• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.219-227
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• 1993

Broadcast-seeded rice in submerged paddy frequently lodge in the field. In general, the causes of lodging in rice cultivation differ with different cultural methods. This study was conducted to investigate the causes of lodging in broadcast-seeded rice (BSR) and hand-transplanted rice (HTR) under four nitrogen (N) levels. Lodging in BSR was mainly a root lodging due to shallow root distribution, while that in HTR showed a bending type owing to deep rooting system. At the upper soil layer (0-5cm from the surface of ground) the root distribution of BSR (65.2%) was much larger than that of HTR (51.6%), whereas at the 5-10cm soil layer the root distribution of BSR (18.5%) was much smaller than that of HTR (28.0%). The depth of buried culm base was much shallower in BSR (1.2cm) than in HTR (4.0cm). The plant height, fresh weight, lodging index, culm diameter and thickness in HTR were much greater than those in BSR, and the breaking strength of lower internode was similar in the two cultivation methods indicating that HTR would have more lodging causes than BSR. In spite of . the more advantages to lodging resistance in BSR it severely lodged in the field. The main lodging-inducing factors of BSR were the shallow root distribution and shallow depth of buried culm base. Besides these, the higher ratio of gravity center of culm was an important factor. This result suggested that for the fundamental prevention of lodging in BSR, an ideotype of rice plant with ' a deep-rooted behavior ' should be developed.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.307-318
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• 2009

KAERI (Korea Atomic Energy Research Institute) has developed the GAMMA+ code for a thermo-fluid and safety analysis of a VHTR (Very High Temperature Gas-Cooled Reactor). A key safety issue of the VHTR design is to demonstrate its inherent safety features for an automatic reactor power trip and power stabilization during an anticipated transient without scram (ATWS) accident such as a loss of forced cooling by a trip of the helium circulator (LOFC) or a reactivity insertion by a control rod withdrawal (CRW). This paper intends to show the ATWS assessment capability of the GAMMA+ code which can simulate the reactor power response by solving the point-kinetic equations with six-group delayed neutrons, by considering the reactivity changes due to the effects of a core temperature variation, xenon transients, and reactivity insertions. The present benchmark calculations are performed by using the safety demonstration experiments of the 10 MW high temperature gas cooled-test module (HTR-10) in China. The calculation results of the power response transients and the solid core temperature behavior are compared with the experimental data of a LOFC ATWS test and two CRW ATWS tests by using a 1mk-control rod and a 5mk-control rod, respectively. The GAMMA+ code predicts the power response transients very well for the LOFC and CRW ATWS tests in HTR-10.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.1
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• pp.181-192
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• 1989

Loss of teeth causes the inevitable reduction of residual ridge. Among the various methods solving this problem, hydroxyapatite proved to be useful for correction of ridge defect and irregularity. The purpose of this study is to evaluate the tissue responses of two types Of hydroxyapatites and resin polymer. Calcitite 2040 (Calcitek Inc.), Interpore 200 (Interpore Int.), and HTR polymer (HTR Sciences) were implanted into the jaw of an adult dog. The procedure was designed to obtain the results of 1 week, 2 week, 4 week, and 12 week-intervals. And after 12 weeks from the first operation day, the dog was sacrificed and evaluated histologically by light microscope. The results were as follows : 1. The mucosa was healed after two weeks. 2. After 1 week, there were acute inflammatory cells, but diminished after 2 weeks and were not seen after 12 weeks. 3. The hydroxyapatites implanted in soft tissues were surrounded by fibrous connective tissue. And some foreign body giant cells were found. 4. Calcitite and Interpore particles implanted subperiosteally were surrounded by newly formed bone after 12 months. And direct contact between bone and particles was noted. 5. The HTR particles implanted in soft tissues were encapsulated by fibrous connective tissues. The sample where the particles contacted directly to bone could not obtained by some probable insufficiencies of surgical technique or care of the animal. And the residue of HTR particles was digested by macrophage.

• Archives of Pharmacal Research
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• v.22 no.2
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• pp.113-118
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• 1999

Previous work in our laboratory has shown that the N-methyl-D-aspartate (NMDA) receptor antagonists, AP-5, CPP, MK-801, ketamine, dextrorphan and dextromethorphan cause a pronounced enhancement of 5-hydroxytryptamine (5-HT)-induced head-twitch response (HTR) in intact mice, suggesting the involvement of NMDA receptors in the glutamatergic modulation of serotonergic function at the postsynaptic $5-HT_{2}$ receptors. The purpose of this study was to extend our previous work on the behavioral interaction between glutamatergic and serotonergic receptors. In the present study, both competitive (AP-5 and CPP) and noncompeti-tive (MI-801, ketamine, dextrorphan and dextromethorphan) NMDA receptor antagonists markedly enhanced 5-HT-induced selective serotonergic behavior, HTR, in p-chlorophenylalanine (PCPA)-treated mice which were devoid of any involvement of indirect serotonergic function, to establish the involvement of the NMDA receptor in 5-HT-induced HTR at the postsyaptic $5-HT_{2}$receptors. In addition, the enhancement of 5-HT-induced HTR was inhibited by a dopamine agonist, apomorphine, NMDA receptor antagonist, NMDA and a serotonin $5-HT_{2}$receptor antagonist, cyproheptadine, in PCPA-treated mice. Therefore, the present results support our previous conclusion that the NMDA receptors play an important role in the glutamatergic modulation of serotonergic function at the poststynaptic $5-HT_{2}$ receptors.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.63-71
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• 2024

