• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.4
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• pp.265-273
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• 2005

Chemical properties and heavy metal concentrations of forest soils of four abandoned coal mine lands affected by coal mining activities in the Mungyeong area were investigated to provide basic information for revegetation of abandoned coal mine lands. Soil pH in abandoned coal mine lands ranged from 5.30 to 6.76 it in the control site was 5.23. Contents of organic matter and total N in abandoned coal mine lands were $4.46\~7.19\%\;and\;0.07\~0.15\%$, respectively. Available P contents were 6.54 for A (Samchang), 6.52 for B (Bongmyeong),3.94 fur C (Kabjung), 5.45 mg/kg for D (Danbong coal mine land) and 5.25 mg/kg for the control site, which had a positive correlation with soil pH. Contents of exchangeable Ca, Mg, K and Na in abandoned coal mile lands averaged 196.1, 88.7, 88.2 and $10.2cmol^+/kg$, with a range of $132.1\~242.1,\;24.2\~138.\; 64.9\~120.8\;and\;8\~12.2cmol^+/kg$, respectively. Those of the control site were 192.8, 95.8, 104 and $21.2 cmol^+/kg$, respectively. Heavy metals such as Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn of forest soil in abandoned coal mine lands have a larger content than those of the control site. Al, Mn and fb content was especially high in abandoned coal mine lands. The Al content of forest soil in abandoned coal mine lands ranged from 397 to 917 ppm, which was considered to be high enough to inhibit tree growth. Therefore, it is suggested that soils of abandoned coal mine lands contaminated by mining activities need to be properly treated for remediation of environmental problems.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.31-39
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• 2017

From July to August 2013, liquid fertilizers produced at 180 liquid manure public resource centers and liquid fertilizer distribution centers were collected. The maturity of liquid fertilizers was measured using the mechanical maturity measurement device. The nutrient contents (nitrogen, phosphorus, and potassium), physicochemical properties, and heavy metal content of 46 liquid fertilizers were investigated in this study. We used a matured liquid fertilizer with a total number of 46, with number of 7 for Gyeonggi-do, 3 for Chungcheongbuk-do, 2 for Chungcheongnam-do, 13 for Jeollabuk-do, 5 for Jeollanam-do, 3 for Gyeongsangbuk-do, 11 for Gyeongsangnam-do, 1 for Daejeon, and 1 for Jeju-do. The physicochemical properties were as follows: pH 8.0, EC 11.6 mS/cm, SS 5,188 mg/L, TKN 847mg/L, ${{NH_4}^+}-N$ 317 mg/L, ${{NO_3}^-}-N$ 170 mg/L, Org-N 360 mg/L, TP 193 mg/L, and TK 2,557 mg/L. The total amount of NPK was 3,596 mg/L. The total amount of N-P-K was as follows: a number of 2 at 1,000-2,000 mg/L (4%), a number of 17 at 2,000-3,000mg/L (37%), a number of 11 at 3,000-4,000mg/L (24%), and a number of 16 at 4,000mg/L or more (35%). Thus, 41% of the mature liquid fertilizers were below the official standard of commercial fertilizer (livestock manure liquid fertilizer) (0.3% of the total amount of N-P-K). Most of the N-P-K total amount showed non-uniform characteristics of low nitrogen and low phosphoric acid due to the potassium concentration. The average heavy metal content in the matured liquid fertilizer was as follows: As, not detected; Cd, 0.01 mg/kg; Hg, not detected; Pb, 0.02 mg/kg; Cr, 0.14 mg/kg; Cu, 6.89 mg/kg; Ni, 0.44 mg/kg; and Zn, 20.70 mg/kg. Thus, the official standard of commercial fertilizer was satisfied in all categories, indicating a safe level.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.306-314
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• 2023

