• 제목/요약/키워드: Detailed Chemistry

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IEA SolarPACES 및 Task 활동 (Activities of IEA SolarPACES & Task Programs)

  • 강용혁;김종규;이현진
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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    • pp.320-323
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    • 2011
  • SolarPACES is an international cooperative network bringing together teams of national experts from around the world to focus on the development and marketing of concentrating solar power systems (also known as solar thermal power systems). It is one of a number of collaborative programs, called Implementing Agreements, managed under the umbrella of the International Energy Agency to help find solutions to worldwide energy problems. Technology development is at the core of the work of Solar PACES. Member countries work together on activities aimed at solving the wide range of technical problems associated with commercialization of concentrating solar technology, including large-scale system tests and the development of advanced technologies, components, instrumentation, and systems analysis techniques. In addition to technology development, market development and building of awareness of the potential of concentrating solar technologies are key elements of the Solar PACES program. The Implementing Agreement specifies broad "Tasks," or thematic areas of work. SolarPACES currently has three ongoing tasks, focusing on concentrating solar electric power systems (Task I), solar chemistry research (Task II), and solar technology and applications (Task III). An Operating Agent, nominated by the ExCo, is responsible for overseeing the work of each task. Each task maintains a detailed program of work that defines all task activities, including their objectives, participants, plans, and budgets. In addition to technical reports of the activities and their participants, accomplishments and progress are summarized in the SolarPACES annual report. Many SolarPACES activities involve close cooperation among member countries (either through sharing of task activities or, occasionally, cost-sharing), although some cooperation is limited to sharing of information and results with other participants. In this paper, structure, works, and members of SolarPACES and Korean activies in the SolarPACES are introduced.

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이엽식 고분자판막의 수력학적 특성평가 및 동물실험 (In-vitro Evaluation of a Bileaflet Polymer Valve and Preliminary Animal Tests)

  • 김철생;박복춘;서수원;한동근;이규백;최진욱;김인영;김희찬;김영하
    • 대한의용생체공학회:의공학회지
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    • 제13권3호
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    • pp.225-234
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    • 1992
  • In order to use a low cost polymer valve in our total artificial heart and ventricular assist device, we have developed a slit-type bileaflet polymer valve[BPV 1. The aim of this study is to determine the hydrodynamic effectiveness of the newly-designed BPV and its feasibility for temporary use in the blood pumps. For hydrodynamic comparison, we investigated in-vitro the pressure drop across the valve, the leakage volume, the flow rate and the flow pattern of the BPV, two mechanical valves and a trileaflet polymer valve. We employed the ventriculo-pulmonary bypassing method for in-vivo tests of the BPV's together vilh our electrohydraulic left venIn ricular assist device in mongrel dogs. The BPV showed adquate gydrodynamic performances and in the preliminary animal bests, there was no xvi dence of thrombus formation on the valve leaflets and around the struts. Detailed results obtained from the animal tests will be separately reported. This report involves the design criteria, fabrication and hydrodynamic charateristics of she BPV, and the basic merits and demerits of the valve are dis- cussed from the hydrodynamic point of view.

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Heme 단백질의 Model로서의 Hemin 착물에 관한 $^1H$ NMR 연구 ($^1H$ NMR Study of mono-and di-cyanide ligated Hemin Complexes as Models of Hemoproteins)

  • 이강봉;김남준;권지혜;이재성;최영상
    • 분석과학
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    • 제7권4호
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    • pp.505-515
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    • 1994
  • DMSO(dimethylsuloxide-$d_6$) 용액 속에 존재하는 CN/CN 리간드의 hemin 착물과 CN/DMSO의 hemin 착물이 $^1H$ NMR로 기록되어지고 분석되어졌다. Hemin으로의 CN 착물화 과정은 온도에 따라 변화함을 NMR 스펙트럼이 보여 주며, 한 개의 CN 리간드에서 두 개의 CN 리간드착물로 바뀌는 과정의 열역학함수는 ${\Delta}H^{\circ}=736.6cal/mol$${\Delta}S^{\circ}=16.4eu$인 흡열과정을 나타낸다. CN/DMSO의 hemin 착물은 Curie behavior로부터의 벗어남은 high-spin 성격의 존재를 나태내고, 이는 Fe-DMSO 결합이 순간적으로 깨짐을 의미하며, 이러한 CN/DMSO hemin 착물이 한 개의 axial ligand가 약한 heme 단백질의 전자 및 분자구조의 model complex로 작용할 수 있음을 보여 준다.