Hydrothermal Reaction (HTR) was applied for the stabilization of contaminated soil with heavy metals, and then the test determined the optimal conditions for HTR. After HTR, the concentration of heavy metals in the contaminated soil increased. However, it was observed that the leachability potential significantly decreased as determined by TCLP and SPLP tests. This decrease was attributed to a decline in fractions 1-2 and an increase in fractions 3-4 as revealed by sequential extraction procedure. Due to the mineralogical characteristics of the dredged soil, distinct changes were not evident in the five-stage fraction. Therefore, it is deemed necessary to understand the chemical and mineralogical characteristics of the target soil for HTR application in order to selectively address contaminants. Comparison among operating conditions determined the optimal condition to be at 240℃ for one hour.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1692-1696
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• 2011

The reactions of 1H-1,2,4-triazole (Htr) with $MX_2$ ($ZnCl_2$ for 1; $CdBr_2$ for 2) resulted in two coordination polymers, [Zn(tr)Cl]$_n$ (1) and $[Cd(Htr)_2Br_2]_n$ (2). The structural analyses indicate that 1 and 2 feature a 2D layer and 1D triple chain, respectively. In 1, neighouring Zn atoms are connected by ${\mu}_3-1$ ${\kappa}N$: 2 ${\kappa}N$: $4{\kappa}N-tr^-$ anionic ligand into 6- and 16-membered rings, further grow into a 2D sheet. Cd atoms in 2 are bonded by two ${\mu}_2-Br^-$ bridges and neutral ${\mu}_2$-1 ${\kappa}N$: 2 ${\kappa}N$-Htr to form a 1D triple chain. The fluorescent characterizations of 1, 2 and the free Htr ligand feature simlilar emission peakes at 444, 446 and 423 nm respectively, which can be assigned to intra-ligand ${\pi}-{\pi}^*$ transition of (H)tr. The energy gaps of 5.90 eV for 1, 5.16 eV for 2, and 5.93 eV for Htr suggest that the compounds behave as insulators.

• Journal of Korea Multimedia Society
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• v.10 no.4
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• pp.462-469
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• 2007

ATM protocol has the techniques such as cell discarding priority, traffic shaping and traffic policing. ATM based MPLS(Multiprotocol Label Switching) is discussed for its provisioning QoS commitment capabilities, traffic engineering and smooth migration for BcN using conventional ATM infra in Korea. This paper proposes preventive congestion control mechanism for detecting HTR(Hard To Reach) LSP(Label Switched Path) in ATM based MPLS systems. In particular, we decide HTR LSP using real time signaling information(etc., PTI,AIS/RDI) for applying HTR concept in circuit switching to ATM based MPLS systems and use those session gap and percentage based control algorithm that were used in conventional PSTN call controls. We concluded that it maximized the efficiency of network resources by restricting ineffective machine attempts. Proposed control can handle 208% call processing and more than 147% success call, than those without control. It can handle 187% BHCA(Busy Hour Call Attempts) with 100 times less than use of exchange memory.

• Biomedical Science Letters
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• v.21 no.4
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• pp.181-187
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• 2015

Osteoporosis is one of the diseases caused by accumulation of effects from complex interactions between genetic and environmental factors. Aging is the major cause for osteoporosis, which normally increases skeletal fragility and bone fracture especially among the elder. "Omics" refers to a specialized research field dealing with high-throughput biological data, such as genomics, transcriptomics, proteomics or metabolomics. Integration of data from multi-omics has been approved to be a powerful strategy to colligate biological phenomenon with multiple aspects. Actually, integrative analyses of "omics" datasets were used to present pathogenesis of specific diseases or casual biomarkers including susceptible genes. In this study, we evaluated the proposed relationship of novel susceptible genes (TREML2, HTR1E, and GLO1) with osteoporosis, which genes were obtained using multi-omics integration analyses. To this end, SNPs of the susceptible genes in the Korean female cohort were analyzed. As a result, one SNP of HTR1E and five SNPs of TREML2 were identified to associate with osteoporosis. The highest significant SNP was $rs6938076^*$ of TREML2 (OR=0.63, CI: 0.45~0.89, recessive P=0.009). Consequently, the susceptible genes identified through the multi-omics analyses were confirmed to have association with osteoporosis. Therefore, multi-omics analysis might be a powerful tool to find new genes associated with a disease. We further identified that TREML2 has more associated with osteoporosis in females than did HTR1E.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.469-474
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• 2014

The high temperature gas-cooled reactor (HTR-10) is designed to produce electricity and hydrogen. Graphite is used as reflector, support structures, and a moderator in reactor core; it has good resistance to neutron and is a suitable material at high temperatures. Friction is generated in the graphite structures for the core reflector, support structures, and moderator because of vibration from the HTR-10 fuel cycle flow. In this study, the wear characteristics of the isotropic graphite IG-110 used in HTR-10 were evaluated. The reciprocating wear test was carried out for graphite against graphite. The effects of changes in the contact load and sliding speeds at room temperature and $400^{\circ}C$ on the coefficient of friction and specific wear rate were evaluated. The wear behavior of graphite IG-110 was evaluated based on the wear surfaces.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.674-680
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• 2020

We used MCNP6 computer code to model HTR-10 core reactor. We used two types of fuel; UO₂ and (Th+Pu)O₂ mixture. We determined the critical height at which the reactor approached criticality in both two cases. The neutronic and burnup parameters were investigated. The results indicated that the core fueled with mixed (Th+Pu)O₂, achieved about 24% higher fuel cycle length than the UO₂ case. It also enhanced safeguard security by burning Pu isotopes. The results were compared with previously published papers and good agreements were found.