• Economic and Environmental Geology
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• v.35 no.1
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• pp.25-41
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• 2002

In order to investigate the hydrogeochemical characteristics and contamination of dissolved major ions and heavy metals in the Tancheon River, river water and sediment samples were collected at 18 locations, along a distance of 69 km, between Yongin-si in Kyunggi-do and Samsung-dong in Seoul on October in 2000 and April in 2001. After appropriate sample preparation, waters were analyzed for the dissolved constituents and sediments. The pH values of river waters were in the range of 7.0 to 9.3 and could be plotted in the area of surface environment. The level of $Ca^{2+}$, , CI-, sol-, N0$_{3}$ and HC0$_{3}$ in the Tancheon River were higher than those in world average river water. Most of dissolved constituents in the river waters increased toward downstream from upstream. In particular, high concentrations of Zn2+, Na$_{+}$, CI$^{-}$, SO$_{4}^{2-}$ and N03- were found near densely residential areas and the Sungnam waste water treatment plant. The relative ion enrichment was caused by the inflow of local domestic and industrial sewages. Also, Ca2+ and HC03- concentrations were enriched in the middle of the Tancheon River due to the dissolution of cements. This indicates that the apartment complexes were built on a large scale in the upriver since these ten years and large amounts of construction materials such as cements were flowed into the Tancheon River. Concentrations of heavy metals (Mn, Cd, Cu, Pb, Zn) in sediments from the Tancheon River exceeded the lower limit of tolerence level in bottom sediment established by the Ontario Ministry of the Environment (OME) of Canada. In particular, these metals were highly elevated in sediment (TSM-12) collected from near the Sungnam waste water treatment plant. Heavy metals were higher enriched in sediments collected from dry period rather than wet period.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.26-36
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• 2020

This study aimed at investigating present research and knowledge-base on climate change adaptation in ecosystem sector and analyzed the current status of basic information on ecosystem that functions as evidence-base of climate change adaptation to deduce the suggestions for the future development for knowledge and information in biodiversity. In this perspective, a questionary survey titled as "the ecological knowledge-base and information needs for climate change adaptation" with the researchers who were engaged with adaptation studies for biodiversity in the ecosystem related-research institutes including national and 17 regional local governments-affiliated agencies in Korea. The results are as follows; current status of utilizing ecological information which supports climate change adaptation strategy, future needs for adaptation knowledge and ecological information, and activation of utilizing ecological information. The majority of respondents (90.7%) replied that the ecological information has high relevance when conducting research on climate change adaptation. However, only half of all respondents (53.2%) agreed with the real viability of current information to the adaptation research. Particularly, urgent priority for researchers was deduced as intensifying knowledge-base and constructing related information on 'ecosystem change from climate change (productivity, community structure, food chain, phenology, range distribution, and number of individuals) with the overall improvement of information contents and its quality. The respondents emphasized with the necessity of conducting field surveys of local ecosystem and constructing ecosystem inventories, advancing monitoring designs for climate change in ecosystem, and case studies for regional ecosystem changes with the guidance or guidelines for monitoring ecosystem change to enhance the quality of adaptation research and produce related information. In terms of activation for ecological information usage, national and local adaptation network should be working based on the integrated ecological platform necessary to support exchanges of knowledge and information and to expand ecosystem types in time and spatial dimension.

• Journal of Environmental Impact Assessment
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• v.29 no.1
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• pp.1-7
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• 2020

This study aims to evaluate the effect of artificial facilities constructed afterthe release of the civilian controlled zone (CCZ) in Cheorwon on the inhabitation of cranes. The study site was released from the CCZ in 2012, and several barns have been built since 2017. The average number of Red-crowned Cranes was 9.3±4.3 individuals (±Standard Deviation) in the period before the release of the CCZ from 2009 to 2012, and it decreased by ca. one third of Red-crowned Crane's average individuals were showing 3.5±0.5 individuals after release. The average number of White-naped Cranes also appeared to be decreased by ca. 90% from 63.3±24.6 to 6.0±6.0 individuals. This results suggest that the construction of greenhouses and barns after the releasing of the CCZ affected the decrease of the population of these two crane species. In the case of Red-crowned Crane, the core area tended to move away from the area where barns were built. However, the distribution range of Red-crowned Cranes did not change significantly we expected because the study area was not their favorite place since 2012 when the area was released from the CCZ. The density of the White-naped Crane was relatively high even in the area where greenhouses were built, but after 2017 when the barn was built intensively, core habitat of crane became shrink and fragmented. These results suggest that both Red-crowned Cranes and White-naped Cranes response sensitively against habitat change due to the construction of barns. Since the release of the CCZ, the construction of the greenhouse has been influenced on the distribution of cranes, but subsequently, the construction of the barn seems to have caused a bigger change in their core habitat because the passage of people to barns is more frequent than the greenhouses.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.227-249
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• 2016

