• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.3
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• pp.229-235
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• 2011

This research aims todevelopa compression/absorption hybrid heat pump system using an $NH_3/H_2O$ as working fluid.The heatpump cycle is based on a combination of compression and absorption cycles. The cycle consists of two-stage compressors, absorbers, a desorber, a desuperheater, solution heat exchangers, a solution pump, a rectifier, and a liquid/vapor separator. The compression/absorption hybrid heat pump was designed to produce hot water above $90^{\circ}C$ using high-temperature glide during a two-phase heat transfer. Distinct characteristics of the nonlinear temperature profile should be considered to maximize the performance of the absorber. In this study, the performance of the absorber was investigated depending on the capacity, shape, and arrangementof the plate heat exchangers with regard tothe concentration and distribution at the inlet of the absorber.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.388-392
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• 2013

A spray chrysanthemum cultivar 'Green Candy' was released by National Institute of Horticultural & Herbal Science, Rural Development Administration, in 2009. The cross between 'Yoko Ono', a spray chrysanthemum cultivar with light yellowish-green double type, and 'Green Bird', a spray chrysanthemum cultivar with vigorous and green double type, was made in Suwon in 2006. After the evaluation of the characteristics under shade culture in summer and retarding culture in spring and consecutive selection from 2007 to 2009, 'Green Candy' was selected finality. The natural flowering time of 'Green Candy' is October 28th, and it is possible to flower all year-round by shade and light culture. It has double flower type with green petals. The growth of plant is very vigorous and the color of the petals is stable when the variety is cultivated under high temperature conditions in summer season. The diameter of flower is 4.1 cm. The numbers of flower per stem and petals per flower are 12 and 217, respectively. The days for flowering under the short day treatment are about 58 and its vase life is 18.1 days in autumn season. 'Green Candy' was applied as No. 2010-212 on March 5, 2010 for variety protection and the plant variety protection rights have been registered as No. 3633 on August 2, 2011 at the Korea Seed and Variety Service.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.261-265
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• 1997

To know the availability of double fractionated palm olein (DFPL) for vegetable oil in commercial mayonnaise preparation, oxidative stability and stability to cold test of DFPL, soybean oil and blended oils (blended soybean oil with DFPL) were tested. Mayonnaises with these oils were prepared and then emulsion stability at low temperature $(-5^{\circ}C)$ were compared. The oxidative stability of vegetable oil by Rancimat test showed that induction time of DFPL (26.9 hr) was longer when compared with soybean oil (13.4 hr), and became longer with increase of DFPL ratio in the blended oil. Emulsion stability of mayonnaises at low temperature $(-5^{\circ}C)$ was decreased with the increase of DFPL ratio in the blended oil. But, mayonnaise with blended oil of below 20% DFPL was comparable to that with soybean oil only. Among quality characteristics of mayonnaises with soybean oil and blended oil (soybean oil 85% plus DFPL 15%) the latter showed stronger oxidative stability and less flavor reversion during high temperature treatment. This result suggested that the possibility of DFPL to substitute for vegetable oil in the preparation of commercial mayonnaise.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.25-33
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• 2010

Several experiments were conducted in growth chambers and a greenhouse to determine the influence of various environmental factors on seed germination and seedling emergence of Indian jointvetch. Fully matured seeds of Indian jointvetch germinated only 42%. The germination percent increased as the storage temperature increased with time. More than 90% seeds germinated when the seeds were kept at $40^{\circ}C$ for seven months, but germination was 58.9 and 55.1% when kept at 25 and $4^{\circ}C$, respectively. Non-dormant seeds of Indian jointvetch germinated 91.1 and 92.4% at 30 and $30/25^{\circ}C$, respectively. Germination percent increased with increasing both prethermal temperature and time. The prethermal temperature of $90^{\circ}C$ for 40 minutes was the best for maximum germination (94.5%). Germination and growth of Indian jointvetch tended to decrease slightly until -0.3 MPa osmotic potential (water stress induction) and then declined drastically and the seeds did not germinate at below -0.5 MPa osmotic potential. Indian jointvetch seems to grow well in moist and flooding conditions since emergence and growth of seedling increased with increasing soil moisture content and the water level.

