• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.94-99
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• 1990

A field experiment was conducted to study seasonal evapotranspiration above soybean canopy and its relationship with dry matter production by the Bowen ratio-energy balance method. The soybean "Paldalkong" was sown with the space of $47{\times}10cm$ at Suwon on May 27, 1988. The daily net radiation ranged from 59 to 76 percents of the total shortwave radiation under cloudless conditions, which was lower than cloud overcast condition with recorded 63 to 83 percents. The latent heat flux under overcast condition was sometimes larger than the sum of net radiation, implying transportation of energy by advection of ambient air. The linear relationship was obtained between daily or daytime net radiation and evapotranspiration. The evapotranspiration calculated by Bowen ratio-energy balance method was about 150 percent of class A pan evaporation during the growing season. The total solar radiation from June 20 to August 27 was $1043MJm^{-2}$. The 85 percent of the total shortwave radiation was used for evaporative heat. The dry matter production within the period was $836gm^{-2}$ and the water use efficiency was $2.31gDM\;kg^{-1}\;H_2O$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.137-145
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• 2004

Long-term wave distribution at Jeju sea is investigated by a numerical simulation based on the thirdgeneration wave model SWAN (Simulating WAves Nearshore). The Jeju sea which retains relatively high wave energy density among Korean coastal regions is considered to be a suitable site for wave power generation and the efficiency of wave power generation is closely related to local wave characteristics. The monthly mean of a large-scale long-term wave data from 1979 to 2002, which is provided by Korea Ocean Research & Development Institute. is used as the boundary condition of SWAN model simulation with 1km grid. An analysis of wave distribution concentrates on the seasonal variation and spatial distribution of significant wave heights, mean wave directions and mean wave periods. Significant wave heights are higher in winter and summer and the west sea of Jeju appears relatively higher than east's. The highest significant wave height occurs at the northeast sea in winter and the second highest significant wave height appears at the southeast sea in summer, while the significant wave heights in spring and autumn are relatively low but homogeneous. The distribution of wave directions reveals that except the rear region influenced by wave refraction, the northwest wave direction is dominant in summer and the southeast in winter. Wave periods are longer in summer and winter and the west sea of Jeju appears relatively longer than east's. The longest wave period occurs at the west sea in winter, and in summer it appears relatively homogeneous with a little longer period at the south sea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.273-281
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• 2013

Based on the results of continuous flux measurements at the Gimje paddy flux site in the southwestern coast of Korea, carbon dioxide and energy exchanges between customarily cultivated rice-barley double cropping paddy field and the atmosphere during the 2012 rice growing season (from $9^{th}$ Jun. 2012 through $20^{th}$ Oct. 2012) were analyzed. Carbon dioxide and energy (H, LE) fluxes were estimated by the eddy covariance method. Environmental parameters (net radiation, precipitation, etc.) and plant biomass (LAI, plant height, etc.) were measured along with fluxes. After the quality control and gap-filling, the observed fluxes were analyzed. The results have been showed that net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) during the rice cropping period were -277.1, 710.3, and 433.2 g C $m^{-2}$, respectively.

• Journal of the Korean Solar Energy Society
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• v.35 no.2
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• pp.73-83
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• 2015

When it comes to these buildings for business use, cooling load during summertime was reported to have great importance which, as a result, impressively increased interest in Solar Heat Gain Coefficient (SHGC). Such SHGC is considered to be lowered with the help of colors and functions of glass itself, internal shading devices, insulation films and others but basically, these external shading devices for initial blocking that would not allow solar heat to come in from outside the buildings are determined to be most effective. Of many different external shading devices, this thesis conducted an analysis on Exterior Venetian Blind. As for vertical shading devices, previous researches already calculated SHGC conveniently using concepts of sky-opening ratios. However in terms of the Venetian Blind, such correlation is not possibly applied. In light of that, in order to extract a valid correlation, this study first introduced a concept called shape factor, which would use the breadth and a space of a shade, before carrying out the analysis. As a consequence, the concept helped this study to find a very similar correlation. Results of the analysis are summarized as follows. (1) Regarding SHGC depending on the surface reflectance of a shade, an average of 2% error is observed and yet, the figure can always be ignored when it comes to a simple calculation. (2) As for SHGC of each bearing, this study noticed deviations of 4% or less and in the end, it is confirmed that extraction can be achieved with no more than one correlation formula. (3) When only the shape factor and nothing else is used for finding a correlation formula, the formula with a deviation of approximately 5% or less is what one would expect. (4) Since the study observed slight differences in bearings depending on ranges of the shape factors, it needed to extract a weighted value of each bearing, and learned that the smaller the shape factor, the wider the range of a weighted value. The study now suggests that a follow-up research to extract a simple calculation formula by dealing with all these various inclined angles of shade, solar radiation conditions of each region (the ratio of diffuse radiation to direct radiation and others) as well as seasonal features should be carried out.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.95-105
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• 2005

