• Journal of Radiation Protection and Research
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• v.38 no.3
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• pp.132-137
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• 2013

Cryogenic particle detectors have recently been adopted in radiation detection and measurement because of their high energy resolution. Many of these detectors have demonstrated energy resolutions better than the theoretical limit of semiconductor detectors. We report the development of alpha spectrometer using a micro-fabricated magnetic calorimeter coupled to a large-area particle absorber. A piece of gold foil of $2{\times}2{\times}0.05mm^3$ was glued to the paramagnetic temperature sensor made of sputtered Au:Er film to serve as an absorber for incident alpha particles. We performed experiments with 241Am source at cryogen free adiabatic demagnetization refrigerator (CF-ADR). A high energy resolution of 6.8 keV in FWHM was obtained for 5.5 MeV alpha particles.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1415-1419
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• 2013

This study was conducted to investigate the seasonal variation characteristics of phytoncide in trail of Ulsan Metropolitan. Air samples were collected from May to December 2011. They were collected using Tenax Ta tube and phytoncides were detected and quantified using a Gas Chromatograph Mass Spectrometer (GC/MSD). This study are summarized as follows; The seasonal concentrations of phytoncide are Munsu Mt. 272.3 ${\mu}g/m^3$, Samho Mt. 192.4 ${\mu}g/m^3$, Shinbul Mt. 50.9 ${\mu}g/m^3$, Sibli Bamboo forest 22.4 ${\mu}g/m^3$ and Joongbu Fire Station 24.4 ${\mu}g/m^3$. In Munsu Mt., Samho Mt. and Shinbul Mt. major component ratio is ${\alpha}$-Pinene > ${\beta}$-Pinene+Myrcene >Limonene >Camphene > ${\gamma}$-Terpinene > ${\alpha}$-Terpinene. Bamboo forest and Joongbu fire station major component ratio is ${\alpha}$-Pinene >Limonene > ${\beta}$-Pinene+Myrcene >Camphene > ${\alpha}$-Terpinene. The variation of seasonal concentration is summer >spring >fall >winter. The phytoncide concentration of coniferous forest(Munsu Mt., Samho Mt.) is higher than broadleaf forest(Shinbul Mt.).

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.24-30
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• 2005

Four compounds, (+)-catechin (1), (-)-epicatechin (2), myricitrin (3), and hinokiflavone (4), were isolated from the needles of Juniperus occidentalis Hook. The structures of the isolated compounds were established by NMR and MS spectrometer. The antioxidant activity of the isolated compounds was determined by measuring free radical scavenging activity with DPPH and the results indicated that compound 1, 2, and 3 showed better activity than the controls, while compound 4 had weak activity compared with ${\alpha}-tocopherol$, BHT, and curcumin.

• Fashion & Textile Research Journal
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• v.4 no.2
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• pp.198-202
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• 2002

Degummed silk from Bombyx mori was dissolved in 9.3M lithium bromide solution. The regenerated silk fibroin films were completely ${\alpha}$-randomcoil type as shown by x-ray diffraction and infrared spectroscopy. The structural changes in silk fibroin induced by immersion into methanol and dilute hydrochloric acid and its photo-yellowing effect was studied. The changes of crystallinity were measured by infrared spectrometer. Yellowness index caused by ultraviolet irradiation were observed as a function of the structural change on silk fibroin. On treatment with methanol, ${\alpha}$-randomcoil silk film is converted to the ${\beta}$-form structure. After the treatment of hydrochloric acid on ${\beta}$-form structure in silk induced by immersion into methanol, ${\beta}$-form in silk fibroin is partially decreased. Crystallization owing to ${\beta}$-form transition reduced the initial yellowness index by ultraviolet irradiation. A little ${\beta}$-form structure in silk fibroin increased the initial yellowness in comparison with more ${\beta}$-form structure.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.473-477
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• 1995

The dichloromethane extracts of the above ground parts of Hymenoxys brachyactis afforded three sesquiterpene lactones already reported, one new sesquiterpene lactone, biennin C and hispidulin as known toxic flavone. Structures of all compounds were established by spectroscopy and biennin C was determined as an adduct of the modified pseudoguanolide and hymenoxon by Gas Chromatograpy and MS spectrometer These sesquiterpene lactones have the same ${\alpha},{\beta}$-unsaturated functional group like that of hymenovin which has been known as major toxic constituent of important livestock poison. And biennin C is also considered as toxic compound because of toxic hymenoxon.

