Many observations have found evidence of the presence of a large number of heavily obscured Active Galactic Nuclei (AGNs). However, the nature of this population is only poorly understood because heavy obscuration by dust prevents one from finding them at optical wavelengths. Mid-infrared AGN searches can overcome this obstacle by penetrating through dust and by detecting direct emission from the dust torus. Thus, we can identify most of the AGN population, including type-2 and buried AGNs. Using the AKARI mid-infrared all-sky survey, we performed an AGN search in the nearby universe. Utilizing the 2MASS photometry, we selected mid-infrared-excess sources and carried out near-infrared spectroscopic observations in the AKARI Phase 3. During these follow-up observations, we have found three galaxies that show strong near-infrared red continuum from hot dust with a temperature of about 500 K, but do not show any AGN features in other wavelengths. The most suitable explanation of near-infrared continuum is the presence of central AGNs. Therefore, we conclude that they are AGNs obscured by dust. We performed X-ray observations of the two galaxies with SUZAKU. No detections in the 0.4-10 keV suggest that the column density may be much higher than NH=1023.5cm−2 . Comparing the masses of the host galaxies with those of the SDSS AGNs, we find that the host galaxies of the dusty AGNs discovered with AKARI are less massive populations than those of optically selected AGNs.

Polycyclic aromatic hydrocarbons (PAHs) in Galactic planetary nebulae (PNe) are investigated by means of the unidentified infrared (UIR) bands. Continuous near- to mid-infrared spectra of PNe are obtained with the AKARI/IRC and the Spitzer/IRS. All 19 PNe in the present study show prominent dust emissions and we investigate the variation in the intensity ratios among the UIR bands. The ionization fraction and the size distribution of PAHs in PNe are derived using the UIR band ratios. We find that the ionization fraction of PAHs in PNe is around 0.0-0.6 and that small PAHs are scarce. The present result indicates a systematic trend of the 3.4 μm aliphatic feature to become weak as the PAH ionization fraction increases.

We show how the rotation emission from isolated interstellar Polycyclic Aromatic Hydrocarbons (PAHs) can explain the so-called anomalous microwave emission (AME). AME has been discovered in the last decade as microwave interstellar emission (10 to 70 GHz) that is in excess compared to the classical emission processes: thermal dust, free-free and synchrotron. The PAHs are the interstellar planar nano-carbons responsible for the near infrared emission bands in the 3 to 15 micron range. Theoretical studies show that under the physical conditions of the interstellar medium (radiation and density) the PAHs adopt supra-thermal rotation velocities, and consequently they are responsible for emission in the microwave range. The first results from the PLANCK mission unexpectedly showed that the AME is not only emitted by specific galactic interstellar clouds, but it is present throughout the galactic plane, and is particularly strong in the cold molecular gas. The comparison of theory and observations shows that the measured emission is fully consistent with rotation emission from interstellar PAHs. We draw the main lines of our PLANCK-AKARI collaborative program which intends to progress on this question by direct comparison of the near infrared (AKARI) and microwave (PLANCK) emissions of the galactic plane.

UBV I CCD photometry of NGC 2353 is performed as a part of the "Sejong Open cluster Survey" (SOS). Using photometric membership criteria we select probable members of the cluster. We derive the reddening and distance to the cluster, i.e., E(B - V ) = 0.10 ± 0.02 mag and 1.17 ± 0.04 kpc, respectively. We find that the projected distribution of the probable members on the sky is elliptical in shape rather than circular. The age of the cluster is estimated to be log(age)=8.1 ± 0.1 in years, older than what was found in previous studies. The minimum value of binary fraction is estimated to be about 48 ± 5 percent from a Gaussian function fit to the distribution of the distance moduli of the photometric members. Finally, we also obtain the luminosity function and the initial mass function (IMF) of the probable cluster members. The slope of the IMF is Γ = -1.3 ± 0.2.

