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        검색결과 71

        3.
        2023.11 구독 인증기관·개인회원 무료
        KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.
        4.
        2023.10 구독 인증기관·개인회원 무료
        Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.
        12.
        2019.04 구독 인증기관·개인회원 무료
        South Korea has over 0.38 million of managed honey bee (Apis cerana) colonies before 2009 years ago, which produce the highest quantity of honey in the Korea; however, almost colony (90%) were collapsed by Korean Sacbrood Virus (KSBV) in South Korea. Korean Sacbrood Virus (KSBV) is the pathogen of A. cerana Sacbrood disease, which poses a serious threat to honeybee A. cerana, and tends to cause bee colony and even the whole apiary collapse. Colony collapse of A. cerana was first reported on the Pyeong-Chang of the South Korea in 2009. Several scientists and governments has been tried research for cure the sacbrood disease in A. cerana colony by medicines and management techniques. Unfortunately, The sacbrood disease dosen’t improve. So, we were developed a better breed of A. cerana for resistance of sacbrood virus by selection and then artificial insemination. A. cerana breeding technique was first successful applied with A. cerana in Korean. Queens was grafted from sacbrood resistance line and then it was growing in sacbrood disease colony that was survived 100%. Altogether selected 18 queens were artificially inseminated and 2,000 drones of A. cerana in Korea was used to evaluate amount of semen collection. We are select two scabrood resistance A. cerana line (R and H). R line be used for rearing the Queen. Drone was reared in H line colony. The RH hybrid were not infected sacbrood virus even spread sacbrood virus (2×106). RH colonies have very excellent hygienic behavior, brood, and sacbrood disease resistance activity.
        16.
        2018.10 구독 인증기관·개인회원 무료
        The hypopharyngeal gland (HPG) of the honeybee worker produces royal jelly (RJ) and has a developmental cycle closely related to the division of labor. In this study, we investigated to compare the HPG acini diameter of differently aged worker bees with high royal jelly producing colony (HRC) or less producing colony (LRC). Additionally, we also evaluated whether the fresh weight of the head is a reliable indicator of the developmental status of HPG. The HRC showed a significantly higher RJ production about two-times as compared with those of the LRC. We measured the HG-diameters on days 1, 3, 6, 9, 12, 15. The microscopic analysis revealed that the acini size of the HRC was significantly larger than the LRC. In addition, the acini diameter of HRC was 15% longer than the LRC on the first day after emerging. It was shown that the fastest development during 3 days which is preparing for nurse the brood. The HPG acini diameters increased in both colonies in a similar fashion until day 12 and then decreased. We also compared the fresh head weight of the experimental colonies, differences were similar to the development of HPG. Therefore, high royal jelly production may have a positive correlation between HPG acini size and the fresh head weight.
        17.
        2018.04 구독 인증기관·개인회원 무료
        The change of phenolic compounds and radical scavenging activity of black soybean flours after germination and roasting treatment were evaluated as a part of the purpose of setting the quality of black soybean flours for each application. The moisture content of roasted black soybean flours decreased significantly according to roasting temperature and time, and the crude ash, protein, and fat contents increased. Water binding capacity of roasted black soybean flours without and with germination increased significantly according to roasting temperature and time, however water solubility index and swelling power decreased. The lightness of roasted black soybean flours was significantly decreased, and the redness and yellowness increased. The phenolic compounds and radical scavenging activity of roasted black soybean flours increase with increasing roasting temperature and time. The total polyphenol contents of roasted black soybean flours without and with germination were 5.43∼7.81 and 4.52∼6.17 mg GAE/g, and total flavonoid contents were 2.90∼3.50 and 2.34∼3.01 mg CE/g, respectively. DPPH radical scavenging activity of roasted black soybean flours without and with germination was 254.98∼415.05 and 171.95∼295.15 mg TE/100 g, and ABTS radical scavenging activity was 459.74∼596.37 and 422.95∼526.85 mg TE/100 g, respectively. As a result, it is necessary to set quality standards for each application considering the quality and antioxidant properties of roasted black soybean flours.
        18.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present experiment was designed to investigate the effects of extruded linseed supplementation on methane production in Holstein steers. Four Holstein steers fitted with permanent cannulas were assigned to two dietary treatments in a duplicated 2 × 2 Latin square design: a control diet consisting of tall fescue straw (65%) and concentrate (35%), and a treatment diet supplemented with 3.8% extruded linseed by replacing a part of ingredients in the concentrate of the control diet. The concentrates of the control and the treatment diet were isoenergetic and isonitrogenous. Extruded linseed supplementation did not affect dry matter intake but significantly (P<0.05) increased the intake of lipid. Rumen pH was significantly (P<0.05) lower for control than for treatment. Although there was no significant difference between treatments, the concentration of total VFA in control was 21% higher than in treatment. The concentrations of acetic acid, propionic acid and butyric acid were not different between treatments. Extruded linseed supplementation significantly (P<0.05) reduced methane output(g/d) and emission factor. Methane conversion rate was lower for treatment than for control but no significant difference was found. The results of the present study showed that extruded linseed supplementation in the diet of Holstein steers could reduce methane output.
        4,000원
        20.
        2016.10 구독 인증기관·개인회원 무료
        The mammary gland is a complex organ, made up of various cell types that work together for mil synthesis. A previous study had established a clonal cell line from primary bovine mammary alveolar cells (MAC-T) for the study of bovine milk production and synthesis. In this study, we transplanted MAC-T bovine alveolar cell line to BALB/C nude mice for regeneration of bovine mammary gland alveolar ducts. The MAC-T cells were suspended with matrigel and injected into the dorsal tissue of 8 weeks old male BALB/C nude mice. After 6 weeks, the injected cells were showed typical morphology of the tubuloalveolar female glands by histological analysis. It was made the branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14 and CK18 positive cells but not in the non-transplanted MAC-T cells. These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14 and CK18 positive MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland.
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