• Journal of the Korean Chemical Society
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• v.42 no.6
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• pp.618-628
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• 1998

Pure CaO, Mn-doped CaO, Mn/CaO, and K/CaO catalysts were prepared and tested as catalysts for the oxidative coupling of methane in the temperature range of 600 to 800$^{\circ}C$ to investigate the effects of Mn- and K-addition on the catalytic activity of calcium oxide. To characterize the catalysts, X-ray powder diffraction(XRD), XPS, SEM, DSC, and TG analyses were performed. The catalytic reaction was carried out in a single-pass flow reactor using on-line gas chromatography system. Normalized reaction conditions were generally $p(CH_4)/p(O_2)=250$ Torr/50 Torr, total feed flow rate=30 mL/min, and 1 atm of total pressure with He being used as diluent gas. Among the catalysts tested, 6.3 mol% Mn-doped CaO catalyst showed the best $C_2$ yield of 8.0% with a selectivity of 43.2% at 775$^{\circ}C$. The $C_2$ selectivity increased on lightly doped CaO catalysts, while decreased on heavily doped CaO([Mn] > 6.3 mol%) catalysts. 6 wt.% Mn/CaO and 6 wt.% K/CaO catalysts showed the $C_2$ selectivities of 13.2% and 30.9%, respectively, for the reaction. Electrical conductivities of CaO and Mn-doped CaO were measured in the temperature range of 500 to 1000$^{\circ}C$ at Po2's of $10^{-3}\; to\;10^{-1}\;atm.$ The electrical conductivity was decreased with Mn-doping and increased with increasing $P0_2$in the range of $10^{-3}\;to\;10^{-1}\;atm,$ indicating the specimens to be p-type semiconductors. It was suggested that the interstitial oxygen ions formed near the surface can activate methane and the formation of interstitial oxygen ions was discussed on the basis of solid-state chemistry.

• Journal of Korea Port Economic Association
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• v.36 no.2
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• pp.19-36
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• 2020

The bidding phase for logistics outsourcing services is critical for both shippers and logistics companies. According to the logistics bidding phase, the shipper should provide logistics operation information to logistics companies to resolve uncertainty. In addition, the logistics company can win the contract volume that was placed in the bid by expressing their experience and know-how, and proposing to share the risks and benefits of the shipper's logistics operation. Therefore, it is necessary to examine the factors that can be identified during the bidding phase for logistics outsourcing and how these factors affect the satisfaction of logistics outsourcing services. Based on the factors identified in the preceding studies on logistics outsourcing partnership factors and those on logistics outsourcing determinants, a survey was conducted on experts engaged in logistics companies, performing logistics for domestic shippers and analyzed using Smart-PLS. This study presents the following implications. First, in the logistics bidding phase, the shipper should provide its logistics operation information to logistics firms to resolve uncertainties. Details An in-depth explanation of the operation details will be presented via the bidding presentation, and on-site tours of manufacturing plants and logistics centers should also be carried out if necessary. Second, in the bidding phase, logistics companies should appeal through proposals to their competitiveness, such as experience and knowledge of the logistics of the shipper, and also consider alliances with other logistics companies to supplement their insufficient logistics services. Third, logistics companies should make proposals to share profits and risks through logistics outsourcing during the bidding phase, propose accepting risks from environmental uncertainties of the shipper within its capacity to an acceptable extent, and share the benefits of carrying out the shipper's logistics.

• Journal of Gastric Cancer
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• v.8 no.2
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• pp.97-103
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• 2008

Purpose: Radical surgery is the standard therapy for patients with resectable cardia cancer. In the case of type II disease with esophageal invasion, a transhiatal extended radical total gastrectomy is needed or a gastroesophagectomy through an abdomino-thoracotomy, depending on the extent of the esophageal invasion. We analyzed the indications and outcome of left colon interposition as an esophageal substitution. Materials and Methods: Between 1 January 1994 and 31 December 2006, 10 patients underwent left colon interposition after gastroesophagectomy through an abdomino-thoracotomy or the tanshiatal approach for type II cardia cancer at the Department of surgery, Yonsei University College of Medicine. The outcomes of these patients were reviewed and compared, with those who underwent a Roux-en-Y, by gender and age matched analysis, retrospectively. Results: There were nine males and one female with a mean age of 52.5 (range, 16~72). The operation time was $449.00{\pm}87.39minutes$. The mean distance between the proximal resection margin and the cancer was $6.56{\pm}3.65cm$; the maximum size of the tumor was $9.90{\pm}3.97cm$. These measures differed significantly from patients who underwent Roux-en-Y. The patients had a double primary cancer in the cardia and esophagus. There were no events of colon necrosis. However, a pneumothorax occurred in one patient (10%) and a proximal anastomotic stricture occurred in one patient. There were no reports of heartburn, regurgitation, thoracic or epigastric fullness, and one patient even gained weight, 16 kg. Conclusion: Colon interposition after esophagogastrectomy was safe and effective and should be considered as an additional surgical option for locally advanced type II cardia cancer patients with esophageal invasion.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.114-122
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• 1986

