• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.3
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• pp.31-39
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• 1999

In this paper, numerical experiment is attempted to analyze and compare the combustion efficiency of the burning sprays due to OFO, FOF triplet / FOOF split doublet injectors. Preconditioned Wavier-Stokes equation system with low Reynolds number $\kappa$-$\varepsilon$ model for turbulence closure, is LU-SGS time-integrated. Spray processes are modeled by DSF analysis with experimentally determined injection characteristics. n-heptane/air global reaction model approximates the combustion for simplicity, and the influence of turbulence on the chemical reaction is included using eddy dissipation model. The results showed the FOF triplet injector of highest combustion efficiency, whereas the OFO type of poet performance. It was also observed that the droplet mean diameter and the average gas temperature due to the mixing efficiency, are the representative parameters for the performance design of combustion.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.3
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• pp.427-436
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• 2016

Protective clothing developed for rose flower farmers has been evaluated to improve the working conditions. The requirements of rose farmers were first identified to design protective clothing for farmers working with thorny plants. A fit test was conducted to assess the thermal comfort and protective function against thorn pricking to compare and evaluate the usability of developed experimental clothing with existing working clothes. Based on the survey results of rose farmers' requirements, protective clothing was designed in the form of an apron (which was the most preferred after gloves) with a pattern designed for the production of experimental clothing. For the developed protective clothing, the strap and buckle closure method was selected to open the back of the body as much as possible; in addition, sleeves were made in the attachable form of a half-sleeve to protect the arms from the thorns. The fit test of the developed protective clothing and existing working clothes revealed the temperature and humidity inside the developed protective clothing to be significantly different in the back compared to existing work clothes. In addition to thermal sensations, the subjective humidity sensations were statistically significant different in the developed protective clothing compared to existing work clothes. The subjective protective function for thorn pricking was also found to be satisfactory.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.6
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• pp.442-450
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• 2011

A three dimensional random walk particle tracking method is applied to the Saemangeum area in order to find stepwise environmental changes according to long term construction. Flow regime around Mangyeong, Dongjin and Geum river estuary changed greatly due to dike construction. It is distinctive that reduction of Byeonsan area's flow field and stagnant change in the northern part of the inner reservoir. Similar characteristics are found through the tidal excursion analysis. By analysis of the vertical mixing structures according to density stratification based on temperature and salinity variation, a salt wedge and very strong stratification arises in the inner part of the reservoir after final closure, while it has been well mixed or partially mixed estuary during construction. Shrinking of horizontal dispersion and vertical mixing capability may cause adverse effect on water quality not only inner part but also outer region of the Saemangeum reservoir.

• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1379-1384
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• 2004

Rearrangements of 1,3-oxathiolane sulfoxides 8 and 9 in the presence of base are described from a mechanistic viewpoint of sigmatropic and elimination reactions. In the presence of triethylamine the (Z)-sulfoxide 8 gave the corresponding thiolsulfinate 10 by way of dimerization of the sulfenic acid intermediate 2 at room temperature while the (E)-sulfoxide 9 was recovered even after refluxing in ethyl acetate by the reversal of the [2,3]-sigmatropic rearrangement of the sulfenic acid 4. Triethylamine promoted the developing charge separation in the transition state of the sigmatropic rearrangement of the (Z)-sulfoxide 8 to facilitate the ring opening to the sulfenic acid 2. The reason for more facile ring opening of the (Z)-sulfoxide 8 in comparison with the corresponding (E)-sulfoxide 9 is attributable to the differences in the reactivity of the hydrogen adjacent to the carbonyl group. Triethylamine was not strong base to deprotonate the carbonyl-activated methylene hydrogen of the (E)-sulfoxide 9 but enough to catalyze the sigmatropic process of the sulfoxides. The sulfenic acid 2 dimerized to the thiolsulfinate 10 while the sulfenic acid 4 proceeded the sigmatropic ring closure. In the presence of strong base such as potassium hydroxide, the elimination reaction was predominant over the sigmatropic rearrangement. In this reaction condition, both sulfoxides 8a and 9a gave a mixture of the disulfide 12, the isomeric disulfide 14, and the sulfinic acid 13. Under the strong alkaline condition an elimination of activated hydrogen from the carbon adjacent to the carbonyl group to furnish the sulfenic acid 2a and the isomeric sulfenic acid 18. The formation of the transient intermediate in the reaction was proven by isolation of the isomeric disulfide 14. The reactive entity was regarded as the sulfenic acid rather than sulfenate anion under these reaction conditions.