• Korean Journal of Materials Research
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• v.10 no.3
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• pp.204-211
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• 2000

The $(Y,Gd)BO_3:Eu$ red phosphors for PDP application were synthesized by ultrasonic spray method and then their photoluminance properties were investigated under 147nm VUV irradiation. The precursor solution of acetates of Y, GD and Eu and boric acid diluted in water was sprayed using 1.7 MHz ultra-sonic sprayer into the reaction tube held at high temperature. The as-sprayed particles were amorphous phase having C-C and C-H bonds due to the insufficient thermal reaction during the pass along the tube. But the sprayed samples followed by heat treatment at $1100^{\circ}C$ had the same crystal structure and chemical composition as those samples followed by solid state reaction. It was found that the $(Y_{0.7}Gd_{0.3})_{0.95} BO_3:Eu_{0.05}^{3+}$ phosphor particles synthesized by spray at $500^{\circ}C$ and then heat treated at $900^{\circ}C$ had a spherical-like shape and fine particle size at $0.7{\mu\textrm{m}}$ having a narrow size distribution, while the phosphor particles made by solid state reaction was $3{\mu\textrm{m}}$ coarse and non-uniform size distribution. The emitting intensity under 147nm VUV excitation for $(Y_{0.7}Gd_{0.3})_{0.95}BO_3:Eu_{0.05}^{3+}$ phosphor prepared by spray method was found to be higher than those phosphor made by solid state reaction and the commercial $(Y,Gd)BO_3:Eu$ product.

• Korean Journal of Materials Research
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• v.4 no.4
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• pp.459-465
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• 1994

A-axis oriened YBCO thin flims were grown on $LaAIO_{3}$ single crystal substrate by off-axis rf magnetron sputtering method. We used two kinds of process to get a-axis oriented fi1ms;one-step process and two-step process. In one-step process, films are grown in single step in which substrate temperature( $T_s$) is in the range of $590^{\circ}C$ to $680^{\circ}C$. On the other hand, in two step process a-axis oriented thin film templates i f about 30nm thickness is deposited at low temperature first, and subsequently films are grown at elevated temperature to the final thickness of about 100nm. In the case of one step process($T_s$ ~)$600^{\circ}C$), prefered a-axis orientation is dominant and Cu-rich phases segregate at the surface. Segregations decrease and ($00 \ell$) peaks increase upon increasing $T_s$. The films prepared by two step method appeared to have strong(h00) peaks as the deposition rate increased. Microstructure shows pin holes resulted from mixed phases of a-axis and c-axis oriented films. In both cases of one step and two step process, as TS decreases, prepared films show stronger a-axis orientation. However electrical properties of the films are depressed with lower $T_c$ and wider $\Delta T$ as $T_s$ decreases.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.163-168
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• 2002

The objective of this study was to investigate the clinical aspects on bovine abortion and stillbirth in Korea. Three hundred thirty eight bovine fetuses were collected from farms and submitted to the College of Veterinary Medicine, Seoul National University. Submitted fetuses were evaluated for season, parity and gestation stage on abortion during a 3 years period (June, 1999 to April, 2002). Out of four seasons, incidence of bovine abortion was significantly higher in summer than other seasons (P＜0.05) due to high temperature and humidity. After surveying of incidence of abortion according to parity, it was concentrated in low parity (1, 2 and 3 parity). However, this result was not caused by parity but because most of surveyed cow was low parity. For surveying the distribution of abortion incidence according to days of gestation, we divided the days of gestation into 3 stages including with early (0∼150 days), middle (151∼250 days) and late (251days∼term). Out of 319 aborted fetuses, incidences of abortion were significantly higher in the middle and late stage than early stage (P＜0.05). A high rate (75％) of stock farms did not vaccinate animals, therefore most of cows in Korea were found to have a high risk of becoming infected upon exposure to pathogens. Many of abortions occurred in stock farms where animals of other species were being bred. More studies will be needed to investigate possible linkages between bovine abortion and the breeding of other animal species.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.1-8
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• 1986

