• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.52-53
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• 2001

The dietary effects of conjugated linoleic acid (CLA) on lipid concentrations and fatty acid composition of various tissues were studied in young chicks. Chicks were fed one of four diets containing 6% tallow (TO), 4% TO-2% CLA, 2% TO-4% CLA or 6% CLA for 3wks. There were no differences in growth performances, but relative liver weight in chicks fed dietary CLA up to 4% was significantly higher than that of 6% TO group. The concentrations of various lipid fractions in serum were not affected by CLA feeding. With the increase in dietary CLA levels, total CLA in liver and leg muscle increased linearly.

• Proceedings of the Korea Forestry Energy Research Society Conference
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• 1999.04a
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• pp.18-21
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• 1999

• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.35-40
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• 2003

This experiment was conducted to investigate the effects of natural and synthetic commercial pigments on the growth performances, skin pigmentation and color difference of broiler chicks. Experimental diet was formulated to have isocalories and isonitrogen for experimental period, and xanthophyll concentration in the diet was 8.45g/1on. The experiment was conducted for six weeks with 450 broiler chicks. The birds were assigned to 10 treatment groups and each group had 15 chicks with three replications. Results showed that the types of pigments did not have any effect on body weight, feed intake and feed efficiency. The mortality was lower with higher pigment supplementation and greater in the natural pigment groups than in the synthetic ones. Dressed carcass, abdominal fat pad and gizzard weight were not significantly different among treatments. The pigmentation of shank skin was increased with high pigment supplementations, and the pigmentation effect was greater with synthetic pigments than in natural pigments. In the shank meat or skin, the color difference(L*, a*, b*, c* and h*) was not consistently related to pigmentation.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.54-64
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• 1995

The effects of swirl on early flame development and late combustion characteristic were investigated using a high speed single-shot visualized 51 engine. LDV measurements were performed to get better understanding of the flow field in this combustion chamber. Spark plugs were located at half radius (R/2) and central location of bore. High speed schlieren photographs at 20,000 frames/sec were taken to visualize the detailed formation and development of the flame kernel with cylinder pressure measurements. This study showed that high swirl gave favorable effects on combustion-related performances in terms of the maximum cylinder pressure and flame growth rate regardless of spark position. However, at R/2 ignition the low swirl shown desirable effects at low engine speed gave worse performances as engine speed increased than without swirl. There were distinct signs of slow-down in flame growth during the period when the flame front expanded from 2.5mm in radius until it reached 5.0mm apparently due to the presence of ground electrode. There seemed to be heat transfer effect on the flame expansion speed which was evidenced in high swirl case by the slowdown of the late flame front presumably caused by relatively large heat loss from burned gas to wall compared with low- or no-swirl cases.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.207-217
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• 1984

Seasonal growth performances or root collar diameter and seedling height of Quercus acutissima. Q. mongolica and Q. variabilis were measured at regular intervals of 10 or 15 days after the treatments of some combinations of soil water regime ${\times}$ fertilization. The treatments of soil water regime and fertilization Influenced on the growth performances of seedlings differently with one another in course of time lapse. The growth performances revealed highly significant differences between soil water regimes, between fertilizations and between their interactions after unlike time lapses by species. The effects of soil water regime were exhibited in retard compared with those of fertilization, and to be different outstandingly in the treatments of N or N+P+K fertilization. The limit of soil water potential influencing critically on the growth performances might be estimated to be in -3~-6 bar in all the species. The growth responses were significantly different between N or N+P+K treatment and P or K treatment or control in all the species, and the treatment effects represented more great differences in moist soil water regime than in dry soil water regime. The interactions of soil water regime ${\times}$ fertilization were revealed s lowly with time lapse in all the treatments. The statistical differences of growth responses of root collar diameter according to the treatments were observed in earlier stage compared with those of seedling height. By comparison of the growth responses of the species studied, Q. variabilis and Q. mongolica seemed to be more resistant to moisture stress than Q. acutissima.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.219-229
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• 1993

Effects of paper mill sludge-fertilizers were investigated on the growth performances of tree seedlings under field conditions. Two types of sludge-fertilizers applied were an organic sludge compost and a processed sludge-pellet fertilizer strengthened with several components of organic and inorganic nutrients. Three species of tree seedlings studied were ibota privet(Ligustrum obtusifolium) and yellow poplar(Liriodendron tulipifera) of 1-0 year seedlings and also eastern white pine(Pinus strobus) of 2-2 year seedlings. Nitrogen and phosphorus contents of plot soil treated with sludge compost+sludge-pellet fertilizer+sludge-pellet fertilizer plot were increased to 8 times and 2.6 times as those of control plot, respectively. The growth performances of root collar diameter and seedling height were repeatedly measured up to five times through the growing season and the results were analyzed statistically by analysis of variance of randomized block design and Duncan's multiple range test. The growth performances of dry weight were measured after last fifth measurements.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.216-219
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• 2000

