• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.75-84
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• 2021

In this study, the correlation between cement quality(chemical composition, mineral composition, and compressive strength) and amount of waste alternative fuels used in the cement manufacturing process and was investigated. Cement manufacturing facility using coal, soft plastics(plastics that are easily scattered by wind power, such as vinyls), hard plastics(plastics that do not contain foreign substances, waste rubber, PP, etc.) and reclaimed oil was analised. Data was collected for 3 years from 2017 to 2019 and let the amount of fuels used as an independent variable and cement quality data as a dependent variable. As a result, depending on the type and quality of the alternative fuel has not a significant effect on the chemical composition(Cl and LSF) and mineral composition(f-CaO, C3S contents). Contrary to the concern that the compressive strength of cement would decrease, there was a significant positive correlation between amount of alternative fuel used and cement compressive strength.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.248-261
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• 2021

The purpose of this study is that the blood nutrient indicator in adult women, is the depressive indicator. This study recruited 77 pre-menopausal women, and excluding missing values, 53 (mean age 44.2±6.5 years) blood indexes were statistically confirmed and then analyzed the effect of indexes on the Beck Depression Inventory. The Beck's Depression Inventory(BDI)'s average of the study subjects was 7.6±7.2, and most of the depression symptoms were within the normal range. Only two women were very serious and other two women were serious state. As a result of this study, 21 questions of BDI was classified into 5 sub-factors. Of these, 2 factors were considered physical depression, 1 factor was mood depression, 1 factor was cognitive depression, and 1 factor undecided. As a result of the correlation analysis, triglyceride, LDL(low density lipoprotein) cholesterol and potassium showed statistically significant positive relationship with depressive factors. On the other hand, HDL(high density lipoprotein) cholesterol, sodium and chloride ions showed negative relationship with depressive factors. When multiple regression analysis was performed. Considering the depression factors was dependent variable, and triglyceride, cholesterol, blood sugar, and ketone bodies was considered as independent variables. HDL(high density lipoprotein) cholesterol had a statistically significant negative effect on the depression factor 3. Considering the depression factors was dependent variable, and minerals were considered as independent variables. Potassium had a positive effect, and chloride ions had a negative effect on the depressive factor 3. This study was limited to 77 pre-menopausal women. In the future, post-menopausal women, men, and clinical neurological disorders group will be possible.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.5
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• pp.20-29
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• 2022

In this study, in order to improve the durability of the cement composite printed with the ME type 3D printer, PDMS, sodium silicate, and a surface hardener were employed. Post-treatment was performed on 3D-printed cement composite by coating after immersion, and the degree of improvement in durability was evaluated. As a result, in all evaluations, the durability performances of the post-processed specimens were improved compared to those of the plain specimens. Water absorption resistance, chloride penetration resistance, and carbonation resistance of the PDMS treated specimens were improved by 36.3 %, 77.1 %, and 50.4 % when compared to plain specimens. Freeze-thaw resistance of the specimens treated with sodium silicate was found to be the most excellent, with an average enhancement of 47.5% compared to plain specimens. It was found that PDMS was the most efficient post-treatment materials for 3D-printed cement composite. However, as suggested in this study, the post-treatment method by coating after immersion may not be applicable to cement composite structures printed with a 3D printer in field. Therefore, a follow-up study needs to be preformed on the durability enhancing materials suitable for 3D printing.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.126-130
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• 2023

In response to environmental demands, pyrolysis is one of the practical methods for obtaining reusable oils from waste plastics. However, the waste plastic pyrolysis oils (WPPO) are consumed as low-grade fuel oil due to their impurities. Thus, this study focused on the upgrading method to obtain naphtha catalytic cracking feedstocks from WPPO by the hydroprocessing, including hydrotreating and hydrocracking reaction. Especially, various transition metal sulfides supported catalysts were investigated as hydrotreating and hydrocracking catalysts. The catalytic performance was evaluated with a 250 ml-batch reactor at 370~400 ℃ and 6.0 MPa H₂. Sulfur-, nitrogen-, and chlorine-compounds in WPPO were well eliminated with nickel-molybdenum/alumina catalysts. The NiMo/ZSM-5 catalyst has the highest naphtha yield.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.89-96
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• 2023

