• Corrosion Science and Technology
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• v.14 no.5
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• pp.213-217
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• 2015

Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.65-69
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• 2005

We have developed a new method of manufacturing salts by horizontal spray drying technique, using the concentrated deep ocean water after desalination processes. We studied the chemical characteristics of the spray-dried salts. Sodium content in the spray salts is $28.4\%$, which is $10-30\%$ lower than that of bay salts, bamboo salts and boiling salts $(32-38.2\%)$. However, the contents of magnesium, potassium and calcium of the spray salts are 2.5 times, 3 times and 4.5 times higher relative to those of bay salts, respectively. On the one hand, sulfur content in spray salts is 14 times lower than those of bay salts, which is caused by their volatilization during spray and vaporization of the concentrated seawater. Enrichment factors of Mg (0.8), K (0.9) and Ca (1.0) in the spray salts are relatively higher than those in bay salt (0.2-0.3), bamboo salt (0.15-0.4) and boiled salt (0.4-0.7), respectively. On the contrary, enrichment factor of sulfur in spray salts is observed to be 0.07, which is considerably lower than those in other salts (0.3-0.7). It means that the minerals like Mg, K and Ca can be well conserved from seawater to salts through spray drying techniques, while volatile elements like sulfur, lead, mercury and organic compounds can be easily removed from seawater via spray and heating processes.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4158-4165
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• 2021

In this study, tissue equivalency (TE) of a newly developed epoxy-based phantom to 3-5 years child's tissue was investigated in paediatric energy range. Epoxy-based TE-phantoms were produced at different glandular/adipose (G/A) ratios of 17/83%, 31/69%, 36/64% and 10/90%. A procedure was developed in which specific amounts of boron, calcium, magnesium, sulphur compounds are mixed with epoxy resin, together with other minor substitutes. In paediatric energy range of 40-60 kV_p half-value layer (HVL) values were measured and then Hounsfield Units (HU) were determined from Computed Tomography(CT) scans taken in the X-ray energy range of 80-120kV_p. It is found that radiation absorption properties of these phantoms in terms of the measured HVL values related to linear attenuation coefficients (µ) are very well mimicking a 3 years child's soft tissue in case a ratio of 10/90%G/A. Additionally, the HU values of phantoms were determined from the CT scans. The HU = 47.8 ± 4.8 value was found for the epoxy-based phantom produced at a ratio of 10/90%G/A. The obtained HVL and HU values also support the suitability of the new epoxy based-phantom produced at a ratio of 10/90%G/A for a satisfactory mimicking a 3 years child's soft tissue by 5%. Thus they can have a potential use to perform the quality controls of medical X-ray systems and dose optimization studies.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.369-376
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• 2022

This study was conducted to investigate the efficacy of rose hip utilization on various diseases. Rose hips are produced on a shrub native to Europe, and have been used for medicinal purposes and nutritional supplementation for centuries. It is rich in minerals, vitamins, and various functional compounds, including calcium, magnesium, phosphorus, potassium, selenium, vitamin B, vitamin C, and vitamin E, quercetin, catechin, β-carotene, β-sitosterol, polyphenol, flavonoid, taxifolin, ellagic acid, and salicylic acid. Extracts and powders of rose hips have been reported to contain antioxidant, free radical scavenging, and anti-inflammatory activity, and exert beneficial effects including amelioration of osteoarthritis, body fat reduction, anti-obesity activity, anti-bacterial activity, antidiabetic properties, and anti-cancer activity. Therefore, rose hips as a functional natural food may be considered effective for use in treating diseases including obesity, diabetes, osteoporosis, cardiovascular disease, and cancer.

• Resources Recycling
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• v.31 no.3
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• pp.3-15
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• 2022

Lithium is the lightest metal and the first metal in the periodic table. Lithium is used in a variety of applications, including the production of organolithium compounds, as an alloying addition to aluminum and magnesium, and as the anode in rechargeable lithium ion batteries especially for electronic devices and electric vehicles. Therefore, lithium is indispensable metal in our daily lives. The use of lithium continues to rise and has increased from about 14,000 tonnes per year worldwide in the 2000 to about 82,200 tonnes in the 2000. However, lithium is a representative rare metal and ranks 32nd among the abundant elements in the earth's crust. This study reviews the current status of the lithium extraction processes as well as the trend in production amount and use. Lithium is extracted by a various methods depending on the type of resources. These extraction methods are essential for the development of new recycling processes that can extract lithium from secondary lithium resources.