본 연구는 도매상에서 판매하고 있는 염소육의 영양학적 및 미생물학적 품질을 평가하기 위하여 수행하였다. 시료는 1년생, 2년생, 3년생 염소육을 대상으로 수행하였으며, 각 연령별에서 3마리씩 4부분의 다른 부위(어깨, 목, 허리, 다리)를 선정하여 총 36점을 대상으로 본 실험을 수행하였다. 염소육의 품질을 평가하기 위하여 각 시료의 외형, 색, 냄새, 육즙, 일반조성분, pH, 총균수, 대장균군과 효모수를 측정하였다. 각 부위별 염소육의 pH는 평균적으로 5.647- 5.692로 나타내어 각 부위별 염소육의 pH는 유의적 차이가 나타나지 않은 반면 연령별 염소육의 pH는 5.585-5.743로 유의적 차이(p < 0.01)를 나타냈다. 각 연령별 염소육의 육즙함량은 32.24-42.10%로 유의적인 차이(p < 0.01)를 나타내었으며, 마블링은 다른 부위보다 목살부위에서 더 명확하게 확인할 수 있었다. 염소육의 단백질 함량은 20.78-27.71% 의 결과로 유의적 차이(p < 0.01)를 나타내었고, 다리부위는 다른 부위에 비하여 높은 단백질 함량을 나타내었으며 각 부위별 염소육의 지방 함량은 2.657-11.469%로 유의적인 차이(P < 0.01)를 나타냈다. 염소육의 수분함량은 69.20- 73.31%, 1년생 염소육의 회분함량은0.989 ± 0.129%로 다른 연령대의 염소육보다 높은 것으로 나타났으며 이 결과 또한 유의적인 차이(P < 0.01)를 나타내었다. 칼슘의 함량은 유의적인 차이를 나타내지 않은 반면 1년생 염소육의 인의 함량은 0.149 ± 0.0251%로 다른 년생의 염소고기에 비하여 높은 것으로 나타냈다. 연령별 염소육의 총균수 수준은 5.05- 5.15 log cfu/g으로써 유의적 차이를 나타내지 않은 반면 각 부위별 염소육의 대장균군의 오염수준은 2.56-3.05 log cfu/g 으로 유의적인 차이(P < 0.01)를 나타냈다. 연령별 염소육 또한 대장균군 오염수준은 2.79-2.84 log cfu/g 으로써 유의적인 차이(P < 0.05) 를 나타냈으며 1년생 염소육의 대장균 오염수준은 다른 연령의 염소육에 비해 높은 것으로 나타났다. 효모의 오염수준 또한 각 부위별(P < 0.01), 연령별(P < 0.05) 로 유의적인 차이를 나타내었다. 결론적으로 염소육의 영양학적, 미생물학적 품질은 염소의 연령과 판매 부위에직접적인 영향을 받는 것으로 사료된다.

Methanol and hot water extracts of Daedalea bien-nis were investigated for its antioxidant activity, poly- phenol content and tyrosinase inhibitory effect. The antioxidant activity was evaluated using 1, 1-diphenyl -2-picrylhydrazyl (DPPH) scavenging assay. The antioxidant activities of hot water and 80% methanol extracts of Daedalea biennis fruiting body were 52.06%. and 92.62% at 1.5mg/ml concentration. Total polyphenol content of hot water and 80% methanol extracts were 12.26㎍ GAEs/mg and 13.69㎍ GAEs/mg. Tyrosinase inhibitory activity of water extract was 19.70% while 80% methanol extract was 15.75% at 1mg/ml concentration.

Methanol and hot water extracts of Suillus granulatus were investigated for its antioxidant activity, polyphenol content and tyrosinase inhibitory effect. The antioxidant activity was evaluated using 1, 1- dipheny l-2-picrylhydrazyl (DPPH) scavenging assay. The antioxidant activities of hot water and 80% methanol extracts of Suillus granulatus fruiting body were 51.49%. and 90.58% at 1.5mg/ml concentration. Total polyphenol content of hot water and 80% methanol extracts were 33.21㎍ GAEs/mg and 27.97㎍ GAEs/mg. Tyrosinase inhibitory activity of water extract was 7.8% while 80% methanol extract was 20.88% at 1mg/ml concentration.

