• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.35 no.2
• /
• pp.102-117
• /
• 1999

Vertical distribution of squids in relation to oceanographic structure was analyzed on the basis of experimental squid hand jigging fishing by R/V Pusan 851 in the area of 34°∼47° N, 150° E∼170°W in the North Pacific in summer from 1987 through 1993 with exception of 1991. The 6 species of squids showed different patterns of vertical and horizontal distribution as following; Boreopacific gonate squid (Gonatopsis borealis) were mainly caught in the layer of 71-80m fishing depth of the Subarctic Domain with water temperature of 6∼11℃ and salinity of 32.2∼33.6‰ and distributed in the latitudes of 41°∼43° N. Boreal clubhook squid (Onychoteuthis borealijaponica) were mainly caught in the layer of 11∼20m fishing depth of the Subarctic Domain with water temperature of 10∼12℃ and salinity of 32.9∼33.6‰ and distributed in the latitudes of 41°∼42N°. Tapanese flying squid (Todarodes pacificus) were mainly caught in the layer of 11∼20m fishing depth of the Transition Zone and the Subtropical Domain with water temperature of 15∼18℃ and salinity of 33.6∼34.0‰ and distributed in the latitudes of 40°∼42°N. Neon flying squid (Ommastrephes bartrami) were mainly caught in the layer of surface∼10m fishing depth of the Subarctic Convergence Zone and the Transition Zone with water temperature of 16∼17℃ and salinity of 33.7∼34.4‰ and distributed in the latitudes of 39 °∼41°N. Luminous flying squid (Symplectoteuthis luminosa) were mainly caught in the layer of 11 20m fishing depth of the Transition Zone and the Subtropical Domain with water temperature of 18∼20℃ and salinity of 33.8∼34.6‰ and distributed in the latitudes of 37°∼39°N. Purpleback flying squid (Symplectoteuthis oualaniensis) were mainly caught in the layer of surface∼10m fishing depth of the Subtropical Domain with water temperature of 24∼25℃ and salinity of 34.2∼34.4‰ and distributed in the latitude of 36°∼37°N.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.13 no.4
• /
• pp.192-203
• /
• 2011

The CERES-Barley crop simulation model was used to assess the impacts of climate change on the potential yield of winter naked barley in Korea. Fifty six sites over the southern part of the Korean Peninsula were selected to compare the climate change impacts in various climatic conditions. Based on the A1B climate change scenarios of Korea, the present climatological normal (1971-2000) and the three future ones (2011-2040, 2041-2070, and 2071-2100) were considered in this study. The three future normals were divided by three environmental conditions with changes in: (1) temperature only, (2) carbon dioxide concentration only, and (3) both temperature and carbon dioxide concentration. The agreement between the observed and simulated outcomes was reasonable with the coefficient of determination of grain yield to be 0.78. We concluded that the CERES-Barley model was suitable for predicting climate change impacts on the potential yield of winter naked barley. The effect of the increased temperature only with the climate change scenario was negative to the potential yield of winter naked barley, which ranges from -34 to -9% for the three future normals. However, the effect of the elevated carbon dioxide concentration only on the potential yield of winter naked barley was positive, ranging from 6 to 31% for the three future normals. For the elevated conditions of both temperature and carbon dioxide concentration, the potential yields increased by 8, 15, and 13% for the 2011-2040, 2041-2070, and 2071-2100 normals, respectively.

• Korean Journal of Poultry Science
• /
• v.31 no.2
• /
• pp.101-108
• /
• 2004

This study was conducted to evaluate the effect of iron reinforcing agent on the performance in laying hens for seven weeks. One hundred ninety eight 30-wk-old Brown Tetran layers were assigned to 9 treatments: control containing 45 mg Fe from iron sulfate per kg diet (FE-45), FE-90 (control multiplied two times), FE-180 (control multiplied four times), YM-45 containing 45mg Fe from yeast mutant, YM-90 (YM-45 multiplied two times), YM-180 (YM-45 multiplied four times), YF-45 containing 45mg Fe from ferritin containing yeast, YF-90 (YF-45 multiplied two times), YF-180 (YF-45 multiplied four times) in the experiment. Each treatment had four replications of 6 birds each. In the average egg production, the YF-180 was highest and the FE-45 (the control) was lowest; the YM-180, YF-90, and YF-180 were significantly (P＜0.05) higher than the control. In the comparisons of egg weight and egg mass, the YF-180 was significantly higher (P＜0.05) than the FE-90 or the control. In the FCR, the YM-90 was highest and the YF-45 was lowest. There was no significant difference between the control and YM-90 although the YF-45 was significantly (P＜0.05) lower in FCR than the control. In the eggshell thickness, the YF-180 was the thickest and the FE-90 was the thinnest; the YF-45 or the YF-180 was significantly thicker (P＜0.05) than the control. In the eggshell strength, the YF-45 was the strongest and the YM-45 was the weakest; the YM-90, YF-45, and YF-180 were significantly stronger (P＜0.05) than the control. In the cholesterol level of egg yolk, the control (FE-45) was the highest and the YF-45 was the lowest; there was a significantly different (P＜0.05) between these two treatments. In conclusion, in case of adding organic iron to feed for layers, it gives improvement on performance of layers and develop chemical composition of eggs.