This study was carried out to file up using effect and requirement of energy for environmental design data of Pleurotus eryngii growing houses. Heating and cooling Degree-Hour (D-H) were calculated and compared for. some Pleurotus eryngii growing houses of sandwich-panel (permanent) o. arch-roofed(simple) type structures modified and suggested through field survey and analysis. Also thermal resistance (R-value) was calculated for the heat insulating and covering materials of the permanent and simple-type, which were made of polyurethane or polystyrene panel and $7\~8$ layers heat conservation cover wall. The variations of heating and cooling D-H simulated for Jinju area was nearly linearly proportional to the setting inside temperatures. The variations of cooling D-H was much more sensitive than those of heating D-H. Therefore, it was expected that the variations of required energy in accordance with setting temperature or actual temperature maintained inside of the cultivation house could be estimated and also the estimated results of heating and cooling D-H could be effectively used far the verification of environmental simulation as well as for the calculation of required energy amounts. When the cultivation floor areas are all equal, panel type houses to be constructed by various combinations of materials were found to by far more effective than simple type pipe house in the aspect of energy conservation maintenance except some additional cost invested initially. And also the energy effectiveness of multi-span house compared to single span together with the prediction of energy requirement depending on the level insulated for the wall and roof area could be estimated. Additionally, structural as well as environmental optimizations are expected to be possible by calculating periodical and/or seasonal energy requirements for those various combinations of insulation level and different climate conditions, etc.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.55-68
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• 2010

The seasonal variation of microbial community, based on the bacteria, heterotrophic nanoflagellates (HNF), phytoplankton and ciliates, was investigated at three sites in the eutrophic brackish water of Lake Shihwa and its adjacent areas from May 2007 through May 2008. At the upstream-region site St. 1, compared to the other two sites, significantly lower salinities and higher concentrations of nutrients and chlorophyll $\alpha$ (Chl. $\alpha$) were recorded. The annual average abundances of bacteria at St. 1, St. 2 and St. 3 were $6.8{\times}10^6$, $7.4{\times}10^6$ and $4.6{\times}10^6\;cells\;mL^{-1}$, respectively. As for the annual average concentrations of HNF, $19{\times}10^2$, $6.7{\times}10^2$ and $5.9{\times}10^2\;cells\;mL^{-1}$, were recorded in St. 1, St. 2 and St. 3 respectively. The highest ciliate abundance appeared at St. 1 on 29 April, 2008 and in which, 99% were autotrophic ciliate Mesodinium rubrum (Myrionecta rubra). Significant linear correlations between the biomass of bacteria and Chl. $\alpha$ were found, however, no significant relationships between ciliates abudance/biomass and their prey organisms were detected in all three sites, implying relatively low energy transfer efficiencies between them. These results indicated that the trophic relationship between ciliates and their prey organisms in the microbial community might be influenced by indirect route since higher trophic level organisms did not directly correlate to those of lower trophic level, although high primary productions were detected in the eutrophic brackish water of Lake Shihwa and its adjacent areas.

• The Korean Journal of Petroleum Geology
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• v.10 no.1_2 s.11
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• pp.10-17
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• 2004

The Doowoo-ri tidal flat in the southwestern Korean coast is a typical open-coast tidal flat which has no barriers in the offshore such as barrier island and sand bars. The difference of induced wave energy with seasons is affected directly on the distribution of surface sediment and the formation of sedimentary structures because the sedimentation by wind wave is relatively much important element in this open-coast tidal flat. This open-coast tidal flat can be classified into tidal beach, intertidal flat and lower mudflat according to the pattern of geomorphology and sediment type. The intertidal flat can be again divided into 3 types: sand flat, mixed flat and mud flat based on the primary sedimentary structure and sand/mud ratio. Doowoori tidal flat shows a seasonal change in the surface sedimentary facies based on sediment composition and primary sedimentary structure. The change is closely related to the direction and magnitude of monsoon wind and also to storm frequency. In winter and spring, when northwesterly wind is most dominant and strong and also storms are common, sand-flat facies is largely distributed on the intertidal flat, whereas mud-flat facies is most dominant during summer when weak southeasterly wind is common. In the fall season, mixed-flat facies is dominant on the flat. The Doowoori intertidal flat is covered by mud sediment which is ca. 20 cm in thickness in summer season. In winter season, surface sediment is changed from mud to sand because the summer mud is mostly eroded by strong wave action. Can-core peels in the intertidal flat show that parallel laminated mud or sand/mud and climbing ripple cross-laminated sandy silt are dominant on the upper intertidal flat $(0-1.3 {\cal}km)$ during summer season. On the other hand, on lower intertidal flat $(1.7-2.3 {\cal}km)$, dominant sedimentary facies is homogeneous mud. In winter, it is changed into parallel laminated and ripple cross-laminated sand facies.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.316-320
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• 2001

