• 제목/요약/키워드: nuclear reactions

검색결과 279건 처리시간 0.032초

Uncertainty Quantification of the Experimental Spectroscopic Factor from Transfer Reaction Models

  • Song, Young-Ho;Kim, Youngman
    • Journal of the Korean Physical Society
    • /
    • 제73권9호
    • /
    • pp.1247-1254
    • /
    • 2018
  • We study the uncertainty stemming from different theoretical models in the spectroscopic factors extracted from experiments. We use three theoretical approaches, the distorted wave Born approximation (DWBA), the adiabatic distorted wave approximation (ADWA) and the continuum discretized coupled-channels method (CDCC), and analyze the $^{12}C(d,p)^{13}C$, $^{14}C(d,p)^{15}C$ reactions. We find that the uncertainty associated with the adopted theoretical models is less than 20%. We also investigate the contribution from the remnant term and observe that it gives less than 10% uncertainty. We finally make an attempt to explain the discrepancy in the spectroscopic factors of $^{17}C(\frac{3}{2}^+)$ between the ones extracted from experiments and from shell model calculations by analyzing the $^{16}C(d,p)^{17}C$ reaction.

7Li-NMR and Thermal Analysis for Lithium Inserted into Artificial Carbon Material

  • 오원춘
    • Bulletin of the Korean Chemical Society
    • /
    • 제22권4호
    • /
    • pp.367-371
    • /
    • 2001
  • Lithium inserted into artificial carbon has been synthesized as a function of the Li concentration. The characteristics of these prepared compounds were determined from the studies using X-ray diffraction(XRD), solid nuclear magnetic resonance (NM R) spectrophotometric and differential scanning calorimeter(DSC) analysis. X-ray diffraction showed that lower stage intercalation compounds were formed with increasing Li concentration. In the case of the AG3, most compounds formed were of the stage 1 structure. Pure stage 1 structural defects of artificial graphite were not observed. 7Li-NMR data showed that bands are shifted toward higher frequencies with increasing lithium concentration; this is because non-occupied electron shells of Li increased in charge carrier density. Line widths of the Li inserted carbon compounds decreased slowly because of nonhomogeneous local magnetic order and the random electron spin direction for located Li between graphene layers. The enthalpy and entropy changes of the compounds can be obtained from the differential scanning calorimetric analysis results. From these results, it was found that exothermic and endothermic reactions of lithium inserted into artificial carbon are related to the thermal stability of lithium between artificial carbon graphene layers.

유엔 안보리 대북제재 결의와 우리 해군의 대응 (UNSC Resolution against North Korea and ROKN's Reactions)

  • 박창권
    • Strategy21
    • /
    • 통권39호
    • /
    • pp.82-113
    • /
    • 2016
  • This paper analyzes the contents and the effects of the UNSC 2270, and its implications to South Korea's defense strategy and navy. The UN Security Council passed strong sanctions against North Korea which punish North Korea's 4th nuclear test. The sanctions compared to the previous ones require international society to take practical actions such as comprehensive trade bans as well as diplomatic isolation which will put significant pains on North Korea. Especially, these measures would greatly hamper economic development policy of Kim Joung-un regime. Because Kim Jung-un regime has inherent legitimacy problems which stems from the third family succession of the power, economic difficulties may play an important cause on the regime instability in the long term. In fact, the United States sees this possibility as an option to coerce North Korea in which North Korea choose denuclearization for its regime survival. Nevertheless, the prospects of the UN sanctions are not so optimistic. Considering North Korea's willingness for nuclear development and its level of nuclear technology, North Korea will try to play a gambit with the US and South Korea by exploiting its strategic advantages. North Korea's response will have three following strategies. First, it would actively pursue political and economic survival strategy by using China's support for the regime, strengthening its power grip in the name of countering US hostile policy, and enhancing peace propaganda. Second, North Korea will accelerate efforts to position its status as a nuclear de facto state. For this purpose, it could create nuclear crisis on the peninsula. Third, it would exploit local provocations as an exit strategy to get over the current situation. In order to counter North Korea's actions and punish North Korea's behavior strongly, South Korea needs following strategies and efforts. It should first make all the efforts to implement the UN sanctions. Strong and practical nuclear deterrence strategy and capability with the U.S. should be developed. Effective strategy and capabilities for the prevention and deterrence of North Korea's provocation should be prepared. For this purpose, North Korea's provocation strategy should be thoroughly reviewed. Active international cooperation is needed to punish and coerce North Korea's behavior. Finally, South Korea should prepare for the possible occurrence of North Korea's contingency and make use of the situation as an opportunity to achieve unification. All these strategies and efforts demand the more active roles and missions of South Korea's navy and thus, nullify North Korea's intention militarily.

