• Clean Technology
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• v.13 no.2
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• pp.109-114
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• 2007

In this study, we performed basic researches to develop wet purification system for improving air qualities of ventilation in semiconductor manufacturing process. Using 0.5 M aqueous solution of $KMnO_4$, 50 ppm of $NH_3$, SOx and NOx were reduced to 99% successfully. However, the removal of $O_3$ was limited to $22{\sim}30%$ for all the tested chemical solutionsincluding $KMnO_4$. Therefore, adoption of a dry ozone filter is necessary to reduce $O_3$ below a satisfactory level. For all the chemical solutions tested, NOx removal efficiency increased as NOx was mixed with $O_3$. As chemical solution was sprayed using water spraying system equipped with air atomizing type nozzle, the removal efficiencies of gaseous pollutants increased due to the increase of gas-liquid interfacial area.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.679-686
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• 2014

In this research, the mix proportion of the antiwashout underwater concrete with the mineral admixture was evaluated. It can reduce the amount used of the antiwashout admixture (hereinafter referred to as "AWA") and satisfy the properties of concrete. In addition, the review for the difference of the test and practical affairs were conducted. Optimized unit quantity of water of antiwashout underwater concrete and the amount used of AWA was revealed by $190kg/m^3$, 0.9%/W, respectively. In particularly, the mix design is reduced by 5% than the W/B of target strength even though the W and AWA reduced. Therefore, it will have the economical feasibility and qualities including the material separation, resistance characteristic and compressive strength, and etc. The stable value was shown in 1 point of minute passed in the measurement of the turbidity amounts using the turbidimeter after the checker insertion. However, it needs to be reviewed for the interrelationship between turbidity measuring machine and KCI-AD102 standard method. There were no significant differences of compressive strength of specimens in the water depending on the production methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.382-387
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• 2008

This study was conducted to determine the effect of rice bran on rice yield, grain quality and weeds control depending on applying times. The redox potential was severely reduced $4{\sim}7$ days after rice bran application but that of conventional practice was reduced 17 days after transplanting. During the decomposing of the rice bran in the water, the dissolved oxygen in the water was exhausted right away after rice bran application. The dry weight of weed increased as the rice bran application time was delayed that weed dry weights increased by 138% in applying before puddling (ABP), 219% in 5 DAT (days after transplanting), 300% in 7 DAT and 619% in 9 DAT compared to conventional practice. The rice yield reduced remarkably in rice bran treatments after transplanting compared to conventional practice and applying before puddling. In the rice quality, the head rice ratio in the rice bran treatment was higher than that in conventional practice, and its protein content decreased. The results confirm that the rice bran application make the rice palatability higher, but there was no difference in rice qualities depending on application times.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.16-25
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• 2014

To identify distribution of epilithic diatom assemblages and the relationship between diatoms and water chemistry, samples were collected twice a year from 2008 to 2012, from at 6 streams in Jeju Island, South Korea. A total of 171 diatom taxa were identified, and Achnanthes lanceolata, Gomphonema pumilum, Melosira varians, Navicula minima and Nitzschia palea were dominantly observed. BOD ranged 0.0~1.6 mg $L^{-1}$, TN 0.230~13.240 mg $L^{-1}$ (average 4.432 mg $L^{-1}$), TP 0.020~0.316 mg $L^{-1}$ (average 0.092 mg $L^{-1}$), and N/P rate ranged 2.5~178.5. Average of epilithic algal chlorophyll-a and AFDM were 1.1 ${\mu}gcm^{-2}$ and 0.6 mg $cm^{-2}$, respectively. According to BOD standard, the water qualities of study area sites were at 'Good' level. However, the healthiness levels assessed from DAIpo and TDI were 'Fair' to 'Poor'.

• Membrane Journal
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• v.31 no.2
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• pp.87-100
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• 2021

With a striking increase in the level of contamination and subsequent degradations in the environment, detection and monitoring of contaminants in various sites has become a crucial mission in current society. In this review, we have summarized the current research areas in membrane-based colorimetric sensors for trace detection of various molecules. The researches covered in this summary utilize membranes composed of cellulose fibers as sensing platforms and metal nanoparticles or fluorophores as optical reagents. Displaying decent or excellent sensitivity, most of the developed sensors achieve a significant selectivity in the presence of interfering ions. The physical and chemical properties of cellulose membrane platforms can be customized by changing the synthesis method or type of optical reagent used, allowing a wide range of applications possible. Membrane-based sensors are also portable and have great mechanical properties, which enable on-site detection of contaminants. With such superior qualities, membrane-based sensors examined in the researches were used for versatile purposes including quantification of heavy metals in drinking water, trace detection of toxic antibiotics and heavy metals in environmental water samples. Some of the sensors exhibited additional features like antimicrobial ability and recyclability. Lastly, while most of the sensors aimed for a detection enabled by naked eyes through rapid colour change, many of them investigated further detection methods like fluorescence, UV-vis spectroscopy, and RGB colour intensity.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.721-733
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• 2019

Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.827-835
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• 2022