• The Korean Journal of Food & Health Convergence
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• v.6 no.2
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• pp.17-21
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• 2020

The response of honeybee (Apis mellifera L.) pollination on canola yield with reference to most suitable number of bee hive need per unit area of crops in order to meet optimum pollination needs and better economic yields by comparing number of hives and yield components an experiment was conducted at Beekeeping and Hill Fruit Pests Research, Station Rawalpindi during 2017-18 in complete randomized block design with two sets of four treatments for comparison: 1 hive acre^-1, 2 hives acre^-1, 3 hives acre^-1 and 0 hive acre^-1. The hives were kept inside the experimental area. Parameters were assessed: pollination density, pollinator's diversity, agronomic and economic yield. In case of pollination density, the cumulative mean abundance bee species revealed that at 1200 hours, Apis mellifera was the most abundant and frequent visitor with a mean population of 8.69 bees/plant followed by A. dorsata (0.72), Syrphid fly (0.2) and other pollinators. Minimum bee population was observed during 1400 hours, mainly due to the closure of flowers and partially due to high temperature (>35℃). Pollinator diversity revealed that A. mellifera was the most dominant pollinator of Brassica crop with highest abundance (71%). A. dosata ranked 2^nd (16%) followed by A. florea (6%) respectively.

• Journal of Mushroom
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• v.21 no.1
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• pp.22-32
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• 2023

To investigate the effect of thinning intensity on environmental factors and ectomycorrhizal mushroom fruiting in forest ecosystems, we studied canopy closure, throughfall, soil temperature, soil moisture, light response of understory vegetation, and ectomycorrhizal mushroom fruiting in a 10-year-old pine forest after 34%, 45%, and 60% thinning. Canopy closure was significantly higher in the 34% treatment and control plots, ranging from 80-85% in April. However, in November, all thinning treatment plots showed a decrease of approximately 5-10% compared with the control plot. The 60% treatment plot had over 200 mm of additional throughfall compared with the control plot, and monthly throughfall was significantly higher by more than 100 mm in October. The soil temperature in each treatment plot increased significantly by up to 1℃ or more compared with the control plot as the thinning rate increased. The soil moisture increased by more than 5% in the thinning treatment plots during rainfall, particularly in the 34% treatment plot, where the rate of moisture decrease was slower. The photosynthetic rate of major tree species (excluding Pinus densiflora)was highest in Quercus mongolica, with a rate of 7 µmolCO₂·m^-2·s^-1. At a lightintensity of 800 μmol·m^-2·s^-1, Q. mongolica showed the highest photosynthetic level of 6 ± 0.3 μmolCO₂·m^-2·s^-1 in the 45% treatment. The photosynthetic rate of Fraxinus sieboldiana and Styrax japonicus increased as the thinning intensity increased. The Shannon-Wiener index of mycorrhizal mushrooms did not significantly differ among treatments, but the fresh weight of mushrooms was approximately 360-840 g higher in the 34% and 45% treatments than in the control. Additionally, the fresh weight of fungi in the 60% treatment was 860 g less than that in the control. There were more individuals of Amanita citrina in the control than in the thinning treatment, while Suillus bovinus numbers increased by more than 10 times in the 34% thinning treatment compared with the control.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.73-85
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• 2015

