KHNP is conducting research to decommission Wolsong Unit 1 Calandria. Establishment of preparation and dismantlement processes, conceptual design of equipment and temporary radiation protection facilities, and waste management are being established. In particular, the ALARA plan is to be established by performing exposure dose evaluation for workers. This study aims to deal with the methodology of evaluating exposure dose based on the calandria dismantling process. The preparation process consists of bringing in and installing tooling and devices, and removing interference facilities to secure work space. The main source term for the preparation process is the calandria structure itself and crud of feeders. In the case of the dismantlement process, a structure with a shape that changes according to the process was modeled as a radiation source. It is intended to estimate the exposure dose by selecting the number of workers, time, and location required for each process in the radiation field evaluated according to the preparation and dismantlement process. In addition, it is also conducting an evaluation of the impact on dust generated by cutting operations and the human impact of C-14, H-3, which are specialized nuclides for heavy water reactors. KHNP is conducting an exposure dose evaluation based on a process based on the preparation and dismantlement process for decommissioning Calandria through computation code analysis. If additional worker protection measures are deemed necessary through dose evaluation according to this methodology, the process is improved to prepare for the dismantling of worker safety priorities.

To understand antioxidant enzyme response of two contrasting Arundinella hirta ecotypes to drought stress, drought-tolerant Youngduk and drought-sensitive Jinju-1, were comparatively analyzed changes in the enzymatic activities of peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR). Two ecotypes, drought-tolerant Youngduk and drought-sensitive Jinju-1 were subjected to drought stress by withholding water for 12 days. ROS accumulation level and electrolytic leakage were significantly increased in both A. hirta ecotypes by drought stress treatment but less in Youngduk than Jinju-1. The RWC significantly decreased in both the drought stress-treated ecotypes as compared to control, but less in Youngduk than Jinju-1. Soluble sugar and protein content were increased more in drought stress-treated Youngduk as compared to Jinju-1. The activities of antioxidant enzymes such as SOD, CAT, POD, APX, and GR increased significantly in both the drought stress-treated ecotypes Youngduk and Jinju-1 as compared to control. The increase in antioxidant enzyme activity level was more prominent in drought stress-treated Youngduk as compared to Jinju-1. Taken together, these results suggest that Youngduk was more tolerant to drought stress than Jinju-1, and seem to indicate that tolerance of A. hirta to drought stress is associated with increased activity of antioxidant enzymes.

KHNP is carrying out international technical cooperation and joint research projects to decommission Wolsong unit 1 reactor. Construction data of the reactor structures, experience data on the pressure tube replacement projects, and the operation history were reviewed, and the amount of dismantled waste was calculated and waste was classified through activation analysis. By reviewing COG (CANDU owners Group) technical cooperation and experience in refurbishment projects, KHNP’s unique Wolsong unit 1 reactor decommissioning process was established, and basic design of a number of decommissioning equipment was carried out. Based on this, a study is being conducted to estimate the worker dose of dismantling workers. In order to evaluate the dose of external exposure of dismantling workers, detailed preparation and dismantling processes and radiation field evaluation of activated structures are required. The preparation process can be divided into dismantlement of existing facilities that interfere with the reactor dismantling work and construction of various facilities for the dismantlement process. Through process details, the work time, manpower, and location required for each process will be calculated. Radiation field evaluation takes into account changes in the shape of structures by process and calculates millions of areas by process, so integrated scripts are developed and utilized to integrate input text data. If the radiation field evaluation confirms that the radiation risk of workers is high, mutual feedback will be exchanged so that the process can be improved, such as the installation of temporary shields. The results of this study will be used as basic data for the final decommissioning plan for Wolsong unit 1. By reasonably estimating the dose of workers through computer analysis, safety will be the top priority when decommissioning.

Complexation of actinides and lanthanides with carboxylic organic ligands is known to facilitate migration of radionuclides from deep geological disposal systems of spent nuclear fuel. In order to examine the ligand-dependent structures of trivalent actinides and lanthanides, a series of Eu(III)-aliphatic dicarboxylate compounds, Eu2(oxalate)3(H2O)6, Eu2(malonate)3(H2O)6, and Eu2(succinate)3(H2O)2, were synthesized and characterized by using X-ray crystallography and time-resolved laser fluorescence spectroscopy. Powder X-ray diffraction results captured the transition of the coordination modes of aliphatic dicarboxylate ligands from side-on to end-on binding as the carbon chain length increases. This transition is illustrated in malonate bindings involving a combination of side-on and end-on modes. Strongly enhanced luminescence of these solid compounds, especially on the hypersensitive peak, indicates a low site symmetry of these solid compounds. Luminescence lifetimes of the compounds were measured to be increased, which is ascribed to the displacement of water molecules in the innersphere of Eu center upon bindings of the organic ligands. The numbers of remaining bound water molecules estimated from the increased luminescence lifetimes were in good agreement with crystal structures. The excitation-emission matrix spectra of these crystalline polymers suggest that oxalate ligands promote the sensitized luminescence of Eu(III), especially in the UV region. In the case of malonate and succinate ligands, charge transfer occurs in the opposite direction from Eu(III) to the ligands under UV excitation, resulting in weaker luminescence.