• Korean Journal of Poultry Science
• /
• v.31 no.2
• /
• pp.93-100
• /
• 2004

This study was conducted to evaluate the effect of organic iron supplemented to feed for broilers. One hundred forty four Ross broiler chicks were assigned to 6 treatments: control containing 80mg Fe from iron sulfate per kg diet(FE-80), FE-160 (control multiplied two times), YM-80 containing 80mg Fe from yeast mutant, YM-160 (YM-80 multiplied two times), YF-80 containing 80mg Fe from ferritin containing yeast, YF-160 (YF-80 multiplied two times) in the experiment. Each treatment had four replications of 6 birds each. The weight gain of the YM-160 was significantly higher (P＜0.05) than that of the control (FE-80). The YM and YF in the serum cholesterol level were significantly higher (P＜0.05) than the control. In the cholesterol level of carcass, although the control (FE-80) was highest and the YM and YF were very low; however, there were no significant differences among treatments. In the iron level of carcass, the control (FE-80) showed the lowest level among treatments; the YM and YF were significantly higher (P＜0.05) than the control. In conclusion, the supplementation with organic iron to broiler chicks improve productivity. We also expect the possibility on chicken meat with reinforcing iron.

• Korean Journal of Poultry Science
• /
• v.38 no.2
• /
• pp.137-144
• /
• 2011

The current work was carried out to investigate the effect of crossbred Korean native chickens (KNC) on fatty acid, amino acid and nucleotide-related compounds contents of chicken meat. A total of 360 male chicks (1d of age) was used in this work and were divided 4 groups as A) (KNC egg-meat type C strains ${\times}$ KNC meat type S strains) ${\times}$ Ross broiler, B) (KNC egg-meat type C strains ${\times}$ KNC meat type H strains) ${\times}$ KNC meat type S strains, C) (KNC native R strains ${\times}$ KNC meat type S strains) ${\times}$ KNC meat type H strains and D(White Semibroiler Chickens) strains for 5 weeks at the flat house. Palmitic acid and vaccenic acid were highest in C strain meat, and myristic acid and linolenic acid were lowest in A strain meat (p<0.05). Saturated fatty acid was lowest in C strain meats (p<0.05). Valine, leucine, phenylalanine and lysine of essential acid were low in A strain meat. Cystine, aspartic acid, glycine, alanine and proline were also low in A strain meat. Hypoxanthin (Hx) was high compared other strains at 5 weeks and low at 10 weeks. IMP was high compared other strains at 5 and 10 weeks. AMP has not significant difference among strains at 5 weeks but B strain was high other strains at 10 weeks. These results showed that C stain was excellent on the fact of nutrients compared to other strains. Consequently, the result of this work gave the basic data that needed to develope the new strains.

• Journal of Soil and Groundwater Environment
• /
• v.8 no.2
• /
• pp.62-69
• /
• 2003