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Determination of a Weak Exchange Interaction in Magnetically Coupled Cluster System by EPR Singlet-Triplet Transition Lines

  • Cho, Young-Hwan;Hyunsoo So
    • 한국자기공명학회:학술대회논문집
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    • 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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    • pp.70-71
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    • 2002
  • Exchange-coupled cluster of transition-metal ions are relevant to many different scientific areas, ranging from chemistry to solid-state physics, biology, material science and has been the subject of much research in recent years(1,2). Single crystal EPR spectroscopy works as a very effective tool for the measurement of J values for small exchange interactions. This makes EPR technique very suitable for detection of weak exchange coupling transmitted over long distances via extended atomic and melecular bridges. Large polyoxometallates (3) may provide ideal structural environments for the study of interactions between paramagnetic ions. The detailed nature of magnetic interaction (positive sign and magnitude of J~0.006 $cm^{-1}$ /) was clearly determined for di-copper(II) system by single crystal EPR spectroscopy (4). The single-triplet (S-T) transitions are forbidden by different symmetries of the wave functions. However, when the singlet ground state is mixed into triplet states, the S-T transitions can be allowed and observed as weak lines. These weak S-T lines are positioned symmetrically with respect to the main transitions in the distance equals to 2J from the center of the spectrum. This lines allow one to determine the J-value with very high accuracy when │J│ < hv 0.32 $cm^{-1}$ /. Unfortunately, the S-T transitions in the single crystal were detected by EPR method only in a few complexes until now. We have measured single-triplet transition lines for several magnetically coupled cluster systems and determined their J values accurately. The temperature dependency of J was studied by monitoring the changes in S-T.

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Mapping and analyzing the distribution of the species in the genus Tulipa (Liliaceae) in the Ferghana Valley of Central Asia

  • DEKHKONOV, Davron;TOJIBAEV, Komiljon Sh.;MAKHMUDJANOV, Dilmurod;NA, Nu-ree;BAASANMUNKH, Shukherdorj;YUSUPOV, Ziyoviddin;CHOI, Hyeok Jae;JANG, Chang-Gee
    • 식물분류학회지
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    • 제51권3호
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    • pp.181-191
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    • 2021
  • Tulips are bulbous geophytes that have considerable commercial value worldwide. This genus primarily originated in the Tien Shan and Pamir-Alai mountain ranges, which surround the Ferghana Valley. The Ferghana Valley is home to five sections of the genus Tulipa L, represented by 23 taxa (22 species). However, there is a lack of detailed information about the distribution of Tulipa species in the natural geographic area of the Ferghana Valley. Therefore, to address this knowledge gap, we comprehensively investigated the spatial distribution of all Tulipa species in the valley. To assess the spatial distribution, the entire area was divided into 32 squares consisting of four latitudinal and eight longitudinal zones. The results showed that latitudinal zones B and C with 15 and 13 taxa, respectively, along with five longitudinal zones (A5, B3, B4, C2, and C3) with 5 to 10 taxa were hotspots for this genus. Additionally, the spatial distributions of the species in terms of the corresponding state borders, mountain ranges, endemism, and conservation issues were assessed. The findings of this study provide comprehensive information about the distribution of Tulipa species to assist with conservation initiatives ultimately to ensure the survival of various species.

