• Title/Summary/Keyword: LOCUST

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Development and validation of wall and interfacial friction models in LOCUST for reactor downcomer with direct vessel injection

  • Rongshuan Xu;Xinan Wang;Caihong Xu;Dongyu He;Ting Wang;Jinggang Li
    • Nuclear Engineering and Technology
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    • v.56 no.10
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    • pp.4397-4403
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    • 2024
  • The multi-dimensional thermal-hydraulic phenomena in the downcomer of advanced pressurized water reactor with direct vessel injection system are the key points for the safety analysis during a loss of coolant accident. In order to improve the accuracy of LOCUST code for the predictions of thermal-hydraulic phenomena in downcomer region, some newly correlations have been implemented into LOCUST code. The wall friction model of LOCUST code was modified based on the correlations which developed by Yang. The interfacial friction models in LOCUST code have been modified as Hibiki-Ishii correlations. In addition, in order to simulate the upward flow of recirculation flow in downcomer region, the Kinoshita-Hibiki correlations have been also implemented into LOCUST code for better simulating the recirculation flow in downcomer region. The modified code was validated with experimental data of DOBO facility. Five tests of DOBO facility have been calculated by LOCUST, and the calculated axial void fraction distributions have been compared with the measurements. The results show that the modified LOCUST with new correlations of distribution parameter and drift velocity shows better accuracy than the original code. The deviations of the modified LOCUST code are less than the original code and are almost within ±20 %.

Utilization of Robinia pseudoacacia as Sawdust Medium for Cultivation of Edible and Medicinal Mushrooms

  • Chai, Jung-Ki;Lee, Sung-Jin;Kim, Yoon-Soo
    • Plant Resources
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    • v.2 no.1
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    • pp.42-48
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    • 1999
  • This study was undertaken to examine the feasibility of black locust (Robinia pseudoacacia) as substrates for several edible mushrooms. For the cultivation of several edible and/or medicinal fungi on black locust, optimum bulk densities, synthetic or semisynthetic additives, natural additives and pretreatment methods were investigated. Fruit body yields of the fungi on various sawdust media composed of different wood species were also analyzed for testing the capability of black locust as a substrate for mushroom production. Mycelial growths decreased proportional when the bulk density increased. The most suitable carbon and nitrogen sources as additives to promote the mycelial growth were sucrose (2%, w/w) and ammonium phosphate (0.2%, w/w) respectively. When corn-powder and beer-waste as natural additives were added to sawdust of black locust showed the significant growth of mycelia. And the optimum mixing ratio was 10:2:1 (sawdust: corn-powder: beer-waste, w/w). Black locust after cold water treatment showed the outstanding mycelial growths. Any significant changes of pH, moisture content (%) and dry-weight losses (%) could not be found among culture substrates (sawdust of black locust, oak and poplar wood) examined before and after harvesting of fruit bodies. Yield of fruit bodies on black locust culture media were comparable with those culture media composed with oak and poplar wood. The present work indicated strongly the potentiality of black locust as raw materials for edible and medicinal mushrooms.

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Quality Characteristics of Mungbean Starch Gels with Various Hydrocolloids (친수성 다당류 첨가가 녹두전분 겔의 품질 특성에 미치는 영향)

