• Journal of Powder Materials
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• v.28 no.4
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• pp.342-351
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• 2021

Because of its unique properties, tungsten is a strategic and rare metal used in various industrial applications. However, the world's annual production of tungsten is only 84000 t. Ammonium paratungstate (APT), which is used as the main intermediate in industrial tungsten production, is usually obtained from tungsten concentrates of wolframite and scheelite by hydrometallurgical treatment. Intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid, and ammonium metatungstate can be derived from APT by thermal decomposition or chemical attack. Tungsten metal powder is produced through the hydrogen reduction of high-purity tungsten oxides, and tungsten carbide powder is produced by the reaction of tungsten powder and carbon black powder at 1300-1700℃ in a hydrogen atmosphere. Tungsten scrap can be divided into hard and soft scrap based on shape (bulk or powder). It can also be divided into new scrap generated during the production of tungsten-bearing goods and old scrap collected at the end of life. Recycling technologies for tungsten can be divided into four main groups: direct, chemical, and semi-direct recycling, and melting metallurgy. In this review, the current status of tungsten smelting and recycling technologies is discussed.

• IE interfaces
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• v.16 no.3
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• pp.352-361
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• 2003

Vehicle manufacturing plant is a typical mixed-model production system. Generally it consists of three main shops including body shop, painting shop and assembly shop in addition to engine shop. Each shop contains diverse manufacturing processes, all of which are integrated in a form of flow line. Due to the high pressure from the market requesting small-volume large variety production, production planning becomes very critical for the competitiveness of automotive industry. In order to save costs and production time, production planning system is requested to meet some designated requirements for each shop: to balance the work load in body and assembly shops, and to minimize the number of color changes in painting shop. In this context, we developed a sequencing module for a vehicle production planning system using the ILOG Solver Library. It is designed to take into account all the manufacturing constraints at a time with meeting hard constraints in body shop, minimizing the number of soft constraints violated in assembly shop, and minimizing the number of color changes in painting shop.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.481-495
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• 2016

Lily, which is one of Korea's main flower exports, is one of the most important agricultural product in the country. Korean lily farmers have difficulty earning more profit from producing lilies, because of the high cost of lily bulbs. Most lily bulbs used in Korea are imported from the Netherlands. Thus, the Korean government has kept trying to supply more and better Korean lily bulbs. However, many experts have questioned the efficiency and economic value of the Korean lily production system. The purpose of this paper is to analyze the economic value of the production of lily bulbs in Korea. Especially, this study evaluates the economic value of the production systems of Korean lily bulbs and compares the results from several cases. The results of the present study presents some useful findings, as follows: first, two Korean production areas (Gangneung and Jeju) show a positive economic value but one Korean production area (Taean) presents problems causing a negative economic value. Second, the Korean production area in Vietnam currently has trouble in the view of economic value but will likely overcome that problem. Third, the production area in the Netherlands shows the best economic value. Thus, Korean lily bulb producers need to benchmark that system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.119-123
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• 2002

Liquefied Natural Gas(LNG) continues to attract modern gas industries as well as domestic markets as their main energy source in the recent years. This is mainly because LNG is inherently cleaner and more energy efficiency than other fuels. Offshore LNG production plant is of interest to many oil producing companies all over the world. This article discuss about the production process encountered while developing such a production facility. Typical offshore oil and gas processing required for oil stabilization and other optional units that can be added to the facilities. The production process can broadly be divided into five major units namely, (i) Oil Stabilization unit, (ii) Gas Treatment unit, (iii) Methane Recovery unit, (iv) Distillation unit and (v) LNG Liquefaction unit. The process simulation was carried out for each unit with a given wellhead composition. The topside facilities of offshore LNG production plant will be very similar to the process adopted in offshore processing platform along with the typical onshore LNG production plant. However, the process design problems associated with FPSO motion to be taken care of while developing floating LNG production plant.

