• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.547-561
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• 2005

General characteristics of groundwater contamination by As were reviewed with several recent researches, and its occurrence in groundwater of Korea was investigated based on a ffw previous studies and a groundwater quality survey in Nonsan and Geumsan areas. In Bangladesh, which has been known as the most serious arsenic calamity country, about $28\%$ of the shallow groundwaters exceeded the Bangladesh drinking water standard, $50{\mu}g/L$, and it was estimated that about 28 million people were exposed to concentrations greater than the standard. Groundwater was characterized by circum-neutral pH with a moderate to strong reducing conditions. Low concentrations of $SO_4^{2-}$ and $NO_3^-$, and high contents of dissolved organic carbon (DOC) and $NH_4^+$ were typical chemical characteristics. Total As concentrations were enriched in the Holocene alluvial aquifers with a dominance of As(III) species. It was generally agreed that reductive dissolution of Fe oxyhydroxides was the main mechanism for the release of As into groundwater coupling with the presence of organic matters and microbial activities as principal factors. A new model has also been suggested to explain how arsenic can naturally contaminate groundwaters far from the ultimate source with transport of As by active tectonic uplift and glaciatiion during Pleistocene, chemical weathering and deposition, and microbial reaction processes. In Korea, it has not been reported to be so serious As contamination, and from the national groundwater quality monitoring survey, only about $1\%$ of grounwaters have concentrations higher than $10{\mu}g/:L.$ However, it was revealed that $19.3\%$ of mineral waters, and $7\%$ of tube-well waters from Nonsan and Geumsan areas contained As concentrations above $10{\mu}g/:L.$. Also, percentages exceeding this value during detailed groundwater quality surveys were $36\%\;and\;22\%$ from Jeonnam and Ulsan areas, respectively, indicating As enrichment possibly by geological factors and local mineralization. Further systematic researches need to proceed in areas potential to As contamination such as mineralized, metasedimentary rock-based, alluvial, and acid sulfate soil areas. Prior to that, it is required to understand various geochemical and microbial processes, and groundwater flow characteristics affecting the behavior of As.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1142-1149
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• 2002

This study was designed to standardize recipe and analyze the nutrients of Aguyjjim (stewed angler), a kind of native local foods in Busan. The results of this study are summarized as follows. The form of angler and its way to catch for a bait were recorded in Jasanobo, but the recipe was not written. While angler was used as manure or feed once, it was boomed for Aguyjjim since 80's, accredited as high-quality fish and protein-rich food. The standard recipe of Aguyjjim was prepared (through 3 times experimental cooking), being based on the recipe of cookbooks and restaurants. Then standard recipe was subjected to sensory evaluation. All sensory properties (appearance, smell, texture etc.) of Aguyiiim were evaluated as “like slight S, moderately”in hedonic scale. Energy per 100 g of the Aguyjjim was 89 kcal. It contained protein (10.7 g), fat (1.3 g), fiber (2.6 g), Ca (45 mg), Fe (1.3 mg) and so on. Amino acid is mainly comprised glutamic acid and aspartic acid. Free amino acid contents such as asparagine, glutamic acid, taurine were high. Fatty acid primarily consisted of unsaturated fatty acid like oleic acid, linoleic acid. Traditional foods are based on that of local foods. However, there has been little study looking into the recipes and nutritional value of local foods. Aiming at development of traditional food, the present study offered the standard cuisine of Aguyiiim that is a kind of local foods in Busan. In addition, it presented the composition of nutrients, amino acids and fatty acids. This data would be helpful for houses, restaurants and food service facilities to revive the local foods.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.229-244
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• 2013

Arsenic contamination may be brought about by a variety of natural and anthropogenic causes. Among diverse naturally-occurring chemical speciations of arsenic, trivalent (As(III), arsenite) and pentavalent (As(V), arsenate) forms have been reported to be the most predominant ones. It has been well known that the behavior of arsenic is chiefly affected by aluminum, iron, and manganese oxides. For this reason, this study was initiated to evaluate the applicability of manganese slag (Mn-slag) containing high level of Mn, Si, and Ca as an efficient sorbent of arsenic. The main properties of Mn-slag as a sorbent were investigated and the sorption of each arsenic species onto Mn-slag was characterized from the aspects of equilibrium as well as kinetics. The specific surface area and point of zero salt effect (PZSE) of Mn-slag were measured to be $4.04m^2/g$ and 7.73, respectively. The results of equilibrium experiments conducted at pH 4, 7 and 10 suggest that the sorbed amount of As(V) was relatively higher than that of As(III), indicating the higher affinity of As(V) onto Mn-slag. As a result of combined effect of pH-dependent chemical speciations of arsenic as well as charge characteristics of Mn-slag surface, the sorption maxima were observed at pH 4 for As(V) and pH 7 for As(III). The sorption of both arsenic species reached equilibrium within 3 h and fitting of the experimental results to various kinetic models shows that the pseudo-second-order and parabolic models are most appropriate to simulate the system of this study.

