• Korean Journal of Microbiology
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• v.24 no.3
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• pp.308-316
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• 1986

Vertical distribution of heterotrophic bacteria and physico-chemical characteristics were measuted in Kum River estuarine sediments. And interrelationship between heterotrophic bacterka and environmental factors was also studied. The type of sediment of Site 1 was silty clay, and sand at Site 2. Annual pH ranges were between 7.1 and 7.7 in the clay type sediment (Site 1) and 6.9-7.2 in the sand type sediment (Site 2). It was shown that organic matter contents were higher in the clay type sediment than those of sand type sediment. Redox potential values of sediments were decreased rapidly with depth at Site 1, but those of Sete 2 showed vertical fluctuation. Nitrogens(ammonia+amino acid-N, nitrate-N, nitrite-N) and phosphate in the clay type sediment showed higher values than those of sand type sediment. Annual distribution of heterotrophic bacteria were ranged $6.71{\times}10^4$ cells/g dry wt. $-2.50{\times}10^6$ cells/g dry wt. In the clay type sediment and $2.67{\times}10^3$ cells/g dry wt. $-1.94{\times}10^6$ cells/g dry wt. in the sand type sediment. Distribution of proteolytic, lipolytic, and amylolytic bacteria were decreased with the depth and the highest density was found in April and the lowest in January. Bacterial populations in sediments were closely correlated with such environmental factors as pH, redox potential, moisture content, organic matter contents, and inorganic nutrients such as nitrite-N and phosphate-P.

• Journal of the Korean Wood Science and Technology
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• v.2 no.2
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• pp.13-21
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• 1974

1. In the past, the smoke-pipe type dry kiln being characterized by the low cost of installation and easy operation was only used by the small scale of wood processing enterprisers for drying softwood and finishing air-dried stocks that were belonged to easy drying properties. The smoke-pipe type dry kiln usually was not suitable for drying hardwoods and green woods because of the difficulties of controlling drying conditions. 2. However, the smoke-pipe type dry kiln heated with smokeless coal which was designed and constructed by the authers was demonstrated to maintain higher accuracy of controlling temperature and humidity than the other smillar types of kiln. Also, since it was constructed with home made equipments, it is supposed to offer the opportunity to install the kiln by the small scale of wood processing enterprisers who could not install the dry kiln because of economical and technical difficulties. Thus, it is expected that promoting the spread of installing the dry kiln will realize the rational use of wood.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.221-226
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• 2006

This study was conducted to investigate the effect of tall type mixtures and turf type mixtures on dry matter yield, botanical composition and quality. The experimental design includes two mixture types : Tall type mixtures; orchardgrass (Potomac) 50+tall fescue (Fawn) 20+ Kentucky bluegrass (Kenblue) 10+red clover (Kenland) 20%) and turf type mixtures; Kentucky bluegrass(Newport) 60%+tall fescue (reboil Jr.) 20+perennial ryegrass (palmer II) 20%. The DM yield was higher obtained in tall type mixture than that of turf type mixture (p<0.05). In the chemical composition, Turf type mixture was higher in crude protein (CP) and dry matter digestibility (DMD), but lower in fibrous compound as NDF, ADF, cellulose and lignin than those of tall type mixture (p<0.05). The crude protein dry matter (CPDM) and digestible dry matter (DDM) yield was higher in tall type mixture than turf type mixture (p<0.05). In this experiment, nutritive value of turf type mixture was higher than that of tall type mixture, but CPDM and DDM yield of turf type mixture were lower than that of turf type mixture due to low dry matter yield. On the other hand, turf type mixture was obtained high feed value, and maintaining the various botanical composition on the 13 th cutting frequency condition. therefore, turf type mixture had a utilization possibility under grazing livestock as sheep and milk goats.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.301-308
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• 2011