At present, the treatments of the radiation-induced diseases are only performing by the palliative treatment technique. Moreover, radiation protective agents are a little toxic for human being and this seriously limits their applicability with various complications in clinical uses. Accordingly, as a part of the aim of gain of the basic data for protective roles of some radioprotectors, the present investigation was carried out to evaluate the comparative radioprotective effects by the administration of DDC, MEA, WR-2721. Results are shown for statistically significant analysis and correlation with each group as follows; 1. The proper doses of the radioprotectors were DDC; 1,550 mg/kg, MEA; 450 mg/kg, WR-2721; 780 mg/kg of the mouse body weight. 2. DMF(Dose modification factor) of LD 50/10 and LD 50/30 for whole body irradiation was DDC; 1.2, MEA; 1.4, WR-2721; 1.9 and DDC; 1.7, MEA; 1.8, WR-2721; 2.5 respectively. 3. DMF for radiation reaction of jejunal crypt was DDC: 1.07, MEA: 1.21 and WR-2721: 1.76 and that of jejunal crypt cell was DDC: 1.04, MEA: 1.08 and WR-2721: 1.38 respectively. 4. Conclusively, WR-2721 was the most effective drung among the three radioprotectors and this result must be a supportive data for further study for clinical application.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1125-1132
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• 2013

In the kimchi manufacturing process, the starter is cultured on a large-scale and needs to be supplied at a low price to kimchi factories. However, current high costs associated with the culture of lactic acid bacteria for the starter, have led to rising kimchi prices. To solve this problem, the development of a new medium for culturing lactic acid bacteria was studied. The base materials of a this novel medium consisted of Chinese cabbage extract, a carbon source, a nitrogen source, and inorganic salts. The optimal composition of this medium was determined to be 30% Chinese cabbage extract, 2% maltose, 0.25% yeast extract, and $2{\times}$ salt stock (2% sodium acetate trihydrate, 0.8% disodium hydrogen phosphate, 0.8% sodium citrate, 0.8% ammonium sulfate, 0.04% magnesium sulfate, 0.02% manganese sulfate). The newly developed medium was named MFL (medium for lactic acid bacteria). After culture for 24 hr at $30^{\circ}C$, the CFU/mL of Leuconostoc (Leuc.) citreum GR1 in MRS and MFL was $3.41{\times}10^9$ and $7.49{\times}10^9$, respectively. The number of cells in the MFL medium was 2.2 times higher than their number in the MRS media. In a scale-up process using this optimized medium, the fermentation conditions for Leuc. citreum GR1 were tested in a 2 L working volume using a 5 L jar fermentor at $30^{\circ}C$. At an impeller speed of 50 rpm (without pH control), the viable cell count was $8.60{\times}10^9$ CFU/mL. From studies on pH-stat control fermentation, the optimal pH and regulating agent was determined to be 6.8 and NaOH, respectively. At an impeller speed of 50 rpm with pH control, the viable cell count was $11.42{\times}10^9(1.14{\times}10^{10})$ CFU/mL after cultivation for 20 hr - a value was 3.34 times higher than that obtained using the MRS media in biomass production. This MFL media is expected to have economic advantages for the cultivation of Leuc. citreum GR1 as a starter for kimchi production.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.351-359
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• 2010

To establish the optimum artificial light illumination method for baby leaf lettuce in closed plant factory system, the effects of red/blue light quality and short-term light quality conversion on growth and anthocyanin content were investigated. The growth of 'Hongha' lettuce was most favorable under red single wavelength LED light after 23 days of treatment, sequentially followed by the growth under red/blue mixed light, blue light, and fluorescent light. Total anthocyanin content in the mixed red/blue light (R57-B43) was 4.1-fold and 6.9-fold increased compared to the red LED and fluorescent light, respectively. With increasing the blue light ratio to 43%, the growth of lettuce was significantly decreased, while the relative chlorophyll content and Hunter's $a^*$ value was increased, indicating that the red/blue light ratio inversely affects on growth and anthocyanin pigment development. By changing light quality from red to red/blue mixed light source (R57-B43) for 9 days before harvest, the growth rate decreased compared to the continuous red light illumination, while the anthocyanin content dramatically increased compared to either red LED or fluorescent light. Whereas, when the light source was changed to red light, the growth rate was increased but anthocyanin content was reversely decreased. The result demonstrated that both growth and anthocyanin expression could be effectively regulated by shifting of light quality between red and red/blue mixed light source at a specific growth stage of lettuce in a plant factory.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.268-275
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• 2017

