% of them responded to electrical stimulation of the right maxillary first molar. 41% of Vo nociceptive neurons responded to noxious heat applied to their RF, and 18% of them showed an immediate burst of discharges following MO application to the right maxillary first molar pulp. These results indicate that Vo is involved in the transmission of nociceptive information mainly coming from intraoral or perioral region including tooth pulp.

• Journal of Electrochemical Science and Technology
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• v.1 no.1
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• pp.31-38
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• 2010

In this study, we have demonstrated the fine structure effect of PdCo electrocatalyst on oxygen reduction reaction activity with different alloy composition and heat-treatment time. In order to identify the intrinsic factors for the electrocatalytic activity, various X-ray analyses were used, including inductively coupled plasma-atomic emission spectrometer, transmission electron microscopy, X-ray diffractometer, and X-ray Absorption Spectroscopy technique. In particular, extended X-ray absorption fine structure was employed to extract the structural parameters required for understanding the atomic distribution and alloying extent, and to identify the corresponding simulated structures by using FEFF8 code and IFEFFIT software. The electrocatalytic activity of PdCo alloy nanoparticles for the oxygen reduction reaction was evaluated by using rotating disk electrode technique and correlated to the change in structural parameters. We have found that Pd-rich surface was formed on the Co core with increasing heating time over 5 hours. Such core shell structure of PdCo/C showed that a superior oxygen reduction reaction activity than pure Pd/C or alloy phase of PdCo/C electrocatalysts, because the adsorption energy of adsorbates was apparently reduced by lowering the dband center of the Pd skin due to a combination of the compressive strain effect and ligand effect.

• Journal of Drive and Control
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• v.12 no.1
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• pp.1-8
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• 2015

The stability of friction characteristics and thermal management for a dry type dual clutch transmission (DCT) are inferior to those of a wet clutch. Too high temperature resulting from frequent engagement of DCT speeds up degradation or serious wear of the pressure plate or burning of the clutch disk lining. Even though it is significantly important to estimate the temperature of a dry double clutch (DDC) in real-time, few meaningful study of the thermal model of DDC has been known yet. This study presented a thermal analytical model of lumped parameters for a DDC by analyzing its each component firstly. Then a series of experimental test was carried out on the test bench with a patented temperature telemetry system to validate the proposed thermal model. The thermal model, whose optimal parameter values were found by optimization algorithm, was also simulated on the experimental test conditions. The simulation results of DDC temperature show consistency with the experiment, which validates the proposed thermal model of DDC.

• Corrosion Science and Technology
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• v.19 no.4
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• pp.203-210
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• 2020

The corrosion behavior of super austenitic stainless steel was studied by examining the characteristics of the sigma phase formed in the steel. A range of experimental and analytical methods was employed, including potentiodynamic polarization tests, critical pitting temperature tests, transmission electron microscopy, and energy-dispersive spectroscopy. Three steel samples with different sigma phase levels were obtained by intentionally adjusting the manufacturing process. The results showed that the corrosion resistance of the samples was strongly dependent upon the size and distribution of the sigma phase precipitated in the samples. The larger the size of the sigma phase, the higher the Mo content in the sigma phase and the higher the depletion level of Mo at the interface between the matrix/sigma phase, the more samples with a coarse-sized sigma phase were susceptible to localized pitting corrosion at the interface. These results suggest that various manufacturing processes, such as welding and the post-heat treatment of the steel, should be optimized so that both the size and fraction of the sigma phase precipitated in the steel are small to improve the resistance to localized corrosion.