Effects of Disease Resistant Genetically Modified Rice on Soil Microbial Community Structure According to Growth Stage

  • Sohn, Soo-In;Oh, Young-Ju;Ahn, Jae-Hyung;Kang, Hyeon-jung;Cho, Woo-Suk;Cho, Yoonsung;Lee, Bum Kyu
    • 한국환경농학회지
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    • 제38권3호
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    • pp.185-196
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    • 2019
  • BACKGROUND: This study investigated the effects of rice genetically modified to be resistant against rice blast and rice bacterial blight on the soil microbial community. A comparative analysis of the effects of rice genetically modified rice choline kinase (OsCK1) gene for disease resistance (GM rice) and the Nakdong parental cultivar (non-GM rice) on the soil microbial community at each stage was conducted using rhizosphere soil of the OsCK1 and Nakdong rice. METHODS AND RESULTS: The soil chemistry at each growth stage and the bacterial and fungal population densities were analyzed. Soil DNA was extracted from the samples, and the microbial community structures of the two soils were analyzed by pyrosequencing. No significant differences were observed in the soil chemistry and microbial population density between the two soils. The taxonomic analysis showed that Chloroflexi, Proteobacteria, Firmicutes, Actinobacteria, and Acidobacteria were present in all soils as the major phyla. Although the source tracking analysis per phylogenetic rank revealed that there were differences in the bacteria between the GM and non-GM soil as well as among the cultivation stages, the GM and non-GM soil were grouped according to the growth stages in the UPGMA dendrogram analysis. CONCLUSION: The difference in bacterial distributions between Nakdong and OsCK1 rice soils at each phylogenetic level detected in microbial community analysis by pyrosequencing may be due to the genetic modification done on GM rice or due to heterogeneity of the soil environment. In order to clarify this, it is necessary to analyze changes in root exudates along with the expression of transgene. A more detailed study involving additional multilateral soil analyses is required.

초임계 유체의 미생물 불활성화 특성 및 기작 (Antimicrobial Activity and Mechanism of Supercritical Fluids)

  • 문성민;김정찬;이윤우;윤제용
    • 공업화학
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    • 제22권5호
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    • pp.453-460
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    • 2011
  • 안전하고 미생물 불활성화 능력이 높은 초임계 유체(이산화탄소 및 일산화이질소)는 최근 식품 및 의료 분야 등에서 비가열 살균기술로 응용 가능성이 높아 관심이 증대되고 있다. 하지만 초임계 유체를 이용한 많은 응용 연구에도 불구하고 초임계 유체 살균기술의 살균 성능 및 기작에 대한 이해 부족으로 아직 널리 활용되고 있지 못하다. 따라서 본 글에서는 기존 연구를 중심으로 초임계 유체 특성, 미생물 불활성화 특성과 기작, 주요 영향 인자, 응용 분야 등에 대해서 정리 및 검토하여 초임계 유체 살균기술의 연구 및 상용화에 도움이 되고자 한다.

Two Unrecorded Apiospora Species Isolated from Marine Substrates in Korea with Eight New Combinations (A. piptatheri and A. rasikravindrae)

  • Kwon, Sun Lul;Cho, Minseo;Lee, Young Min;Kim, Changmu;Lee, Soo Min;Ahn, Byoung Jun;Lee, Hanbyul;Kim, Jae-Jin
    • Mycobiology
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    • 제50권1호
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    • pp.46-54
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    • 2022
  • Although Apiospora Sacc. has previously been considered a sexual morph of Arthrinium species on the basis of phylogenetic, morphological, and ecological diagnoses, a recent study delimited these as different species. Recently, 14 species, including eight new species, of marine Arthrinium have been reported from Korea. Six known species have previously been renamed as species in the genus Apiospora (A. arundinis, A. marii, A. piptatheri, A. rasikravindrae, A. sacchari, and A. saccharicola). However, the eight new species of marine Arthrinium (Ar. agari, Ar. arctoscopi, Ar. fermenti, Ar. koreanum, Ar. marinum, Ar. pusillispermum, Ar. sargassi, and Ar. taeanense) are yet to be studied, and thus the taxonomic status of these species remains to be clarified. In this study, we conducted phylogenetic analyses using the internal transcribed spacer, 28S large subunit ribosomal RNA gene, translation elongation factor 1-alpha, and beta-tubulin regions to confirm the phylogenetic position of these eight species. Based on these analyses, we re-identified the eight Arthrinium species as new combinations in Apiospora. Additionally, among the six known Apiospora species, two (A. piptatheri and A. rasikravindrae) have not previously been recorded in Korea. On the basis of morphological and molecular analyses, we report these as new species in Korea. Herein, we present scanning electron micrographs detailing the morphologies of these species, along with phylogenetic trees and detailed descriptions.