The aim of research is the evaluation of the $Cr^{6+}$ emission features of the liquid injection through emission experiments in varying conditions, based on a field-mixing ratio. The results showed that the content of $Cr^{6+}$ content in cement measured had an Ordinary Potland Cement (OPC) of 25.3 mg/kg, which constitute the largest portion among the other materials. Likewise, the emission experiment of homo-gel and sand-gel generally satisfied the standard of KSLT (Korea Standard Leaching Test) in waste of 1.5 mg/L, but in case of the standard of KSLT in soil the emission of OPC $Cr^{6+}$ of 4.85 mg/kg. These conditions is a little exceeded the criteria in the ‘Ga’ area in terms of Korea Soil Environmental Preservation Law. In addition, results generated by the mock-up injection facilities revealed that $Cr^{6+}$ emission increased as Water/Cement and injection pressure increased. At injection pressure higher than 4 kg/㎤, $Cr^{6+}$ emission exceeded the water preservation standard of 0.5 mg/L. Similarly, a pattern experiment of C $r^{6+}$ emission according to pH was conducted, in order to evaluate the $Cr^{6+}$ emission features of grout materials in leachate below pH 5 such as pH 4 acid rain or landfill. Results show that $Cr^{6+}$ emission dramatically increased in high acidic or basic state. It indicates that $Cr^{6+}$ emission will probably increase in an environment where grout materials are injected. On the other hand, concentration of leachate was determined in areas where grout materials are used. The results show that the concentration of emission in an ultra purity condition does not manifest intensity, and is affected in the OPC>MC>SC order. It means that the pollutants or $Cr^{6+}$ emission increases with decreasing concentration. As such, $Cr^{6+}$ emission will probably exceed the countermeasure criteria according to the types of gout materials. Similarly, high pressure or injection will cause increased $Cr^{6+}$ emission. Therefore, the selection of materials or mixing ratio should be considered in general as well as according to specific industries, based on the strength and pH of $Cr^{6+}$ emission.

• The Korean Journal of Nuclear Medicine
• /
• v.28 no.1
• /
• pp.75-84
• /
• 1994

The need for assessment of ureteric function in the patient with an obviousely dilated ureter has increased particularly with the added spectrum of asymptomatic patients presenting with hydrone-phrosis and hydroureter on antenatal and perinatal ultrasound. To assess the influence of ureteral status on kidney washout during $^{99m}Tc$-DTPA diuretic renography, ureteral images were reviewed in 80 children referred for hydronephrosis. A scintigraphically abnormal ureter was defined as an intense and continuous image of > 10 min during diuretic renography. Out of them, a total of 16 nephroureteral systems in 12 children with scintigraphically abnormal ureter were analyzed. A diuretic washout index using response half time (t1/2) by linear fitting after lasix injection, was determined on renal (Kt1/2) and ureteral (Ut1/2) curves (diuretic renogram vs. diuretic ureterogram). Diuretic ureterogram curve patterns corresponding to normal (type I), obstructive (II) and non-obstructive (III) cases were described. Compared with X-ray data, diuretic renography was highly sensitive (88%) and specific (99%) for detecting any ureteral abnormality. Despite an obstructive Kt1/2 (>20 min), no patient with an abnormal ureter underwent therapy at the ureteropelvic junction because the hydronephrosis regressed after surgery at the lower level. Our data indicate that the abnormal ureter findings during diuretic renography have to be recognized before therapy for children with hydeonephrosis.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.19 no.1
• /
• pp.4312-4322
• /
• 1977

In order to investigate the effect of the water content and the accelerated curing on the strength of the soil-cement mixtures, laboratory test of soil cement mixtures was performed at five levels of water content, four levels of accelerated curing temperatures, three levels of normal curing periods, and six levels of accelerated curing time. Also this study was carried out to investigate the effect of grain size distribution of 21 types of soils on the strength of soil-cement mixtures at four levels of cement content and three levels of curing time. The results are summarized as follows: 1. Optimum moisture content increased with increase of the cement content, but maximum dry density was changed ununiformly with cement content. Water content corresponding to the maximum strength was a little higher than the optimum moisture content along the increase of cement content. 2. In molding the specimens with the optimum moisture content, the maximum strength appeared at the wet side of the optimum moisture content. 3. According to increase of curing temperature as 30, 40, 50, and 60$^{\circ}C$, unconiiend compressive strength of soil-cement mixtures increased, the rate of increase at the early curing period was large, and approximately 120 hours was suifficient to harden soil-cement mixtures completely. 4. The strength of soil-cement mixtures at the curing temperature of 10$^{\circ}C$ decreased at the rate of 30 to 50 percent than at the curing temperature of 20$^{\circ}C$, and the strength of soil-cement mixtures at the curing temperature of 0$^{\circ}C$ increased a little with increase of curing time. 5. Although the strength of soil-cement mixtures seemed to be a little affected by the temperature difference between day time and night, it was recommended that reasonable working period was the duration from July to August of which average maximum temperature of Korea was approximately 30$^{\circ}C$. 6. Accelerated curing time corresponding to the normal curing time of 28-day was shorten with increase of curing temperature, also it was a little affected by the cement. Accelerated curing time that the strength of soil-cement mixtures for the cement of 9 percent and the curing temperature of 60was shorten with increase of curing temperature, also it was a little affected by the cement. Accelerated curing time that the strength of soil-cement mix- tures for the cement of 9 percent and the curing temperature of 60$^{\circ}C$ was 45 hours at the KY sample, 50 hours at the MH, 40 hours at the SS, and 34 hours at the JJ respectively. 7. Accelerated curing time was depended upon the grain size distribution of soil, it decreased with increase the percent passing of No. 200 sieve. 8. Relationship between the normal curing times and the accelerated curing times showed that there was a linear relationship between them, its slope decreased with increase of curing temperature. 9. The most reasonable soil of the soil-cement mixtures was the sandy loam which was a well graded soil. Assuming the base of road requiring 7-day strength of 21 kg/$\textrm{cm}^2$ being used, the soil-cement mixtures could be obtained with adding 6 percent of cement in such a sails S-7, S-8, S-9, S-10, S-11, S-12, S-13. 10. The regression equation between the 28-day and the 7-day strength was obtained as follow; q28=1.12q7,+6.5(r=0.96).

