• Journal of Hydrogen and New Energy
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• v.35 no.2
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• pp.216-229
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• 2024

Pipeline steels for hydrogen transmission may cause hydrogen embrittlement due to absorption and diffusion of hydrogen through metals. Hydrogen pipes exhibited similar mechanical properties to atmospheric conditions in terms of tensile and yield strength in a hydrogen atmosphere. This paper aims to provide relevant information regarding hydrogen embrittlement in hydrogen transmission pipeline.

• Food Science and Preservation
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• v.24 no.1
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• pp.68-73
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• 2017

The main objective of this study was to investigate the effects of various commercial pectin enzyme treatments on juice yield from Aronia fruits (Aronia melanocarpa) as well as changes in physicochemical properties such as pH, total acid, reducing sugar, soluble solid, total anthocyanin, total phenolic compounds, and DPPH radical scavenging activity. Different types and reaction conditions of pectinase were also investigated in order to improve extraction yield of Aronia juice. The optimal conditions of enzyme treatment were 0.1% of concentration (w/w) at $50^{\circ}C$ for 120 min. Among enzymes used in this study, extraction yield with Rapidase Press L treatment from Aronia juice was the highest and resulted in a significant increase in juice from 51.0 to 69.1%. Rapidase C80 MAX showed 68.83% extraction yield while Plantase TCL showed 66.70% extraction yield. Reducing sugar and soluble solid contents increased after enzyme treatment. Total acids also slightly increased after enzyme reaction. No significant difference was observed in pH regardless of pectin enzyme treatment. However, enzyme treatment resulted in an increase in total phenolic compounds, total anthocyanin, and DPPH radical scavenging in Aronia juice compared to the juice prepared juice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.344-352
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• 2019

Drought stress caused by global climate change is a serious problem for rice cultivation. Increasingly frequent abnormal weather occurrences could include severe drought, which could cause water stress to rice during the seedling stage. This experiment was conducted to clarify the effects of drought during the seedling period on yield and quality of rice. Drought conditions were created in a rain shelter house facility. The drought treatment was conducted at 3, 10, and 20 days after transplanting. Soil water content was measured by a soil moisture sensor during the whole growth stage. In this study, we have chosen 3 rice cultivars which are widely cultivated in Korea: 'Haedamssal' (Early maturing), 'Samkwang' (Medium maturing), and 'Saenuri' (Mid-late maturing). The decrease in yield due to drought treatment was most severe 3 days after transplanting because of the decrease in the number of effective tillers. The decrease in grain quality due to drought treatment was also most severe 3 days after transplanting because of the increased protein content and hardness of the grains. The cultivar 'Haedamssal' was the most severely damaged by water stress, resulting in about a 30% yield loss. Drought conditions diminished the early vigorous growth period and days to heading in early-maturing cultivars. The results show that drought stress affects yield components immediately after transplanting, which is a decisive factor in reducing yield and grain quality. This study can be used as basic data to calculate damage compensation for drought damage on actual rice farms.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.317-331
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• 2011

The CERES-Barley crop simulation model of DSSAT package was used to assess the impacts of climate change on potential yield of winter covered barley in Korea. 56 sites over the southern part of Korean peninsula were selected to compare the climate change impacts in various climatic conditions. The climatological normals (1971~2000) and the three future climatological normals (2011~2040, 2041~2070, and 2071~2100), based on A1B climate change scenarios of Korea, were used in this study, and the three future climatological normals were simulated under three environmental conditions, where only temperature change, only carbon dioxide change, and both of temperature and carbon dioxide change with future A1B climate change scenarios, respectively. Results: The CERES-Barley model was suitable for predicting climate change impacts on the potential yield of winter covered barley, because of the agreement between observed and simulated outcomes (e.g., the coefficient of determination of grain yield equals 0.84). (1) The only increased temperature effect with the climate change scenarios was mostly negative to the potential yield of winter covered barley and its magnitude ranges from -21% to +1% for the three future normals. (2) The effect of the only elevated carbon dioxide on the potential yield of winter covered barley was positive and its magnitude ranged from 12% to 43% for the three future normals. (3) For increased temperature and elevated carbon dioxide change cases, potential yields increased by 13%, 21%, 19% increase for the 2011~2040, 2041~2070, 2071~2100 normals, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.253-258
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• 2002