In this paper, a ferrosilicon by-product was evaluated to confirm the feasibility of recycling it as supplementary cementitious material of ordinary Portland cement in concrete. Three different levels of replacement ratio (10 %, 20 % and 30 % of total binder) were applied to find which is the most beneficial to be used as a binder. Ferrosilicon concrete was initially assessed at setting time and compressive strength. Durability was evaluated by the resistance to chloride penetration test(RCPT) and alkali-silica reaction(ASR) with a comparison to silica fume concrete due to their similarity in chemical composition. The porosimetry and X-ray diffraction analysis along with energy dispersive X-ray spectroscopy give information on the microstructural characteristics of the ferrosilicon concrete. It was found that 10 % ferrosilicon concrete has higher strength while 20 %, 30 % have lower strength than OPC concrete. However, chemical resistance to chloride attack is higher when replacement is increased. Compared to silica fume, the durability of ferrosilicon might be less efficient however, it is obviously beneficial than OPC. High SiO₂ content in ferrosilicon results in producing more C-S-H gel which could make denser pore structure. Most of the risk of alkali silica reaction to silicate binders through length change tests was less than 0.2 %, and both mortar using ferrosilicon and silica fume showed better resistance to alkali silica reaction as the substitution rate increased.Reuse of industrial waste rather than producing highly refined additives might reduce environmental load during manufacture and save costs.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.651-659
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• 2022

This study was conducted to investigate the effects of different water temperatures (8, 11, 14 and 17℃) on growth, survival and hematological parameters of juvenile chum salmon(Oncorhynchus keta) for eight weeks. At the end of the experiment, at 14℃, the final body weights of the O. keta group were the highest compared to the other groups. Also, the O. keta showed a higher tendency in the 14℃ group than the 8, 11, and 17℃ groups in terms of growth performances, including specific growth rate (SGR), feed conversion ratio (FCR), feed efficiency (FE), weight gain (WG), and condition factor (CF). The survival rate (SR) was 100% at 8 and 11℃ groups, 96% at 14℃ group and 98% at 17℃ group. In the plasma components, the alanine aminotransferase (ALT) was significantly decreased at 17℃ group, whereas there was no significant change in the albumin (ALB), total protein (TP), sodium (Na⁺), potassium (K⁺) and chloride (Cl^-) levels. Among the whole-body composition of salmon, moisture, crude protein, and ash were not significantly affected by water temperature. However, crude lipid in the 8℃ group was significantly higher than in other water temperature groups. The results of this study demonstrated that the optimal temperature to stable growth performance for juvenile O. keta was 14℃.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.123-130
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• 1995

This study was performed to obtain the basic data on the serum components of several marine fish species commonly cultured in Korea. Blood samples taken from five species of fish were analyzed for various components of serum, total protein (TP), albumin (ALB), triglyceride (TG), cholesterol (CHOL), glucose (GLC), sodium (Na). Potassium (K), chloride (Cl), Phosphorus (P), lipase (LIPA), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The fish used were coho salmon(Oncorhynchus kisutch), rock fish (Sebastes schlegeli), sea bass (Lateolabrax japonicus), olive flounder ( Paralichthys olivaceus) and parrot fish (Oplegnathus fasciatuss) reared at the Chungmu Experimental Fish Culture Satation of KORDI. TP concentration of warm-water species (2.9-5.1 g/dl) was higher than that of cold-water species, and ALB concentration was ranged at the level of 1.2-1.9 g/dl. Coho salmon showed the highest ration of A/G(1.1), and the other species were about 0.5-0.6. The concentrations of TG and CHOL, components of lipids, varied with the different species. The concentration of TG was high, but CHOL concentration was low in olive flounder, while the reversed results were shown by sea bass. The sum of these two components was the highest with 600mg/d1 in olive flounder, and about 400mg/d1 for sea bass and rock fish, and 300mg/d1 for parrot lish and coho salmon. Concentration ot GLC in coho salmon and rock fish ranged from 61 to 76mg/d1 which were about lour times higher than that of flounder. The highest lipase activity was observed in coho salmon, while it was nearly nil in flounder. The reversed tendency was found for TG concentration. Mineral concentrations of Na, Cl and K were 160-204 mmol/l, 137-183mmo1/1 and 0.5-3.1 mmol/l, respectively, but no significant difference between the species was observed. However, the concentrations of P were high in relatively active species such as coho salmon and rockfish. AST activity in all species examined was higher than that of ALT with being highest in coho salmon. The highest ALT activity was found in olive flounder.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.319-325
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• 2016

