• Fashion & Textile Research Journal
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• v.21 no.4
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• pp.509-514
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• 2019

Cotton fabrics were treated with gelatin to enhance dyeability and color strength when using Caesalpinia sappan dye. Gelatin was used as the protein and a pad-dry- cure method was used for the treatment process (2, 4, 6, 8, 10, 12, 14g/l concentration). Pretreated fabrics were mordanted with 10% alum. Fabrics were then dyed with freeze-dried sappan wood water extract powder form. Dyed samples were assessed in regards to dyeing behavior and color fastness. Comparing untreated and gelatin treated samples from the SEM images indicated that the Gelatin treatment (10g/l) resulted in an enhanced surface roughness that was relative to that of untreated cotton. Padding cotton with gelatin at 6g/l concentration afforded dyed fabrics with a 2 times increase in the K/S value over that of untreated fabrics. All dyed samples were red color with a significant enhancement in the sample color strength (K/S) being observed for pretreated samples. pH values favor dye absorption with pH 7 yielding the highest color strength. Dyeing at an elevated temperature resulted in a lower color strength and reddish-dull color. Longer dyeing times created greater color strengths for untreated and gelatin treated cotton. Increased dye concentrations resulted in higher K/S values for both gelatin treated and untreated cotton. As for color fastness, gelatin treated and untreated cotton fabrics dyed with sappan wood extract showed a relatively low rating in washing fastness (color change 1 rating), light fastness (1 rating), and rubbing fastness (wet:1-2, dry:3-4 rating).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.475-482
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• 2019

Over 3,200 large baleen whales including 3,173 fin whales, 7 blue whales and 28 humpback whales were hunted by Japanese whaling companies in the Yellow Sea during Japanese colonial period (1916~1944). As a result, these large baleen whales are under the endangered state in the Yellow Sea. The Yellow Sea had good living conditions for large baleen whales in the water temperature ($4{\sim}26^{\circ}C$) and food supply. The whaling on the large baleen whales was carried out mainly from early winter to late spring. The possibility of large scale whaling was caused by the migration of these baleen whales from other areas for the feeding on abundances of Euphausia pacifica in the surface layer during these seasons. During summer and autumn season, the baleen whales moved to other areas (good feeding ground as Woolsan offshore waters), because Euphausia pacifica stayed below the strong themocline which was formed from June to October in the Yellow Sea.

• Ocean and Polar Research
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• v.41 no.3
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• pp.159-168
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• 2019

Understanding the interaction between climate and the water cycle is critical especially in a drought sensitive region such as California. This study explored hydrologic changes in central and southern California in relation to the glacial-interglacial climate cycles over the last 30 thousand years. To do this, we reconstructed paleovegetation using plant wax carbon isotopic compositions (${\delta}^{13}C$) preserved in marine sediment cores retrieved from the central California continental shelf (ODP Site 1018) and Santa Barbara Basin (ODP Site 893A). The results were then compared to the existing sea surface temperature (SST) and pollen records from the same cores to understand terrestrial hydrology in relation to oceanographic processes. The Last Glacial was generally dry both in central and southern California, indicated by grassland expansion, confirming the previously suggested notion that the westerly storm track that supplies the majority of the precipitation in California may not have moved southward during the glacial period. Southern California was drier than central California during the Last Glacial Maximum (LGM). This drying trend may have been associated with the weakening of the California Current and northerly winds leading to the early increase in SST in southern California and decline in both offshore and coastal upwelling. The climate was wetter during the Holocene in both regions compared to the glacial period and forest coverage increased accordingly. We attribute this wetter condition to the precipitation contribution increase from the tropics. Overall, we found a clear synchronicity between the terrestrial and marine environment which showed that the terrestrial vegetation composition in California is greatly affected by not only the global climate states but also regional oceanographic and atmospheric conditions that regulate the timing and amount of precipitation over California.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.3
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• pp.436-442
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• 2022

