• Title/Summary/Keyword: Sr-89

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Electrochemical Performance of LSCF Cathode with GDC lnterlayer on ScSZ Electrolyte

  • Hwang, Hae-Jin;Moon, Ji-Woong;Lim, Yongho;Lee, Seunghun;Lee, Eun-A
    • Journal of the Korean Ceramic Society
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    • v.42 no.12 s.283
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    • pp.787-792
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    • 2005
  • A symmetrical LSCF $(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-\delta})\;ScSZ(89ZrO_2-10Sc_2O_3-1CeO_2)/LSCF$ electrochemical cell with a GDC (Gadolinium-Doped Ceria, $90CeO_2-10Gd_2O_3$) interlayer that was inserted between the LSCF cathode and ScSZ electrolyte was fabricated, and the electrochemical performance of these cells was evaluated. The GDC interlayer was deposited on a ScSZ electrolyte using a screen-printing technique. The GDC interlayer prevented the unfavorable solid-state reactions at the LSCF/ScSZ interfaces. The LSCF cathode on the GDC interlayer had excellent electrocatalytic performance even at $650^{\circ}C$. The Area Specific Resistance (ASR) was strongly dependent on the thickness and heat-treatment temperature of the GDC interlayer. The impedance spectra showed that the cell with a $15\~27{\mu}m$ thick GDC interlayer heat-treated at $1200^{\circ}C$ had the lowest ASR.

ABSORBED INTERNAL DOSE CONVERSION COEFFICIENTS FOR DOMESTIC REFERENCE ANIMALS AND PLANT

  • Keum, Dong-Kwon;Jun, In;Lim, Kwang-Muk;Choi, Yong-Ho
    • Nuclear Engineering and Technology
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    • v.42 no.1
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    • pp.89-96
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    • 2010
  • This paper describes the methodology of calculating the internal dose conversion coefficient in order to assess the radiological impact on non-human species. This paper also presents the internal dose conversion coefficients of 25 radionuclides ($^3H,\;^7Be,\;^{14}C,\;^{40}K,\;^{51}Cr,\;^{54}Mn,\;^{59}Fe,\;^{58}Co,\;^{60}Co,\;^{65}Zn,\;^{90}Sr,\;^{95}Nb,\;^{99}Tc,\;^{106}Ru,\;^{129}I,\;^{131}I,\;^{136}Cs,\;^{137}Cs,\;^{140}Ba,\;^{140}La,\;^{144}Ce,\;^{238}U,\;^{239}Pu,\;^{240}Pu$) for domestic seven reference animals (roe deer, rat, frog, snake, Chinese minnow, bee, and earthworm) and one reference plant (pine tree). The uniform isotropic model was applied in order to calculate the internal dose conversion coefficients. The calculated internal dose conversion coefficient (${\mu}Gyd^{-1}$ per $Bqkg^{-1}$) ranged from $10^{-6}$ to $10^{-2}$ according to the type of radionuclides and organisms studied. It turns out that the internal does conversion coefficient was higher for alpha radionuclides, such as $^{238}U,\;^{239}Pu$, and $^{240}Pu$, and for large organisms, such as roe deer and pine tree. The internal dose conversion coefficients of $^{239}U,\;^{240}Pu,\;^{238}U,\;^{14}C,\;^3H$, and $^{99}Tc$ were independent of the organism.

Effectiveness of Acupuncture, Mind and Body Practices, and Natural Products for Insomnia: an overview of systematic reviews