Stream sediments are an important component of water quality management because they are receptors of various pollutants such as heavy metals and organic matters emitted from upland sources and can be secondary pollution sources, adversely affecting water environment. To effectively manage the stream sediments, identification of primary sources of sediment contamination and source-associated control strategies will be required. We evaluated the performance of machine learning models in identifying primary sources of sediment contamination based on the physico-chemical properties of stream sediments. A total of 356 stream sediment data sets of 18 quality parameters including 10 heavy metal species(Cd, Cu, Pb, Ni, As, Zn, Cr, Hg, Li, and Al), 3 soil parameters(clay, silt, and sand fractions), and 5 water quality parameters(water content, loss on ignition, total organic carbon, total nitrogen, and total phosphorous) were collected near abandoned metal mines and industrial complexes across the four major river basins in Korea. Two machine learning algorithms, linear discriminant analysis (LDA) and support vector machine (SVM) classifiers were used to classify the sediments into four cases of different combinations of the sampling period and locations (i.e., mine in dry season, mine in wet season, industrial complex in dry season, and　industrial complex in wet season). Both models showed good performance in the classification, with SVM outperformed LDA; the accuracy values of LDA and SVM were 79.5% and 88.1%, respectively. An SVM ensemble model was used for multi-label classification of the multiple contamination sources inlcuding landuses in the upland areas within 1 km radius from the sampling sites. The results showed that the multi-label classifier was comparable performance with sinlgle-label SVM in classifying mines and industrial complexes, but was less accurate in classifying dominant land uses (50~60%). The poor performance of the multi-label SVM is likely due to the overfitting caused by small data sets compared to the complexity of the model. A larger data set might increase the performance of the machine learning models in identifying contamination sources.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.197-197
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• 2010

음식물쓰레기의 삼성분은 수분, 휘발분, 회분이며 이들이 차지하는 비율은 계절, 지역별로 다소 상이하지만 수분 약 80%, 회분3%, 휘발분 17%이다. 음식물쓰레기 전처리과정으로 이물질제거, 탈수공정이 있으며 탈수공정에서 다량의 탈리액이 발생한다. 본 연구에서는 탈리액을 데칸타를 이용하여 1차로 원심분리하여 고.액 분리한 액을 실험대상으로 하였다. 실험대상 탈리액의 물성은 BOD 78,800[mg/l], COD 41,000[mg/l], 부유물질 25,900[mg/l], 총질소 928[mg/l]이었다. 탈리액에는 기름성분(육류, 식용유등), 입자상물질등이 포함되어 있으며 이들은 난분해성 유기물질로, 이를 제거하는데 기존의 처리방법으로 많은 어려움이 있어 주요한 수질오염 발생원이 되고 있다. 예를들면 하수처리장 폭기조 수면에 유막을 형성하여 산소공급을 방해함으로 미생물번식을 방해하는 요인이 된다. 본 연구는 음식물쓰레기 탈리액의 수분, 고형분, 유분으로의 삼상분리에 관한 것이다. 유분은 에멀젼형태로 안정되게 수층에 분산되어 존재한다. 미세기포를 이용한 부상법의 경우 미세기포 표면과 유분의 화학적친화력이 낮아 기포표면에 유분이 잘 부착되지 않으며, 원심분리 방법만으로는 유분 분리효율이 낮고, 추출에 의한 분리시 추출액이 다량 소요되고 처리시간이 길며 추출액 비용이 많이 소요된다. 탈리액을 유분, 슬러지, 수분으로 분리하면 환경오염을 일으키는 주요성분을 신재생에너지 원료로 활용할 수 있다. 유분의 주성분이 동식물성 유지이므로 전처리시 산촉매를 이용 수분과 유리지방산을 제거하고 염기성촉매를 이용하여 전이에스테르화 반응을 거치면 바이오디젤인 FAME과 글리세롤으로 변환하므로 글리세롤을 분리하면 바이오디젤을 얻을 수 있다. 슬러지는 입자상 물질로 착화가 잘 되고 건조하면 발열량이 높으며 중금속등에 오염되지 않아 청정연료로 활용이 가능하다. 실험실에서의 탈리액 삼상분리방법은 다음과 같다. 탈리액 30ml당 추출액으로 노말헥산을 1ml를 가한 다음 플라스크에서 $80^{\circ}C$로 가열 후 방냉한다. 가열중 노말헥산의 손실을 방지하기 위하여 증발가스를 콘덴서에서 응축하여 플라스크로 재순환한다. 탈리액을 플라스크에서 꺼내어 원심분리기 rack에 300-400g씩 병에 각각 넣고 4,000rpm으로 30분간 운전한다. 탈리액은 상부로부터 유분층, 미세입자층, 수층, 슬러지층으로 분리된다. 각 층의 계면에서 2종의 성분이 약간 섞일 수 있다. 유분을 분리한 후 유분층 잔존물과 미세입자층, 수층 상층부의 혼합물을 취하여 50g씩 병에 넣고 3,500rpm으로 10분간 운전한 후 유분을 분리한다. 마지막으로 미세입자층만을 3,500rpm으로 10분간 원심분리한 후 유분을 따로 분리한다. 얻어진 유분은 rotary evaporator에서 $120^{\circ}C$로 가열하여 유분과 노말헥산을 분리하며 분리효율을 제고하기 위하여 감압하에서 운전한다. 분리된 유분의 고위발열량이 9,450[Kcal/kg]이었으며 원소분석 결과 탄소 74.7%, 수소 12.55%, 질소 0.08%, 유황분 0.0003%이었다. 분리된 유분의 양은 계절별로 시료별로 다르며 가을철에는 1.6-1.9%, 여름철은 1.0-1.3%이었다. 분리된 슬러지로부터 Hg, As, Cr, Cd, Pb 중금속 성분이 검출되지 않았으며 수분 2.8%, 휘발분 76.85%, 회분 7.52%, 고정탄소 12.83%이었고 원소분석결과 탄소 45.25%, 수소 7.46%, 질소 5.05%, 산소 34.39%, 유황분 0.33%이었으며 저위발열량은 4,480[Kcal/kg]이었다. 분리된 슬러지 양은 11-19% 이었다.