A field study was carried out to compare the performances of mulching with recycled paper, oil-treated paper and urea-coated paper in spring season potato culture. Soil temperature, weed occurrence, and the growth and yield of potato (cv. Sumi) were compared with unmulched control. The average soil temperatures at 5cm soil depth during the first 10 days after planting were 18.9$^{\circ}C$, under paper mulch and 20.6$^{\circ}C$, under oil-treated paper mulch, being lower 0.8$^{\circ}C$ and higher 1.2$^{\circ}C$, respectively, than unmulched control. Paper mulch lowered maximum soil temperature by 4.6$^{\circ}C$, on a fine day, while oil-treated paper mulch elevated it by over 6.6$^{\circ}C$, Urea-coated paper was decomposed fester than the mulch paper without urea coating. The former was decomposed 50% by 80days after mulching, but the later only 20%. In all mulch treatments, weeds were effectively controled throughout the potato growing season. The percent emergence of potato was not different significantly among treatments. However, a little lower emergence and poor early growth were observed under oil-treated paper mulch because of higher soil temperature. Except oil-treated paper mulch, the paper mulches with and without urea coating showed no difference in growth and yield of potato from the unmulched control. The growth and yield performances were poorest under oil-treated paper mulch. Oil-treated paper mulch would result in difference growth and yield performances if potato is planted earlier than April IS in the present experiment. Further researches are needed for this aspect.

• Journal of Animal Environmental Science
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• v.19 no.2
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• pp.141-148
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• 2013

This study was conducted to evaluate the effect of different housing systems on the performances of sows and their piglets during gestation. A total of 90 sows (Landrace ${\times}$ Yorkshire) were employed into 3 experimental farms to give 3 treatments, stall housing, group housing in either slatted floor or litter floor. Individual sow was used as an experimental unit. Group housed sows were fed with electronic sow feeder during gestation. Performance measures were taken on sows and piglets. Back-fat thickness and body condition score of sows were not affected by housing systems for pregnant sows. There was no difference of estrus interval of pregnant sows between housing systems. The lower number of still-birth was observed in group housing type. The number of wounded sows in slatted floor was remarkably increased compared with sows in litter floor. This study showed that the housing systems could fairly impact sow and piglet performances.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.5
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• pp.296-304
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• 2023

Cavitation tests for a waterjet propulsor of an amphibious vehicle are carried out in the Large Cavitation Tunnel. Waterjet pump performances and cavitation characteristics including thrust breakdown performances are investigated in the tests. In addition, cavitation characteristics for waterjet propulsors working inside the intake are calculated by using a commercial CFD code, Star-CCM+. Sliding mesh is implemented to a rotating impeller and the k-epsilon turbulence model is chosen. Cavitation bubble growth and collapse are estimated using the Schnerr-Sauer cavitation model based on Rayleigh-Plasset equation. Calculated results agree fairly well with experimental results. The re-design of the waterjet propulsor is performed to enhance waterjet cavitating performances and calculated results show that waterjet thrust breakdown characteristics are significantly improved.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.186-196
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• 2010

Fertilization increases the crop productivity and produces high quality seedlings for plantation. We quantitatively measured both physical performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted species in Korea, to nitrogen, phosphorus, and potassium fertilization. We analyzed the growth performances by using Dickson's quality index (QI) and the nutrient status by using vector diagnosis. Nitrogen or phosphorus treatment increased height and root collar diameter growth of F. rhynchophylla and F. mandshurica, however, did not increase those of P. koraiensis and A. holophylla. The order of QI was N > P > K > control for F. rhynchophylla, P ${\geq}$ N > Control ${\geq}$ P for F. mandshurica, P > Control ${\geq}$ K > N for P. koraiensis and A. holophylla. In F. rhynchophylla, fertilization diluted N concentration in tissues by 5-25% because growth responses were higher than fertilization uptake. P. koraiensis and A. holophylla showed N excess showing "toxic accumulation". F. rhynchophylla and F. mandshurica showed P deficiency with P fertilization, however, P. koraiensis and A. holophylla showed "luxury accumulation". Vector diagnosis indicated that more fertilization was applicable for F. rhynchophylla and F. mandshurica, and high fertilization rates were inefficient for P. koraiensis and A. holophylla. Both QI and vector diagnosis can be applied to verify seedling quality in the light of growth responses and nutrient status in fertilization trials.