• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.459-468
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• 1986

This study was attempted to process low-sodium salt fermented small shrimp as substitutes for traditional high-sodium salt fermented one which has widely been favored and consumed in Korea. Low-salt fermented small shrimp was prepared with $4\%$ sodium chloride and $4\%$ potassium chloride, and various additives such as $0.5\%$ lactic acid, $6\%$ sorbitol and $4\%$ ethylalcohol extract of red pepper as preservatives and flavor enhancers. And the changes of taste compounds, volatile compounds and fatty acid composition in low-salt fermented small shrimp were analyzed and compared with those of conventional $20\%$ sodium salt fermented one during the fermentation of 120 days at $25{\pm}3^{\circ}C$. The most favorable taste for fermented small shrimp were reached at 60 days of fermentation. Judging from sensory evaluation, little difference of taste was detected between the low-salt fermented small shrimp and high-sodium salt fermented one. The principal taste compounds in fermented small shrimp were free amino acids, and betaine and nucleotides and their related compounds played an assistant role. The major amino acids in fermented small shrimp were glutamic acid, leucine, proline, glycine, lysine and aspartic acid. The major fatty acids in fermented small shrimp samples were 16:0, 20:5, 22:6, 16:1 and 18:1, and unsaturated fatty acids decreased slightly while saturated fatty acids increased during fermentation. At 60 days of fermentation 8 kinds of volatile fatty acids (acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isocarproic acid, carproic acid), 6 kinds of carbonyl compounds (ethanal, propanal, 2-methylpropanal, 3-methylbutanal, pentanal, 2-methylpentanal), and 3 kinds of volatile amines (methylamine, trimethylamine, isopropylamine) were identified.

• Journal of Life Science
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• v.19 no.10
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• pp.1417-1423
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• 2009

Previous studies have suggested that docosahexaenoic acid (DHA) supplementation into n-3 fatty acid deficient diet improved spatial learning performance, but there was no significant difference in brain related function when DHA was added into a n-3 fatty acid adequate diet. Here, we investigated the effect of adding DHA into an n-3 fatty acid deficient or adequate diet on brain and liver fatty acid composition. On the second day after conception, Sprague Dawley strain dams were divided into four groups as follows; n-3 fatty acid deficient (Def), n-3 fatty acid deficient plus DHA (Def+DHA, 10.2% DHA), n-3 fatty acid adequate (Adq, 3.4% linolenic acid), and n-3 fatty acid adequate plus DHA (Adq+DHA, 3.31% linolenic acid plus 9.65% DHA). After weaning, male pups were fed on the same diets of their respective dams until adulthood. In brain fatty acid composition, the Def group showed a lower brain DHA (64% decrease), which was largely compensated for by an increase in docosapentaenoic acid (22:5n-6). Brain DHA in the Def+DHA group was increased to almost the same extent as in the Adq and Adq+DHA groups and there were no significant differences among them. Liver fatty acid composition showed a similar pattern to that of the brain, but liver DHA in the Def+DHA showed the highest percentage among the diet groups. In conclusion, n-3 fatty acid deficiency from gestation to adulthood leads to decreased brain DHA, which has been shown to be highly associated with poor spatial leaning performance. Thus, adequate brain DHA levels are required for optimal nervous function.

• Journal of the Mineralogical Society of Korea
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• v.15 no.2
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• pp.104-113
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• 2002

The sorption of Cd$^{2+}$ on calcite was studied in aqueous solutions of several electrolytes. The Cd$^{2+}$ concentration, 10$^{-8}$ M, was kept well below saturation with respect to CdCO$_3$(s). Sorption behavior of Cd$^{2+}$ in different ionic strengths of NaClO$_4$solutions shows that sorption is independent of ionic strength. This result suggests that Cd$^{2+}$ sorption on calcite surface is of a specific nature, and adsorption is controlled by an inner-sphere type of surface complex. Two stages in the sorption behavior could be identified: an initial rapid uptake, followed by slower uptake reaching a maximum steady state by 145 hrs. No evidence was observed for surface precipitation, although it can not be entirely ruled out. Desorption of Cd$^{2+}$ from the calcite surface after resuspension into Cd-free solution is initially very rapid, but depends partly on the previous sorption history. Desorption behavior of Cd$^{2+}$ show that an initial rapid desorption followed either by slow uptake reaching a maximum, as in the adsorption experiments, or slowing desorption to reach a steady state minimum. This irreversible behavior of Cd$^{2+}$ sorption and desorption may act as one of the controls for regulating the mobility of dissolved Cd$^{2+}$ natural aqueous systems. Calculated adsorption partition coefficients suggest that overall sorption and desorption process in the concentration range are controlled by d single mechanism.ingle mechanism.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.636-642
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• 2013