In this paper, the performance of the selective combining according to the channel selection decision method of frequency diversity is evaluated in the underwater frequency selective channel. The underwater acoustic channel in the shallow sea has a complex multipath characteristic by combining various environmental factors such as boundary surface reflection and sound wave refraction according to the water temperature layer. In particular, frequency selectivity due to multipath causes energy fluctuation in a communication channel, which reduces SNR (Signal to Noise Ratio) and deteriorates communication performance. In this paper, we applied the frequency diversity technique using multiple channels to secure the communication performance according to the frequency selectivity by multipath. For each channel, 4-FSK (Frequency Shift Keying) and selective combining were applied, the performance was evaluated by applying the maximum value, average value, and majority decision of the signal in order to decide the demodulation channel selection of the selective combining.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.65-71
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• 2023

Cesium discharged from nuclear power plants requires technology for safely treating, due to its harmfulness to the human body. In this work, activated carbon impregnated with triethylenediamine (TEDA) process was applied to effectively remove cesium dissolved in aqueous solution. The surfaces on the activated carbon were chemically modified with various TEDA concentrations (2.5, 5.0, 7.5, 10.0, and 12.5%) and the optimal TEDA concentration was obtained to be 5.0% by the assessment for cesium removal efficiency. In addition, when 5.0% TEDA-impregnated activated carbon was used to treat 5.0 and 10.0 mg/L of cesium, the removal efficiency was 71.5% and 61.1%, respectively. Also, it was found to be the chemical adsorption from the adsorption kinetics experiment by temperature change. A novel remediation technology developed in this study could be practically employed for removing cesium contained in surface and ground water.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.707-716
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• 2023

The influence of waste technological waters of thermal and fast reactors of Beloyarsk NPP (Russia) on the accumulation of ⁶⁰Co, ⁹⁰Sr and ¹³⁷Cs in macrophytes and ichthyofauna of the cooling pond has been studied. Critical radionuclides, routes of their entry into the ecosystem and periods of maximum discharge of radioisotopes into the cooling pond have been determined. It is shown that the technology of electricity generation at the Beloyarsk NPP, based on fast reactors, has a much smaller effect on the release of artificial radionuclides into the environment. Therefore, during the entire period of monitoring studies (1976-2019), the decrease in the specific activity of radionuclides of NPP origin in macrophytes was 13-25800 times, in ichthyofauna 1.5-44.5 times. The maximum discharge of artificial radionuclides into the Beloyarsk reservoir was noted during the period of restoration and decontamination work aimed at eliminating the emergencies at the AMB reactors of NPP. The factors influencing the accumulation of artificial radionuclides in the components of the freshwater ecosystem of the Beloyarsk cooling pond have been determined, including: the physicochemical nature of radioisotopes, their concentration in surface water, the temperature of the aquatic environment, the trophicity of the reservoir, the species of hydrobionts.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.601-609
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• 2022

In August 2007, coastal upwelling occurred off the east coast of Korea, and vertical water temperature and salinity data were obtained from a real-time surface ocean buoy. Based on the time series observation data, a vertical sound velocity structure was calculated before, during, and after the occurrence of the coastal upwelling, and how the coastal upwelling affects the sound propagation and detection environment through acoustic modeling considering the horizontal scale and actual seabed topography. As a result of comparing and analyzing the low-frequency (500 Hz) sound transmission loss and the target detection range by depth using the parabolic equation model, it was analyzed that if coastal upwelling occurs, a detection gain of up to about 10 dB can be expected. In addition, through this study, it was confirmed that the characteristics of sound propagation can be greatly changed even in a short period of about 2 to 3 days before and after coastal upwelling.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.535-548
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• 2023

The intermittent nature of renewable energy is a challenge to overcome for safety and stable performance in water electrolysis systems linked to renewable energy. Oxygen removal using the catalyst is suitable for maintaining the oxygen concentration in hydrogen below the explosive level (4%) even in intermittent power supply. Metals such as Pd, Pt, and Ni are expected to be effective materials due to their hydrogen affinity. The oxygen removal performance was compared under high hydrogen concentration conditions by loading on γ-Al₂O₃ with high reactivity and large surface area. The characteristics of the catalyst before and after the reaction were analyzed through X-ray diffraction, transmission electron microscope, H₂-temperature programmed reduction, X-ray photoelectron spectroscope, etc. The Pd catalyst that showed the best performance was able to lower 2% oxygen to less than 5 ppm. Changes in catalyst characteristics after the reaction indicate that oxygen vacancies are related to oxygen removal performance and catalyst deactivation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.11 no.4
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• pp.1775-1782
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• 1969