• Economic and Environmental Geology
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• v.42 no.2
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• pp.121-131
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• 2009

The distribution characteristics of heavy metals for surface sediments in east oceanic dumping area (EDA) and west oceanic dumping area (WDA) are evaluated by grain sizes, minerals, sedimentation rates and compositions of heavy metals. The mean grain sizes in EDA and WDA range from $7.95{\Phi}$ to $8.51{\Phi}$ and $7.42{\Phi}$ to $8.15{\Phi}$, respectively. These are mostly belonging to the M (mud) type. Minerals in the surface sediments consist of illite with chlorite, smectite, and kaolinite. Sedimentation rates estimated by $^{210}Pb$ method in EDA and WDA are 1.11 mm/yr$\sim$1.73 mm/yr and 1.87 mm/yr, respectively. According to the interrelationship, concentrations of Ni, Cu, Cr, and Zn are closely associated with mean grain size, Al, and Fe, whereas concentrations of Cd and Pb are poorly associated with ones. The enrichment factors of these elements are higher than 1.5, suggesting that the concentrations of Cd and Pb in the surface sediments are affected by anthropogenic sources. The $I_{geo}$-class numbers of Cd and Pb in the surface sediments are mostly classified in 2 to 4, showing moderate to strongly polluted. These numbers in EDA are higher than that of WDA, and the highest number is 4, indicative of the strongly polluted class. Our results show that the disposed wastes at EDA include mineralogical wastes, dredged materials from sewage disposals, and sludges from constructions having materials of WDA. The annual amount of oceanic dumping in EDA is double than that in WDA.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.489-494
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• 2020

A total of 101 samples of convenience baby food products were analyzed by microwave digestion and mineral nutrients (iron, zinc, calcium, magnesium) were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). By type, the samples included 44 rice porridges, 40 soft-boiled rices, 11 purees, and 6 powders. The mean values for iron (Fe) content were 0.05 to 0.45 mg/100 g (excepted powder type, mg/l0 g). This was equivalent to 22.35% for rice porridge, 10.55% for soft-boiled rice, 9.88% for puree and 2.74% for powder type compared to the KDRIs (Dietary Reference Intakes for Koreans), respectively. The mean values for zinc (Zn) was 0.06 to 0.28 mg/100 g (excepted powder type, mg/l0 g) and the KDRI ratio was the lowest at 5.94% in puree, with 27.76%, 28.95% and 10.91% in rice porridge, soft-boiled rice and powder type, respectively. Calcium (Ca) content relative to KDRIs was relatively low compared to other minerals, with 6.65% for rice porridge, 3.61% for soft-boiled rice, 6.24% for puree and 3.07% for powder type, respectively. The magnesium (Mg) content of baby food ranged from 13.4% to 39.0% compared to KDRIs, and was included in all baby food as a whole. For balanced nutritional mineral supply to infants, it is recommended that information on mineral sources and ingredients in convenience baby food be clearly provided to ensure proper growth and development.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1246-1250
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• 2005

This study was carried out to analyze the components of the stem of bush clover, Lespedeza bicolor to obtain basic data on the studies of the physiological function and a possibility of utilizing L. bicolor. General components of L. bicolor were 82.35$\%$ carbohydrate, 13.38$\%$ moisture, 2.80$\%$ crude protein, 0.86$\%$ crude ash and 0.61$\%$ crude fat. The content of reducing sugar was 147.58 mg/100 g. The total amount of free sugar was 52.4 mg/100 g that was composed of 31.0 mg/100 g fructose, 16.7 mg/100 g glucose and 4.7 mg/100 g sucrose. In the results of mineral analysis, the content of Ca was the highest (472.97 mg/100 g) and followed by 206.70mg/100 g of K. The total amount of hydrolyzed amino acid was 148.95 mg/100 g that consist of 31.74 mg/100g of essential amino acid and 117.24 mg/100 g of non-essential amino acid. Total free amino acids were contained 106.39 mg/100 g that was composed of 8.41 mg/100 g essential amino acids and 97.98 mg/100 g the non-essential, and proline (62.92 mg/100 g) was the highest that account for 59.8$\%$ of total free amino acids. Total content of amino acid derivatives was 30.01 mg/100g and that of $\gamma$ -aminoisobutyric acid was the highest as 12.57 mg/100 g among them.