Arsenic and its compounds vary in their toxicity according to the chemical forms. Inorganic arsenic is more toxic and known as carcinogen. The provisional tolerable weekly intake (PTWI) of $15{\mu}g/kg$ b.w./week established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has been withdrawn, while the EFSA panel suggested $BMDL_{0.1}$ $0.3{\sim}8{\mu}g/kg\;b.w./day$ for cancers of the lung, skin and bladder, as well as skin lesions. Rice, seaweed and beverages are known as food being rich in inorganic arsenic. As(III) is the major form of inorganic arsenic in rice and anaerobic paddy soils, while most of inorganic arsenic in seaweed is present as As(V). The inorganic arsenic in food was extracted with solvent such as distilled water, methanol, nitric acid and so on in heat-assisted condition or at room temperature. Arsenic speciation analysis was based on ion-exchange chromatography and high-performance liquid chromatography equipped with atomic absorption spectrometry and inductively coupled plasma mass spectrometry. However, there has been no harmonized and standardized method for inorganic arsenic analysis internationally. The inorganic arsenic exposure from food has been estimated to range of $0.13{\sim}0.7{\mu}g/kg$ bw/day for European, American and Australian, and $0.22{\sim}5{\mu}g/kg$ bw/day for Asian. The maximum level (ML) for inorganic arsenic in food has established by EU, China, Australia and New Zealand, but are under review in Korea. Until now, several studies have conducted for reduction of inorganic arsenic in food. Inorganic arsenic levels in rice and seaweed were reduced by more polishing and washing, boiling and washing, respectively. Further research for international harmonization of analytical method, monitoring and risk assessment will be needed to strengthen safety management of inorganic arsenic of foods in Korea.

• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.332-341
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• 2010

The chemical composition characteristics of jujube wine using different preparation methods including extraction in -soju (25%) and fermentation were investigated. The jujube wine was prepared by soaking in soju using- whole fruit(WJ-S1) or seed-removed fruit(WJ-S2). Fermentations of the jujube wine were started by using whole fruit(WJ-F1), seed-removed fruit(WJ-F2) or extracts of whole fruit(WJ-F3) after adding 24% sucrose. The pH of all samples decreased from a range of 4.92~5.42 at the start time to 3.66~4.97 after 100 days. The treatment WJ-F3 showed the lowest pH among all treatments. Total acid content was 0.67~1.01% at the initial stage and then changed to 0.51~0.88% after 100 days. Total sugar and reducing sugar contents were 1.20~13.8% and 0.50~4.45% at initial stage and then changed to 1.53~4.52% and 1.75~3.82% after 100 days respectively. These sugars decreased during the preparation and fermentation of the jujube wine. The amounts of free sugars including fructose, glucose, and sucrose ranged from 1.53~4.52% and treatment WJ-F3 showed the highest amount(1.95~13.64%) compared the other treatment. Glucose level were high in treatment WJ-S1 and WJ-S2, and fructose was increased in treatments WJ-F1, WJ-F2, and WJ-F3 after 60 days. Amino nitrogen content was 0.02~0.11% after 20 days and 0.07~0.14% after 40 days respectively. Solid content was 2.68~7.76% at the initial fermentation stage and changed to 4.81~9.73% after 100 days. Hunter color(L values) were 88.45~96.74 at the initial stage and then changed to 92.62~100.45 after 100 days. Preference tests a significant difference between the two types (extraction and fermentation) of jujube wine. And treatment WJ-S2 received the highest preference scores among the all treatments.

