In this work we present the results of light curve analysis for two cataclysmic variables detected recently in the SDSS project: SDSS J090350.73+330036.1 and J150240.98+333423.9. Photometric observations of the rst were obtained during a superoutburst in May 2010. Our observations clearly indicate the presence of superhumps in the light curves, suggesting SDSS J090350.73+330036.1 is an SU UMa dwarf nova. We determined the period of the superhumps. We also carried out fitting using a spiral-arm model in order to determine parameters of the accretion disk, hot line, and other components of this system. Photometric observations of the second, J150240.98+333423.9, were obtained during the post-maximum decline, during April-June 2012. Photometric variability of this system has been studied in an inactive state. We obtained its parameters via a combined model fitted to the observed light curves by X2 mini- mization.

Classical novae (CNe) are interacting binary systems whose outbursts are powered by a thermonuclear runaway in accreted material onto the surface of a white dwarf (WD). The secondary star in such systems fills its Roche lobe and material is transferred onto the WD primary star via an accretion disk. Recurrent novae (RNe) show many similarities to CNe, but have had more than one recorded outburst. RNe play an important role as one of the suspected progenitor systems of Type Ia supernovae, which are used as primary distance indicators in cosmology. Thus, it is important to investigate the nature of their central binary systems to determine the relation between the parameters of the central system and the outburst type, and finally ascertain the population of novae that might be available to give rise to the progenitors of Type Ia SNe. A low outburst amplitude is adopted as a criterion that may help distinguish RNe from CNe and was therefore used to select targets for observations from ground-based observatories including the Liverpool Telescope and the Southern African Large Telescope as well as the full-sky space-based archive of the Solar Mass Ejection Imager (SMEI). We found that at least four objects currently classified as CNe are possibly RNe candidates based on their quiescent spectra. We also searched the SMEI archive for additional outbursts of bright CNe that might otherwise have been missed but did not find a conclusive example.

큰실말(Cladosiphon novae-caledoniae kylin, C. novae-caledoniae kylin) 부산물을 이용하여 화장 품 소재로써 가능성을 조사하고자, 항산화 효과(DPPH 자유 라디칼 소거 활성), 항균(anti-microbial activity), 미백(tyrosinase inhibition assay), 주름개선(elastase inhibition assay) 및 B16F10 mouse melanoma cell (MTT assay)을 이용한 세포 생존률을 측정하였다. 큰실말 추출물 원물(MC)과 불용성(MI)은 Staphyloccus aureus (S. aureus)와 항생제내성균주인 MRSA에 대하여 활성을 나타내었지만 항곰팡이 활성은 나타내지 않 았다. 큰실말 추출물 수용성(MS)은 tyrosine에 대한 tyrosinase 저해효과가 49%로 표준물질인 arbutin 보다 미백효과가 우수하였지만 주름개선효과는 비교적 낮은 활성을 나타내었다. DPPH 라디칼 소거능력은 500 μ g/mL에서 89%로 나타내었다. 따라서 본 연구인 큰실말 추출물은 화장품 미백소재로써 좋은 후보군임을 확인 할 수 있었다.