• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.189-197
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• 1989

This study was carried out to produce the grafts of Juglans sinensis by juvenile grafting method which epicotyl of newly germinated seeds were used as stocks and juvenile fresh shoots were used as scion. The results obtained were as follows ; 1. When plastic tube installed covering up seed with soil up to 6cm height for diameter increment of epicotyl, the epicotyl can be grown up to thickness of 10mm. 2. When the soft fruit branches and the soft water sprout with the terminal bud 8cm to 12cm long were used as scions, the survival rates showed 90 Percent. 3. The optimum date for making juvenile grafts was around the 20th of May, and the survival rates of grafted seedlings showed 86 percent in average. 4. The grafted seedlings showed first sprouting the 15th of June, that is 25 days after making graft, and the sprouting rate was 72 percent. 5. The height-growth of grafted seedlings finished at the end of July, and diameter growth lasted into the end of October. 6. There was positive correlation between the height of grafted seedlings and the diameter at root collar. 7. In general, it takes two years to make plantable graft seedlings from hardwood scion and stock, but the juvenile graft seedlings can be easily obtained in a year and so it seems to be economic.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.286-290
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• 2008

Many important traits have been tagged allowing plant breeders to apply marker assisted selection (MAS) in rice. PCR itself is simple to set up, and requires little hands-on time. However, a crucial limiting step of MAS programs is the reliable and efficient extraction of DNA which can be performed on thousands of individuals. In this study, We describe a modification of the DNA extraction method, in which cetyltrimethylammonium bromide (CTAB) is used to extract DNA from leaf tissues for suitable MAS in rice. We followed the standard 2% CTAB extraction method in all the procedure. In addition we used the 1.2 ml 8-strip tube instead of 1.5 ml E-tubes to fit the 8-multichannel pipette and employ the 96 well plate to use the swing bucket centrifuge. Our modified CTAB DNA extraction method offers several advantages with respect to traditional and simple methods. 1) adult leaf samples collected in paddy field are applicable. 2) 96 leaf samples can be homogenized only one-time by using tungsten carbonate bead and 96well block. 3) semiautomatic loading method using 8-multichannel pipette from DNA extraction to electrophoresis of PCR products. 4) our system can extract about 400 leaf samples per day by only one technicion. Therefore, this method could be useful for marker assisted breeding in rice.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1734-1744
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• 2019

Objective: In this study, two glycosidases (XMosidases), ${\beta}$-xylosidase and ${\beta}$-mannosidase, were investigated on their in vitro hydrolysis activities of feed and on the improvement of growth performance in vivo in weanling pigs. Methods: Enzyme activities of XMosidases in vitro were evaluated in test tubes and simulation of gastric and small intestinal digestion, respectively, in the presence of NSPase. In vivo study was performed in 108 weaned piglets in a 28-d treatment. Pigs were allotted to one of three dietary treatments with six replicate pens in each treatment. The three treatment groups were as follows: i) Control (basal diet); ii) CE (basal diets+CE); iii) CE-Xmosidases (basal diets+ CE+${\beta}$-xylosidase at 800 U/kg and ${\beta}$-mannosidase at 40 U/kg). CE was complex enzymes (amylase, protease, xylanase, and mannanase). Results: In vitro XMosidases displayed significant activities on hydrolysis of corn and soybean meal in the presence of non-starch polysaccharide degrading enzymes (xylanase and ${\beta}$-mannanase). In vitro simulation of gastric and small intestinal digestion by XMosidases showed XMosidases achieved $67.89%{\pm}0.22%$ of dry matter digestibility and $63.12%{\pm}0.21%$ of energy digestibility at $40^{\circ}C$ for 5 hrs. In weanling pigs, additional XMosidases to CE in feed improved average daily gain, feed conversion rate (p<0.05), and apparent total tract digestibility of crude protein (p = 0.01) and dry matter (p = 0.02). XMosidases also altered the gut bacterial diversity and composition by increasing the proportion of beneficial bacteria. Conclusion: Addition of a complex enzyme supplementation (contained xylanase, ${\beta}$-mannanase, protease and amylase), XMosidases (${\beta}$-xylosidase and ${\beta}$-mannosidase) can further improve the growth performance and nutrient digestion of young pigs.