  • Yeo, Jin Ju;Lee, Jang Won;Kim, Kyung Sik;Hyun, Min Kyung
    • Journal of Pharmacopuncture
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    • v.25 no.3
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    • pp.186-198
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    • 2022
  • Objectives: This overview summarizes the evidence for the effectiveness and safety of complementary therapies for insomnia through systematic reviews (SRs) and meta-analyses (MAs). Methods: A comprehensive literature search on SRs and MAs for complementary therapies for insomnia was conducted using six databases. Results: This overview included 30 SRs/MAs. The Pittsburgh Sleep Quality Index (PSQI) analysis of insomnia included 383 randomized controlled trials and 31,748 participants. Twenty-four SRs/MAs (80%) out of 30 SRs/MAs reported a positive result, and six SRs/MAs reported a partially positive result. The most frequently used form of acupuncture reported a positive effect in 89.5% (17/19) of SRs/MAs and a superior effect to western medicine, sham/placebo, and no treatment. The lack of protocol registration and the excluded studies list resulted in generally poor methodological and reporting quality in SRs/MAs with AMSTAR 2. Conclusion: This overview confirmed that complementary therapies positively affected the PSQI scores in patients with insomnia. However, better-designed primary studies are needed to strengthen the relevant evidence in the future. A more stringent assessment of multiple systematic reviews 2 must be followed when performing SR and MA.

High Functional $GdB_2C_3O_{7-x}$ Thin Films Fabricated by Pulsed Laser Deposition

  • Song, S.H.;Ko, K.P.;Song, K.J.;Moon, S.H.;Yoo, S.I.
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.4
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    • pp.15-18
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    • 2006
  • REBCO coated conductors (RE: rare earth elements) have recently drawn great attention since they are known to possess stronger flux pinning centers in high magnetic fields compared with YBCO coated conductors. In this study, $GdBa_2Cu_3O_{7-d}(GdBCO)$ was selected to investigate the influence of the distance between target and substrate and substrate temperature on the superconducting properties of GdBCO films on the $SrTiO_3(100)$ substrate. Samples were fabricated by pulsed laser deposition (PLD) with a Nd:YAG laser (355nm). Under a given oxygen pressure of 800mTorr, we changed the distance between target and substrate from 5.5cm to 7.0cm and the substrate temperature from $750^{\circ}C\;to\;850^{\circ}C$. The crystallinity and texture of GdBCO films were analyzed by X-ray diffraction (XRD), and the surface morphology was observed by the scanning electron microscopy (SEM). Tc and Jc values were measured by the four point probe method. High quality GdBCO films with Tc of 89.7K and Jc over $1MA/cm^2$ at 77 K in self field were successfully fabricated by optimizing processing parameters. The detailed processing conditions, microstructure and superconducting properties will be presented for a discussion.

Nano Yttrium-90 and Rhenium-188 production through medium medical cyclotron and research reactor for therapeutic usages: A Simulation study

  • Abdollah Khorshidi
    • Nuclear Engineering and Technology
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    • v.55 no.5
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    • pp.1871-1877
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    • 2023
  • The main goal of the coordinated project development of therapeutic radiopharmaceuticals of Y-90 and Re-188 is to exploit advancements in radionuclide production technology. Here, direct and indirect production methods with medium reactor and cyclotron are compared to evaluate derived neutron flux and production yield. First, nano-sized 186W and 89Y specimens are suspended in water in a quartz vial by FLUKA simulation. Then, the solution is irradiated for 4 days under 9E+14 n/cm2/s neutron flux of reactor. Also, a neutron activator including three layers-lead moderator, graphite reflector, and polyethylene absorbent- is simulated and tungsten target is irradiated by 60 MeV protons of cyclotron to generate induced neutrons for 188W and 90Sr production via neutron capture. As the neutron energy reduced, the flux gradually increased towards epithermal range to satisfy (n/2n,γ) reactions. The obtained specific activities at saturation were higher than the reported experimental values because the accumulated epithermal flux and nano-sized specimens influence the outcomes. The beta emitters, which are widely utilized in brachytherapy, appeal an alternative route to locally achieve a rational yield. Therefore, the proposed method via neutron activator may ascertain these broad requirements.