• Journal of the Korean Society of Food Culture
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• v.28 no.1
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• pp.57-69
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• 2013

Recently, an interest in functional foods has been increasing. It was recommended placing a short definition. Therefore, we performed research on the chemical functions and antioxidant ability of broccoli. This research is vital for preparing the most favorable conditions and environment for highly-functional broccoli. Broccoli produced after applying sprouting and light sources were used for research. The chemical properties of the broccoli, including composition, free sugar, citric acid, mineral and vitamin (A, C, E) content, were analyzed. In addition, the ability of broccoli compounds to reduce total phenolic compounds, SOD-liked activity, EDA (electron donating ability), and hydroxyl radicals were inspected. Total analysis relied on the SAS (statistical analysis system). Broccoli sprouts produced through plant factory system's photosynthesis, treated under different light sources, had superior amounts of crude protein, crude fat, and crude ash, compared to normal sprouts under fluorescent light. Is it a facility or does it refer to the inner metabolism of the cell? Broccoli sprouts under red light had superior amounts of glucose, fructose, malic acid, and oxalic acid, while broccoli sprouts under turquoise light had superior amounts of citric acid. Broccoli sprouts under white light had superior amounts of various minerals, such as potassium, magnesium, and sodium. In terms of antioxidant activity, data from the plant factory system shows an increase in EDA antioxidants (1.63 mg/mL, 30.82%). Sprouts applied with turquoise light had superior amounts of hydroxyl radical scavenging (65.62%), and sprouts applied with white light had superior amounts of activated SOD-like activity (52.69%). Research on dehydrated broccoli sprouts showed that sprouts dehydrated with cold air had superior amount of malic, citric, oxalic acid compared to sprouts dehydrated with hot air. In terms of vitamin levels, sprouts dehydrated with cold air had five times the normal amount of vitamin A and E, whereas sprouts dehydrated with hot air had higher amounts of vitamin C. Dehydration at low temperature also produced a higher amount of activated antioxidants (1.6 mg/mL of activated antioxidant ability, 63.04% of SOD-like activity, and 67.76% of hydroxyl radical scavenging). Our results show that antioxidant ability can vary by the type of photosynthesis and temperature level in which the sprouts are dehydrated. Therefore, thorough foundational data is required to product the most functional broccoli.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.50-55
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• 1999

The proximate composition, mineral content, fatty acid composition, ATP related compounds, amino acid composition, color and texture were investigated with dorsal and ventral muscle from olive flounder, spotted flounder and hybrid (olive flounder m $\times$spotted flounder f). Spotted flounder and hybrid were higher in moisture content, and lower in crude protein content than those of olive flounder, Potassium content in hybrid was higher than that in olive flounder and spotted flounder. Hybrid was lower in calcium, iron, manganese content, and higher in magnesium content than olive flounder and spotted flounder. The contents of saturated fatty acid, unsaturated fatty acid and docosahexaenoic acid (DHA) in hybrid were intermediate level of spotted flounder and olive flounder. Fatty acid composition of dorsal muscle was slightly similar to ventral muscle. Adenosine triphosphate (ATP) and its related compounds contents and amino acid content in hybrid were intermediate level of spotted flounder and olive flounder, and these compounds of dorsal muscle were slightly similar to those of counterpart. The major amino acids such as aspartic acid, glutamic acid, leucine and Iysine were very similar to all the samples. Total amino acid and essential amino acid contents in dorsal muscle were slightly higher than those in ventral muscle. Free amino acid content and composition in hybrid were similar to spotted flounder, and free amino acid content in dorsal muscle was higher than in ventral muscle, The lightness of hybrid and spotted flounder was stronger than that of olive flounder, and was stronger in dorsal muscle. The breaking strength of hybrid was slightly lower than that of spotted flounder, and was stronger in dorsal muscle.

• Korean Chemical Engineering Research
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• v.59 no.3
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• pp.399-409
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• 2021

In order to utilize dolomite as a calcium/magnesium compound material, it was prepared highly reactive calcined dolomite(CaO·MgO) using a microwave kiln (950 ℃, 60 min). The experiment was performed according to the standard of the hydration test (ASTM C 110) and hydration reactivity was analyzed as medium reactivity (max 74.1 ℃, 5 min). Experiments were performed with calcined dolomite and salt (MgCl₂·6H₂O) (a) 1:1, (b) 1:1.5, and (c) 1:2 wt% based on the hydration reaction of calcined dolomite. The result of X-ray diffraction analysis confirmed that MgO of calcined dolomite increased to Mg(OH)₂ as the salt addition ratio increased. After the separating reaction, calcium was stirred at 80 ℃, 24 hr that produced CaCl₂ of white crystal. XRD results, it was confirmed calcium chloride hydrate (CaCl₂·(H₂O)x) and CaO of calcined dolomite and salt additional reaction was separated into CaCl₂. And it was synthesized with Ca(OH)₂ 99 wt% by NaOH adding reaction to the CaCl₂ solution, and the synthesized Ca(OH)₂ was manufactured CaO through the heat treatment process. In order to prepare calcium carbonate, CaCO₃ was synthesized by adding Na₂CO₃ to CaCl₂ solution, and the shape was analyzed in cubic form with a purity of 99 wt%.