• The Journal of Korean Academy of Prosthodontics
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• v.19 no.1
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• pp.17-27
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• 1981

This study was conducted to determine the chemical composition and the mechanical properties of four commercially available low gold-based crown and bridge alloy produced in Korea. Four dental casting gold-silver-palladium alloys, i.e., A, B, C and D (code of alloys) were selected for the evaluation of chemical composition, ultimate tensile strength, elongation. values and Vickers hardness. The chemical composition of test specimens was analyzed by both emission spectrography and wet gravitation method with a 1.5gm of low gold ingot. The tensile properties and Vickers hardness was determined with cast specimens treated in following three conditions; as-cast, softening heat treatment and hardening heat treatment. The tensile testing bars were cast in accordance with the model designed by Gettleman and Harrison (1969) which was modified from the A. D. A. Specification No. 14 for dental chromium-cobalt casting alloy. Nine tensile test specimens were made from a split silicone mold for each of the test alloys to the size of 2.5mm in diameter and a gauge length of 10mm. All four alloys were handled in accordance with conventional methods used in Type III gold alloys. Ultimate tensile strength and elongation were measured on an Instron Universal Tensile Testing Machine (Model 1125, Japan) operated at a crosshead rate of 0.1cm/min. Elongation values were measured using Digital Measuring Microscope (MS-152, FUSOH, Japan). Vickers hardness was determined with a Vickers Hardness Tester (Model VKH-l, Japan) at a 1.0kg load on a mounted tensile test specimen. The following results were obtained from this study; 1. All tested alloys were composed of Au, Ag, Pd, Cu, Zn and Fe in common. The composition rate of gold for all four alloys was found in the range of $42{\sim}47$ weight % as shown below. Alloy A; Au 45%, Ag 40.2%, Pd 5.76%, others 9.04%. Alloy B; Au 47.1%, Ag 29.03%, Pd 6.98%, others 16.92%. Alloy C; Au 45%, .Ag 26.9%, Pd 6.83%, others 21.07%. Alloy D; Au 41.8%, Ag 34.4%, Pd 6.95%, others 16.85%. 3. The ultimate tensile strength of the four alloys was in the range of $31{\sim}82kg/mm^2$. The test results were shown in the below order from the highest value; As-cast condition; D, B, C, A. Softening heat treament; B, C, D, A. Hardening heat treatment; D, B, C, A. 4. The test :results of the elongation rate for each alloy were in the range of $0.5{\sim}18%$. The test results were shown in the below order from the highest value; As-cast condition; A, D, B, C. Softening heat treatment; A, C, D, B. Hardening heat treatment; C, D, B, A. 5. Vickers hardness for each of the four alloys was in the range of $120{\sim}230$. The test results were shown in the below order from the highest value; As-cast condition; C, B, D, A Softening heat treatment; D, B, C, A. Hardening heat treatment; D, A, C, B. 6. There were no differences in the physical properties between as-cast condition and softening heat treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1008-1017
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• 2005

The purpose of this study was to evaluate the Quantity and Quality of food and nutrient intake of preschool children. The subjects were 57 children aged 3 to 6 years in Gumi day-care centers. Total daily dietary intakes were calculated by weighing food consumed at the day-care centers taken together with dietary records by children's mothers for intakes at home. This survey was conducted during 3 days including week and weekend days. Diet Quality was assessed by NAR (Nutrient Adequacy Ratio), MAR (Mean Adequacy Ratio), food group pattern and DDS (Dietary Diversity Score). The daily food intake was 992.7g, the plant food intake $(68\%)$ was higher than animal food intake $(32\%)$. The daily energy intake was 1249.2 kcal $(85\%\;RDA)$ and protein 43.8g $(153.6\%\;RDA)$. Percentage of calcium, iron, and niacin consumed below $75\%$ of RDAs were $29.8\%,\;35.1\%\;and\;28.1\%$, respectively. Proportions of energy from carbohydrate, protein and fat were $61.0\%,\;14.1\%\;and\;25.5\%$, respectively. Calorie intake proportion of breakfast, lunch, dinner and snack were $15\%,\;20\%,\;19\%\;and\;46\%$, respectively. The NAR of Ca and Fe and MAR were 0.84, 0.85 and 0.92, respectively. Thirty-one point six percent of children consumed 5 food groups (GMFVDS=110111) per day. Persons who had higher DDSs correlated positively with NAR and MAR. As a result, dietary intake of preschool children partially showed a problem of over and under nutrition in Quantity or Quality. We hope that the result of this study could be helpful for developing the nutrition education program for the health and nutrition of preschool children.