• Journal of Life Science
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• v.25 no.10
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• pp.1098-1102
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• 2015

FABPpm (plasma membrane-bound fatty acid binding protein ) is highly expressed in skeletal muscle. The principal role of this protein is modulating fatty acid uptake and metabolism. The influence of insulin-like growth factor-I (IGF-I), which is a major regulator of skeletal muscle cells, on FABPpm in skeletal muscle cells has not been investigated. To determine the effect of IGF-I on the expression of FABPpm, differentiated C2C12 murine skeletal muscle cells were treated with 20 ng/ml of IGF-I for different times. IGF-I increased the expression of FABPpm in a time-dependent manner. The mRNA level of FABPpm was measured by real-time quantitative PCR to determine whether the IGF-1-induced induction of FABPpm was regulated pretranslationally. The IGF-I treatment resulted in very rapid induction of the FABPpm mRNA transcript in the C2C12 myotubes. After 24 and 48 hr of the IGF-I treatment, FABPpm mRNA increased 130 and 179%, respectively. The increase in the protein expression returned to control levels after 72 hr of the IGF-I treatment, suggesting that IGF-1 regulated the FABPpm gene pretranslationally in skeletal muscle cells. This is the first evidence that IGF-I has a modulatory effect on the expression of FABPpm. In conclusion, IGF-I induced rapid transcriptional modification of the FABPpm gene in C2C12 skeletal muscle cells and exerted modulatory effects on FABPpm.

• Analytical Science and Technology
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• v.25 no.6
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• pp.441-446
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• 2012

In this study, mercury, methylmercury and heavy metals in sediment from the lake Andong were analyzed, along with the estimation of mercury flux between sediments and water in the lake Andong. Average mercury concentrations in sediments sampled in 2009~2011 were $155.0{\pm}71.9$ ng/g, $211{\pm}62$ ng/g and $198{\pm}6.88$ ng/g, respectively. The average methylmercury concentration were $1.85{\pm}1.09$ ng/g (2009) and $3.49{\pm}1.79$ ng/g (2011), and %methylmercury, the fraction of methylmercury in total mercury were $1.17{\pm}0.39%$ and $1.77{\pm}0.94%$, respectively. Heavy metal (Zn, Cd, Pb, Cu) concentrations of the sediments exceeded ERL (Effect Range Low) level of US NOAA (National Oceanic and Atmospheric Administration)'s sediment quality criteria. Estimated mercury sedimentation flux was found to be 83.7 $ng/cm^2{\cdot}yr$ and mercury diffusion flux was estimated as 1.24 $ng/cm^2{\cdot}yr$.

• Herbal Formula Science
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• v.25 no.4
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• pp.483-497
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• 2017

Background : Behavioral stress has been suggested as one of the significant factors that is able to disrupt physiological systems and cause depression as well as changes in various body systems. The stressful events can alter cognition, learning, memory and emotional responses, resulting in mental disorders such as depression and anxiety. Results : We used a restraint stress model to evaluate the alteration of behavior and stress-related blood parameter. The animals were randomly divided into two groups of five animals each group. Furthermore, we assessed the change of body weight to evaluate the locomotor activity as well as status of emotional and anxiety in mice. After 7 days of restraint stress, the body weight had significantly decreased in the restraint stress group compared with the control group. We also observed stress-associated behavioral alterations, as there was a significant decrease in open field and forced swim test, whereas the immobilization time was significantly increased in the stress group compared to the control group. We observed the morphological changes of neuronal death and microglia by immunohistochemistry and western blot. In our study restraint stress did not cause change in neuronal cell density in the frontal cortex and CA1 hippocampus region, but there was a trend for an increased COX-2 and iNOS protein expression and microglia (CD11b) in brain, which is restraint stress. Conclusion : Our study, there were significant alterations observed in the behavioral studies. We found that mice undergoing restraint stress changed behavior, confirming the increased expression of inflammatory factors in the brain.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.2
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• pp.193-199
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• 2017