• Journal of the Korean Wood Science and Technology
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• v.7 no.2
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• pp.3-30
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• 1979

Larch ($\underline{Larix}$ $\underline{leptolepis}$ GORDON), one of the major afforestation species in Korea in view of its growing stock and rate of growth, is not favored as a raw material for pulp due to its low yield of pulp and difficulties with bleaching arising from the high content of extractives in wood, and the high heartwood ratio and the active phenolics, respectively. The purpose of this study is to investigate the characteristics of firstly pulping with various additives of cellulose protector for the yield of pulp, and secondly bleaching with oxygen for chlotination-alkali extraction of five stage-sequence to reduce chlorine compounds in bleaching effluents. The kraft cooking liquor for five age groups of larchwood was 18 percent active alkali with 25 percent sulfidity and 5 : 1 liquor-to-wood ratio, and each soda liquor for sap-and heart-wood of the 15-year-old larchwood was 18 percent alkali having one of the following cellulose protectors as the additive; magnesium sulfate ($MgSO_4$, 2.5%), zinc sulfate ($ZnSO_4$, 2.5%), aluminium sulfate ($Al_2(SO_4)_3$, 2.5%), potasium iodide (KI, 2.5%), hydroquinone (HQ, 2.5%), anthraquinone (AQ, 0.1%) and ethylene diamine (EDA, 2.5%). Then each anthraquinone-soda liquor for the determination of suitable cooking condition was the active alkali level of 15, 17 and 19 percent with 1.0, 0.5 and 0.1 percent anthraquinone, respectively. The cooking procedure for the pulps was scheduled to heat to 170$^{\circ}C$ in 90 minutes and to cook 90 minutes at the maximum temperature. The anthraquinone-soda pulps from both heartwood and sapwood of 15-year-old larchwood prepared with 0.5 percent anthraquinone and 18 percent active alkali were bleached in a four-stage sequency of OCED. (O: oxygen bleaching, D: chlorine dioxide bleaching and E: alkali extraction). In the first stage oxygen in atmospheric pressure was applied to a 30 percent consistency of pulp with 0.1 percent magnesium oxide (MgO) and 3, 6, and 9 percent sodium hydroxide on oven dry base, and the bleached results were compared pulps bleached under the conventional CEDED (C: chlorination). The results in the study were summarized as follows: 1. The screened yield of larch kraft pulp did not differ from particular ages to age group, but heartwood ratio, basic density, fiber length and water-extractives contents of wood and the tear factor of the pulp increased with increasing the tree age. The total yield of the pulp decreased. 2. The yield of soda pulp with various chemicals for cellulose protection of the 15-year-old larchwood increased slightly more than that of pure soda pulp and was slightly lower than that of kraft pulp. The influence of cellulose protectors was similar to the yield of pulps from both sapwood and heartwood. The effective protectors among seven additives were KI, $MgSO_4$ and AQ, for which the yields of screened pulp was as high as that of kraft pulp. Considering the additive level of protector, the AQ was the most effective in improving the yield and the quality of pulp. 3. When the amount of AQ increased in soda cooking, the yield and the quality of the pulp increased but rejects in total yield increased with decreasing the amount of active alkali from 19 to 15 percent. The best proportion of the AQ seemed to be 0.5 percent at 17 percent active alkali in anthraquinone-soda pulping. 4. On the bleaching of the AQ-soda pulp at 30 percent consistency with oxygen of atomospheric pressure in the first stage of the ODED sequence, the more caustic soda added, the brighter bleached pulp was obtained, but more lignin-selective bleaching reagent in proportion to the oxygen was necessary to maintain the increased yield with the addition of anthraquinone. 5. In conclusion, the suitable pulping condition for larchwood to improve the yield and quality of the chemical pulp to the level for kraft pulp from conventional process seemed to be. A) the selection of young larchwood to prevent decreasing in yield and quality due to the accumulation extractives in old wood, B) the application of 0.5 percent anthraquinone to the conventional soda cooking of 18 percent active alkali, and followed, C) the bleaching of oxygen in atmospheric pressure on high consistency (30%) with 0.1 percent magnesium oxide in the first stage of the ODED sequence to reduce the content of chlorine compounds in effluent.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.276-286
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• 2013

The goal of this study was to investigate change of thermal decomposition feature of miscanthus (Miscanthus sacchariflorus) after removal of inorganic constituents using distilled water (D.I-w; 30, 60 and $90^{\circ}C$). The carbon content was increased whereas the oxygen content was decreased with the temperature of D.I-w treatment. Moreover, ash content was slightly decreased from 4.6% of control to 3.2% of $90^{\circ}C$ D.I-w treated sample. Results of total monomeric sugar contents and X-ray diffraction (XRD) analysis showed that structural changes of cellulose/hemicellulose regions did not occurr during D.I-w treatment. Results of inductively coupled plasma emission spectrometer (ICP-ES) showed that miscanthus has the largest amount of inorganic constituents such as potassium (5,644 ppm), phosphorus (3,995 ppm), magnesium (1,403 ppm) and calcium (711 ppm). Thermogravimetric analysis (TGA) confirmed that the yield of char slightly decreased whereas the yield of volatiles increased with increasing D.I-w treatment temperature. In addition, differential thermogravimetric analysis (DTGA) indicated that the maximum decomposition rate ($V_M$) and temperature ($T_M$) corresponding to VM were varied from $0.82%/^{\circ}C$, $360.60^{\circ}C$ of control to $1.17%/^{\circ}C$, $362.62^{\circ}C$ of $90^{\circ}C$-D.I-w treated sample.