• Journal of Nutrition and Health
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• v.53 no.5
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• pp.445-451
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• 2020

Purpose: Breastfeeding is the optimal method for feeding a newborn. But insufficient breast milk is the major reason why mothers give up breastfeeding. Herbal galactagogues have been used increasingly to treat postpartum hypogalactia. This study examined the effect of an herbal tea containing Chrysanthemum indicum, as the main ingredient, on milk production in lactating rats. Methods: The herbal tea contained C. indicum (27%), Foeniculum vulgare Mill (21%), Pimpinella anisum (18.2%), Carum carvi (16.1%), Urtica dioica (14.7%), and Gardenia jasminoides (3%). Sixteen lactating Sprague-Dawley (SD) rats were divided randomly into 2 groups, the normal control group (NC; n = 8), and the galactagogue herbal tea group (GHT; n = 8) for 7 days. Lactating rats were administered the decoction of an herbal galactagogue mixture by oral gavage or the same amount of distilled water and milk production was assessed by measuring the pups' weights during the suckling period. The blood concentrations of prolactin, cortisol, oxytocin levels and mammary gland tissues were examined to assess the effects of the galactagogue. Results: Milk production was 9.2% higher in the GHT group given the herbal tea than in the NC group and the difference was statistically significant. The cortisol level in the GHT group was 17.2% higher than the NC group. The herbal tea containing C. indicum increased the size of the alveoli epithelium cells and the mammary lobe. Conclusion: The present study revealed the potential of herbal tea containing C. indicum to enhance milk production in postpartum SD rats.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.229-234
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• 2017

Photoperiod is one of the factors affecting productivity of cucumber plant by inducing ethylene hormone production and so triggering flower sex differentiation into female flower. However, only few studies have been perfomed in order to reveal the effect of photoperiod in molecular level in relation to the flower differentiation. Therefore, in this study, Mercy cultivar of cucumber (andromonoecious) was treated with photoperiod of 8, 12, 16 hours of light, while control received no treatment of additional light. Photoperiod of 8 hours was achieved by blocking the sunlight with shade net and 16 hours by giving longer light exposure using white LEDs. Cucumber's flowers were quantified and the apical and lateral shoots were extracted to evaluate the gene profile related to the photoperiod, ethylene production, and female flower differentiation, which were CsACS2, CsETR1, CsCaN, and CsPIF4 using PCR method. Photoperiod of 8 hours affected the production of female flower with average number of 6.7 flowers in main stem and 8.0 flowers in lateral stem, compared to photoperiod of 12 and 16 hours which produced 3.7 and 2.0 flowers in main stem with 7.0 and 11.3 in lateral stem, respectively. In silico studies in this experiment resulted in proposed model of signal transduction that showed the connection between ethylene production and flower differentiation. PCR analysis confirmed the expression of CsACS2, CsETR1, and CsCaN, that was positively correlated with numbers of female flowers in cucumber, but the expression of CsPIF4 that represent photoperiod haven't been confirmed correlated with the ethylene production and flower differentiation.

• Korean Journal of Medicinal Crop Science
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• v.28 no.4
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• pp.245-253
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• 2020

Background: Research on hot water extracts of medicinal plants that are easily applicable in the clinical setting is essential. To confirm the anti-inflammatory-related active compounds present in the hot water extract of Eriobotrya japonica leaves, ability to inhibit nitric oxide (NO) production was measured and active compounds isolated from the extract were analyzed. Methods and Results: Sovent fractionation by solvent was performed to identify the active compounds present in the hot water extract, and the ability of the extract and the fractions obtained to inhibit NO production was measured. Subsequently, based on the results of liquid chromatography (LC) profile analysis of the n-butanol fraction that had a relatively high inhibitory ability of NO production, six subfractions were separated around the main peak. Among the separated subfractions spectra from mass spectroscopy (MS) were analyzed and standard comparisons were performed on the compounds of the three main peaks on the chromatogram. NO production inhibitory activity of subfraction 2 identified as neochlorogenic acid was the highest with an IC₅₀ of 18.49 ㎍/㎖ followed by that of subfraction 5 identified as cryptochlorogenic acid with IC₅₀ of 25.82 ㎍/㎖. Conclusions: Our result, it was confirmed that several caffeoylquinic acids, including neochlorogenic acid and cryptochlorogenic acid present in the hot water extract of E. japonica leaves have an important role as compounds exhibiting anti-inflammatory activity.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.371-384
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• 2013