This study investigated the extent and magnitude of the woodland edge effects on users' thermal environments according to distance from woodland border. A series of experiments to measure air temperature, relative humidity, wind velocity, MRT and UTCI were conducted over six days between July 31 and August 5, 2015, which corresponded with extremely hot weather, at the south-facing edge of Hadongsongrim(pure Pinus densiflora stands, tree age: $100{\pm}33yr$, tree height: $12.8{\pm}2.7m$, canopy closure: 75%, N $35^{\circ}03^{\prime}34.7^{{\prime}{\prime}}$, E $127^{\circ}44^{\prime}43.3^{{\prime}{\prime}}$, elevation 7~10m) and east-facing edge of Hamyangsangrim (Quercus serrata-Carpinus tschonoskii community, tree age: 102~125yr/58~123yr, tree height: tree layer $18.6{\pm}2.3m/subtree$ layer $5.9{\pm}3.2m/shrub$ layer $0.5{\pm}0.5m$, herbaceous layer coverage ratio 60%, canopy closure: 96%, N $35^{\circ}31^{\prime}28.1^{{\prime}{\prime}}$, E $127^{\circ}43^{\prime}09.8^{{\prime}{\prime}}$, elevation 170~180m) in rural villages of Hadong and Hamyang, Korea. The minus result value of depth means woodland's outside. The depth of edge influence(DEI) on the maximum air temperature, minimum relative humidity and wind speed at maximum air temperature time during the daytime(10:00~17:00) were detected to be $12.7{\pm}4.9$, $15.8{\pm}9.8$ and $23.8{\pm}26.2m$, respectively, in the mature evergreen conifer woodland of Hadongsongrim. These were detected to be $3.7{\pm}2.2$, $4.9{\pm}4.4$ and $2.6{\pm}7.8m$, respectively, in the deciduous broadleaf woodland of Hamyansangrim. The DEI on the maximum 10 minutes average MRT, UTCI from the three-dimensional environment absorbed by the human-biometeorological reference person during the daytime(10:00~17:00) were detected to be $7.1{\pm}1.7$ and $4.3{\pm}4.6m$, respectively, in the relatively sparse woodland of Hadongsongrim. These were detected to be $5.8{\pm}4.9$ and $3.5{\pm}4.1m$, respectively, in the dense and closed woodland of Hadongsongrim. Edge effects on the thermal environments of air temperature, relative humidity, wind speed, MRT and UTCI in the sparse woodland of Hadongsongrim were less pronounced than those recorded in densed and closed woodland of Hamyansangrim. The gradient variation was less steep for maximum 10 minutes average UTCI with at least $4.3{\pm}4.6m$(Hadongsongrim) and $3.5{\pm}4.1m$(Hamyansangrim) being required to stabilize the UTCI at mature woodlands. Therefore it is suggested that the woodlands buffer widths based on the UTCI values should be 3.5~7.6 m(Hamyansangrim) and 4.3~8.9(Hadongsongrim) m on each side of mature woodlands for users' thermal comfort environments. The woodland edge structure should be multi-layered canopies and closed edge for the buffer effect of woodland edge on woodland users' thermal comfort.

• Proceedings of the Korean Quaternary Association Conference
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• 2004.06a
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• pp.24-25
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• 2004

It is well known that there is an inverse relationship between the strength of Indian summer monsoon Rainfall (ISMR) and extent of Eurasian snow cover/depth in the preceding season. Tibetan snow cover/depth also affects the Asian monsoon rainy season largely. The positive correlation between Tibetan sensible heat flux and southeast Asian rainfall suggest an inverse relationship between Tibetan snow cover and southeast Asian rainfall. Developments in Regional Climate Models suggest that the effect of Tibetan snow on the ISMR can be well studied by Limited Area Models (LAMs). LAMs are used for regional climate studies and operational weather forecast of several hours to 3 days in future. The Eta model developed by the National Center for Environmental Prediction (NCEP), the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) and Regional Climate Model (RegCM) have been used for weather prediction as well as for the study of present-day climate and variability over different parts of the world. Regional Climate Model (RegCM3) has been widely . used for various mesoscale studies. However, it has not been tested to study the characteristics of circulation features and associated rainfall over India so far. In the present study, Regional Climate Model (RegCM-3) has been integrated from 1 st April to 30th September for the years 1993-1996 and monthly mean monsoon circulation features and rainfall simulated by the model at 55km resolution have been studied for the Indian summer monsoon season. Characteristics of wind at 850hPa and 200hPa, temperature at 500hPa, surface pressure and rainfall simulated by the model have been examined for two convective schemes such as Kuo and Grell with Arakawa-Schubert as the closure scheme, Model simulated monsoon circulation features have been compared with those of NCEP/NCAR reanalyzed fields and the rainfall with those of India Meteorological Department (IMD) observational rainfall datasets, Comparisons of wind and temperature fields show that Grell scheme is closer to the NCEP/NCAR reanalysis, The influence of Tibetan snowdepth in spring season on the summer monsoon circulation features and subsequent rainfall over India have been examined. For such sensitivity experiment, NIMBUS-7 SMMR snowdepth data have been used as a boundary condition in the RegCM3, Model simulation indicates that ISMR is reduced by 30% when 10cm of snow has been introduced over Tibetan region in the month of previous April. The existence of Tibetan snow in RegCM3 also indicates weak lower level monsoon westerlies and upper level easterlies.