The photosynthetic rates of crops depend on growth environment factors, such as light intensity and temperature, and their photosynthetic efficiencies vary with growth stage. The objective of this study was to compare two different models expressing canopy photosynthetic rates of romaine lettuce (Lactuca sativa L., cv. Asia Heuk romaine) using three variables of light intensity, temperature, and growth stage. The canopy photosynthetic rates of the plants were measured 4, 7, 14, 21, and 28 days after transplanting at closed acrylic chambers ($1.0{\times}0.8{\times}0.5m$) using light-emitting diodes, in which indoor temperature and light intensity were designed to change from 19 to $28^{\circ}C$ and 50 to $500{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. At an initial $CO_2$ concentration of $2,000{\mu}mol{\cdot}mol^{-1}$, the canopy photosynthetic rate began to be calculated with $CO_2$ decrement over time. A simple multiplication model expressed by simply multiplying three single-variable models and a modified rectangular hyperbola model were compared. The modified rectangular hyperbola model additionally included photochemical efficiency, carboxylation conductance, and dark respiration which vary with temperature and growth stage. In validation, $R^2$ value was 0.849 in the simple multiplication model, while it increased to 0.861 in the modified rectangular hyperbola model. It was found that the modified rectangular hyperbola model was more suitable than the simple multiplication model in expressing the canopy photosynthetic rates affected by environmental factors (light Intensity and temperature) and growth factor (growth stage) in plant factory modules.

• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.171-182
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• 2018

Papaya (Carica papaya L.) is one of the crops widely planted in tropical and subtropical areas. The papaya fruit has low calories and are plentiful in vitamins A and C and in minerals. A major problem in papaya production is a plant disease caused by the papaya ringspot virus (PRSV). The first PRSV-resistant GM papaya expressing a PRSV coat protein gene was developed by USA scientists in 1992. The first commercial GM papaya cultivars derived from the event was approved by the US government in 1997. Development of transgenic papayas has been focused on vaccine production and limited agricultural traits, including insect and pathogen resistance, long shelf life, and aluminum and herbicide tolerance. Approximately 17 countries, including the USA and China, produced transgenic papayas and/or commercialized them, which provoked studies on biosafety assessment and development of GM-detection technologies. For the biosafety assessment of potential effects on human health, effects of long-term feeding to model animals have been studied in terms of toxicity and allergenicity. Studies on environmental safety assessment include influence on soil-microbial biodiversity and transfer to soil bacteria of GM selection markers. Many countries, such as Korea, the European Union, and Japan, that have strict regulations for GM crops have serious concerns about unintended introduction of GM cultivars and food commodities using unauthorized GM crops. Transgene- and/or GM event-specific molecular markers and technologies for genomics-based detection of unauthorized GM papaya have been developed and have resulted in the robust detection of GM papayas.

• Korean Journal of Poultry Science
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• v.39 no.4
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• pp.297-303
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• 2012

To investigate the effects of dietary substituent of corn distiller's dries grains with solubles (CDDGS) on the amino acid digestibility of broiler diet, twenty four Ross broilers (6-wk-old) were used in this study. Basal diet (CP 19%, ME 3,150 kcal/kg) was formulated on corn-soybean meal and two levels of CDDGS (6 and 12%) were supplemented to basal diet. CDDDS levels (0, 6 and 12%) and 4 different sites of chicken intestines (distal end of jejunum, the middle part of the ileum, the distal end of ileum and the distal end of the rectum) were evaluated factorial as $3{\times}4$ three arrangement. Statistical analysis did not show any significant interaction between dietary treatments and the sites of the intestines in amino acid digestibility (P>0.05). There was no significant difference among the sites of chicken intestines in the digestibility (P<0.05). The digestibility of lysine (essential amino acid) and glycine (non-essential amino acid) decreased at increasing supplementation of CDDGS (P<0.05). There was no significant difference on the digestibility of other amino acids studied. In conclusion, the result of this work showed that CDDGS can use as alternative resources in broiler diets.

• Journal of Life Science
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• v.18 no.11
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• pp.1561-1569
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• 2008

This study was conducted to investigate the effects of steam flaking of corn grains on in situ dry matter degradability in the rumen and contents of mycotoxins (aflatoxin, ochratoxin) during storage. Yellow dent corns imported from USA and India were flaked, and stored for 8 weeks under the standard temperature and pressure (STP; $25^{\circ}C$/ 1 atm.). Experimental treatments were composed of four corn grains (untreated-USA corn, USCW; steam flaked-USA corn, USCF; untreated-India corn, IDCW; steam flaked-India corn, IDCF) with 4 replications according to 9 storage periods (0, 1, 2, 3, 4, 5, 6, 7, 8 week). Two ruminally cannulated Holstein bulls were used for in situ trial. Pathogen contamination trial was performed by comparing the mycotoxin contents in corns during storage periods. Dry matter disappearance rate in the rumen was about 3.0 to 44.1% higher (P<0.05) for USCW than IDCW, but was not difference between USCF and IDCF. With steam flaking of corn, dry matter degradability in the rumen was significantly (P<0.05) increased in corn from India, but was not affected in corn from USA. Aflatoxin content was very low level in corns from USA and steam flaked corns, but was higher than the tolerance limit of domestic aflatoxin content regulation when IDCW was stored over 6 week under STP. Ochratoxin content was low level in all treatments. From above results, it is reasonable that the corn imported from India might be flaked for enhance the ruminal DM degradability and safe from aflatoxin pathogen.