본 연구에서는 한국기상청의 장기예측시스템 현업모형인 GloSea5의 성층권 극소용돌이 강화사례에 대한 예측성 을 진단 및 검증하였다. 진단에 사용된 통계량은 이상상관계수(ACC, Anomaly Correlation Coefficient)와 평균제곱근 예측성(MSSS, Mean Squared Skill Score)으로, 1991-2010년간 발생한 14개 극소용돌이 강화사례에 대한 GloSea5의 예측성한계는 ACC를 기준으로 13.6일, MSSS를 기준으로 18.5일로 나타났다. 모형의 평균제곱오차(MSE, Mean Squared Error)의 각 성분을 정량적으로 비교분석한 결과, 예측성을 저하시키는 가장 큰 요인은 맴돌이(에디)오차로, 그 중 에디의 위상오차가 전체 예측오차의 큰 부분을 차지하는 것으로 나타났다. 또한 극소용돌이 현상이 수평적으로 큰 규모를 가지는 만큼 동서파수 1의 에디와 관련한 오차가 더 작은 규모의 에디에 비해 가장 크게 예측오차에 기여하는 것으로 나타났다. 한편, 분석한 사례들에 대하여 GloSea5의 대류권 순환에 대한 예측성은 성층권 예측성과는 큰 관련이 없는 것으로 나타났다. 이는 단순히 GloSea5 모형이 성층권-대류권 접합과정을 잘 모의하지 못하기 때문에 나타난 결과로 유추할 수 있다. 하지만, 극소용돌이 강화에 의한 영향에 비해 대류권에서 내부변동성의 절대적인 크기가 종종 크게 나 타난다는 점을 감안하면, 모형에서 성층권-대류권 접합을 잘 모의하고 있더라도 극소용돌이 강화 자체만의 영향이 뚜렷 하게 나타나지 않았을 가능성 또한 간과하면 안 될 것이다.

In order to increase the efficiency of the sputtering method widely used in thin film fabrication, a dc sputtering apparatus which supplies both high frequency and magnetic field from the outside was fabricated, and cobalt thin film was fabricated using this apparatus. The apparatus can independently control the applied voltage, the target-substrate distance, and the target current, which are important parameters in the sputtering method, so that a stable glow discharge is obtained even at a low gas pressure of 10−3 Torr. The fabrication conditions using the sputtering method were mainly performed in Ar+O2 mixed gas containing about 0.6% oxygen gas under various Ar gas pressures of 1 to 30 mTorr. The microstructure of Co thin films deposited using this apparatus was examined by electron diffraction pattern and X-ray techniques. The magnetic properties were investigated by measuring the magnetization curves. The microstructure and magnetic properties of Co thin films depend on the discharge gas pressure. The thin film fabricated at high gas pressure showed a columnar structure containing a large amount of the third phase in the boundary region and the thin film formed at low gas pressure showed little or no columnar structure. The coercivity in the plane was slightly larger than that in the latter case.

N-type porous silicon (PS) layers and thermally oxidized PS layers have been characterized by various measuring techniques such as photoluminescence (PL), Raman spectroscopy, IR, HRSEM and transmittance measurements. The top surface of PS layer shows a stronger photoluminescence peak than its bottom part, and this is ascribed to the difference in number of fine silicon particles of 2~3 nm in diameter. Observed characteristics of PL spectra are explained in terms of microstructures in the n-type PS layers. Common features for both p-type and n-type PS layers are as follows: the parts which can emit visible photoluminescence are not amorphous, but crystalline, and such parts are composed of nanocrystallites of several nm’s whose orientations are slightly different from Si substrate, and such fine silicon particles absorb much hydrogen atoms near the surfaces. Light emission is strongly dependent on such fine silicon particles. Photoluminescence is due to charge carrier confinement in such three dimensional structure (sponge-like structure). Characteristics of visible light emission from ntype PS can be explained in terms of modification of band structure accompanied by bandgap widening and localized levels in bandstructure. It is also shown that hydrogen and oxygen atoms existing on residual silicon parts play an important role on emission stability.