• Journal of Aerospace System Engineering
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• v.11 no.4
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• pp.48-53
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• 2017

Liquid rocket engines (LREs) are very complex systems that include combustion chambers, turbopumps, gas generators, ducts and tubes, valves and etc. Most components of the LREs require higher than or equal to level 6 IT (ISO Tolerance). The components along with pipe line and/or tubing must dispose not to interfere each other. In addition, effectiveness of maintenance and service after assembling should be considered when the allocation of the components are determined. Especially at the stage of the development, tolerance accumulations or unpredictable errors may result in misalignment and/or mismatches at interfaces of the parts. Namely, it is the engine assembling process that many inherent risks are realized and crises or incidents occur. Therefore, a rapid reaction system should be prepared. In this research, 7 tonf class liquid rocket assembling process was studied and actual building steps were introduced.

• Nuclear Engineering and Technology
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• v.42 no.6
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• pp.662-669
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• 2010

To develop the manufacturing methods for the blanket first wall (FW) of the International Thermonuclear Experimental Reactor (ITER) and to verify the integrity of the joint, Be/Cu mockups were fabricated and tested at the KoHLT-1 (Korea Heat Load Test facility), a graphite heater facility located at the Korea Atomic Energy Research Institute (KAERI). Since Be and Cu joining is the focus of the present study, the fabricated mockups had a CuCrZr heat sink joined with three Be tiles as an armor material, unlike the original ITER blanket FW, which has a stainless steel structure and coolant tubes. Hot isostatic pressing (HIP) was carried out at $580^{\circ}C$ and 100 MPa for 2 hours as the method for Be/Cu joining. Three interlayers, namely, $1{\mu}mCr/10{\mu}mCu$, $1{\mu}mTi/0.5{\mu}mCr/10{\mu}mCu$, and $5{\mu}mTi/10{\mu}mCu$ were applied as a coating to the Be tiles by a physical vapor deposition (PVD) method. A shear test was performed with the specimens, which were fabricated by the same methods as those used to fabricate the mockups. The average values were 125 MPa to 180 MPa, and the samples with the $1{\mu}mCr/10{\mu}mCu$ interlayer showed the lowest value. No defect or delamination was found in the joints of the mockups by the developed ultrasonic test using a flat-type probe with a 10 MHz frequency and a 0.25 inch diameter. High heat flux (HHF) tests were performed at $1.0\;MW/m^2$ heat flux for each mockup using the given conditions, and the results were analyzed by ANSYS-CFX code. For the test criteria, an expected fatigue lifetime about 1,000 cycles was obtained by analysis with ANSYS-mechanical code. Mockups using the interlayers of $1{\mu}mTi/0.5{\mu}mCr/10{\mu}mCu$ and $5{\mu}mTi/10{\mu}mCu$ survived up to 1,100 cycles over the required number of cycles. However, one of the Be tiles in the other two mockups using the $1{\mu}mCr/10{\mu}mCu$ interlayer was detached during the screening test, and others were detached by discharge after 862 cycles. The integrity of the joints using the proposed interlayers was proven by the HHF test, but the other interlayer requires more study before it can be used for the joining of Be to Cu. Moreover, it was confirmed that the measured temperatures agreed well with the analysis temperatures, which were used to estimate the lifetime and that the developed facility showed its capability of the long time operation.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.543-553
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• 2021

This research focused on the investigation of isoprene and terpene emissions from 30 major urban tree species. We conducted sampling using a specific dynamic enclosure system between August and September 2020. Seedlings less than three years old were enclosed in a chamber consisting of a 400 L transparent Tedlar bag. The air-flows from the chamber's outlet were sampled using Tenax-filled sorbent tubes in the presence of standard conditions (temperature: 30℃, PAR: 1,000 μmol/m²/sec). A thermal desorption GC/MS system was used to analyze 38 BVOC compounds (isoprene, monoterpene, sesquiterpene, oxygenated monoterpene, and sesquiterpene). Isoprene emitters included Phyllostachys bambusoides, Quercus serrata, Daphniphyllum macropodum, and Buxus Koreana. Monoterpene emitters included Pinus rigida, Acer pictum subsp. mono, Larix kaempfer, Magnolia denudata, Metasequoia glyptostroboides, Pinus koraiensis, Pinus densiflora, and Abies holophylla. The monoterpene emission profiles were dominated by α-pinene, myrcene, limonene, β-pinen, and sabinene, while caryophyllene and farnesene were the prominent sesquiterpenes. Predominant oxygenated monoterpene compounds were also discovered as pulegone, borneol, menthol, eucalyptol, and nerol, while caryophyllene oxide were the prominent oxygenated sesquiterpenes. Sesquiterpenes and oxygenated sesquiterpenes had relatively lower contributions for all species.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.63-68
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• 2021