This paper deals with the coupled electromagnetic-mechanical field analysis for short-circuit electromagnetic force of the dry-type transformer. The short-circuit currents are calculated using external circuit in accordance with short-circuit test equipment. According to short-circuit current, the generated magnetic leakage flux density in dry-type transformer model is calculated by finite element method. The radially-directed electromagnetic forces in windings are calculated using electromagnetic field analysis and then axially-directed electromagnetic forces in windings are calculated using electromagnetic-mechanical field analysis. The calculated axially-directed electromagnetic forces in high voltage winding are compared to those of measured ones and showed good agreement with experimental results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.2
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• pp.143-148
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• 2004

This paper discussed on the stability of elastic material subjected to dry friction force for low boundary conditions: clamped free, clamped-simply supported, simply supported-simply supported, clamped-clamped. It is assumed in this paper that the dry frictional force between a tool stand and an elastic material can be modeled as a distributed follower force. The friction material is modeled for simplicity into a Winkler-type elastic foundation. The stability of beams on the elastic foundation subjected to distribute follower force is formulated by using finite element method to have a standard eigenvalue problem. It is found that the clamped-free beam loses its stability in the flutter type instability, the simply supported-simply supported beam loses its stability in the divergence type instability and the other two boundary conditions the beams lose their stability in the divergence-flutter type instability.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.4
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• pp.353-360
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• 2000

The purpose of this research is to find the fundamental data for the design and optimum operation condition for the disk atomization comparing the atomization characteristics of the modified straight vane type disk atomizer and the cup type atomizer widely used in the field of spray dry. First, the experimental comparison of the characteristics of $Na_2SO_4$ atomization has been carried out using the cup type disk atomizer and the three kinds of vane type atomization designed specially for the experiment. After the comparison of the experimental data of the $Na_2SO_4$ and raw milk have been conducted using vane type atomizer.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.3
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• pp.341-352
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• 2012

In large-type goats that were fed on dry forage twice daily, dry forage intake was markedly suppressed after 40 min of feeding had elapsed. The objective of this study was to determine whether or not marked decreases in dry forage intake after 40 min of feeding are mainly caused by the two factors, that is, ruminal distension and increased plasma osmolality induced thirst produced by dry forage feeding. Six large-type male esophageal- and ruminal-fistulated goats (crossbred Japanese Saanen/Nubian, aged 2 to 6 years, weighing $85.1{\pm}4.89kg$) were used in two experiments. The animals were fed ad libitum a diet of roughly crushed alfalfa hay cubes for 2 h from 10:00 to 12:00 am during two experiments. Water was withheld during feeding in both experiments but was available for a period of 30 min after completion of the 2 h feeding period. In experiment 1, saliva lost via the esophageal fistula was replenished by an intraruminal infusion of artificial parotid saliva (RIAPS) in sham feeding conditions (SFC) control, and the treatment was maintained under normal feeding conditions (NFC). In experiment 2, a RIAPS and non-insertion of a balloon (RIAPS-NB) control was conducted in the same manner as the SFC control of experiment 1. The intraruminal infusion of hypertonic solution and insertion of a balloon (RIHS-IB) treatment was carried out simultaneously to reproduce the effects of changing salt content and ruminal distension due to feed entering the rumen. The results of experiment 1 showed that due to the effects of multiple dry forage suppressing factors when feed boluses entered the rumen, eating rates in the NFC treatment decreased (p<0.05) after 40 min of feeding and cumulative dry forage intake for the 2 h feeding period reduced to 43.8% of the SFC control (p<0.01). The results of experiment 2 indicated that due to the two suppressing factors of ruminal distension and increased plasma osmolality induced thirst, eating rates in the RIHS-IB treatment were, as observed under NFC, reduced (p<0.05) and cumulative dry forage intake for the 2 h feeding period decreased to 34.0% of the RIAPS-NB control (p<0.01). The combined effects of ruminal distension and increased plasma osmolality accounted for 77.5% of the suppression of dry forage intake 40 min after the start of dry forage feeding. The results indicate that ruminal distension and increased plasma osmolality induced thirst are the main factors in the suppression of dry forage intake in large-type goats.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.4
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• pp.237-242
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• 2000