• Food Science of Animal Resources
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• v.23 no.2
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• pp.128-136
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• 2003

This study was peformed to evaluate physico-chemical and textural properties, and shelf-life effect of low-fat functional sausages(LFFS) manufactured with sodium lactate(SL), lac color and various molecular weights of chitosans(low=1.5 kDa, medium=30∼40 kDa and high=200 kDa) during storage at 4$^{\circ}C$ for 8 weeks. LFFS had a pH range of 6.39∼6.50, 76∼78% moisture, <2% fat, 14∼15% protein. The combination of SL and low molecular weight(MW) of chitosan improved water holding capacity(WHC), however those of SL and medium MW of chitosan reduced WHC. Vacuum purge(VP) reduced with increased MW of chitosans during refrigerated storage. The addition of chitosans reduced the lightness and yellowness, but increased the redness values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm. LFFS containing SL and medium MW of chitosan increased most texture profile analysis(TPA) values, as compared to controls with 75 and 150 ppm. The addition of SL in LFFS retarded the microbial growth for Listeria monocytogenes, however no synergistic effect with the addition of chitosans were observed. E coli O157:H7 and Salmonella typhimurium reduced during refrigerated storage, regardless of SL and chitosan treatments. Increased storage time increased values for VP, yellowness and textural properties. These results indicated that the combination of SL and various MW of chitosans affected the functional and textural properties, and inhibited the microbial growth for LM effectively. In addition, 0.5% lac color as a replacer for sodium nitrite improved the color development, resulting in similar hunter color values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.555-561
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• 2008

Ninety-nine samples of powdered infant formula in a market were collected from the local market and their contaminations for total aerobic bacteria, coliform, FAO/WHO Category A, B, and C pathogens were analyzed. Total aerobic bacteria were detected in 92 of 99 samples (93%) at levels of $1.83{\pm}0.68\;Log\;MPN/g$. These levels were below legal levels specified for infant formulas except for one sample detected by 4.5 Log CFU/g. Coliform was detected in 12 of 99 samples (12%) at levels of $1.26{\pm}1.03\;Log\;MPN/g$ whereas non-detection was required according to the specification of coliform in infant formulas. Escherichia coli was detected in 1 of 99 samples by 0.48 Log MPN/g. Salmonella and Enterobacter sakazakii among Category A weren't detected in all the samples. Enterobacteriaceae, Category B group, were detected in 25 samples of total 99 samples (25%) by $0.83{\pm}1.37\;Log\;MPN/g$. Enterobacteriaceae identified by API 20E were Escherichia vulneris, Es. hermannii, Pantoea spp., Citrobacter koseri, Klebsiella pneumoniae, En. cloaceae. Bacillus cereus among Category C was highly detected in 29 of 99 samples (29%) at levels of $0.69{\pm}0.32\;Log\;MPN/g$ with the most probable number count method, which were below legal levels for the specification of B. cereus in infant formulas. Clostridium perfringens, E. coli O157, Staphyloccus aureus, Listeria monocytogenes, Yersinia enterocolitica, and Campylobacter jejuni/coli were not detected. Contamination level of major pathogens was low and falls within the range of specification of infant formulas. However, Enterobacteriaceae and B.cereus showed the high prevalence and some Enterobacteriaceae causing disease were detected. Therefore, it is necessary to monitor the potential pathogens continually and reduce them to improve the microbial quality of non-sterilized powdered infant formulas.

• Journal of Life Science
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• v.27 no.10
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• pp.1152-1160
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• 2017

A unicellular green alga was axenically isolated from a tidal pool on Ulleung-do, Korea. Morphological, molecular, and biochemical analyses revealed that the isolate belonged to Auxenochlorella protothecoides. The current study is the first record of this species in Korea. The microalgal strain was named as A. protothecoides MM0011 and its growth, lipid and pigment compositions, and biomass properties were investigated. The strain is able to thrive in a wide range of temperatures ($5{\sim}35^{\circ}C$) and to withstand up to 1.5 M NaCl. The results of GC/MS analysis showed that the isolate was rich in nutritionally important polyunsaturated fatty acids (PUFAs). Its major fatty acids were linoleic acid (27.6%) and ${\alpha}-linolenic$ acid (39.6%). Thus, this indigenous microalga has potential as an alternative source of ${\omega}3$ and ${\omega}6$ PUFAs, which currently come from fish and plant oils. Also, the HPLC analysis revealed that the value-added antioxidant, lutein, was biosynthesized as the accessory pigments by the microalga. A proximate analysis showed that the volatile matter content was 85.6% and an ultimate analysis indicated that the gross calorific value was $20.3MJ\;kg^{-1}$. Since 40.5% of total nitrogen and 27.9% of total phosphorus were removed from the medium, respectively, it also has potential as a feedstock for biofuel applications which could be coupled to wastewater treatment. In addition, the biomass may also serve as an excellent animal feed because of its high protein content (51.4%). Therefore, A. protothecoides MM0011 shows promise for application in production of microalgae-based biochemicals and as a biomass feedstock.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.3
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• pp.203-212
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• 2005