토마토 온실에서 담배가루이 (Bemisia tabaci) 유인을 위한 작물에 따른 선호도를 조사하였다. 피망, 토마토, 오이, 가지의 4 종류의 작물을 아크릴케이지에 같이 넣어두고 담배가루이 성충 30쌍을 방사하여 선호도 및 산란수를 조사하였다. 담배가루이 성충은 오이(약 40%)와 가지(약 40%)에서 가장 선호하였으며, 토마토(10%)와 피망(10%)의 선호도는 낮았다. 기주에 따른 담배가루이의 성충 30쌍의 산란수는 오이에서 485개로 가장 높았으며 가지(250), 토마토(131), 피망(126)의 순으로 조사되었다. 토마토 온실에 가지묘를 정식하였을 경우에는 토마토에서는 주당 약 20마리의 담배가루이가 조사되었으나 가지에서는 주당 400∼500마리의 담배가루이가 조사되어 토마토 온실에서 가지를 이용한 담배가루이 유인이 가능함을 알 수 있었다.

In the current study, a total of 102 common Todarodes pacificus squid caught in the East Sea were investigated for parasitological research. The results revealed that 33 (32.35%) out of 102 squid were infected by Nybelinia surmenicola, the mean intensity was 5.58 parasites per squid, and the maximum abundance was 11. Morphological analysis using a field emission scanning electron microscope showed the characteristic features of N. surmenicola. Molecular identification based on the 28S rRNA gene confirmed the isolated parasite as N. surmenicola, while phylogenetic analysis revealed that N. surmenicola isolated in this study was clustered with N. surmenicola isolated from Japan. This is the first report of phylogenetic characterization of N. surmenicola isolated from Korea.

1분 간격 자동 잎면적 분석을 통해 온도에 따른 담배거세미나방 유충의 섭식과 발육을 조사하였다. 20, 25, 30℃의 세 온도에서 피망 잎을 배지에 부착하여 담배거세미나방 유충에 제공하였고 하루에 한번내지 두번 새로운 잎을 갈아주었다. 30℃에서 담배거세미나방 유충은 탈피 직후 섭식을 즉시 시작하여 1회 섭식은 10~15분 지속하고, 60~90분 간격으로 섭식을 하였다. 이러한 섭식 행동은 약 30~50시간 지속되며 탈피 직전 10~16시간 동안은 섭식이 중단되었다. 탈피 후 앞서의 섭식 패턴은 다음 영기에서 동일하게 반복되었다. 25℃에서 담배거세미나방 유충의 영기 내 섭식 기간은 약 32~53시간 지속되며 탈피 전 비섭식 기간은 16~22시간 지속되었다. 20℃에서는 영기 내섭식 기간은 60~133시간으로 크게 증가하고 비섭식 기간도 11~38시간으로 다른 온도에 비해 길어졌으며 다른 온도와 달리 7령충까지 발육하였다. 2령충에서 고치 형성 전까지의 발육 시간은 20℃에서는 39046분(27.1일)이 소요되었고 25℃에서는 17626분(12.2일), 30℃에서는 14168분(9.8일)으로 조사되었다. 각 온도별 유충의 섭식량은 영기에 따라 지수적으로 증가하였다.

약제 처리에 따른 담배거세미나방(Spodoptera litura) 유충의 섭식 행동 및 반응을 조사하기 위해 1분 간격으로 잎면적을 자동 측정하였다. 담배거세미나방 유충의 섭식 행동은 섭식기와 비섭식기가 뚜렷하게 구분되었으며, 섭식기가 끝나면 비섭식기를 거쳐 탈피를 하고 다시 섭식기에 들어갔다. 1회 섭식 지속 시간은 약 15분으로 조사되었고, 영기 내 평균 섭식 회수는 약 27.5회로 섭식 지속 시간과 마찬가지로 영기에 따른 차이는 없었다. 약제 처리는 피망 잎을 Buprofezin methoxyfenozyd과 BT (Bacillus thuringiensis) 500ppm 약액에 10초간 침지 처리하였다. Buprofezin methoxyfenozyd를 처리 하였을 경우 섭식 시간은 평균 8~9분으로 감소하였고, 치사 전까지 섭식량은 각각 176mg으로 조사되었다. 하지만 BT제를 처리 시에는 담배거세미나방 유충은 치사하지 않았다.

The cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) is an important pest on several species of legumes. We investigated the development periods and survivorship of A. craccivora nymph, and longevity and fecundity of A. craccivora adult. The study was conducted at five constant temperatures of 10, 15, 20, 25, and 30°C, respectively. The lower developmental threshold (LDT) and thermal constant (K) of A. craccivora nymph stage were estimated by linear regression. Higher temperature threshold (TH) and lower temperature threshold (TL) were calculated by biophysiological model. Developmental completion of A. craccivora nymph stage was described using a two-parameter Weibull distribution model. Life table parameters were estimated by the jackknife method.

The squid Todarodes pacificus is a commercially important fishery species in East Asia. As East Asians consume raw or lightly cooked squids, there has been growing concern about parasitic infections associated with squid consumption. In the current study, five squids caught in the East Sea were sampled for parasitological research from the biggest fishery market in Seoul, Republic of Korea. They were dissected and examined for parasites using a light microscope. Proteocephalus sp. was isolated and identified using field emission scanning electron microscopy, PCR, and sequencing. Given that Proteocephalus spp. can be affected by water temperature and geographical characteristics, further research on Proteocephalus spp. with respect to changes in water temperature in the East Sea is important.

바다에 기름오염 사고가 발생하면 여러 가지 방제 방법 중 물리적 회수 방법을 우선적으로 사용하고 유처리제는 최후 수단으로 고려하는 경향이 있다. 유처리제는 수중으로 기름이 신속히 분산되도록 하여 해수면으로부터 제거하는 방법이다. 해수면으로부터 신속히 기름을 제거하는데 대한 유처리제의 효용성은 널리 증명되어 왔으나 아직도 대부분의 국가들은 해양환경에 미치는 독성을 우려하여 적극적인 사용을 하지 않고 있는 실정이다. 보고된 자료에 의하면 유처리제 사용 후 수중생물에 대한 독성은 발견되지 않았으며, 유처리제와 혼합된 기름이 기 름 그 자체보다 독성이 더 크게 나타나지 않았다. 멕시코만 기름유출 사고 시 미국 정부와 BP사는 최대한 해안에 기름이 도달하지 않는데 중 점을 두고 해수면뿐만 아니라 수중의 기름에 대해서도 유처리제를 사용하였다.

A generalization of the original ¨ O p i k ′ s cellular convection theory has been made to accomodate a rotating convective medium. With the use of the formulation, a set of rotating model envelopes of the sun and late type main sequence stars have been constructed under three different rotation periods. Their thermal structures are presented and characteristics of their convection are discussed in the context of stellar dynamo. In the present study it is noted that the rotational angular velocity increases in wards with depth, and its increase turns out to be about 6% at the bottom of the solar convection zone.

Chronological aging and photoaging affect appearance, causing wrinkles, pigmentation, texture changes, and loss of elasticity in the skin. Phragmites communis is a tall perennial herb used for its high nutritional value and for medicinal purposes, such as relief from fever and vomiting and facilitation of diuresis. In this study, we investigated the effects of ethanol extract of P. communis rhizome (PCE) on skin aging. The total flavonoid and total phenolic content in PCE were 2.92 ± 0.007 ㎍ of quercetin equivalents (QE) and 231.8 ± 0.001 ㎍ of gallic acid equivalents (GAE) per 100 ㎎ of dried extract (n = 3). The half-maximal inhibitory concentration (IC50) values of PCE for 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and hydrogen peroxide scavenging activities were 0.96 and 0.97 ㎎/mL, respectively. PCE showed inhibitory effects on tyrosinase when L-tyrosine (IC50 = 1.25 ㎎/mL) and L-3,4-dihydroxyphenylalanine (IC50 = 0.92 ㎎/mL) were used as substrates. PCE treatment up to 200 ㎍/mL for 24 h did not cause any significant cytotoxicity in B16F10 melanocytes, human dermal fibroblasts (HDFs), and HaCaT keratinocytes. In B16F10 melanocytes, PCE (25 and 50 ㎍ /mL) inhibited melanin production and cellular tyrosinase activity after challenge with α-melanocyte-stimulating hormone (α-MSH; p < 0.05). In HDFs, PCE suppressed the mRNA expression of matrix metalloproteinase-1 (MMP-1) and reduced the activity of elastase (p < 0.05). In addition, ultraviolet B (UVB)-mediated downregulation of hyaluronic acid synthase-2 gene expression in HaCaT keratinocytes was also effectively suppressed by PCE treatment. Overall, our results showed that PCE has potential anti-skin aging activity associated with the suppression of hyperpigmentation, wrinkle formation, and reduction in dryness. PCE is a promising candidate for the development of an anti-skin aging cosmetic ingredient.