• Natural Product Sciences
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• v.13 no.4
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• pp.279-282
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• 2007

The aim of the present study was to investigate the various chemical components present in the cone volatile oil of Cupressus macrocarpa and also determine its antimicrobial activity. Totally 13 compounds were identified with 99.99% by GC-MS analysis. The major compounds identified were terpinene-4-ol (19.42%), dinopol (15.63%), ${\alpha}$-pinene (13.58%), and ${\beta}$-pinene (12.16%). The antimicrobial activity was carried out for the oil and a 2% cream formulation using cup plate method by measuring the zone of inhibition. The gram positive organisms used were Bacillus subtilis, Staphylococcus aureus, Bacillus megaterium, and Bacillus cogulans. The gram negative organisms used were Escherichia coli, Kleibseilla pneumonia, Pseudomonas aeruginosa and Salmonella typhi. In vitro antifungal studies were also carried out by using organisms, Candida albicans, Aspergillus flavus, Trichoderma lignorum and Cryptococcus neoformans. The standard drugs used were penicillin ($100{\mu}g/mL$), gentamycin ($100{\mu}g/mL$) and griseofulvin ($100{\mu}g/mL$) for gram positive bacteria, gram negative bacteria and fungi respectively. Both oil and cream formulation showed good activity against fungi than bacteria. This study is being reported for the first time on cone volatile oil of this plant.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2709-2716
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• 2020

Compositions of large nuclear cores (e.g. boiling water reactors) are highly heterogeneous in terms of fuel composition, control rod insertions and flow regimes. For this reason, they usually lack high order of symmetry (e.g. 1/4, 1/8) making it difficult to estimate their neutronic parameters for large spaces of possible loading patterns. A detailed hyperparameter optimization technique (a combination of manual and Gaussian process search) is used to train and optimize deep neural networks for the prediction of three neutronic parameters for the Ringhals-1 BWR unit: power peaking factors (PPF), control rod bank level, and cycle length. Simulation data is generated based on half-symmetry using PARCS core simulator by shuffling a total of 196 assemblies. The results demonstrate a promising performance by the deep networks as acceptable mean absolute error values are found for the global maximum PPF (~0.2) and for the radially and axially averaged PPF (~0.05). The mean difference between targets and predictions for the control rod level is about 5% insertion depth. Lastly, cycle length labels are predicted with 82% accuracy. The results also demonstrate that 10,000 samples are adequate to capture about 80% of the high-dimensional space, with minor improvements found for larger number of samples. The promising findings of this work prove the ability of deep neural networks to resolve high dimensionality issues of large cores in the nuclear area.

• Journal of the Korean Wood Science and Technology
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• v.31 no.2
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• pp.38-44
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• 2003

This study was carried out to evaluate the feasibility of using HDF as surface panels as well as core materials for flush door manufacturing. Six core constructions were developed and applied to manufacture door specimens and conventional skin door specimen was also manufactured for comparison. Door specimens were tested under changing interior environmental condition for 3~4 months during winter and summer seasons. During the test period, deformation of doors were measured weekly, and temperature and relative humidity of testing area were also recorded. From this study, it was concluded that HDF can be used to manufacture quality flush doors and core construction developed in this study showed good quality compared to conventional skin door. Deformation of doors increased as temperature and relative humidity of the surrounding environment increased. Flush doors generally showed less deformation than skin doors, and evaluated to be stable and good quality when compared to skin door.

• Korean Journal of Materials Research
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• v.32 no.4
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• pp.216-222
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• 2022

The capacity of high nickel Li(Ni_xCo_yMn_1-x-y)O₂ (NCM, x ≥ 0.8) cathodes is known to rapidly decline, a serious problem that needs to be solved in a timely manner. It was reported that cathode materials with the {010} plane exposed toward the outside, i.e., a radial structure, can provide facile Li⁺ diffusion paths and stress buffer during repeated cycles. In addition, cathodes with a core-shell composition gradient are of great interest. For example, a stable surface structure can be achieved using relatively low nickel content on the surface. In this study, precursors of the high-nickel NCM were synthesized by coprecipitation in ambient atmosphere. Then, a transition metal solution for coprecipitation was replaced with a low nickel content and the coprecipitation reaction proceeded for the desired time. The electrochemical analysis of the core-shell cathode showed a capacity retention of 94 % after 100 cycles, compared to the initial discharge capacity of 184.74 mA h/g. The rate capability test also confirmed that the core-shell cathode had enhanced kinetics during charging and discharging at 1 A/g.

• Journal of Oral Medicine and Pain
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• v.36 no.3
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• pp.161-167
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• 2011

Sialolith is one of the most common pathologic conditions found in the salivary glands. The mechanisms responsible for the formation of sialoliths have not been elucidated so far. In this article, the chemical composition and micromorphology of a sialolith of a 58-year old female patient suffering from chronic sialoadenitis of the submandibular gland was analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). In a SEM evaluation, the highly mineralized amorphous core surrounded by lamellar and concentric structures was revealed, however no foreign body, organic material, or signs of microorganism were observed in the core of the sialolith. EDX analysis showed the central core was composed of only Ca, O and P, and that a high level of C was detected near the central area as well. These results indicated that the inorganic composition of the sialolith was hydroxyapatite crystals, and that inorganic and organic substances existed around the central cores. This study suggests that the sialolith was composed mainly of hydroxyapatite crystals and the formation of the nucleus of the sialolith in the submandibular gland duct was secondary to sialadenitis, which favors the growth of an inorganic crystalline nucleus.