• Journal of Electrochemical Science and Technology
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• v.10 no.3
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• pp.257-270
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• 2019

The inhibition performance of sodium gluconate (SG), cetyltrimethylammonium bromide (CTAB) and their mixture (SG/CTAB) on the corrosion behavior of ${\alpha}$-brass in 0.5 M $H_2SO_4$ solution has been investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning Electron Microscope with Energy-Dispersive Spectrometer (SEM-EDS), Inductively Coupled Plasma Spectrometry (ICPS) and molecular dynamics (MD) simulation techniques. The results reveal that SG with 5ppm CTAB, noted SG/CTAB, acts as a good corrosion inhibitor and its inhibition efficiency reached 89% after 24 h immersion in sulfuric acid solution, but slightly decreased at higher temperatures. The polarization curves displayed that SG/CTAB acts as a cathodic-kind inhibitor. Electrochemical impedance spectroscopy (EIS) studies revealed that the addition of 5ppm CTAB to different concentrations of SG considerably increases the corrosion resistance of ${\alpha}$-brass. The SEM-EDS and ICPS analyses support the experimental results. Further, molecular dynamics (MD) simulations were used to understand the adsorption profiles of SG/CTAB on Cu(111) and Zn(111) surfaces.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.49-57
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• 2000

To understand the effects of drying conditions on changes of volatile compounds in fruits of Schizandra chinensis, we analyzed SDE (steam distillation and extraction) extract and Headspace vapor of fresh and dried samples using GC/MS (Gas chromatograph/Mass spectrometer). Contents of essential oils from samples with different drying conditions were 0.58% in fresh ones, 0.60% in freeze dried ones, and 0.30% in hot-air dried ones. In SDE extract, major volatile compounds in fresh samples were terpinen-4-ol(9.01%), ${\gamma}-terpinene(7.02%),\;{\beta}-myrcene(7.55%)$, unidentified sesquiterpenes(28.48%), showing almost the same composition as that in freeze-dried ones, but those in hot-air dried samples at $60^{\circ}C$ were ${\gamma}-terpinene(5.40%),\;{\alpha}-elemene(8.28%)$, unidentified sesquiterpenes(50.38%), indicating the chemical changes during drying procedure. In Headspace vapor, major compounds in fresh samples were ${\beta}-myrcene(22.05%),\;{\gamma}-terpinene(9.47%),\;{\alpha}-pinene(8.91%)$, sabinene(8.48%), which were different from those in SDE extract. In chemical compositions of volatile compounds in dried samples, ${\beta}-myrcene,\;{\alpha}-terpinene$ decreased in the order of freeze-drying > hot-air drying at $60^{\circ}C$ > hot-air drying at $60^{\circ}C$, and ${\alpha}-ylangene,\;{\alpha}-pinene$, camphene increased in the reverse order of the former. We observed the changes of the contents and compositions of essential oils compounds during drying procedure, especially a decrease in monoterpenes and alcohols and an increase in sesquiterpenes with relatively weak volatility.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1478-1480
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• 2001

ZnO : Al transparent conductive thin films were prepared by facing targets sputtering system with a DC power supply which can deposit a high quality thin films and control deposition condition in all range of $O_2$ gas ratio using ZnO target containing 8 at% of Al. Sputtering was carried out at a substrate temperature of R T with a DC current of 0.6 A and $O_2$ flow rate of 0 $\sim$ 0.9. The characteristics of ZnO : Al thin films was investigated by $\alpha$-step, four point probe, X-ray diffraction and UV/VIS spectrometer.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.415-418
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• 1996

Space Solar Telescope (SST) is a space project for solar research, its main parameters are that total weight 2.0T, sun synchronous polar circular orbit, altitude of the orbit 730KM, 3 axis stabilized attitude system, power 1200W, telemetry of the downlink rate 30Mb/s, size $5{\ast}2{\ast}2\;M^3$, mission life 3 years. It is expected it will be launched in 2001 or later. The main objective is structure and evolution of solar vector magnetic field with very high spatial resolution. The payloads are consisted of 6 instruments: Main optical telescope with 1-M diameter and diffraction limited resolution 0.1 arc second, EUV imaging telescope with a bundle of four telescopes and 0.5 arc second resolution, spectrometric optical coronagraph, wide band spectrometer, H-alpha and white light telescope and solar and interplanetary radiospectrometer. An assessment study between China and Germany is under operation.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.63.1-63.1
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• 2011

In understanding AGN physics, it is fundamental to determine black hole masses. Based on the gas kinematics of the broad-line region, black hole masses can be derived from the product of the width of the broad emission lines and the continuum/line luminosities. For a sample of 37 intermediate-luminosity AGN at z~0.4, we obtained high quality spectra (S/N~100) using the Low Resolution Imaging Spectrometer(LRIS) at the KECK telescope, in order to calibrate various black hole mass estimators based on the Mg II (2798A), the $H{\beta}$ (4861A), and the $H{\alpha}$ (6563$\bar{A}$) emission lines. Based on our multicomponent fitting analysis, we subtract continuum, FeII emission, and host galaxy starlight, reducing systematic errors in measuring emission line widths. Combining low S/N SDSS spectra with our high S/N keck spectra, we determine a set of ~30 black hole masses of the sample for each emission line. Then by comparing various sets of black hole masses, we internally calibrate each mass estimators and investigate uncertainties and limitations of each mass estimator.