  • Choi, Eun-Jung;Oh, Myung-Suk
    • Journal of the Korean Society of Food Culture
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    • v.24 no.5
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    • pp.540-551
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    • 2009
  • This study was conducted to investigate the quality characteristics of mungbean starch gels containing various hydrocolloids (carrageenan, locust bean gum and xanthan gum) during room temperature storage ($25^{\circ}C$ for 24, 48 and 72 hours). Carrageenan and xanthan gum reduced the pasting viscosity of mungbean starch, whereas the locust bean gum increased the viscosity. The melting characteristics, as assessed by DSC, showed that carrageenan and xanthan gum delayed gelatinization of mungbean starch and the locust bean gum had no effect on this property. The lightness (L) of the gels with the locust bean gum was similar to that without the additive during storage, whereas that with carrageenan and xanthan gum was higher than that without the additive. Hardness, chewiness and gumminess of the gels with the locust bean gum was higher than that without the additive during storage, whereas that with carrageenan and xanthan gum was lower than that without the additive. The rupture stress, rupture strain and rupture energy of the gels with carrageenan and xanthan gum was lower than that without the additive during storage, whereas that with the locust bean gum was similar to that without the additive. In the sensory evaluation, springiness and cohesiveness of the gels with carrageenan and xanthan gum were lower than those without the additive, whereas springiness, brittleness and hardness of the gels with the locust bean gum were higher than those without the additive. In addition, the overall acceptability of the gels with the locust bean gum improved. The above results showed that carrageenan and xanthan gum lowered the quality characteristics of the mungbean starch gel and the locust bean gum improved them. Thus, the addition of 0.5% locust bean gum is an appropriate method for improving the quality characteristics of mungbean starch gel.

Changes of Soil Properties in Black Locust(Robinia pseudoacacia L.) Stand and Adjacent Stand (아까시나무(Robinia pseudoacacia L.)조림지와 인접 임분의 토양특성 변화)

  • Jung, Sung-Chul;Huh, Tae-Chul;Joo, Sung-Hyun
    • Current Research on Agriculture and Life Sciences
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    • v.21
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    • pp.39-47
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    • 2003
  • The object of this study was to analyze influence which Black locust afforestation affected to soil, to research change of soil environment of Black locust planted stand and adjacent stands through comparative analyzing physichemical property of soil of them. It was investigated that the soil texture of Black locust planted stand and the adjacent stands was mostly SL. and LS. According to this result I could know that transformation of soil texture by vegetation easily happened because transformation soil texture results from the parent rock. I could ascertain that difference existed between Black locust planted stand and the other stands in soil pH and Carbon content of planted stand of Black locust pH, contents of Available $P_2O_5$ Carbon, Total Nitrogen. In other words, pH and Carbon content of Black locust planted stand were lower than that of Oak forest, higher than that of Pine forest. These results showed that Black locust was which fix nitrogen. I could infer that Black locust afforestation made forest soil fertilized. In soil of Black locust planted stand and the adjacent stands, statistical value appeared highly in pH and existed in content of Carbon, Total nitrogen, too. And high interrelationship appeared in the order of pH, C/N Ratio, CEC, Total nitrogen content was in each stands. I suppose that the trespassing extent of Black locust to Oak forest and Pine forest which are adjacent to planted stand of Black locust is different because of low pH, lackness of Available $P_2O_5$ Carbon, and what not.

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Mosaic Disease of Black Locust on Rodinia pseudo-acacja L.(Par. 2) (아까시아나무 모자익병에 관한 연구 2)

  • 김종진
    • Korean Journal of Microbiology
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    • v.3 no.2
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    • pp.22-26
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    • 1965
  • In order to investigate the host range of the mosaic disease of black locust in the Chunchon area, the sap of the mosaic-diseased leaves of black locust itself and the cowpea leaves infected with the above mentioned sap, were inoculated to 53 species of plants belong to 12 families. As to the result, no difference in infection was found as related to the virus sources, and the infection was recognized in 4 species of the family Chenopodiaceae and 8 species of the family Leguminosae. The plants recognized as hosts are as follows: the plants which showed local infection are Chenopodium album, Ch. ambrosioides, Ch. quinoa; the plants which showed systemic infection are Chenopodium amaranticolor, Phaseolus vulgaris, Robinia pseudo-acacia, Vigna sinensis; and Astragalus sinicus, Melilotus indicus, Phaseolus angularis, Pisum sativum and Vicia faba were recognized as carriers. Through investigating its host ranges and symptoms, this mosaic virus of black locust seems not to be regarded as the group of the black locust mosaic virus in southeastern Europe reported by Milinko et al (1961). And, too, it is thought hardly to exist in combination with the cowpea mosaic virus. It appears, therefore, that this mosaic virus was confined to that of black locust.