This study was conducted to bring light on inducing factors for non-sprouting occured in the mulberry field of Kyungpook Province in 1983. The results are as follws ; 1. In spring, winter buds were suddenly died during germination, necrosis appeared in pholem and cortex of non-sprouting stem and measles at the bottom of non-sprouting stem. 2. The depth of available of soil was more shallow in the non-sproutiong field than in healthy field. 3. There was no signifioant difference between the healthy field and non-sprouting field in siol PH, the content of organic matter, available phosphorous and exchangeble cations. 4. Available boron content in soil was significantly more in healthy field than in non-sprouting field. 5. Boron content in leaf and bark was significantly lower in the non-sproutiong tree than in the healthy tree. 6. The non-sprouting fields were completely controlled by the application of 6kg/10a borax. 7. Cold tolerance of the mulberry tree was higher in the mulberry tree with boron than in the mulberry tree without boron. 8. Mulberry tree in Kyungpook Province in 1983 may absorb water earlier compared with the average year because of high temperature at the end of March, 1983 and they had been damaged by frost injuary due to the lowest temperature (-6.4$^{\circ}C$) on the grass at the beginning of April 1983. As the above results, non-sprouting bud in the mulberry fields of Kyungpook Province in 1983 had been occured by low temperature and boron deficiency and boron deficiency of mulberry trees accelerared the frost injury.

• The Korean Journal of Zoology
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• v.29 no.3
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• pp.201-207
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• 1986

The authors attempted to investigate the oxygen consumption rate of sexuals in the water-striders, Gerris paludum insuralis, at four temperature groups of 25, 30, 35 and $40^\\circ C$ in a series of studies on respiration of a heminetabolous insects. THe results are summarised as follows: (1) At $30^\\circ C$, the change of oxygen consumption rate according to the lapse of time was small in comparison with the other three temperature groups which shows a cyclic decreasing pattern. The rate during initial and final 5 minutes was much alike. Thereupon, the optimum temperature was regarded as $30^\\circ C$. (2) The oxygen consumption rate of male was higher than that of female. (3) The oxygen consumption rates at 25, 30, 35 and $40^\\circ C$ were 0.42, 0.49, 0.79 and 1.11 $\\mu$l/mg/h respectively. That is, the rate was increased as the temperature was increased. (4) The $Q_10$ of male showed a high value in the lower temperature interval ($25^\\circ C \\sim 35^\\circ C$), but the female showed a high value in the higher temperature interval ($30^\\circ C \\sim 40^\\circ C$). The mean $Q_10$ was 2.12. (5) The respiratory rate was decreased as the body weight was increased in the above fresh weight of 10mg and dry weight 5 mg. (6) The upper temperature threshold for respiration was $48.31^\\circ C$ and the lower temperature threshold was $17.68^\\circ C$. (7) The ceasing time of breathing at the other three temperature groups except $30^\\circ C$ was infered to be about 110 minutes after the start of experiment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.112-118
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• 2018

In order to meet the strict emission regulations for internal combustion engines based on fossil fuel, the proportion of after-treatments for vehicles and vessels is gradually increasing. Diesel engines have high power, good fuel economy, and lower $CO_2$ emissions, and their market shares are increasing in commercial vehicles and passenger cars. However, NOx is generated in the localized high-temperature combustion regions, and particulate matter is formed in the zones of diffusion combustion. LNT and urea-SCR catalysts have been developed for after-treatment of the exhaust gas to reduce NOx in diesel vehicles. This study aims to improve the NOx reduction performance of Cu SCR catalyst, which is widely used in light, medium, and heavy-duty diesel engines. The de-NOx performance of $5Cu-2ZrO_2$/93Zeolyst(Si/Al=13.7) SCR catalyst was about 5-50% higher than that of $5Cu-2ZrO_2$/93Zeolite(Si/Al=2.9) at catalyst temperatures of $300^{\circ}C$ or higher. The zeolite had lower metal dispersion than zeolyst, and the reaction rate of the catalyst decreased as the average particle size increased. The $10Cu-2ZrO_2$/88Zeolyst catalyst loaded with 10wt% Cu had the highest NOx conversion rate of 40% at $200^{\circ}C$ and about 65% at $350^{\circ}C$. The ion exchange rate of Cu ions increased with that of Al, the crystalline compound of zeolite, and the de-NOx performance was improved by 20-40% compared to other catalysts.