In this study, we investigated the overpotential of precipitation related to the catalytic activity of electrodes on the initial process of electrodeposition of Co and Co-Ni alloys on polycrystalline Cu substrates. In the case of Co electrodeposition, the surface morphology and the magnetic property change depending on the film thickness, and the relationship with the electrode potential fluctuation was shown. Initially, the deposition potential(−170 mV) of the Cu electrode as a substrate was shown, the electrode potential(Edep) at the Ton of electrodeposition and the deposition potential(−600 mV) of the surface of the electrodeposited Co film after Toff and when the pulse current was completed were shown. No significant change in the electrode potential value was observed when the pulse current was energized. However, in a range of number of pulses up to 5, there was a small fluctuation in the values of Edep and Eimm. In addition, in the Co-Ni alloy electrodeposition, the deposition potential(−280 mV) of the Cu electrode as the substrate exhibited the deposition potential(−615 mV) of the electrodeposited Co-Ni alloy after pulsed current application, the Edep of electrodeposition at the Ton of each pulse and the Eimm at the Toff varied greatly each time the pulse current was applied. From 20 % to less than 90% of the Co content of the thin film was continuously changed, and the value was constant at a pulse number of 100 or more. In any case, it was found that the shape of the substrate had a great influence.

Unidirectionally solidified TiAl alloys were prepared by optically-heated floating zone method at growth rates of 10 to 70 mm/h in flowing argon. The microstructures and tensile properties of these crystal bars were found to depend strongly on the growth rate and alloy composition. TiAl alloys with composition of 47 and 50 at.%Al grown under the condition of 10 mm/h showed Ti3Al(α2)/TiAl(γ) layer structures similar to single crystals. As the growth rate increased, the alloys with 47 and 50 at.%Al compositions showed columnar-grain structures. However, the alloys fabricated under the condition of 10 mm/ h had a layered structure, but the alloy with increased growth rate consisted of γ single phase grains. The alloy with a 53 at.%Al composition showed a γ single phase regardless of the growth rate. Room-temperature tensile tests of these alloys revealed that the columnar-grained material consisting of the layered structure showed a tensile ductility of larger than 4 % and relatively high strength. The high strength is caused by stress concentration at the grain boundaries; this enhances the secondary slip or deformation twinning across the layered structure in the vicinity of the grain boundaries, resulting in the appreciable ductility.

Binary Ti-Al alloys containing 50 to 60 atomic percent aluminum are rapidly solidified by hammer anvil method under an argon atmosphere. Constituent phases in each alloy are identified by X-ray diffractometry and microstructures of the alloys are investigated using a transmission electron microscope. In alloys with aluminum content between 50 and 54 percent, a second phase exists besides TiAl(γ); this second phase is identified as Ti3Al(α2). The α2 phase is observed in two types of morphology. One is as fine lamellar alternating with γ and the other is as a particle. It is concluded that the existence of a metastable phase with the morphologies stated above should arise from a higher quenching rate attained by the hammer anvil method as compared to the conventional roll or splat-quench method. Implications of the above observation are discussed with respect to the phase relations in the Ti-Al binary system; these implications are still controversial in many respects.

Ni-C composite films were prepared by co-deposition using a combined technique of plasma CVD and ion beam sputtering deposition. Depending on the deposition conditions, Ni-C thin films manifested three kinds of microstructure: (1) nanocrystallites of non-equilibrium carbide of nickel, (2) amorphous Ni-C film, and (3) granular Ni-C film. The electrical resistivity was also found to vary from about 102 μΩcm for the carbide films to about 104 μΩcm for the amorphous Ni-C films. The Ni-C films deposited at ambient temperatures showed very low TCR values compared with that of metallic nickel film, and all the films showed ohmic characterization, even those in the amorphous state with very high resistivity. The TCR value decreased slightly with increasing of the flow rate of CH4. For the films deposited at 200 oC, TCR decreased with increasing CH4 flow rate; especially, it changed sign from positive to negative at a CH4 flow rate of 0.35 sccm. By increasing the CH4 flow rate, the amorphous component in the film increased; thus, the portion of Ni3C grains separated from each other became larger, and the contribution to electrical conductivity due to thermally activated tunneling became dominant. This also accounts for the sign change of TCR when the filme was deposited at higher flow rate of CH4. The microstructures of the Ni-C films deposited in these ways range from amorphous Ni-C alloy to granular structures with Ni3C nanocrystallites. These films are characterized by high resistivity and low TCR values; the electrical properties can be adjusted over a wide range by controlling the microstructures and compositions of the films.