• The Journal of the Petrological Society of Korea
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• v.17 no.1
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• pp.1-15
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• 2008

The metasedimentary rocks of the Nampo Croup consisting of metaconglomerates, metasandstones, phyllites are exposed in the area of the Daechcon beach and Maryangri, Seocheon-gun. Their typical metamorphic assemblages of Bt-Mus-Grt-Qtz (${\pm}Pl{\pm}Chl$) and Bt-Mus-Qtz (${\pm}Pl{\pm}Chl$) indicate that they have been under intermediate P/T type metamorphism and were metamorphosed to garnet zone grade of amphibolite-facies during the Daebo Orogeny. Pressure-temperature conditions of peak metamorphism estimated from geothermobarometries are $560{\sim}595^{\circ}C$, $6.9{\sim}8.2\;kb$ respectively. The results of K-Ar biotite age determination are $143.2{\pm}3.6\;Ma$, $122.6{\pm}2.4\;Ma$ and $124.8{\pm}2.4\;Ma$ and the last two ages are considered as the results of later-stage thermal perturbation. On the bases of the formation age of Daedong Supergroup of $187{\sim}172\;Ma$ (Han et al., 2006; Jeon et al., 2007) combined with the results of this study, the hypothetical model of tectonometamorphic evolution of the study area during Daebo Orogeny is proposed. Crustal thickening resulted from folding and duplexing of thrusts in the area initiated at around 175 Ma just after sedimentation of Nampo Croup. And then rapid cooling by normal faulting due to crustal extention followed immediately after the peak metamorphism to the closure temperature of biotite.

• The Journal of the Petrological Society of Korea
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• v.7 no.2
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• pp.69-76
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• 1998

$^{40}Ar/^{39}Ar$ analytical data of hornblende and muscovite separates from granitic rocks in southwestern region of Ogcheon belt shows fellowing tectonic implication, $^{40}Ar/^{39}Ar$ data of 5 samples yield apparent age spectra and $^{37}Ar_{ca}/^{39}Ar_k$ and $^{38}Ar_{CI}/^{39}Ar_k$ plateaus for more than 60% of the $^{39}Ar$ release. Except for HN-100, the $^{36}Ar/^{40}Ar$ versus $^{39}Ar/^{40}Ar$ corelalation diagrams indicate the presence of one distint line. Muscovite of sample PKJ-44 yield flate apparent age plateau for > 60% of the $^{39}Ar_k$ release. In the high temperature steps, the $^{37}Ar_{ca}/^{39}Ar_k$ values are irregular with a correlative increase in $^{38}Ar_{CI}/^{39}Ar_k$, suggesting some Ca and CI rich phase, tapped between the silicate sheet is being argon degassed. The $^{40}Ar/^{39}Ar$ total gas age and the high temperature age of HN-100 is 918.2 Ma and 1360 Ma, respectively. The former affectted by recystallized age of Daebo Orogeny, and the latter indicated age of hornblende closure temperature for cooling stage of amphibole xenolith in granite gneiss. Three rock types of Kwangju granites show about 165 Ma hornblende and muscovite ages with some degassed argon at low temperature steps. These ages of 4 samples indicate also recrystallized age by Daebo Orogeny. In $^{40}Ar/^{39}Ar$ mineral age, Rb/Sr whole age and K/Ar mineral age, discordant ages of southwestern region of Ogcheon belt suggesting cooling rates approaching 3~4$^{\circ}C$/m. y. Such slow cooling rates can be produced by uplift rate of 100m/m.y. or slightly slower than isothem-migration rate derived from the hornblende samples. We conclude that the strongest Orogeny and igneous activity of southwestern region of Ogcheon belt are middle proterozoic era (about 1360 Ma) and middle Jurassic period (about 165 Ma).