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The Effect of Addition of Grape Pomace on Chemical Composition and Quality of Silage (포도박 첨가가 사일리지의 화학적 성분과 발효품질에 미치는 영향)

  • 조익환;이주삼
    • Korean Journal of Organic Agriculture
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    • v.9 no.3
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    • pp.73-83
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    • 2001
  • The qualities of the rice straw, black locust and orchardgrass silage added with grape pomace were investigated in this study and the amount of grape pomace added in different treatments were 0, 20, 40 and 50%, respectively. Crude protein contents of rice straw(6.5-10.6%) and orchardgrass silage(13.2-14.8%) added with grape pomace were significantly higher(p<0.05) than that of 100% rice straw(5.3%) and orchard grass silage(12.8%), however the crude protein contents(14.9-15.6%) of black locust silage in supplementation were lower than that of 100% black locust silage(16.3%). With higher amount of addition of grape pomade to rice straw, black locust and orchardgrass silages, ADF, NDF and crude ash contents decreased significantly(p<0.75). Moisture contents decreased according to the higher proportion of grape pomace in the rice straw silages, but increased according to the higher proportion of grape pomace in the black locust and orchardgrass silage. Values of pH in 20∼60% addition of grape pomace in rice straw(4.0∼4.2), black locust(4.1∼4.3) and orchardgrass silages(4.2∼4.4) were lower than that of 100% in rice straw(4.6), black locust(5.4) and orchardgrass silages(4.7). The contents of acetic acid and total volatile fatty acid significantly increased according to higher levels of addition of grape pomace compared to the respective values of silage. However the contents of lactic acid in supplementation of grape pomace were lower than that of 100% black locust silage.

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The Effect of Addition of Apple Pomace on Quality and In situ Degradability of Black locust Silage (사과박 첨가가 아까시나무 사일리지의 품질과 in situ 소실율에 미치는 영향)

  • 조익환;황보순;안종호;김현진;이주삼
    • Korean Journal of Organic Agriculture
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    • v.9 no.4
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    • pp.123-134
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    • 2001
  • The quality including in situ degradability in the rumen of Holstein of the black locust silage added with apple pomace was investigated in this study. The amount of apple pomace added in different treatments were 0, 20, 40 and 60% respectively. With higher amount of addition of apple pomace in black locust, crude protein content in the silage decreased. Crude protein contents in the apple pomace added silage were in the range between 11.7 and 13.7% and those were significantly lower than 16.3% of 100% black locust silage. The contents of ADF, NDF and crude ash were in the same trend as with crude protein, which were shown more clearly in the 40∼60% addition of apple pomace. Moisture content of 100% black locust silage was 56.7% however it significantly increased according to higher levels of addition of apple pomace(67.1∼73.8%). pH, lactic acid and total organic acid contents in 20∼60% addition of apple Pomace were 3.7∼4.3, 1.3∼2.2%, and 2.1∼6.0% respectively, however in 100% black locust silage those were significantly lower except pH as 5.4, 0.6% and 1.0% respectively. In situ disappearance rates of dry matter and NDF in the rumen were significantly higher at the stapes of incubation after 12h and 24h respectively in 20∼40% addition of apple pomace than in 100% black locust silage. No statistical differences were observed with quickly degradable fraction (a) in the disappearance rates of dry matter and NDF. In dry matter, however slowly degradable fractions (b) of 100% black locust and 60% addition of apple pomace were significantly higher as 99.7 and 99.8% respectively than 37.7∼50.5% of 20∼40% addition of apple pomace. On the contrary, fractional rate of disappearance (c) and effective degradability(ED) were significantly higher in 20∼40% addition of apple pomace as 0.0115∼0.0149 and 30.4∼31.9% respectively than the respective values of 0.0027 and 24.9% of 100% black locust. In NDF, b was significantly higher in apple pomace added silage(38.5∼99.8%) than in 100% black locust silage(14.9%). However, C was significantly lower in apple pomace added silage than in 100% black locust silage.