• Economic and Environmental Geology
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• v.19 no.spc
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• pp.113-119
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• 1986

A characteristic mineralogical zonal distribuion is observed in a large scale(whole ore- body) small scales(handy specimens). They show similar chemical variations: most of elements except CaO were supplied by hydrothermal fluids to form skarns. Garnets occuring in the pyroxene-garnet skarn have a wide range of chemical composition ranging from andradite to grossularite, while individual grains of the garnets also show a similar zonation of chemical composition varied between grossularite and andradite. Highly contained Mo-bearing scheelites are generally concentrated in the central part of the Sang- dong skarn orebody. Similarly, some large grains of scheelite show a nice zonation due to different contents of Mo, highly enriched in the core of the scheelite crystal. This geochemical similarity in the large scale and small scales suggests the Sangdong skarn formation was achieved under a certain chemical environment, and detailed studies on a small scale texture could be a clue to understand a whole ore deposit.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.3.1-3.1
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• 2011

Nanoengineered materials with advanced architectures are critical building blocks to modulate conventional material properties or amplify interface behavior for enhanced device performance. While several techniques exist for creating one dimensional heterostructures, electrospinning has emerged as a versatile, scalable, and cost-effective method to synthesize ultra-long nanofibers with controlled diameter (a few nanometres to several micrometres) and composition. In addition, different morphologies (e.g., nano-webs, beaded or smooth cylindrical fibers, and nanoribbons) and structures (e.g., core-.shell, hollow, branched, helical and porous structures) can be readily obtained by controlling different processing parameters. Although various nanofibers including polymers, carbon, ceramics and metals have been synthesized using direct electrospinning or through post-spinning processes, limited works were reported on the compound semiconducting nanofibers because of incompatibility of precursors. In this work, we combined electrospinning and galvanic displacement reaction to demonstrate cost-effective high throughput fabrication of ultra-long hollow semiconducting chalcogen and chalcogenide nanofibers. This procedure exploits electrospinning to fabricate ultra-long sacrificial nanofibers with controlled dimensions, morphology, and crystal structures, providing a large material database to tune electrode potentials, thereby imparting control over the composition and shape of the nanostructures that evolved during galvanic displacement reaction.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.105-112
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• 1998

Characteristics of species distribution in the Baekdoo Great Mountain Chain of Kangwon Province were discussed. Resulting from Detrending Correspondence Analysis based on the floristic composition of 48 mountains, the mountains of the Baekdoo chain tended to aggregate on DCA axis. it represented that there was the peculiar floristic composition of the Baekdoo chain separated from the other mountains. High altitude, longitude near the East Sea and large number of vascular species were main factors for the distribution pattern. And exponential relationships between endemic rare species and number of species were clarified. Even though the regions of the Baekdoo Great Mountain Chain had been conserved relatively well, many regions have been faced to be disturbed for tourism, agriculture, forestry, livestock industry and mining since the local autonomy. Thusm, the necessity for the establishment of large area network through the connection of scattered protected areas in the Baekdoo Great Mountain Chain was suggested. it would play a role as a core of nature conservation to sustain species diversity in Korea.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2001.05a
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• pp.95-99
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• 2001

This study aims from being meaning of centrality to possibility of space composition in the Contemporary Interior Space os forming of center and way of being. There it is studied analysed architect's work on character of certrality. This study mentiones not as analysis of location and perception aspect on uabanism but as various forming and changing in the contemporary interior space composition. it is definitioned as centrality in architecture space which is base in the course of congiting and organizing and is core space in forming area, It is moaned not as Euclidean plan but as three demeasional vector space in space express architectual space exists except for perception of human and takes center and direction in perculiarly.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.159-165
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• 2009

The purpose of this study was to investigate the effects of thinning on fine root biomass and vertical distribution. and litterfall amount in a 50 year old Pinus koraiensis plantation in Chuncheon, Kangwon Province. Fine root (< 2 mm in diameter) biomass ($367\;g/m^2$) in the site 'OC_75', thinning once in 1975, was 68% of those in the site 'CON', no thinning after planting, and in the site 'TC_00', thinning twice in 1975 and 2000. There were no significant differences of dead roots among treatments. Diameter $0{\sim}1\;mm$ roots were vertically decreased only in the TC_00 site. The litterfall was very similar between OC_75 ($5.2\;Mg\;ha^{-1}\;yr^{-1}$) and TC_00 ($4.7\;Mg\;ha^{-1}\;yr^{-1}$), but the composition of litterfall was different: The proportion of leaves and branches was 80% and 13% in OC_75 and 56% and 36% in TC_00, respectively. Reduction of P. koraiensis density by thinning decreased leaf litter as well as fine roots of P. koraiensis, but increased fine roots production by neighboring understory plants offset the reduction of fine roots of P. koraiensis. We suggest that belowground as well as aboveground responses, including both over- and understory vegetation, should be considered to measure the responses of trees in thinned forest ecosystems.