In order to overcome drawbacks (i.e., filtration and recovery) of conventional powder type photocatalysts, nano-ZnO/Laponite/PVA (ZLP) photocatalyzed adsorption balls were developed by using in situ mixing of nanoscale ZnO as a photocatalyst, and Laponite as both adsorbent and supporting media in deionized water, followed by the poly vinyl alcohol polymerization with boric acid. The optimum mixing ratio of nano-ZnO:Laponite:PVA:deionized water was found to be 3:1:1:16 (by weight), and the mesh and film produced by PVA polymerization with boric acid might inhibit both swelling of Laponite and detachment of nanoscale ZnO from ZLP balls. Drying ZLP balls with microwave (600 watt) was found to produce ZLP balls with stable structure in water, and various sizes (55~500 ${\mu}m$) of pore were found to be distributed based on SEM and TEM results. In the initial period of reaction (i. e., 40 min), adsorption through ionic interaction between methylene blue and Laponite was the main removal mechanism. After the saturation of methylene blue to available adsorption sites for Laponite, the photocatalytic degradation of methylene blue occurred. The effective removal of methylene blue was attributed to adsorption and photocatalytic degradation. Based on the results from this study, synthesized ZLP photocatalyzed adsorption balls were expected to remove recalcitrant organic compounds effectively through both adsorption and photocatalytic degradation, and the risks of environmental receptors caused by detachment of nanoscale photocatalysts can be reduced.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.148-152
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• 2003

The phosphorus(P) adsorption capacities of various filter media were investigated in relation to the size and types of fitter media to screen the optimum condition. The objective of this study was to evaluate the constructed wetland longevity by improving P adsorption capacity. The maximum P adsorption capacities of filter media A($4{\sim}10\;mm$), B($2{\sim}4\;mm$) and C($0.1{\sim}2\;mm$) were 8, 10 and 22 mg/kg, respectively, showing those increased as the filter media size decreased. Among the experimental media, the optimum filter media size was $0.1{\sim}2\;mm$. When the filter Medium was supplemented with organic materials which were piled up and decayed in the constructed wetland, the P adsorption capacity was significantly enhanced Under the conditions of optimum fitter media size, the respective Maximum P adsorption capacities of filter media C when supplemented with Ca, Mg, Al and Fe were higher than that of filter media C. However the addition of Ca, Mg, Al and Fe to constructed wetland were not recommended because of the possibility of their secondary pollution. The maximum P adsorption capacity of filter media C was 22 mg/kg, but this was increased to 36 mg/kg when filter media C was supplemented with 2% oyster shell.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.217-223
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• 2008

Amylose and protein contents are important traits determining the edible quality of rice, especially in East Asian countries. Near-Infrared Reflectance Spectroscopy (NIRS) has become a powerful tool for rapid and nondestructive quantification of natural compounds in agricultural products. To test the practically of using NIRS for estimation of brown rice amylose and protein contents, the spectral reflectances ($400{\sim}2500\;nm$) of total 9,483 accessions of rice germplasm in Rural development Administration (RDA) Genebank ere obtained and compared to chemically determined amylose and protein content. The protein content of tested 119 accessions ranged from 6.5 to 8.0% and 25 accessions exhibited protein contents between 8.5 to 9.5%. In case of amylose content, all tested accessions ranged from 18.1 to 21.7% and the grade from 18.1 to 19.9% includes most number of accessions as 152 and 4 accessions exhibited amylose content between 20.5 to 21.7%. The optimal performance calibration model could be obtained from original spectra of brown rice using MPLS (Modified Partial Least Squares) with the correlation coefficients ($r_2$) for amylose and protein content were 0.865 and 0.786, respectively. The standard errors of calibration (SEC) exhibited good statistic values: 2.078 and 0.442 for amylose and protein contents, respectively. All these results suggest that NIR spectroscopy may serve as reputable and rapid method for quantification of brown rice protein and amylose contents in large numbers of rice germplasm.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.31-34
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• 1979

In this study, enzymatic hydrolysis of the substrate of the waste wood of Cortinellus edodes was investigated using crude cellulase preparation of Trichoderma viride Pers. ex. Fr. SANK 16374. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. Reducing sugar was determined by the dinitrosalisylic acid (DNS) method. 1. The chemical composition of the waste wood was crude protein 2.26%, c. fat 2.57%, c. fibre 44.60%, c. ash 5.58% and lignin 13.62%. In amino acid composition, no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, niacine and chloride were detected. (Table 1) 2. As heat treatment of the substrate was found to produce the highest reducing sugar yield being reacted for 48hr. with T.v cellulase, the substrate was heated to $190{\pm}5^{\circ}C$. for 45 min. either before or immediately after milling. 3. The substrate heated and ball milled at $190{\pm}5^{\circ}C$. for 45 min. the reducing sugar yield reached to 11.5%. 4. The substrate without any treatment was found to produce the highest reducing sugar yield being reacted 72hr. with T. v cellulase, the reducing sugar yield reached to 10.1%. 5. The rate of reducing sugar per each treated substrate was decreased by the order of the substrated, heated and then ball milled at $190{\pm}5^{\circ}C$. for 45 min. (11.5%)> without any treatment (10.1)> ball milled and heated at $190{\pm}5^{\circ}C$. for 45 min. (6.9%). 6. Saccharification of waste wood has been shown to be possible by heat treated and milling the substrate in contact with cellulase. And it is likely to be recommended that the waste wood may be valuable for raw materials of saccharification.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.63-71
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• 1977