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Effects of Medium Components and Growth Regulators on Callus Development and Shoot Regeneration from Shoot Explants of Black Locust (Robinia pseudoacacia)

  • Shin, Dongill;Han, Kyung-Hwan;Sul, Ill-Whan
    • Journal of Life Science
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    • v.9 no.1
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    • pp.50-53
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    • 1999
  • Effects of growth regulators and medium components were tested for shoot multiplication and callus growth from shoot explants of black locust. During shoot multiplication, callus growth at the cut end of shoot explants proceeded shoot development. The basal callus growth seemed to be a function of both mineral components and cytokinin supplemented in the medium. Maximum callus growth was induced by 0.5${\mu}$M BAP and the callus growth decreased as the level of BAP increased. Positive correlations were found between basal callus growth, and shoot multiplication and growth. Shoot multiplication was greatest on BSM medium (black locust shoot culture medium) supplemented with 1 $\mu$M BAP. With medium containing high nitrogen content, both shoot multiplication and growth were significantly enhanced. A new BRM medium was the most effective for rooting of black locust among three rooting media tested.

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Optimization of Medium for $\beta$-Mannanase Production by Aspergillus oryzae (Aspergillus oryzae에 의한 $\beta$-Mannanase 생산배지의 최적화)

  • 오덕근;김종화이태규
    • KSBB Journal
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    • v.11 no.5
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    • pp.565-571
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    • 1996
  • Medium optimization for ${\beta}$-mannanase production by Aspergillus oryzae ATCC 2114 was performed. Effect of carbon source (locust bean gum) concentration on ${\beta}$-mannanase production was investigated. Above 20 g/L locust bean gum, a lag time for ${\beta}$-mannanase production was appeared because high concentration of locust bean gum caused high viscosity which made the mixing of medium poor. As the locust bean gum concentration in the medium increased, ${\beta}$-mannanase activity and cell growth increased proportionally. Effect of various nitrogen sources on ${\beta}$-mannanase production was also studied. (NH4)2SO4 and malt extract were the most effective for ${\beta}$-mannanase production among the inorganic nitrogenous compounds and organic nitrogen nutrients. Inorganic compounds such as KH2SO4, NaCl, Na2CO3, and MgSO4, on ${\beta}$-mannanase production were optimized for ${\beta}$-mannanase production. Locust bean gum of 10 g/L, malt extract of 3 g/L, (NH4)2SO4 of 2 g/L, KH2SO4, of 10 g/L were selected as the optimal medium. Culture in a fermentor by using the optimal medium was carried out. Lag time of ${\beta}$-mannanase production was shorter due to the better mixing of the fermentor. The maximum ${\beta}$- mannanase activity of 9.7 unit/mL and specific ${\beta}$-mannanase activity of 1.9 unit/mg-cell could be obtained at 27 hours and the productivity of ${\beta}$-mannanase was 0.36 unit/mL$.$h.

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Study on the Application of Microwave-Heating System for Making Bent-Wood Furniture(I) - Solid-Wood Bending Properties of Robinia pseudo-acacia L. by Microwave-Heating - (국산재(國産材) 곡목가구(曲木家具) 제조(製造)를 위한 Microwave-Heating System 활용에 관한 연구(I) - Microwave-Heating에 의한 아까시나무의 소재(素材)휨가공 특성 -)

  • So, Won-Tek;Chai, Jyung-Ki
    • Journal of the Korean Wood Science and Technology
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    • v.23 no.3
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    • pp.73-82
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    • 1995
  • Black locust trees(Robinia pseudo-acacia L.) are growing widely in Korea and have been used to get honey and animal feed, but they have seldom been used as manufacturing materials. This study was carried out to evaluate the possibility of using black locust as bent-wood furniture materials. Softening methods were steaming and micro-wave heating. The specimens of 15${\times}$15${\times}$350mm were all air-dried. For softening, specimens were steamed at 100$^{\circ}C$ for 7 min, or microwave heated for 35 seconds. It is known that microwave heating softens wood much faster than steaming. The bending processing conditions are showed in Table 7. The minimum solid-bending radii of black locust were 40mm for steaming and 150mm for micro-wave heating, respectively. In conclusion the steamed black locust, showed very good solid bending properties, but the bending properties of micro-wave heated black locust were not sufficient for bent-wood furniture.

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