Accuracy Assessment of Forest Degradation Detection in Semantic Segmentation based Deep Learning Models with Time-series Satellite Imagery

  • Woo-Dam Sim;Jung-Soo Lee
    • Journal of Forest and Environmental Science
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    • v.40 no.1
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    • pp.15-23
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    • 2024
  • This research aimed to assess the possibility of detecting forest degradation using time-series satellite imagery and three different deep learning-based change detection techniques. The dataset used for the deep learning models was composed of two sets, one based on surface reflectance (SR) spectral information from satellite imagery, combined with Texture Information (GLCM; Gray-Level Co-occurrence Matrix) and terrain information. The deep learning models employed for land cover change detection included image differencing using the Unet semantic segmentation model, multi-encoder Unet model, and multi-encoder Unet++ model. The study found that there was no significant difference in accuracy between the deep learning models for forest degradation detection. Both training and validation accuracies were approx-imately 89% and 92%, respectively. Among the three deep learning models, the multi-encoder Unet model showed the most efficient analysis time and comparable accuracy. Moreover, models that incorporated both texture and gradient information in addition to spectral information were found to have a higher classification accuracy compared to models that used only spectral information. Overall, the accuracy of forest degradation extraction was outstanding, achieving 98%.

High Quality and High Yielding Rice Variety 'Cheongdam' Adaptable to Direct Seeding (고품질 다수성 직파재배적성 신품종 '청담벼')

  • Choi, Im-Soo;Kang, Kyung-Ho;Jeong, O-Young;Jeong, Eung-Gi;Cho, Young-Chan;Kim, Yeon-Gyu;Kim, Myeong-Ki;O, Myeong-Gyu;Choi, In-Bea;Jeon, Yong-Hee;Won, Young-Jae;Shin, Young-Seoup;Oh, In-seok
    • Korean Journal of Breeding Science
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    • v.43 no.6
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    • pp.581-586
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    • 2011
  • 'Cheongdam' is a japonica rice variety developed from a cross between SR19200-HB826-34, a line of good germination ability and shoot emergence at low temperature and Juanbyeo, good quality and direct-seeding adaptable cultivar by the rice breeding team of National Institute of Crop Science, RDA in 2006. This variety has 153 days of total growth duration from seeding to maturity in direct-seeding, and 160 days of growth duration from seeding to maturity in transplanting. This is erect plant type with culm length of 74 cm, thick culm, and green leaves. It has large panicle shape with 126 and 140 spikelets per panicle in direct-seeding and transplanting, respectively. Milled rice is transluscent and medium in grain size of non-glutinous endosperm. This variety is susceptible to leaf and neck blast, bacterial blight, stripe virus disease and brown planthopper. The yield potential of 'Cheongdam' is 5.84 MT/ha at ordinary transplanting culture and 5.62 MT/ha and 5.89 MT/ha at wet direct-seeding and dry direct-seeding cultures, respectively in the local adaptability test for three years. 'Cheongdam' would be adaptable to middle and southern plain of Korea for direct-seeding culture and transplanting rice culture.

The Characteristics of Social Anxiety Symptoms in the Korean Nonclinical Population (한국인 일반인구에서의 사회 불안 증상의 특성)

  • Kang, Yeo-Jin;Ha, Ju-Won;Lim, Se-Won;Oh, Kang-Seob
    • Anxiety and mood
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    • v.7 no.1
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    • pp.22-28
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    • 2011
  • Objective : Social anxiety disorder (SAD) has been characterized by a marked sense of anxiety provoked by exposure to one or more social situations. It has been well-known that the cultural characteristics of a society strongly affect the expression of SAD symptoms. The current study attempted to explore clinical and cultural characteristics of social anxiety symptoms in the Korean nonclinical population. Methods : 801 volunteers who participated in the national social anxiety screening day, which was held by Korean academy of anxiety disorders, were invited to complete the self-report version of Liebowitz social anxiety scale (LSAS-SR). A total of 691 participants completed the LSAS-SR and other information related to this study. Results : Social anxiety symptoms were reported by a great percentage of subjects, as displayed by the relatively high mean LSAS scores (44.58 ; SD=25.60). There were no significant differences in total LSAS score according to sex, education, or marital status. The three most fearful or avoided situations for participants, as measured by the percentage of subjects who had a score of more than 3 on each LSAS item were as follows: item 6 (acting, performing, or giving a talk in front of an audience ; 29.67% for fear and 22.72% for avoidance), item 16 (speaking up in a meeting ; 25.62% for fear and 21.56% for avoidance), and item 15 (being the center of attention; 13.89% for fear and 9.70% for avoidance). Conclusion : The Korean participants in this study demonstrated a high level of SAD symptoms. Our subjects reported that they were more likely to be fearful or avoid passive situations such as being the center of attention as compared with results from a study of western society which indicated that western people were more likely to be fearful or avoid active situations. These findings emphasize the importance of considering a patient's cultural background when evaluating SAD symptoms.