The results of the study on the consumptine use of irrigated water in paddy fields during the growing season of rice plants are summarized as follows. 1. Transpiration and evaporation from water surface. 1) Amount of transpiration of rice plant increases gradually after transplantation and suddenly increases in the head swelling period and reaches the peak between the end of the head swelling poriod and early period of heading and flowering. (the sixth period for early maturing variety, the seventh period for medium or late maturing varieties), then it decreases gradually after that, for early, medium and late maturing varieties. 2) In the transpiration of rice plants there is hardly any difference among varieties up to the fifth period, but the early maturing variety is the most vigorous in the sixth period, and the late maturing variety is more vigorous than others continuously after the seventh period. 3) The amount of transpiration of the sixth period for early maturing variety of the seventh period for medium and late maturing variety in which transpiration is the most vigorous, is 15% or 16% of the total amount of transpiration through all periods. 4) Transpiration of rice plants must be determined by using transpiration intensity as the standard coefficient of computation of amount of transpiration, because it originates in the physiological action.(Table 7) 5) Transpiration ratio of rice plants is approximately 450 to 480 6) Equations which are able to compute amount of transpiration of each variety up th the heading-flowering peried, in which the amount of transpiration of rice plants is the maximum in this study are as follows: Early maturing variety ; Y=0.658+1.088X Medium maturing variety ; Y=0.780+1.050X Late maturing variety ; Y=0.646+1.091X Y=amount of transpiration ; X=number of period. 7) As we know from figure 1 and 2, correlation between the amount evaporation from water surface in paddy fields and amount of transpiration shows high negative. 8) It is possible to calculate the amount of evaporation from the water surface in the paddy field for varieties used in this study on the base of ratio of it to amount of evaporation by atmometer(Table 11) and Table 10. Also the amount of evaporation from the water surface in the paddy field is to be computed by the following equations until the period in which it is the minimum quantity the sixth period for early maturing variety and the seventh period for medium or late maturing varieties. Early maturing variety ; Y=4.67-0.58X Medium maturing variety ; Y=4.70-0.59X Late maturing variety ; Y=4.71-0.59X Y=amount of evaporation from water surface in the paddy field X=number of period. 9) Changes in the amount of evapo-transpiration of each growing period have the same tendency as transpiration, and the maximum quantity of early maturing variety is in the sixth period and medium or late maturing varieties are in the seventh period. 10) The amount of evapo-transpiration can be calculated on the base of the evapo-transpiration intensity (Table 14) and Tablet 12, for varieties used in this study. Also, it is possible to compute it according to the following equations with in the period of maximum quantity. Early maturing variety ; Y=5.36+0.503X Medium maturing variety ; Y=5.41+0.456X Late maturing variety ; Y=5.80+0.494X Y=amount of evapo-transpiration. X=number of period. 11) Ratios of the total amount of evapo-transpiration to the total amount of evaporation by atmometer through all growing periods, are 1.23 for early maturing variety, 1.25 for medium maturing variety, 1.27 for late maturing variety, respectively. 12) Only air temperature shows high correlation in relation between amount of evapo-transpiration and climatic conditions from the viewpoint of Korean climatic conditions through all growing periods of rice plants. 2. Amount of percolation 1) The amount of percolation for computation of planning water requirment ought to depend on water holding dates. 3. Available rainfall 1) The available rainfall and its coefficient of each period during the growing season of paddy fields are shown in Table 8. 2) The ratio (available coefficient) of available rainfall to the amount of rainfall during the growing season of paddy fields seems to be from 65% to 75% as the standard in Korea. 3) Available rainfall during the growing season of paddy fields in the common year is estimated to be about 550 millimeters. 4. Effects to be influenced upon percolation by transpiration of rice plants. 1) The stronger absorbtive action is, the more the amount of percolation decreases, because absorbtive action of rice plant roots influence upon percolation(Table 21, Table 22) 2) In case of planting of rice plants, there are several entirely different changes in the amount of percolation in the forenoon, at night and in the afternoon during the growing season, that is, is the morning and at night, the amount of percolation increases gradually after transplantation to the peak in the end of July or the early part of August (wast or soil temperature is the highest), and it decreases gradually after that, neverthless, in the afternoon, it decreases gradually after transplantation to be at the minimum in the middle of August, and it increases gradually after that. 3) In spite of the increasing amount of transpiration, the amount of daytime percolation decreases gadually after transplantation and appears to suddenly decrease about head swelling dates or heading-flowering period, but it begins to increase suddenly at the end of August again. 4) Changs of amount of percolation during all growing periods show some variable phenomena, that is, amount of percolation decreases after the end of July, and it increases in end August again, also it decreases after that once more. This phenomena may be influenced complexly from water or soil temperature(night time and forenoon) as absorbtive action of rice plant roots. 5) Correlation between the amount of daytime percolation and the amount of transpiration shows high negative, amount of night percolation is influenced by water or soil temperature, but there is little no influence by transpiration. It is estimated that the amount of a daily percolation is more influenced by of other causes than transpiration. 6) Correlation between the amount of night percoe, lation and water or soil temp tureshows high positive, but there is not any correlation between the amount of forenoon percolation or afternoon percolation and water of soil temperature. 7) There is high positive correlation which is r=+0.8382 between the amount of daily percolation of planting pot of rice plant and amount and amount of daily percolation of non-planting pot. 8) The total amount of percolation through all growin. periods of rice plants may be influenced more from specific permeability of soil, water of soil temperature, and otheres than transpiration of rice plants.