NC+4880, a forage com hybrid, is bred by NC+hybrids Co. in US, and Gast 8396 IT is by Garst Seeds Co. We have tested these two cultivars in Suwon and Chonan over three years to test their regional yield trial. Through above experiments, the excellence is testified, in result, they are determined as new recommended cultivars by NACF. The main characteristics of these cultivars are as tallows ; 1. NC+4880 a. The seed coat is yellow, the mean tasseling date is 7th of July and it takes about 74 days from emergence to tasseling date. This hybrid is a day ahead and the culm length is 242 cm, moreless shorter comparing with a check hybrid, Suwon 19. The ear height 117 cm which is short and its stay green is moderate. b. It shows resistance to H maydis, and MBSDV is barely observed and its stay green is moderate. c. The fresh yield, dry matter yield, and TDN yield per a ha are 55.4 tons, 18.3 tons, 12.4 tons, respectively, which are increased by 6%, 7%, and 9%, respectively, comparing with a check hybrid, Suwon 19. The percent ear among total dry matter yield is 50.9%. 2. Garst 8396 IT a. The seed coat is yellow, the mean tasseling date is 9th of July and it takes about 76 days from emergence to tasseling date. This hybrid represent a day delayed compared with a check hybrid, Suwon 19. The Culm length and the ear height are 275 cm, and 138 cm, respectively. b. It resists moderately to H. maydis, and highly resists to lodging in the field conditions. MBSDV is barely observed and its stay green is moderate. c. The fresh yield per a ha is 64.9 tons, dry matter yield, 20.9 tons, and TDN, 13.8 tons, respectively, which are increased by 25%, 23%, and 22% comparing with a check hybrid, Suwon 19. The percent ear among total dry matters is 43.3%.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.15-23
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• 1979

In the first paper of the series the five soil fertility factors were evaluated by means of principal component analysis and varimax method. They are interpreted as representing, 1) skeletal available phosporus status, 2) organnic matter status, 3) salt status 4) base status, and 5) free oxide status. In order to resynthesize such fragmented information for the overall soil fertility evaluation, the method of multiple regression analysis was adopted, using the five factor scores and yield data for Korean paddy soils as independent and dependent variables respectively. As test of linear models with different combinations of independent variables the results of t-test of regression coefficient were revealed that the organic matter status (FII) has no relevance to the yield of paddy and that the free oxides and salt supply has by it self only an insignificant contribution to the yield. The multiple correlation coefficient (R) revealed its multiple regression analysis was as low as 0.43. Introduction of quadratic terms to the linear model bettered the result. Thus multiple correlation coefficient (R) was increased as 0.59. Therefore, a coefficient of determination 0.35 was obtained by a quadratic model with interaction terms among the five fertility constituents. Generally we think that the fertility factor has more contribution to raise the rice yield in paddy and that the failure of yield prediction by fertility factor scores was caused by one of follows; 1) the roughness of the yield inspection, and 2) missextraction of fertility constituents. The second step in this study, assuming that the residuals by multiple regression analysis were due to factors other than soil fertility, we can now proceed to predicting the yield from the field characters with the classified fertility groups by means of Hayashi's theory of quantification No. 1. Such variables as fertility groups (FTYG), water availability (WATER), soil drainage (DRNG), climatic zone (CLIZ), surface soil's stickiness (STCKT), surface soil's dry consistence (DCNST), and surface soil's texture (FTEXT) are taken up as the explanatory variables. The quantification appears reasonable; the well to extremely well in soil drainage, very sticky of surface soil, inefficiency in water availability, coarse texture, and very hard to extremely hard dry consistence in soil are detrimental to the rice yield. The R was as high as 0.90 for the set of variables. But the given explanatory variables in this study were not quite effective in explaining rice yield. The method developed seems to be promising only if properly collected data are available. Conditions that should be satisfied in the yield inspection obtained from common cultivator for the purpose of deriving a prediction equation were put forward.

• Journal of the Korean Wood Science and Technology
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• v.12 no.4
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• pp.19-30
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• 1984

This experiment was carried out to investigate the effects of autohydrolysis and extraction conditions on the separation of the chemical substances, the extractability of lignin by dioxane, and the yield of reducing sugars from cellulosic substrates by using a commercial cellulase derived from Trichoderma viride. Air-dried wood meals through 0.42mm (40 mesh) screen and retained on 0.25 mm (60 mesh) of Populus alba-glandulosa and Pinus koraiensis were autohydrolyzed with water at $180^{\circ}C$ for 30 and/or 60 minutes in a 6 liter stainless-steel digester with or without 2% 2-naphthol. The hydrothermally-treated wood meals were extracted the lignin with 100%, 90%, 75% and 50% dioxane solutions at $70^{\circ}C$ for 4 hours, respectively. The results obtained were as follows; 1) After autohydrolysis of Populus alba-glandulosa, the yield of wood meals decreased with lengthening the auto hydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. In case of Pinus koraiensis, the yield was not affected by 2%, 2-naphthol addition at the autohydrolysis in the digester. 2) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the yield of wood meals decreased with lengthening the autohydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. Extraction of 50% dioxane solution was the best solvent for the yield among the solutions of 100%, 90%. 75% and 50% dioxane. In case of Pinus koraiensis, the yield was not affected by 2% 2-naphthol addition and the solution of 90% dioxane was the poorest solvent for the yield. 3) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the Klason lignin content in cellulosic substrates for enzymatic hydrolysis decreased with lengthening the autohydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. Klason lignin content was the lowest after extraction by 90% or 75% dioxane solution. The content was also affected by interaction of the three factors-autohydrolysis time, 2% 2-naphthol addition and concentration of dioxane. In case of Pinus koraiensis, the Klason lignin content increased with 2% 2-naphthol addition but was not affected by the concentration of dioxane solution. 4) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the extractable Klason lignin content by extraction increased with lengthening the auto hydrolysis time from 30 minutes to 60 minutes and with 2% 2-naphthol addition. The extractable lignin content was the highest after extraction by 90% or 75% dioxane solution. In case of Pinus koraiensis, the extractable lignin content increased with 2% 2-naphthol addition. Extractions by 100%, 90% and 50% dioxane solutions were more effective for the extraction of Klason lignin than by 75% dioxane solution. 5) After autohydrolysis and lignin extraction of Populus alba-glandulosa, the yield of reducing sugars increased with lengthening the autohydrolysis time from 30 minutes to 60 minutes but was not affected by 2% 2-naphthol addition and the concentration of dioxane. The yield of reducing sugars after enzymatic hydrolysis was slightly higher by extractions with 90%, 75% and 50% dioxane solutions than with 100% dioxane. In case of Pinus koraiensis, the yield of reducing sugars was not affected by 2% 2-naphthol addition but affected by the concentration of dioxane. The yield of reducing sugars was the highest in cellulosic substrates extracted by 100% dioxane solution.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.111-123
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• 1975