Quality characteristics of different parts of garlic sprouts produced by smart farms during growth (스마트팜 생산 새싹마늘의 부위별 및 생육 기간에 따른 품질 특성)

  • Yu-Ri Choi;Su-Hwan Kim;Chae-Mi Lee;Dong-Hun Lee;Chae-Yun Lee;Hyeong-Woo Jo;Jae-Hee Jeong;Imkyung Oh;Ho-Kyung Ha;Jungsil Kim;Chang-Ki Huh
    • Food Science and Preservation
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    • v.30 no.2
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    • pp.272-286
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    • 2023
  • Garlic sprouts can provide data on functional and food processing materials. This study compared the leaves, bulbs, and roots of garlic sprouts grown on smart farms during two growth periods (20 and 25 days). In addition, data for garlic bulbs grown in open fields were presented as reference materials. All garlic sprouts' total free sugar content decreased as the growth period increased. All plant parts' total organic acid content decreased as the growth period progressed, except for the root section. Potassium, phosphorus, and sulfur content increased during growth in all parts of the garlic sprouts. Alliin content decreased in all parts of the plant over time, whereas thiosulfinate content increased in the roots but decreased in the leaves and bulbs. Total polyphenol content increased in all parts of the plant during the growth period, except for the bulb, whereas the flavonoid content did not change significantly over time. The 2,2-diphenyl-1-picrylhydrazy (DPPH) and 2,2'-azinobis (3-ethylben-zothiazoline 6-sulfonate) (ABTS) free radical scavenging activities, as well as the superoxide dismutase (SOD)-like activity of garlic sprouts were 37.45-65.47%, 59.12-89.81%, and 89.52-98.59%, respectively. These activities tend to decrease during the growth period. Here, we showed that garlic sprouts have higher levels of functional substances and physiological activities than general garlic sprouts. It was also determined that a growth period of 20 days was suitable for garlic sprouts. Data for research on functional and food-processing materials can be obtained by analyzing garlic sprouts produced by smart farms.

Clinical Results from Single-Fraction Stereotactic Radiosurgery (SRS) of Brain Arteriovenous Malformation: Single Center Experience (뇌동정맥기형에서 선형가속기를 이용한 방사선 수술 후의 임상적 결과)

  • Lim, Soo-Mee;Lee, Re-Na;Suh, Hyun-Suk
    • Progress in Medical Physics
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    • v.21 no.3
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    • pp.274-280
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    • 2010
  • The purpose of this study was to analyze the effect of single-fraction stereotactic radiosurgery (SRS) for the treatment of 15 cases of cerebral arteriovenous malformations (AVMs). Between 2002 and 2009, of the 25 patients who had SRS for the treatment of cerebral AVM, 15 patients (6 men, 9 women) taken a digital subtraction angiography (DSA) over 12 months after SRS were included. We retrospectively evaluated the size, location, hemorrhage of nidus, angiographic changes on follow-up on the MR angiography and DSA, and clinical complications during follow-up periods. At a median follow-up of 24 months (range 12-89), complete obliteration of nidus was observed in all patients (100%) while residual draining veins was observed in 3 patients (20%). There was no clinical complication during the follow-up period except seizure in 1 patient. The mean nidus volume was 4.7cc (0.5~11.7 cc, SD 3.7 cc). The locations of nidus were in cerebral hemisphere in 11 patients, cerebellum in 2 patients, basal ganglia in 1 patient, and pons in 1 patient respectively. 9 cases were hemorrhagic, and 6 cases were non-hemorrhagic AVMs. The SRS with LINAC is a safe and effective treatment for cerebral AVMs when the follow up period is over 4 years. However, it is recommended to continue to follow up until the draining vein on arterial phase of follow up DSA disappears completely.