This study was conducted to investigate the effects of cutting frequency on dry matter yield and nutritive value between heading and headless varieties of sorghumxsudangrass hybrid in 1998. Treatments were var. TE hay grazer(heading type) and Jumbo(headless type) as main plot, and 1, 2, and 3 cutting times per a year as sub plot. Although plant height of sorghumxsudangrass hybrid was no significant difference among treatments, headless type was very slightly higher than that of heading type, and both of variety decreased with 1, 2, and 3 cutting times in order. Also, dry matter yield of sorghum~sudangrass hybrid was no significant difference between heading and headless type. Dry matter yield of first cutting plot in heading type and in headless type was the higher than those of second and third cutting plot. Acid detergent fiber and neutral detergent fiber of headless type were slightly higher than that of heading type. Acid detergent fiber of sorghumxsudangrass hybrid was highest at first cutting plot in both varieties. Neutral detergent fiber of second cutting plot in heading type and first cutting plot in headless type were the highest respectively. In vitro dry matter digestibility of headless type was very slightly higher than that of heading type. And in vitro dry matter digestibility of second cutting plot was the highest in both varieties. In vitro digestible dry matter of sorghumxsudangrass hybrid was no significant difference among treatments. The results demonstrated that although there was not significant difference, cultivation of headless type and first cutting plot per a year were very good for nutritive value and DM yield of sorghumxsudangrass hybrid as summer forage crops in Korea. (Key words : Heading, Headless type, Cutting frequency, Sorghum X Sudangrass Hybrid)

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.538-546
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• 2008

Large-type goats eating dry forage secreted large volumes of saliva which resulted in the loss of $NaHCO_3$ from the blood and decreased plasma volume (hypovolemia). This research investigated whether or not the loss of $NaHCO_3$ from the blood and hypovolemia brought about by dry forage feeding actually depresses feed intake in large-type goats under free drinking conditions. The present experiment consisted of three treatments (NI, ASI, MI). All treatments in this experiment were carried out under free drinking conditions. In the NI control (NI), a solution was not infused. In the ASI treatment, i.v. infusion of artificial saliva was initiated 2 h before feeding and was continued for a total of 3 h concluding 1 h after the commencement of the feeding perod. In the MI treatment, mannitol solution was infused to replenish only water lost from the blood in the form of saliva. The hematocrit and plasma total protein concentrations during feeding in the NI control were observed to be higher than pre-feeding levels. This indicated that dry forage feeding-induced hypovolemia was caused by the accelerated secretion of saliva during the initial stages of feeding in freely drinking large-type goats. Increases in hematocrit and plasma total protein concentrations due to dry forage feeding were significantly suppressed by the ASI treatment. While hematocrit during feeding in the MI treatment was significantly lower than the NI control, plasma total protein concentrations were not different. From these results, it is clear that the MI treatment was less effective than the ASI treatment in mitigating the decreases in plasma volume brought about by dry forage feeding. This indicates that plasma volume increased during dry forage feeding in the ASI treatment which inhibited production of angiotensin II in the blood. The ASI treatment lessened the levels of suppression on dry forage feeding, but the MI treatment had no effect on it under free drinking conditions. The results indicate that despite the free drinking conditions, increases in saliva secretion during the initial stages of dry forage feeding in large-type goats caused $NaHCO_3$ to be lost from the blood into the rumen which in turn caused a decrease in circulating plasma volume and resulted in activation of the renin-angiotensin system and thus feeding was suppressed.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.725-728
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• 1999

The bridge slab of express railway was designed for high strength concrete (design strength 400kgf/$\textrm{cm}^2$). In case the slab is made with the concrete using type I cement, used much amount of cement can cause cracks through concrete by hydration heat or dry shrinkage. In this study we targeted to solve above problems using type III cement. We could decrease the cement ratio in concrete using type III cement than type I cement. The concrete using type III cement showed good workability and compressive strength, and showed better properties in hydration heat and dry shrinkage than that using type I cement