• Ocean and Polar Research
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• v.42 no.3
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• pp.233-247
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• 2020

This study was carried out at 5 sites 11 times over two years to identify the variation of benthic environments and benthic polychaetous community and analyze the benthic healthiness in Dangdong Bay, a small semi-enclosed inner bay of Jinhae Bay. The temperature of bottom water showed the typical temporal fluctuation of a temperate zone and was in the range of 5.94 ~ 23.94℃. The salinity did not change significantly during the study period and was in the range of 32.93 ~ 35.72 psu. The concentration of dissolved oxygen of bottom water fluctuated a great deal and was in the range of 0.31 ~ 10.20 mg/L. The lowest DO value was recorded in July 2015, as 0.31±0.04 mg/L corresponding to the hypoxic water mass. The hypoxic water mass was formed continuously at some sites also in July and August 2016. The mean grain size was in the range of 7.57 ~ 9.81Ø and the average was 8.89±0.20Ø. The surface sediments were mainly composed of fine sediment (mud) above 85%. The mean of TOC was 3.09±0.22% and LOI was 13.30±0.47%, showing very high levels in Korean coastal waters. The concentration of AVS was in the range of 0.33 ~ 1.28 mgS/g-dry. The high values of organic contents and AVS indicated that there had been the serious organic enrichment in Dangdong Bay. The number of species and the density of the benthic polychaetous community in Dangdong Bay were in the range of 2 ~ 38 species and 2 ~ 2,185 ind./㎡ during the study period. The number of species and density were highly sustained in winter and spring, and then decreased gradually with the formation of a hypoxic water mass in summer, and the lowest number of species and density were recorded in autumn. In September and November 2015, the dead zone expanded to almost the whole study area. Dominant polychaetous species were Capitella capitata, Lumbrineris longifolia, Paraprionospio patiens and Sigambra tentaculata, each known as opportunistic species and potential organic pollutant indicator species. In particular, Paraprionospio patiens showed a very high population density of 2,019 ind./㎡ in December 2016. Polychaetous communities at each sampling time were classified into 4 temporal groups according to dominant species in each period by cluster analysis and nMDS. 'Period Group AI' was formed in winter and spring of 2015, dominated by Capitella capitata, 'Period AII' in summer dominated by Lumbrineris longifolia, 'Period B' in autumn with no fauna in the dead zone, and particularly 'Period C' in winter of 2016 dominated by Paraprionospio patiens. As a result of analysis of benthic healthiness, the study area was estimated to be in a Fair~Very Poor condition by AMBI and in a Poor~Very Poor condition by BPI during the study period. Both AMBI and BPI showed that the study area was in a Very Poor condition in September and November 2015, and when the dead zone occurred. In Dongdong Bay, the fact that the formation of a hypoxic water mass occurred in summer and a dead zone in autumn were confirmed. In addition, the dominance of opportunistic and organic pollutant indicator species was also observed clearly. The benthic healthiness indexes such as AMBI and BPI showed that organic enrichment was serious in Dangdong Bay.