Sixteen growing crossbred Anglo-Nubian goats, 10-12 months old, pre-experimental average body weights of $18.3{\pm}0.28kg$ were randomly allotted to four diets to investigate the efficiency of utilisation of diets containing increasing levels of desiccated coconut waste meal (DCWM) in the tropical environment of Samoa, South Pacific region. The four diets were designated as 1, 2, 3 and 4. Diet 1 that has no DCWM served as the control, while diets 2, 3 and contained different levels of DCWM. Voluntary concentrate intake, growth rate, feed efficiency and nutrient digestibility coefficients were measured. Gross energy (GE) and organic matter (OM) values of the diets increased linearly with increase in the levels of DCWM in the diets. Voluntary concentrate intake decreased with increasing proportion of DCWM in the diets. Forage intake increased with increase in the levels of DCWM diets offered to the growing goats. Total voluntary feed intakes were statistical significant (p<0.05) and the goats on diet 4 had the least intake followed by those on diet 3. Goats an diets 1 and 2 were different in total feed intake but not at a significant level (p>0.05). Feed efficiency (FE) followed the trend of voluntary concentrate intake and daily live weight gains. Dry matter digestibility (DMD) was significantly different (p<0.05) among the goats offered the different diets. DMD improved with increasing levels of DCWM. The goats accepted all, the diets that were compounded with the different levels of dried DCWM and this seems to suggest that DCWM have no deleterious effects. However, the best level at which dried DCWM could replace brewers dried grains in the diets of growing goats is at 38.5% (diet II). Based on voluntary feed intake, live-weight gain and apparent nutrient digestibility coefficients of the goats it could be concluded that DCWM based diets merits further attention as a locally available feed source in ruminants nutrition in the Pacific Island countries where feed availability is seasonal.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.36-40
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• 2007

Proteins and lipids not only provide a source of energy to the cell, but also play vital roles in modifying the physical properties and function of the biological membranes. In the present study, we investigated the biochemical constituents, viz. proteins and lipids, in growing oocytes of goat antral follicles during summer and winter seasons. Goat genitalia in phosphate buffered saline (pH 7.4) were brought to the laboratory within one hour of slaughter under aseptic conditions at $37^{\circ}C$. Oocytes were aspirated from normal small (<3 mm in diameter) and large (>3 mm) follicles and pooled for biochemical estimations. A significant increase in the amount of protein and lipid was observed with the growth of the oocyte. The amount of protein varied non-significantly with the season, while the amount of lipid varied significantly. The amounts of phospholipid, cholesterol, free fatty acid, and triglyceride increased with the growth of the oocyte, but no significant effect of season in these constituents was observed. Lysolecithin, sphingomyelin, and sterols were the polar lipids identified in both oocytes prepared from small follicles (small oocytes) as well as large follicles (large oocytes). In addition, the small oocytes also contained phosphatidyl serine, while large oocytes contained phosphatidyl glycerol phosphate and phosphatidyl inositol. Among non-polar lipids, triglycerides and long chain alcohols appear only in small oocytes and not in large oocytes. Monoglycerides, 1,2-diglycerides, 1,3-diglycerides and o-dialkyl glycerol ethers, fatty acids, fatty acid methyl esters, and wax esters were identified in both small and large oocytes. Information on biochemical composition of growing oocytes is relevant to oocyte and embryo competence, culture and cryopreservation.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1395-1403
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• 2012

The objective of the study was to quantify annual and seasonal differences in the chemical composition, in vitro gas production, in situ degradability and ruminal fermentation of grazing steers… diets. Diet samples were collected with four esophageal cannulated steers ($350{\pm}3$ kg BW); and four ruminally cannulated heifers ($342{\pm}1.5$ kg BW) were used to study the dry matter degradation and fermentation in rumen. Data were analyzed with repeated measurements split plot design. The crude protein, in vitro dry matter digestibility and metabolizable energy were higher during the first year of trial and in the summer (p<0.01). The values of calcium, phosphorus, magnesium, zinc and copper were higher in summer (p<0.05). The gas produced by the soluble and insoluble fractions, as well as the constant rate of gas production were greater in summer and fall (p<0.01). The ammonia nitrogen ($NH_3N$) and total volatile fatty acids concentrations in rumen, the soluble and degradable fractions, the constant rate of degradation and the effective degradability of DM and NDF were affected by year (p<0.05) and season (p<0.01). Our study provides new and useful knowledge for the formulation of protein, energetic and mineral supplements that grazing cattle need to improve their productive and reproductive performance.