6 years data on the plant growth and grain yield of 13 rice varieties were investigated to define the relations between meteological conditions and plant growth of rice including grain yield. The results obtained are summarized as follows; 1. Variation of average temperature by years showed great number at early and middle July, middle August and early November, however smallest figure at late June and late July. And that of sunshine hours by years were least at late June and late July, and largest at middle July. 2. Among rice yield components variation of panicle number per hill by years was biggest and that of 1000 grain weight least. Rate of variation of plant growth and rice yield was different by rice varieties. 3. Direct effects on rice yield was greatest at maturing ratio and next at 1000 grain weight. The effects of yield factor on the rice yield wers different by years. 4. Higher temperature and longer sunshine delayed the miaxmum tillering stage but shortened the days from seeding to heading. 5. A significant negative correlation was recognized between the number of panicles per hill and average temperature of 11 to 40 days after transplanting, and number of grains per panicle was correlated with the average temperature of 11 to 70 days after transplanting. High temperature before heading time showed atime decreased maturing ratio. 6. Accumulated temperature was highly correlated with 1000 grain weight in all season. Highest positive correltaion was recognized between grain yield of rice and average temperature of 61 to 70 days after transplanting but correlations between rice yield and average temperature after heading stage were negative. 7. Highly significant correlations were confirmed between maturing ratio and sunshine hours of 31 to 50 days as well as 61 to 70 days after transplanting, and maturing ratio was highly correlated with accumulated hours of sunshine. Correlation between rice yield and hours of sunshine was significant at 51 to 60 days after transplanting.

• Polymer(Korea)
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• v.32 no.4
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• pp.295-304
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• 2008

This study examined the oxidative polycondensation reaction of 2-[(pyridin-4-yl-) methyleneamino] pyridine-3-ol (2-PMAP) using air $O_2$ and NaOCl oxidants at various temperatures and times in aqueous alkaline and acidic media. Under these reactions, the optimum reaction conditions using air $O_2$ and NaOCl oxidants were determined for 2-PMAP. The number-average molecular weight ($M_n$), weight average molecular weight ($M_w$), and polydispersity index (PDI) values of O-2-PMAP synthesized in aqueous alkaline media were found to be 960, 1230, and $1.281\;g\;mol^{-1}$ using NaOCl, and 1030, 1520, and $1.476\;g\;mol^{-1}$ using air $O_2$, respectively. At the optimum reaction conditions, the yield of O-2-PMAP in aqueous alkaline media was 92.50% and 85.70% for air $O_2$ and NaOCl oxidants, respectively. The yield of O-2-PMAP in aqueous acidic media was 88.5% and 88.0% for NaOCl and air $O_2$ oxidants, respectively. O-2-PMAP was characterized by $^1H-$, $^{13}C$-NMR, FT-IR, UV-vis, SEC, and elemental analysis. TGA-DTA analysis revealed O-2-PMAP and its oligomer metal complex compounds, such as $Co^{+2}$, $Ni^{+2}$, and $Cu^{+2}$, to be stable against thermal decomposition and their weight losses at $1000^{\circ}C$ were found to be 73.0, 58.0, 53.5%, and 50.0%, respectively. In addition, the antimicrobial activities of the monomer and oligomer were tested against E. Coli (ATCC 25922), E. Faecelis (ATCC 29212), P. Auroginasa (ATCC 27853), and S. Aureus (ATCC 25923).

• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.70-74
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• 2016

In this study, the effects of citrate buffer pretreatment conditions (solid-to-liquid ratio, reaction temperature, pH and concentration of buffer) on enzymatic hydrolysis of E. intestinalis for total reducing sugar (TRS) production were investigated. As a results of the citrate buffer pretreatment, a 5.40% hydrolysis yield was obtained under conditions including 1:10 solid-to-liquid ratio, 0.25 M citrate buffer (pH 3.5) at $140^{\circ}C$ for 60 min. The maximum hydrolysis yield of 18.68% was obtained to enzymatic hydrolysis after pretreatment. This result is 1.81 times higher than that of control.