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.7 no.2
• /
• pp.132-140
• /
• 2005

This study was conducted to develop regional site index equations for main tree species in Gangwon, Gyunggi-Chungcheong, Gyungsang, and Jeolla area of Korea, using environmental and soil factors obtained from a digital forest site map. Using the large data set obtained from the digital forest map, a total of 28 environmental and soil factors were regressed on site index by tree species for developing the best site index equations for each of the regions. The selected main tree species were Larix 1eptolepis, Pinus koraiensis, Pinus densiflora, Pinus thunbergii, and Quercus acutissima. Finally, four to five environmental and soil factors by species were chosen as independent variables in defining the best regional site index equations with the highest coefficients of determination $(R^2)$. For those site index equations, three evaluation statistics such as mean difference, standard deviation of difference and standard error of difference were applied to the data sets independently collected from fields within the region. According to the evaluation statistics, it was found that the regional site index equations by species developed in this study conformed well to the independent data set, having relatively low bias and variation. It was concluded that the regional site index equations by species had sufficient capability for the estimation of site productivity.

• Korean Journal of Ecology and Environment
• /
• v.41 no.2
• /
• pp.237-246
• /
• 2008

Filtration rates and fecal production of freshwater bivalve, Unio douglasiae on two kinds of hibernal diatom communities were measured simultaneously in a laboratory. One community is the Han River (HAN), which dominated by Asterionella Formosa. Stephanodiscus hantzschii (ca. 98% of total phytoplankton). The other community is the Ilgam Lake (IL), which dominated by Synedra ulna, Scenedesmus sp. Microcystis aeruginosa (ca. 82%). The HAN water has higher concentrations of nutrient (TN and TP) and chlorophyll $\alpha$ (Chl-$\alpha$), lower turbidity and conductivity than the IL water. Water sampling for the feeding experiment was conducted in the same day (Jan 15, 2008) and similar time (AM 10:00 for HAN, AM 11:00 for IL). Mussels with the similar size ($0.0{\pm}0.5\;cm$) were collected from the Gunsan and Okgu district (Jeonbuk), and starved in a laboratory for 2 days before the experiment. The experiment comprised CON (no addition of mussel), LOW (addition of mussel at 0.3 indiv. $L^{-1}$), MID (1.0 indiv. $L^{-1}$) and HIGH (2.0 indiv. $L^{-1}$), respectively. With the increment of mussel density and time, the concentration of Chl-$\alpha$ in two diatom communities were clearly decreased; Chl-$\alpha$ of HAN gradually decreased after 1 hour of mussel treatment, while that of IL decreased as soon as mussel introduction. In 7 hours of treatment, the former was removed finally up to about 90% of control, while the later was remained as about 50%. Under the presence of mussel, total phytoplankton density was shifted as the similar patterns to that of Chl-$\alpha$ (r=0.705, P<0.0001), however, there showed the drastic differences following a species. Based on the concentration of Chl-$\alpha$, filtration rate of U. douglasiae averaged 0.266 $L\;g^{-1}\;h^{-1}$ (0.115 to 0.442) on HAN and $0.577\;L\;g^{-1}\;h^{-1}$ (0.146 to 1.428) on IL water, respectively. There were no differences in feces production among the mussel density in the HAH water (ANOVA, P>0.5), while in IL water, including lots of seston, the HIGH mussel produced the higher fecal materials, over one hundred times of LOW. These results suggest that freshwater bivalve Unio douglasiae have the alternative potential, as a filter-feeder of seston in turbid lake, and a biological controller of diatom bloom in cold stream.