The impact of probiotics and vitamin C on the prevention of upper respiratory tract symptoms in two preschool children cohorts

  • Zuzana Paduchova;Zuzana Nagyova;Duolao Wang;Jana Muchova
    • Nutrition Research and Practice
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    • 제18권1호
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    • pp.98-109
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    • 2024
  • BACKGROUND/OBJECTIVES: The efficacy of Lab4 probiotic and vitamin C combination on the prevention of upper respiratory tract infections (URTIs) was investigated in two studies with children. Our objective was to pool dataset of 57 preschool children from the PROCHILD study (ISRCTN28722693) and the dataset of 50 preschool matched cohort from the PROCHILD-2 study (ISRCTN26587549) to evaluate the impact of probiotic/vitamin C combination on the prevention of upper respiratory tract symptoms and provide a more robust assessment of effect using detailed individual level data. SUBJECTS/METHODS: The children were supplemented daily for 6 months with either the multistrain probiotic (1.25×1010 cfu/tablet consisting of two strains of Lactobacillus acidophilus CUL21 and CUL60, Bifidobacterium bifidum CUL20 and Bifidobacterium animalis subsp. lactis CUL34) plus 50 mg vitamin C or a placebo. RESULTS: In the pooled analysis of the individual participant data (per protocol population), significant reductions were observed for the incidence (-25%; 95% confidence interval [CI], 0.66, 0.85; P < 0.0001) and duration (-14.9 days; 95% CI, -24.8, -5.1; P = 0.0030) of typical URTI symptoms in the active group compared with the placebo. The incidence rates of absenteeism from preschool (IR ratio, 0.75; 95% CI, 0.66, 0.86; P < 0.0001), paediatric visits (IR ratio, 0.56; 95% CI, 0.47; 0.68; P < 0.0001) and antibiotic usage (IR ratio, 0.53; 95% CI, 0.39, 0.71; P < 0.0001) were also significantly reduced. CONCLUSION: The pooled analysis findings of comparable preschool cohorts from two studies indicate that the supplementation with probiotic and vitamin C combination is beneficial in the prevention and management of URTI symptoms.

Hematological characteristics and endocrine profiles of cloned dromedary camels (Camelus dromedaries)

  • Young-Bum Son;Mohammad Shamim Hossein;Yeon Ik Jeong;Mina Kang;Huijeong Kim;Yura Bae;Kung Ik Hwang;Alex Tinson;Singh Rajesh;Al Shamsi Noura;Woo Suk Hwang
    • 한국동물생명공학회지
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    • 제39권1호
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    • pp.12-18
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    • 2024
  • Background: Somatic cell nuclear transfer (SCNT) is a prominent technology that can preserve superior genetic traits of animals and expand the population in a short time. Hematological characters and endocrine profiles are important elements that demonstrate the stability of the physiological state of cloned animals. To date, several studies regarding cloned camels with superior genes have been conducted. However, detailed hemato-physiological assessments to prove that cloned camels are physiologically normal are limited. In this study, We evaluated the hemato-physiological characteristics of cloned male and female dromedary camels (Camelus dromedaries). Methods: Therefore, we analyzed variations in hematological characteristics and endocrine profiles between cloned and non-cloned age-matched male and female dromedary camels (Camelus dromedaries). Two groups each of male and female cloned and non-cloned camels were monitored to investigate the differences in hemato-physiological characteristics. Results: All the animals were evaluated by performing complete blood count (CBC), serum chemistry, and endocrinological tests. We found no significant difference between the cloned and non-cloned camels. Furthermore, the blood chemistry and endocrine profiles in male and female camels before maturity were similar. Conclusions: These results suggest that cloned and non-cloned camels have similar hematological characteristics and endocrine parameters.