Observation of standard stars is of crucial importance in stellar photometry. We have studied the standard transformation relations of the UBV RI CCD photometric system at the Maidanak Astronomical Observatory in Uzbekistan. All observations were made with the AZT-22 1.5m telescope, SITe 2k CCD or Fairchild 486 CCD, and standard Bessell UBV RI filters from 2003 August to 2007 September. We observed many standard stars around the celestial equator observed by SAAO astronomers. The atmospheric extinction coefficients, photometric zero points, and time variation of photometric zero points of each night were determined. Secondary extinction coefficients and photometric zero points were very stable, while primary extinction coefficients showed a distinct seasonal variation. We also determined the transformation coefficients for each filter. For B, V , R, and I filters, the transformation to the SAAO standard system could be achieved with a straight line or a combination of two straight lines. However, in the case of the U filter and Fairchild 486 CCD combination, a significant non-linear correction term - related to the size of Balmer jump or the strength of the Balmer lines - of up to 0:08 mags was required. We found that our data matched well the SAAO photometry in V , B - V , V - I, and R - I. But in U - B, the difference in zero point was about 3:6 mmag and the scatter was about 0:02 mag. We attribute the relatively large scatter in U -B to the larger error in U of the SAAO photometry. We confirm the mostly small differences between the SAAO standard UBV RI system and the Landolt standard system. We also attempted to interpret the seasonal variation of the atmospheric extinction coefficients in the context of scattering sources in the earth’s atmosphere.

An in vitro study was conducted to investigate the effect of propionate precursor (malate or fumarate) on fermentation characteristics, production of conjugated linoleic acid (CLA) and methane (CH₄) by rumen microbes when incubated with linoleic acid (C18:2) as a CLA precursor. Total CH₄ production for 12h incubation, however, was greatly reduced (P＜0.0001) by all the supplements compared to that of control, and its production from M-LA or F-LA treatment was smaller than that from LA treatment. Supplementation of M-LA or F-LA also increased concentrations of cis9, trans11-CLA (P＜0.039 - P＜0.001) for all incubation times and trans10,cis 12-CLA at 1h (P＜0.013), 3h(P＜0.036) and 12h (P＜0.025) incubation times compared to LA supplementation.

Experiments with a URT-0.5 accelerator (0.5 MeV, 50 ns, 1 kW) generating a nanosecond electron beam for irradiation of silver nitrate in various liquid solutions (water and toluene) were performed with the aim of producing silver nanopowders. A radiochemical reaction allows making weakly agglomerated pure Ag powders with particles of 10-15 nm and 30-50 nm in size by irradiation in toluene and water respectively. The injection of the nanosecond electron beam energy to the solution is optimal. As the absorbed dose increases, the output of the radiochemical reaction does not grow, but more agglomerated powders are synthesized.

Understanding of the basic characteristics of an astronomical instrument is a prerequisite to obtaining reliable data from the instrument. We have analyzed more than 1,000 calibration images from the Fairchild 486 CCD (hereafter the Maidanak 4k CCD system) attached to the AZT-22 1.5m telescope at Maidanak Astronomical Observatory in Uzbekistan. The Maidanak 4k CCD system supports three readout modes through 1, 2, or 4 amplifiers. In most cases observers use 4-amplifier readout mode to save time. We have tested the stability and seasonal variation of zero levels and confirm that two quadrants of the images (Amp 1 & 2) show no appreciable seasonal variation. but the other two quadrants (Amp 3 & Amp 4) show an evident seasonal variation in the bias level. The Cryo Tiger, the cooling system used at the Maidanak 4k CCD system, maintains the CCD temperature at -108'E, and effectively suppresses the dark electrons. The mean value versus the variance plot of the flat images does not show the expected relation for an ideal Poisson noise distribution and this is attributed to the large variation in quantum efficiency between different pixels. In addition, we confirm that there is no appreciable difference in gain between readout amplifiers, but there is a large variation in quantum efficiency across CCD chip especially in U. Due to the finite length of shutter opening and closing time, the effective exposure time varies across the science images. We introduce two parameters to quantify the effect of this uneven illumination and present a method to remove these effects. We also present a method to remove the interference patterns appearing in the images obtained with longer wavelength filters and investigate the spatial variation of the point spread function.