• Food Science and Preservation
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• v.16 no.5
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• pp.705-713
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• 2009

We prepared salmon patties and compared the quality characteristics thereof with those of commercial tuna and pork patties. The moisture and crude ash contents of salmon patty were lower, whereas the crude protein content was higher, than those of commercial patties. The crude lipid content of salmon patty was higher than that of tuna patty, but lower than that of pork patty. The pH value and the volatile basic nitrogen content of salmon patty were lower than those of the commercial patties. Hunter color values (L, a, b) in a cross-section of cooked salmon patty were higher, whereas the ${\Delta}E$ value was lower, than those of the two commercial patties. The lipophilic browning index (0.397) of salmon patty was higher, whereas the hydrophilic browning index (0.047) was lower, than those of commercial patties. Trichloroacetic acid-soluble N content (272 mg/100 g) of salmon patty was lower than of commercial patties. The major fatty acids of salmon patty were palmitic acid (11.9%), oleic acid (27.6%), and linoleic acid (30.1%), whereas small amounts of eicosapentaenoic acid (EPA, 3.7%) and docosahexaenoic acid (DHA, 8.4%) were also found. The predominant amino acids of all patties were arginine, glutamic acid, aspartic acid, leucine, threonine, and proline, and the contents of these amino acids in salmon patty were higher than in the two commercial patties. The Fe, Ca, K, P, and Mg contents of salmon patty were 2.4 mg/100g, 42.6 mg/100g, 207.5 mg/100g, 211.6 mg/100 g, and 29.9 mg/100 g, respectively. The sensory quality of salmon patty was higher than that of pork patty. These results indicate that salmon patty may have good quality characteristics, comparable to those of the two commercial patties.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.257-271
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• 2002

One of the main interests in relation to heavily contaminated gully-pot sediment in urban area is the short term mobility of heavy metals, which depends on the pH of acidic rainwater and on the buffering effects of carbonate minerals. The buffering effects of carbonates are determined by titration (acid addition). Leaching experiments are carried out in solutions with variable initial HN03 contents for 24h. The gully-pot sediment appears to be predominantly buffered by calcite and dolomite. In case of sediment samples, which highly contain carbonates, pH decreases more slowly with increasing acidity. On the other hand, for the sediment samples, which less contain carbonate minerals, pH rapidly drops until it reaches about 2 then it decreases slowly. The leaching reactions are delayed until more acid is added to compensate for the buffering effects of carbonates. The Zn, Cu, Pb and Mn concentrations of leachate rapidly increase with decreased pH, while Cd, Co, Ni, Cr and Fe dissolutions are very slow and limited. The solubility of heavy metals depends not only on thc pH values of leachatc but also on the speciation in which metals are associated with sediment particles. In slightly to moderately acid conditions, Zn, Cd, Co, Ni and Cu dissolutions become increasingly important. As deduced from leaching runs, the relative mobility of heavy metals at pH of 5 is found to be: Zn > Cd > Co > Ni > Cu » Pb > Cr, suggesting that moderately acid rainwater leach Zn, Cd, Co, Ni and Cu from thc contaminated gully-pot sediment, while Pb and Cr would remain fixed. The buffering effects of Ca- and Mg-carbonates play an important role in delaying as well as limiting the leaching reactions of heavy metals from highly contaminated gully-pot sediment. The extent of such a secondary environmental pollution will thus depends on how well the metals in sediment can be leached by somewhat acidic rain water. Changes in the physicochemical environments may result in the severe environmental pollution of heavy metals. These results are to be taken into account in the management of contaminated sediments during rainstorms.