• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.285-285
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• 2011

EUVL (Extreme Ultra Violet Lithography) is one of competitive lithographic technologies for sub-30nm fabrication of nano-scale Si devices that can possibly replace the conventional photolithography used to make today's microcircuits. Among the core EUVL technologies, mask fabrication is of considerable importance since the use of new reflective optics having a completely different configuration compared to those of conventional photolithography. Therefore new materials and new mask fabrication process are required for high performance EUVL mask fabrication. This study investigated the etching properties of SnO2 (Tin Oxide) as a new absorber material for EUVL binary mask. The EUVL mask structure used for etching is SnO2 (absorber layer) / Ru (capping / etch stop layer) / Mo-Si multilayer (reflective layer) / Si (substrate). Since the Ru etch stop layer should not be etched, infinitely high selectivity of SnO2 layer to Ru ESL is required. To obtain infinitely high etch selectivity and very low LER (line edge roughness) values, etch parameters of gas flow ratio, top electrode power, dc self - bias voltage (Vdc), and etch time were varied in inductively coupled Cl2/Ar plasmas. For certain process window, infinitely high etch selectivity of SnO2 to Ru ESL could be obtained by optimizing the process parameters. Etch characteristics were measured by on scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses. Detailed mechanisms for ultra-high etch selectivity will be discussed.

• Mass Spectrometry Letters
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• v.8 no.3
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• pp.59-64
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• 2017

In clinical diagnosis, it's well known that the abnormal level of uric acid (UA) in human body is implicated in diverse human diseases, for instance, chronic heart failure, gouty arthritis, diabetes, and so on. As a primary method, an isotope dilution mass spectrometry (IDMS) has been used to obtain the accurate quantity of UA in blood or serum and also develop the certificated reference material (CRM) so as to provide a SI-traceability to clinical laboratories. Due to the low solubility of UA in water, an ammonium hydroxide ($NH_4OH$) has been considered as a promising solvent to increase the solubility of UA that enables the preparation of both UA and its isotope standard solution for next IDMS-based absolute quantification. But, because of using this $NH_4OH$ solvent, it gives rise to the unwanted degradation of UA. In this study, we sought to optimize condition for the stability of UA in $NH_4OH$ solution by varying the mole ratios of UA to $NH_4OH$, followed by ID-LC-MRM analysis. In addition, we also inspected minutely the effect of the storage temperatures. Additionally, we also performed the quantitative analysis of UA in the KRISS serum certificated reference material (CRM, 111-01-02A) with diverse mixing ratios of UA to $NH_4OH$ and then compared those values to its certification value. Based on our experiments, adjusting the mole ratio of 1/2 ($UA/NH_4OH$) with the storage temperature of $-20^{\circ}C$ is an effective way to secure both the solubility and stability of UA in $NH_4OH$ solution for next IDMS-based quantification of UA in serum.

• Economic and Environmental Geology
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• v.29 no.3
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• pp.293-304
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• 1996

The Wolchul Mt. area is composed of a biotite granite and a pink feldspar granite. These granites are distinctly different in terms of their field occurrence, mineralogy, trace element and REE composition, as well as their isotope ages. The biotite granite has higher ferromagnesian elements and lower lithophile trace element abundances than the pink feldspar granite. The biotite granite has high Sr and Ba while the pink feldspar granite has high Rb. On the Rb-Sr-Ba diagram the biotite granite plots as a granodiorite while the pink feldspar granite belongs to a strongly differentiated granite. The ${\Sigma}$ LREE/ ${\Sigma}$ REE for the biotite granite is 0.95 and for the pink feldspar granite it is 0.88. The ratio shows a steep decrese in LREE while HREE is essentially constant. Based on the Eu/Sm, $[La/Lu]_{cN}$ and low Eu(-), the biotite granite has quartz diorite to granodiorite composition while the pink feldspar granite, with a relatively high Eu(-) anomaly, falls into the monzo- to syenogranite classification. The silica vs. trace element diagrams for the two granites indicate that the biotite granite could have formed near to a continental margin or volcanic island setting environment while the pink feldspar granite formed within a continental plate or as result of plate collision. The biotite granite has a U-Pb zircon age of 175 Ma, i.e. Middle Jurassic. The pink feldspar granite is younger, it has a K-Ar orthoclase age $93.6{\pm}1.5$ Ma which is Late Cretaceous age.

• Journal of Broadcast Engineering
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• v.13 no.5
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• pp.636-650
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• 2008

DTV has a great advantage as compared to Analog TV in picture quality under low reception field strength. Various high quality tuners have been developed to result in much smaller Noise Figure of the receivers and many trials for receiving DTV signal through indoor antenna. In this paper, results of intensive field tests on the indoor reception of DTV are presented. Tests were carried out around Seoul-Gyeonggi Metropolitan area. Commercial directional and omni-directional antennas and 5th generation receiver were used for reception availability tests. The effects of heights, locations, and types of the house as well as the distance to the transmitter on the reception performances are analyzed. Our test results will be applied to improve the indoor reception environment of DTV.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.4
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• pp.181-190
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• 2001

This study was conducted to investigate the effect of swine liquid manure(SLM) and phosphorus fertilizer from September, 1998 to July, 1999 on the soil fertility on Italian ryegrass field, Cheju volcanic ash soil. pH(lst investigated), Mg (2nd investigated) and Cu content (2nd investigated) on soil grown by Italian ryegrass were significantly increased by an increase of fertilizer P(P

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.291-295
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• 2000