The appearance of abnormal weather caused by climate change have both direct and indirect impact on the society. Especially, agriculture is brought up as a socially important interest having direct impact of climate change in growth and harvest of crops. This study aims to perform vulnerability assessment for the South Korea's two main imported grains, maize and wheat. The production vulnerability assessment of maize and wheat in USA and China to temperature variability, which has a great impact in production, is performed. First, grain cultivation period which affects productivity of main grain production country was selected based on the main cultivation period from several references and previous studies. Then, Intergovernmental Panel on Climate Change AR5 greenhouse gas scenario RCP(representative concentration pathways)8.5 scenarios was used to select the future climate that correspond to the cultivation period of maize and wheat for each producing country. According to the result of production vulnerability analysis using adaptation (temperature changing trend) and sensitivity(temperature variability), the productivity of wheat was higher in USA, while productivity of maize was higher in China. In the future, the result showed that productivity of all two grains will be favorable in USA. The result of production vulnerability assessment through this study can later be used as a preparation data for the coming fluctuation in grain price due to climate change.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.147-157
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• 2013

Rice is a main crop and rice field is the most important farmland in Korea. This study was conducted to propose the methodology assessing impact and vulnerability on rice production by climate change at the regional and national level in Korea. We evaluated a vulnerability of rice paddy according to the outbreak of a main disease and pest of a rice plant. As results, Jeju-do, Gyeongsangnam-do, and Jeollanam-do were more vulnerable area than others. In contrast, the southern central region including Gyeonggi-do was less vulnerable than others. The vulnerable index was significantly higher in 2050s (0.5589) than in present (0.3500). This result showed that the vulnerable to the disease and pest enlarge in the future. The adaptive capacity highly contributed to the vulnerability assessment index. The daily maximum temperature of June and the daily average temperature from May to August also contributed the climate exposure index. The area of occurring sheath blight, rice leaf blast and striped rice borer was related to the system sensitivity index. The ability of water supply (readjustment area of arable land per paddy field area) and rice production technique (rice yield per hectare) were the highly contributed variables to the adaption capacity index.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.2
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• pp.129-138
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• 2023

The proportion of agricultural products handled through the Agricultural Products Processing Center (APC) is also steadily increasing every year, and in the case of Seongju Korean melon, a total of 10 APCs of Nonghyup and farming association corporations are in operation, and the distribution ratio is about 60% based on total production. In this study, Seongju Korean melon was selected as a target to analyze the environment load during carrying (production farm ~ APC) in the production area and the transport environment load during distribution of domestic fruits, and to analyze the environmental load for handling at APC. The vertical average vibration intensity (overall G_rms of 1~250 Hz) of truck transport measured at three transport routes from Seongju Korean melon producer ~ APC, Seongju ~ Seoul and Seongju ~ Jeju was about three times larger than that in the lateral direction and 4.5 times larger than that in the longitudinal direction, respectively. The frequency of occurrence of high-amplitude events (G) in the vertical direction compared to the measuring time was deeply related to pavement conditions in the order of unpaved farm-roads, concretepaved farm-roads, and asphalt-paved main-roads, but overall G_rms for the entire frequency band is believed to have a greater impact on vehicle traveling speed than road conditions. On the other hand, the difference in the size and direction of the vibration intensity measured by the forklift truck's main-body and the attachment (fork carrier) during handling at Seongju Korean melon APC was clear, and the vibration intensity of the forklift truck's main-body was largely affected by the stiffness of the fork and the mast according to the handling weight. Based on the field-data of the transport environment during domestic distribution measured through this study, it is believed that it is possible to develop a lab-based simulation protocol for appropriate packaging design.