${\times}$Populus albaglandulosa has been needed optimum stand density according to various site and its wood usage. It is assumed that optimum stand density can be estimated by investigating of response of ${\times}$P. albaglandulosa to the light factor of stand. For that reason, the photosynthesis of ${\times}$Populus albaglandulosa grown under the controlled planting density was studied in relation to its leaf age by the aid of the Infrared gas analyzer. Rate of net photosynthesis was smaller in matured leaves than young leaves below $8^{\circ}C$, while, it was larger than young leaves above $8^{\circ}C$. Temperature for the maximum net photosynthesis of young leaves and old leaves was about $30^{\circ}C$ and $25^{\circ}C$ respectively. Saturated light intensity varied slightly as leaf age from 28 Klux to 35 Klux, but net photosynthesis rate in the range of light intensity showed deep differences. Old leaves marked the lowest rate, $1.6\;CO_2\;mg/dm^2/hr$, young leaves marked the medium rate, 1.7 to $2.2\;CO_2\;mg/dm^2/hr$, and matured leaves marked the most efficient photosynthesis, 2.9 to $3.5\;CO_2\;mg/dm^2/hr$. Young leaves of 5 days old had the highest light compensation point, while matured leaves of 35 days-old had the lowest point. Rates of dark respiration in both young leaves and old leaves were higher than that of matured leaves. Trees which were planted at space $80cm{\times}80cm$ showed productive assimilation function over the one-third of height where relative light intensity is 35%.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.563-576
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• 2023

In this study nitrogen dioxide (NO₂), formaldehyde (HCHO) from the Ozone Monitoring Instrument (OMI) and TROPOspheric Monitoring Instrument (TROPOMI), OMI/ Microwave Limb Sounder (MLS) tropospheric column ozone (TCO), and Airkorea ground-based O₃ data were analyzed to examine the photochemical reaction relationship between tropospheric ozone and its precursors nitrogen oxides (NOx) and volatile organic compounds (VOCs). As a result of analyzing the trend of long-term changes from 2006 to 2020 using OMI satellite data, TCO showed an increasing trend, NO₂ steadily decreased, and HCHO continued to increase in Northeast Asia. In addition, formaldehyde nitrogen dioxide ratio (FNR; HCHO/NO₂ ratio), an indicator of ozone sensitivity, is gradually increasing, which means that the VOC-limited regime is decreasing. This study conducted a sensitivity analysis of ozone generation using TROPOMI FNR and ground-based ozone (O₃) over the recent years (2019~2022) to identify the possible cause for the continuous increase of ozone in Korea. Similar to the previous studies, VOC-limited and transitional regimes appeared in megacities, and VOC-limited regimes also appeared in areas where major power plants were located. In VOC-limited regimes, in other words, areas where NOx is excessively saturated, the reduction in NOx emissions may have weakened the ozone titration and thus led to the increase of ozone. Therefore, VOC emissions should be reduced in the short term rather than NOx emissions to reduce ozone concentrations under the VOC-limited regime.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.385-394
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• 2002

Background : Flexible fiberoptic bronchoscopy(FFB) has become a widely performed technique for diagnosing and managing pulmonary disease because of its low complication and mortality rate. Since the use of FFB can in patients with severely depressed cardiorespiratory function is increasing and hypoxemia during the FFB can induce significant cardiac arrhythmias, the early detection and adequate management of hypoxemia during FFB is clinically important. Method : To evaluate the necessity of the continuous monitoring of the oxygen saturation($SaO_2$) during the FFB, the $SaO_2$ was continuously monitored from the finger tip using pulse oximetry before, during and after the FFB in 379 patient. The patients were then divided into two groups, those with and without hypoxemia($SaO_2$<90%). The baseline pulmonary function data and the clinical characteristics of the two groups were compared. Results : The mean baseline $SaO_2$ was $96.9{\pm}2.85%$. An $SaO_2$ <90% was recorded at some point in 62(16.4%) out of 379 patients, with 12 out of 62 experiencing this prior to the FFB, in 37 out of 62 during the FFB, and in 13 out of 62 after the FFB. No differences were observed in the smoking and sex distribution between those with and without hypoxemia. The mean age was older in those with hypoxemia than in those without. Significant differences were observed in the mean baseline $SaO_2$ and the mean time for the procedure between the two groups. The $FEV_1$ was significantly lower in those with hypoxemia, and both the FVC and $FEV_1/FVC$ also tended to decrease in this group. Managing hypoxemia included deep breathing in 20 patients, a supplemental oxygen supply in 39 patients, and the abortion of the procedure in 3 patients. Conclusion : These results suggest that the continuous monitoring of the oxygen saturation is necessary during fiberoptic bronchoscopy, and it should be performed in patients with a depressed pulmonay function in order for the early detection and adequate management of hypoxemia.