Genetic polymorphisms within immunity-related candidate genes in pigs have been identified to control variations in immune functions and/or disease resistance. It has become necessary to evaluate the effects of other genetic markers of economically important traits prior to introducing them into marker-assisted selection programs. In this study, polymorphisms of porcine genes coding Interferon-induced Gunylate binding protein 1 (GBP1), GBP2, CD163, and CD169 were investigated for their association with growth and meat quality traits in a Korean native pig breed -Yorkshire inter-crossed F2 pig population (KY-F2). KY-F2 animals (n=346) have been successfully used for linkage mapping to identify quantitative loci that control meat quality, growth, and immunity traits. In our results, polymorphisms in genes GBP1 and GBP2 showed association with pig growth rate as well as meat quality traits such as crude fat, drip loss, and meat color (yellowness) in the KY-F2 population. The polymorphism in gene CD163 only showed association with crude fat, as a meat quality trait. CD169 gene was associated with pork tenderness. In conclusion, four immune-related genetic markers were validated for their association with growth and meat quality traits to gauge their potential use in a swine selection program. The results warrant further studies in other commercial pig populations.

One of the major problems in the modern pig industry is infectious disease. Susceptibility to infectious diseases is influenced by both constitutional (e.g. genotype, age, gender, and reproductive status) and environmental factors (e.g. nutrition, management, infections, and other forms of stress). Genetic variations within individual animals or herds can cause differences in the execution of immune functions against infectious agents in domestic pigs. The objectives of the present study were to identify genetic factor(s) responsible for piglet survival and mortality under commercial field conditions with infectious diseases as well as determine QTL regions for immune capacity in a pig reference family. Sex ratio was examined between normal grown and presumed dead groups of F2 animals generated by Korean native pigs (KNP) and Yorkshire (YS) breeds. The ratio of males was significantly higher in the presumed dead group than in the normal grown group. In order to study genetic factors associated with presumed mortality under disease outbreak, allelic frequencies of 239 single nucleotide polymorphisms (SNPs) were compared between normal grown and presumed dead groups. Exactly 22 SNPs showed significant differences in their allelic frequencies between the two groups, and four of them were validated with another commercial population divided by normal and emaciated pigs. Furthermore, the relationships between 239 SNPs and immune-related traits were studied. These results demonstrate that identification of genetic components of animal immune systems and susceptibility to infectious diseases is possible and will be useful to improve disease resistance in individuals as well as in breeding programs.

The antioxidant activities and total phenolics of four Rosaceae species Pourthiaea villosa (Thunb.) Decne, Sorbus commixta Hedlund, Sorbaria sorbifolia var. stellipila Maxim and Pyrus pyrifolia (Burm.f.) Nakai were determined. Phenolic content (polyphenol and flavonoid), radical scavenging activities [2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylnezthiazoline-6-sulfoic acid) (ABTS)] and ferrous ion chelating effect were evaluated. Total polyphenol and flavonoid contents were highest in Pourthiaea villosa (Thunb.) Decne and lowest in Pyrus pyrifolia (Burm.f.) Nakai. Phenolic contents of Pourthiaea villosa (Thunb.) Decne was 331.45±7.78 and 90.4±3.5 mg·g-1. DPPH and ABTS radical scavenging activities were found to be lowest in Sorbus commixta Hedlund whereas Sorbaria sorbifolia var. stellipila Maxim and Pourthiaea villosa (Thunb.) Decne showed relatively good DPPH and ABTS radical scavenging activities. Ferrous ion chelating effect was highest in Pyrus pyrifolia (Burm.f.) Nakai (1.05±0.04 mg·ml-1) and lowest in Sorbus commixta Hundlund (4.22±0.71 mg·ml-1).