Domestic electric heater manufacturers are focusing on technology development to improve the efficiency of existing products. The electric heater for ship fuel is large in size and has high difficulty in miniaturization/high efficiency, so there are not many companies that try to develop technology yet. The existing electric heater has a structure of low heating efficiency because the contact time with the heat exchange tube of the heating medium is very short because the flow path of the ship engine fuel is monotonous. Since it is manufactured in a tubular shape, the volume is very large regardless of the heating efficiency. As a result, the tubular electric heater device applied by overseas advanced companies has difficulty in maintaining and repairing because it is necessary to decompose all tubular heaters when a specific part of the inside is damaged and if the heat exchange tube is damaged, all the heat exchange tubes must be decomposed. In this study, a basic study on plate type electric heaters capable of heating 10 tons of ship engine fuel per hour and setting a maximum temperature of up to 150℃ was conducted through a 250kW capacity plate type electric heater.

• Food Engineering Progress
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• v.14 no.3
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• pp.229-234
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• 2010

The applicability of a commercial enzymatic time-temperature integrator (TTI) for monitoring spoilage of ground beef was investigated under isothermal storage condition at different temperatures. The volatile basic nitrogen (VBN) value was used as a spoilage index for ground beef. The time taken to reach the spoilage of ground beef stored at 4, 10, 15, 20, and ${25^{\circ}C}$ were 168, 114, 60, 48, and 24 hrs, respectively. However, these quality losses of beef were not coincided with the endpoints of the three different C-type TTIs (C-1, C-4, and C-7). In order to match the TTI response to the quality loss of beef, some ingredients such as enzyme and substrate solutions were extracted from C-1TTI and remixed with different amount of them in the tubes to constitute the modified TTIs. The responses of the modified CM-1 TTI were very close to the quality loss of beef stored at 20 and ${25^{\circ}C}$, but not at other temperatures tested. The response of the other modified CM-2 TTI was only matched to the quality loss of beef stored at ${15^{\circ}C}$. Therefore, systematic kinetic studies of food spoilage and the TTI response are required to apply the TTI as a quality indicator for a specific food.

• Clean Technology
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• v.25 no.2
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• pp.147-152
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• 2019

Electrostatic precipitator that shows a good performance for the removal of particulate matter is important for controlling emissions from industrial facilities and power plants. The efficiency of the electrostatic precipitator on the removal of particulate matter is highly affected by the flow pattern inside the electrostatic precipitator. A number of studies have been conducted to obtain uniform flow distribution inside electrostatic precipitators. An electrostatic precipitator (ESP) with a length of 3.5 m and a height of 0.875 m was designed and installed in this study. The ESP included an inlet duct, diffuser, body, and contractor. Three perforated plates were installed in the diffuser of the ESP. Five pitot tubes were installed vertically and used to measure flow distribution in the cross section of the ESP body. Root mean square deviation value (RMS%) was used to examine the flow distribution inside the ESP when the perforated plates were installed in the diffuser. Flow distribution was also investigated in relation to the porosity of the perforated plate. The results showed that the perforated plates improved greatly the flow distribution inside the electrostatic precipitator. In addition, the most uniform flow distribution was found with 40%, 50%, and 50% porous perforated plates located from the inlet of the diffuser.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.127-137
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• 2019

Zr electrorefining is demonstrated herein using Zirlo tubes in a chloride-fluoride mixed molten salt in the presence of $AlF_3$. Cyclic voltammetry reveals a monotonic shift in the onset of metal reduction kinetics towards positive potential and an increase in intensity of the additional peaks associated with Zr-Al alloy formation with increasing $AlF_3$ concentration. Unlike the galvanostatic deposition mode, a radial plate-type Zr growth is evident at the top surface of the salt during Zr electrorefining at a constant potential of -1.2 V. The diameter of the plate-type Zr deposit gradually increases with increasing $AlF_3$ concentration. Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray photoelectron spectroscopy (XPS) analyses for the plate-type Zr deposit show that trace amount of Al is incorporated as Zr-Al alloys with different chemical compositions between the top and bottom surface of the deposit. Addition of $AlF_3$ is effective in lowering the residual salt content in the deposit and in improving the current efficiency for Zr recovery.