Commercial boiled frozen ark shell Scapharca subcrenata (BFAS) is generally used as a seasoned seafood products. One problem facing the industry is that quality decreases during thawing. This study investigated ways to improve quality and shelf-stability of BFAS for use as a non-thermally prepared seasoned seafood products. The Viable bacteria were detected in BFAS after thawing under running water, but were not detected after blanching for over 2 min at 95±5℃. Blanching and dewatering times were optimized by response surface methodology (RSM) to reduce the initial number of bacteria and improve BFAS texture. Experimental design was deemed appropriate because no significant difference (P>0.05) was observed between predicted and actual moisture content, hardness, and overall acceptance values. Optimal blanching and dewatering times were 210 s and 80 s, respectively. Optimized blanching and dewatering processes can significantly improve safety and BAFS qualities including texture. These results indicate that BFAS demand as a staple for home meal replacements can be increased by application of optimized blanching and dewatering processes, especially in Korean seafood processing companies where running water thawing is common.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2191-2205
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• 1971

In this research, Nong-rim No. 6 was adopted as a test variety of rice. Rice seedlings were transplanted on June 14, 1970. Roots were settled into soil on June 20 and a total number of days irrigated of $21cm{\times}21cm$ and an area of $9.9m^2$ for a test plot were accepted, planting 70 stumps of rice in a test plot. The soil in test plots are classified by soil test as oam, and its chemical contents are as shown in Table 3. Irrigation water was secured by pumping from the Sudun stream that originates at the Suho reservoir. Accordingly, the qualities of irrigation. water are considered to be the same as those of water stored in the Suho reservoir. There were 54 days of intermittent rainfalls in total during the whole 110-day period of irrigation. As a result, it is likely that the growth of rice plants was influenced by rainfall at a comparatively great degree. In order to measure the amounts of water consumption, infiltrometers, measuring devices for the decreases of water depths and lycimeters were provided. As a result of measurements, an average daily rate of infiltration was observed to be 14mm/day. It is expected from this research that the effect of increased yield will be secured by supplying optimum amounts of water for irrigation on proper times, and that the amounts of water consumption for irrigation can be saved by applying suitable irrigation methods. The test results obtained are summarized as follows: 1. Yields produced in the test plots of continuous irrigation are lower than those in the test plots of rotational irrigation, i.e., yields produced at the test plots irrigatied once in a period of 8 days are higher by 27% in average than those produced at test plots of continuous irrigation. 2. The amounts of irrigation water for test plots, which have a clay layer of 9cm in thickness and vynil diaphragm without holes, are saved by about 52% in comparison with ordinary test plots. 3. Ears are sprouted 5 days earlier at continuous irrigation plots as compared with other test plots. 4. It seems that there are growing stages of rice plants such as those of forming and sprouting of ears, in which the amounts of irrigation water are consumed more in comparison with the other stages. Therefore, it may be possible to increase of decrease the amount of irrigation water, according to the growing stage of rice plant, so as to save irrigation water.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.324-332
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• 2014

In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.7-13
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• 1990

The water environmental characters of the Nakdong River, Geumho River and Sin Stream, both before-flood (Aug. 24) and after-flood (Sept. 8), have been compared, and their effects on the growth of Spirodela polyrhiza Shleiden have been examined. Before the flood, the concentrations of most of the chemical components of the Geumho River were similar to those of the Sin Stream; (COD, 19.6~21.4; alkalinity, 177~183; $NH_4\;^+$, 20.7~24.4; $NO_3\;^-$, 3.9~4.3; $PO_\;4^{3-}$, 3.4~3.7; $Mg^{2+}$, 42; $Ca^{2+}$, 68.5~69.7; $Cl^-$, 90~92; $SiO_2$, 10.4~11.2; , 11~32; LAS, 3.0~3.8; , 0.007~0.010ppm) but much higher than those of the Nakdong River (30~40 fold for $NH_4\;^+$, , $PO_\;4^{3-}$ and LAS, and 2~5 fold for COD, alkalinity, $NO_3\;^-$, $Mg^{2+}$, Cl- and ). Especially in the Geumho River, Secchi disk transparency was very low (17cm) and DO was not detected. The flood caused significant increases in some chemical components: $NH_4\;^+$, 1.0;$NO_3\;^-$, 9.6; , 12.8 and , 5.4 ppm in the Nakdong River; DO, 1.0; $NO_2\;^-$, 0.92; $NO_3\;^-$, 22.2 and $SiO_2$, 17.6ppm in the Geumho River; DO, 3.0; $NO_2\;^-$, 1.4; $NO_3\;^-$, 22.2; SiO2$SiO_2$, 19.2 and , 25.0ppm in the Sin Stream. General species diversity index (H) of phytoplankton community in the Nakdong River, Geumho River and Sin Stream before flood was 3.1, 2.7 and 1.6, respectively. After the flood, the phytoplankton growth was highly sparse in each river water, hence indices have no significance. The growth of S. polyrhiza was enhanced in Geumho River water (max. RGR=26%/day), while it ceased within 7days in Nakdong River water.