$^{18}F$-플루오린 표지를 위한 신개념 반응용매에서 친핵성 불소화 반응 (Nucleophilic Fluorination Reactions in Novel Reaction Media for $^{18}F$-Fluorine Labeling Method)

  • 김동욱;정환정;임석태;손명희
    • Nuclear Medicine and Molecular Imaging
    • /
    • 제43권2호
    • /
    • pp.91-99
    • /
    • 2009
  • Noninvasive imaging of molecular and biological processes in living subjects with positron emission tomography(PET) provides exciting opportunities to monitor metabolism and detect diseases in humans. Measuring these processes with PET requires the preparation of specific molecular imaging probes labeled with $^{18}F$-fluorine. In this review we describe recent methods and novel trends for the introduction of $^{18}F$-fluorine into molecules which in turn are intended to serve as imaging agents for PET study. Nucleophilic $^{18}F$-fluorination of some halo- and mesyloxyalkanes to the corresponding $^{18}F$-fluoroalkanes with $^{18}F$-fluoride obtained from an $^{18}O(p,n)^{18}F$ reaction, using novel reaction media system such as an ionic liquidor tert-alcohol, has been studied as a new method for $^{18}F$-fluorine labeling. Ionic liquid method is rapid and particularly convenient because $^{18}F$-fluoride in $H_2O$ can be added directly to the reaction media, obviating the careful drying that is typically required for currently used radiofluorination methods. The nonpolar protic tert-alcohol enhances the nucleophilicity of the fluoride ion dramatically in the absence of any kind of catalyst, greatly increasing the rate of the nucleophilic fluorination and reducing formation of byproducts compared with conventional methods using dipolar aprotic solvents. The great efficacy of this method is a particular advantage in labeling radiopharmaceuticals with $^{18}F$-fluorine for PETimaging, and it is illustrated by the synthesis of $^{18}F$-fluoride radiolabeled molecular imaging probes, such as $^{18}F$-FDG, $^{18}F$-FLT, $^{18}F$-FP-CIT, and $^{18}F$-FMISO, in high yield and purity and in shorter times compared to conventional syntheses.

경수로 구조재 내 불순물 조성 및 함량이 중성자 방사화 핵종 재고량에 미치는 영향 분석 (The Effects of Impurity Composition and Concentration in Reactor Structure Material on Neutron Activation Inventory in Pressurized Water Reactor)

  • 차길용;김순영;이재민;김용수
    • 방사성폐기물학회지
    • /
    • 제14권2호
    • /
    • pp.91-100
    • /
    • 2016
  • 경수로 원전을 대상으로 원전 내 방사화 대상 물질인 스테인리스강, 탄소강 및 콘크리트의 불순물 정보 적용여부에 따른 방사화 핵종 재고량을 계산하였다. 본 연구에서 탄소강은 압력용기 물질에 사용되었고, 스테인리스강은 압력용기 내부 물질에 사용되었으며, 일반 콘크리트가 생체 차폐체에 사용되었다. 금속 물질에 대해서는 참고자료 1개의 불순물 함량 정보를 적용하였고, 콘크리트 물질에서는 참고자료 5개의 불순물 함량 정보를 적용하여 평가를 수행하였다. 방사화 핵종 재고량 전산해석 시 중성자속 계산에는 MCNP 전산코드를, 방사화 계산에는 FISPACT 전산코드를 각각 사용하였다. 계산 결과, 금속 물질에서 불순물을 포함한 경우가 그렇지 않은 경우보다 비방사능이 2배 이상 높았으며, 특히 콘크리트에서는 불순물을 포함한 경우가 그렇지 않은 경우보다 최대 30배 이상 비방사능이 높게 계산되었다. 방사화 핵종의 생성반응과 재고량을 분석한 결과, 금속 구조물에서는 불순물 중 Co원소와 중성자에 의해 생성되는 방사화 핵종인 Co-60이, 콘크리트에서는 불순물 중 Co, Eu 원소와 중성자에 의해 생성되는 방사화 핵종인Co-60, Eu-152, Eu-154 이 방사성폐기물 준위 결정에 큰 영향을 미치고 있음을 확인하였다. 본 연구의 결과는 원전 해체 계획 수립 시 방사화 핵종 재고량 평가 및 규제에 활용될 수 있을 뿐 아니라, 해체를 고려한 원전 또는 원자력시설의 설계 단계에서도 참고자료로 활용 될 것으로 판단된다.