The pyroelectric property of $Pb_{0.9}La$_{0.1}TiO_3$ceramics in a range of 1.3-4.1$\mu\textrm{m}$, fabricated by conventional solid sintering, was investigated as a function of poling field. The pyroelectric of the 4.1$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics is higher than that of the 1.3$\mu\textrm{m}$ and 1.7$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics at a low poling field and the pyroelectric coefficient is 25nC/$\textrm{cm}^2$K at a 4kV/mm poling field in every grain size. In order to explain this phenomenon, the intrinsic and extrinsic effects in view of the definition of the pyroelectric coefficient are introduced. The intrinsic and extrinsic effects on the pyroelectric property were investigated by measuring the tetragonal ratio and the $I_{002}$ with temperature with high temperature X-ray diffractometer. The change of spontaneous polarization and the $90^{\circ}$domain wall motion with temperature in the 1.3$\mu\textrm{m}$ and 4.2$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics have no effects on the pyroelectric coefficient. In our study, it can be seen that the pyroelectric coefficient is related to the quantity of $180^{\circ}$domain switching after poling treatment.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2007-2009
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• 1999

In this paper, discharge domain of wire-cylindrical plasma reactor was separated from a gas flow duct to avoid unstable discharge by aerosol particle deposited on discharge electrode and grounded electrode. The NOx, SOx removal was experimentally investigated by a reaction induced to ammonium nitrate, ammonium sulfate using a low price of aqueous NaOH solution and a small quantity of ammonia. Volume percentage of aqueous NaOH solution used was 20% and $N_2$ flow rate was 2.5[$\ell$/min] for bubbling aqueous NaOH solution. Ammonia gas(14.82%) balanced by argon was diluted by air and was introduced to a main simulated flue gas duct through $NH_3$ injection system which was in downstream of reactor. The $NH_3$ molecular ratio[MR] was determined based on $NH_3$ to [NO+$SO_2$]. MR is 1.5. The NOx removal rates increased in the order of DC, AC and pulse, but SOx removal rates was not significantly effected by source of electricity. The NOx removal rate slightly decreased with increasing initial concentration but SOx removal rate was not significantly effect by initial concentration, and NOx, SOx removal rates decreased with increasing gas flow rate.

• Resources Recycling
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• v.8 no.5
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• pp.44-50
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• 1999

The sbdy iwestlgaled ihc propa-ties of Lhe dust\ulcorner rrom fe~~oallomya ~~ufacturTeh. e chemical composition, cornpasitlon material, p d c l e sire md shapes of the bulk dust, sired dust and magnetically separated durl were mvesligaled. As the re\ulcornerulL, we suppose that the dust from &gh Carbon Fenama~~gunesMc anuiact~vingP rocess is not sufiicient as solulce material of Mn because of ale low Mn canlenl (13.5%) and complicaled composition mate~ial. The dust from Bug F!lter or AOD Proccss is mi~inlym ade up of 0.2-2 pm Mn30, (Hausmam~iu)p iutlde in spherical shape and thc Mn content is 63.190.The dust from Cooler of AOD Process is inninly made up of coarse Ca(O1-Or)zM. n,FeyO,, SiO, and fine Mn30d.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.81-88
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• 2000

Composting of N-rich wastes such as food waste and wastewater sludges can be associated loss of with substantial gaseous N, which means loss of an essential plant nutrient but may also lead to environmental pollution. We investigated the behavior of nitrogenous materials during the first high-rate phase in composting of food waste. Air dried food waste was mixed with shredded waste paper or wood chip and reacted in a bench scale composting reactor. Samples were analyzed for pH, ammonia, oxidized nitrogen and organic nitrogen. The volatilized ammonia nitrogen was also analyzed using sulfuric acid as an absorbent solution. Initial progress of composting reaction greatly influenced the ammonification of organic nitrogen. A well-balanced composting reaction with an addition of active compost as an inoculum resulted in the promoted mineralization of organic nitrogen and volatilization of ammonia. The prolongation of initial low pH period delayed the production of ammonia. It was also found that nitrogen loss was highly dependent on the air flow supplied. With an increase in input air flow, the loss of nitrogen as an ammonia also increased, resulted in substantial reduction of ammonia content in compost. The conversion ratio of initial nitrogen into ammonia was in the range of 28 to 38% and about 77~94% of the ammonia produced was escaped as a gas. Material balance on the nitrogenous materials was demonstrated to provide an information of importance on the behavior of nitrogen in composting reaction.

• Research in Plant Disease
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• v.12 no.1
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• pp.5-9
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• 2006

Grain discoloration, caused by several microorganisms, is a minor disease, but it is gaining importance in almost all rice growing areas of the world in recent years. Such grains are of low market value and consumption appeal in addition to their abnormal performance as seed of source of nutrient value. When the casual agents were inoculated on rice plant,'Ilmi-byeo'(at right before heading time and on heading time), the incidence of rice ear blight caused by Alternaria alternate and Nigrospora oryzae was higher in a plot inoculated at right before heading time than (in n plot inoculated) on heading time. Meanwhile, the incidence of rice ear blight caused by Bipolaris oryzae and Curvularia lunate was higher in a plot inoculated on heading time than in a plot inoculated at right before heading time. In rice quality, the ratio of imperfect grains was increased at right before heading time or on heading time by Nigrospora oryzae or Alternaria alternata, respectively. As discoloration rate of rice grains increased on 'Ilmi-byeo', the percentage of perfect grains decreased proportionally and the percentage of damaged rice grains increased remarkably.