This study was conducted to investigate residual organochlorine pesticides in green house soil and oriental melon, green pepper, and lettuce. The majority of them were designated as persistent organic pollutants (POPs) by the international community at the Stockholm Convention on Persistent Organic Pollutant. Extraction and clean-up method were developed using the QuEChERS method for residual organochlorine pesticides (OCPs) in soil and oriental melon, green pepper and lettuce. Recovery of OCPs in greenhouse soil and oriental melon, green pepper, and lettuce ranged from 73.3-110.6%. Limit of detection (LOD) of OCPs in soil and 3 crops were 0.01-0.08 and $0.11-0.17{\mu}g/kg$. The residues of OCPs in oriental melon, green pepper and lettuce greenhouse soil were analyzed by the developed method, and dieldrin, ${\beta}-endosulfan$ and endosulfan sulfate were detected at 1.4-72.5, 0.1-78.7 and $0.0-214.1{\mu}g/kg$, respectively. The detection frequency of 3 compounds in soils were 52 (29.7%), 34 (19.4%) and 57 (32.6%) among 175 samples, respectively. However, these compounds were not detected in all crop samples. The residue level in 3 crops were lower than 1/58.8 of maximum residue level of them. These results showed that the OCPs residue in oriental melon, green pepper, and lettuce greenhouse soil were not as high as crop safety threatening.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1312-1317
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• 2008

Physicochemical changes were investigated for the shelf-life extension of cultured wild-ginseng roots during storage with various pre-treatments with blanching, CAMICA-SD and DF-100 and treatments with citric acid and vitamin C. The pH of cultured wild-ginseng roots showed the range of $6.06{\sim}6.42$ at $10^{\circ}C$, but showed higher ranges of $6.08{\sim}6.91$ and $6.08{\sim}8.68$ at 20 and $30^{\circ}C$, respectively. Browning index (a/b) was increased with increasing storage temperature, and the index at 10 and $30^{\circ}C$ were 0.405 and 0.469 after 2 weeks, respectively. Browning index and viable cell number of CAMICA-SD pre-treatment showed little changes compared to pre-teatment with blanching or DF-100. When the cultured wild-ginseng roots were treated with 1.0% citric acid and 0.2% DF-100 after pre-treatments with CAMICA-SD, viable cell number was slightly increased to $4.9{\times}10^2CFU/g$ for 3 weeks storage at $10^{\circ}C$. The mixture of citric acid and DF-100 was also used to prevent the growth of microbiology and to reduce browning reaction, especially enzymatic browning reaction. The mixture might effectively extend shelf life of the cultured wild-ginseng roots.

• Journal of Aquaculture
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• v.11 no.4
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• pp.547-556
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• 1998

This study was performed to obtain the basic data on the serum constituents of several marine fish spesies commonly cultured in Korea. Blood samples taken from six species of fish were analyzed for various components of serum, total protein (TP), albumin (ALB), triglyceride (TRIG), cholesterol (CHOL), glucose (GLC), lipase (LIPA), amylase (AMYL), aspartate transaminoferase (AST), sodium (Na), potassium (K), chloride (CI) and phosphorus (PHOS). The fish used were coho salmon (Oncorhynchus kisutch), rock fish (Sebastes schlegeli), sea bass (Lateolabrax japonicus), olive flounder (Paralichthys olivaceus), rock fish (Sebastes schlegeli), sea bass (Lateolabrax japonicus), olive flounder (Paralichthys olivaceus), parrot fish (Oplegnathus fasciatus) and jack mackerel (Trachurus jaonicus) reared at the Chungmu Experimental Fish Culture Station of KORDI when the water tempetature was ca. 16.5$^{\circ}C$. There were significant differences in TRIG, CHOL, LIPA and AMYZ among the species analyzed. TRIG concentratin were ranged 178~180mg/dl in jack mackeerel and rock fish, 126~159 mg/dl in olive flounder and sea bass, and 102~114 mg/dl in coho salmon and parrot fish, respectively. Jack mackerel showed the highest levels in CHOL (255mg/dl) and GLC(138mg/dl) among species. LIPA levels were recorded 256 U/dl in coho salmon, 41~42 U/dl in parrot fish and rock fisk, and 5~11 U/dl jack mackerel and sea bass, respectively. AMYL activity of coho salmon was measured as 2, 665 U/dl, and that of jack mackerel was 1,210 U/dl while sea bass showed 60 U/dl and parrot fish, olive flounder and rock fish had at most 5 U/dl. On the other hand, there was no significant difference in the concentration of Na and CI. Na and K were proved that they were negatively correlated in all the species. Generally, among blood components, PHOS and CHOL levels were different depending on environmental temperature of each fish species, especially in olive flounder. Rock fish and parrot fish showed high blood concentration of those components during low temperature period while olive flounder and jack mackerel reached high level during their optimal environmental temperature period. The electrolyte concentration and LIPA activity were high during low water temperature period, in general, but TP and ALB concentrations were high during optimal temperature period. The concentrations of TRIG, CHOL and GLC, those which were used as energy sourses, were different among species by season.