Socioeconomic impact of traditional Korean medicine, Pyeongwee-San (KMP6) as an anti-allergic inflammatory drug

  • Song, Young-Hoon;Nam, Sun-Young;Choi, Young-Jin;Kim, Jeong-Hwa;Kim, Young-Sick;Jeong, Hyun-Ja
    • 셀메드
    • /
    • 제2권3호
    • /
    • pp.29.1-29.9
    • /
    • 2012
  • The prevalence of allergic disease has been increasing over the past few decades in the majority of Western industrialized nations. There are some socioeconomic disparities regarding allergic disease status and management. Pyeongwee-San (KMP6) is Korean medicine for the treatment of gastrointestinal tract disease. It is known that KMP6 has an improving effect on the spleen and stomach functions in traditional Korean medical theory. Here, we hypothesized that KMP6 could be used to regulate the inflammatory reaction. We show the molecular mechanisms of Pyeongwee-San (KMP6) on inflammatory reactions. A molecular docking simulation showed that hesperidin, component of KMP6, regulate the enzymatic activity by interaction in the active site of caspase-1. KMP6 control the activity of caspase-1 in activated human mast cell line (HMC-1 cells). KMP6 reduced the expression of receptor interacting protein (RIP)-2 in HMC-1 cells. Thymic stromal lymphopoietin protein production and mRNA expression were inhibited by KMP6. In the activated HMC-1 cells, KMP6 suppressed the activation of mitogen-ativated protein kinase and nuclear factor-kappaB. In addition, KMP6 significantly inhibited the expression of inflammatory cytokines. Our findings indicate that KMP6 may attenuate allergic reactions via the regulation of caspase-1/RIP-2 signaling pathway. These studies will help advance the social welfare system.

Specific and common antigens of Clonorchis sinensis and Opisthorchis viverrini (Opisthorchidae, Trematoda)

  • Choi, Min-Ho;Ryu, Jin-Sook;Lee, Me-Jeong;Li, Shun-Yu;Chung, Byung-Suk;Chai, Jong-Yil;Sithithaworn, Paiboon;Tesana, Smarn;Hong, Sung-Tae
    • Parasites, Hosts and Diseases
    • /
    • 제41권3호
    • /
    • pp.155-163
    • /
    • 2003
  • The antigenic characterizations and serological reactions of human liver flukes, Clonorchis sinensis and Opisthorchis viverrini, were analyzed by immunoblot. The antigenic profiles of the crude extract of Clonorchis contained major proteins of 8, 26-28, 34-37, 43, and 70 kDa, and those of Opisthorchis 34-37, 43, 70, and 100 kDa. Of these, the 8, 26-28 and 34-37 kDa bands of Clonorchis and the 100 kDa of Opisthorchis were major components of each excretory-secretory antigen. The 8 and 26-28 kDa bands were specific to Clonorchis but the 100 kDa of Opisthorchis cross-reacted with the sera of clonorchiasis, and the 34-37, 70 and 100 kDa bands cross-reacted with sera of other helminthiases. The frequency and intensity of the immunoblot reactions were positively correlated with the intensity of the liver fluke infection.

회생산(回生散) 에탄올 추출물이 비만세포 매개성 염증반응에 미치는 영향 (Effects of Hoesaeng-san Ethanol Extract on the Human Mast cell-mediated Inflammatory Responses)

  • 박지혜;권동렬;이수경
    • 동의생리병리학회지
    • /
    • 제28권1호
    • /
    • pp.45-52
    • /
    • 2014
  • Hoesaeng-san is known to be effective for treating diarrhea and vomiting. However the therapeutic mechanism of Hoesaeng-san is still not well understood. The aim of the present study was to demonstrate the effects of Hoesaeng-san ethanol extract (HSSEE) on the expression of pro-inflammatory cytokines, as well as to elucidate its mechanism of action in the human mast cell line (HMC-1). Mast Cell were stimulated with phorbol 12-myristate 13-acetate (PMA) plus A23187 in the presence or absence of HSSEE. To study the possible effects of HSSEE, ELISA, RT-PCR, Western blot analysis were used in this study. HSSEE significantly inhibited the PMA plus A23187-induction of inflammatory cytokines such as tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and IL-8. In activated HMC-1 cells, phosphorylation of extra-signal response kinase (ERK) 1/2 and c-jun n-terminal kinase (JNK)1/2 decreased after treatment with HSSEE. Moreover HSSEE inhibited PMA plus A23187-induced nuclear factor (NF)-${\kappa}B$ activation and $I{\kappa}B$ degradation. HSSEE suppressed the expression of TNF-${\alpha}$, IL-6, IL-8 through a decrease in the ERK 1/2 and JNK 1/2, as well as activation of NF-${\kappa}B$. These results indicated that HSSEE exerted a regulatory effect on inflammatory reactions mediated by mast cells.