Cellulose insulation is primarily manufactured from recycled newsprint and treated with fire retardants for the fire resistance. Thanks to the fire retardants, it is not combustible and flammable. In addition to that, Its thermal resistance is much better than that of fiberglass or rock wool. It is made from waste paper and easily decayed when it is demolished, and it has small embodied energy. So it is very environment-friendly building material. For broader use of cellulose insulation in buildings in Korea, it is necessary to test its physical performance to compare the results with the requirements on the Korean Building Code. To this end, apparent thermal conductivity (ka) measurements of Korean-made loose-fill cellulose insulations were recently completed using equipment that was built and operated in accordance with ASTM C 518 and the fire resistance was tested in accordance with ASTM C 1485. Korean loose-fill cellulose has thermal conductivity about 5% greater than the corresponding U.S. product at the same density. This is likely due to differences in the recycled material being used. Both spray-applied and loose-fill cellulose insulation lose about 1.5% of their thermal resistivity for $5.5^{\circ}C$ increase in temperature. The fire resistance of cellulose insulation is increased in linear proportion to the increase of the rate of fire retardant. Thanks to the high fire resistance, cellulose insulation can be used as a substitution of Styrofoam or Urethane foam which is combustible. The thermal conductivity of cellulose insulation was $0.037-0.043W/m{\cdot}K$ at the mean specimen temperature from $4-43^{\circ}C$. It corresponds to the thermal resistance of "Na Grade" according to the Korean Building Code. The effect of chemical content on thermal conductivity was negligible for all but the chemical-free specimen which had the highest value for the thermal conductivity over the temperature range tested. The thermal resistance of cellulose insulation is better than that of fiberglass or rock wool, and its fire resistance is higher than that of Styrofoam or Urethane foam. Therefore it can be substituted for those above considering its physical performance. Cellulose insulation is no more expensive than Styrofoam or rock wool, so it is recommended to use it more widely in Korea.

• Tuberculosis and Respiratory Diseases
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• v.46 no.4
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• pp.564-573
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• 1999

Background: With variable symptoms and nonspecific radiographic appearances, pulmonary embolism (PE) is a frequent and often undiagnosed cause of mortality and morbidity. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study suggested that the majority of patients undergoing ventilation-perfusion (V-Q) scan would require additional studies to establish or to exclude the diagnosis of PE. Pulmonary angiography has been regarded as gold standard for diagnosis of PE. However, it is an invasive procedure that may be associated with significant notable morbidity and mortality. Thus, availability of an accurate, noninvasive screening examination is highly desirable. Method: From October 1994 to February 1997, twenty patients (male 13, female 7, range 23-91 years, median 58 years) who were suspected as pulmonary embolism on the basis of clinical evidence and underwent the spiral volumetric computed tomography (spiral CT), were studied retrospectively to evaluate the effectiveness of spiral CT as a diagnostic tool in PE. Results: PE could be excluded with spiral CT in 4 patients ; diagnoses of these patients were lung cancer, pneumonia with lung abscess, bilateral pleural effusion due to congestive heart failure, nonspecific pulmonary abnormality retrospectively. One patient who disclosed high probability in V/Q scan, could be diagnosed as pneumonia with lung abscess and underlying emphysema with spiral CT. Among 4 patients who showed intermediate and low probability in V/Q scan, 3 patients could be confirmed as PE with spiral CT. Spiral CT was helpful in 3 patients, in whom V/Q scan could not be performed due to other reasons (e.g. night time, mechanical ventilation) to confirm the diagnosis of PE. Spiral CT could demonstrate embolus above lobar artery level in 11 patients, and up to segmental artery level in 5 patients. Conclusion: This study demonstrated that spiral CT could allow accurate demonstration of thrombotic clots in centrally localized embolism. Spiral CT could be effective, specific, noninvasive and useful diagnostic screening modality for the diagnosis of pulmonary embolism.