Can denosumab be a substitute, competitor, or complement to bisphosphonates?

  • Kim, Su Young;Ok, Hwoe Gyeong;Birkenmaier, Christof;Kim, Kyung Hoon
    • The Korean Journal of Pain
    • /
    • 제30권2호
    • /
    • pp.86-92
    • /
    • 2017
  • Osteoblasts, originating from mesenchymal cells, make the receptor activator of the nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in order to control differentiation of activated osteoclasts, originating from hematopoietic stem cells. When the RANKL binds to the RANK of the pre-osteoclasts or mature osteoclasts, bone resorption increases. On the contrary, when OPG binds to the RANK, bone resorption decreases. Denosumab (AMG 162), like OPG (a decoy receptor), binds to the RANKL, and reduces binding between the RANK and the RANKL resulting in inhibition of osteoclastogenesis and reduction of bone resorption. Bisphosphonates (BPs), which bind to the bone mineral and occupy the site of resorption performed by activated osteoclasts, are still the drugs of choice to prevent and treat osteoporosis. The merits of denosumab are reversibility targeting the RANKL, lack of adverse gastrointestinal events, improved adherence due to convenient biannual subcutaneous administration, and potential use with impaired renal function. The known adverse reactions are musculoskeletal pain, increased infections with adverse dermatologic reactions, osteonecrosis of the jaw, hypersensitivity reaction, and hypocalcemia. Treatment with 60 mg of denosumab reduces the bone resorption marker, serum type 1 C-telopeptide, by 3 days, with maximum reduction occurring by 1 month. The mean time to maximum denosumab concentration is 10 days with a mean half-life of 25.4 days. In conclusion, the convenient biannual subcutaneous administration of 60 mg of denosumab can be considered as a first-line treatment for osteoporosis in cases of low compliance with BPs due to gastrointestinal trouble and impaired renal function.

Temperature-Dependent Hydrolysis Reactions of U(VI) Studied by TRLFS

  • Lee, J.Y.;Yun, J.I.
    • Journal of Nuclear Fuel Cycle and Waste Technology
    • /
    • 제1권1호
    • /
    • pp.65-73
    • /
    • 2013
  • Temperature-dependent hydrolysis behaviors of aqueous U(VI) species were investigated with time-resolved laser fluorescence spectroscopy (TRLFS) in the temperature range from 15 to $75^{\circ}C$. The formation of four different U(VI) hydrolysis species was measured at pHs from 1 to 7. The predominant presence of $UO{_2}^{2+}$, $(UO_2)_2(OH){_2}^{2+}$, $(UO_2)_3(OH){_5}^+$, and $(UO_2)_3(OH){_7}^-$ species were identified based on the spectroscopic properties such as fluorescence wavelengths and fluorescence lifetimes. With an increasing temperature, a remarkable decrement in the fluorescence lifetime for all U(VI) hydrolysis species was observed, representing the dynamic quenching behavior. Furthermore, the increase in the fluorescence intensity of the further hydrolyzed U(VI) species was clearly observed at an elevated temperature, showing stronger hydrolysis reactions with increasing temperatures. The formation constants of the U(VI) hydrolysis species were calculated to be $log\;K{^0}_{2,2}=-4.0{\pm}0.6$ for $(UO_2)_2(OH){_2}^{2+}$, $log\;K{^0}_{3,5}=-15.0{\pm}0.3$ for $(UO_2)_3(OH){_5}^+$, and $log\;K{^0}_{3,7}=-27.7{\pm}0.7$ for $(UO_2)_3(OH){_7}^-$ at $25^{\circ}C$ and I = 0 M. The specific ion interaction theory (SIT) was applied for the extrapolation of the formation constants to infinitely diluted solution. The results of temperature-dependent hydrolysis behavior in terms of the U(VI) fluorescence were compared and validated with those obtained using computational methods (DQUANT and constant enthalpy equation). Both results matched well with each other. The reaction enthalpies and entropies that are vital for the computational methods were determined by a combination of the van't Hoff equation and the Gibbs free energy equation. The temperature-dependent hydrolysis reaction of the U(VI) species indicates the transition of a major U(VI) species by means of geothermal gradient and decay heat from the radioactive isotopes, representing the necessity of deeper consideration in the safety assessment of geologic repository.