Objectives : Insomnia may be one of the risk factor for suicidal ideation, but little is known about the mechanism by which sleep disturbances confer risk for suicide. The aim of this study was to investigate examine whether insomnia severity would be associated with resilience and suicidal ideation, and whether resilience would mediate the relationship between insomnia and suicidal ideation. Methods : A total of 432 community-dwelling adults(227 male, 205 female,) completed the self-report questionnaire that covered basic socio-demographic data. To assess the psychological variables, the following instruments were applied: Insomnia Severity Index(ISI), Korean Version of the Connor-Davidson Resilience Scale(K-CD-RISC), Beck Hopelessness Scale(BHOP) and Scale for Suicidal Ideation(SSI-Beck). People with an ISI score of 8 or higher were defined as insomnia. Results : Greater insomnia symptom severity was significantly associated with higher level of suicidal ideation and lower level of resilience, adjusting for hopelessness, age, sex, presence of family members living together, and household income. Additional analysis revealed that disturbance of sleep initiation and disturbance of sleep maintenance were significantly associated with suicidal ideation. Mediation analyses revealed that resilience significantly accounted for the relationship between insomnia symptom severity and suicidal ideation. Conclusions : These findings suggest that the evaluation and control of insomnia and resilience may be needed to reduce the risk of suicide.

• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.628-635
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• 1999

Direct preparative method of 2,6-diformyl-p-cresol and 2-hydroxy-3-hydroxy-5-methylbenzaldehyde from 2,6-bis(hydroxymethyl)-4-methylphenol using activated $Mn(IV)O_2$ was described. Hexadentate compartmental Iigands, $H_4L[A]\;and\; H_4L[B]$ were prepared by condensation reactions of 2-hydroxy-3-hydroxy methyl-5-methylbenzaldehyde with ethylenediamine and 1,3-diaminopropane respectively. By the reaction of macrocycle($H_4[20]DOTA$) with Ln(III) nitrate {Ln(III)=Pr, Sm, Cd, Dy }, discrete mononuclear Ln(III) complexes of the type $[Ln(H_2[20]DOTA)(ClO_4)(H_2O)]\;{\cdot}\;3H_2O$ were synthesized in the solid state. $[Ln([20]DOTA)(NO_3)(H_2O)](NO_3)_2\;{\cdot}\;xH_2O$ was placed in methanol for 2 days, and $[Ln([20]DOTA)(NO_3)(CH_3OH)]^{2+}$ was formed. The equilibrium constants(K) for the substitution of coordinated $CH_3OH$ in the Ln-[20]DOTA complexes by various auxiliary ligand, $L_a$(=salicylic acid, p-chlorobenzoic acid, benzoic acid, acetic acid, 4-bromophenol) were determined spectroscopically at 25$^{\circ}C$ and 0.1M $NaClO_4$. The K values calculated were in the order of salicylic acid > p-chlorobenzoic acid > benzoic acid > acetic acid > 4-bromophenol, while pKa of auxiliary ligands was in the opposite trend.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.137-145
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• 2004

Limestone zone in korea have been distributed to diagonal line so that it is wide from the Gangwondo to the Jeonlanamdo. The limestone cavity and fractured zone were formed by chemical weathering. Limestone cavity and fractured zone was reinforced with cemented milk(w/c=60%)by high pressure jet grouting by tripple -pipe to establish bridge foundation on the ground condition like limestone cavity. To analyze property of limestone and solid of cement milk(w/c=65%), mixed solid of cement, core NX size in the limestone cavity and fractured zone and compressive strength. Seismic tomograpy exploration was pcrforn1cd to analyze deformation modulus of limestone. The analysis suggests that deformation modulus of limestone has effect on uniaxial compressive strength, seismic velocity, seismic elasticity modulus. Average static elasticity modulus of limestone is $5.08{\times}10^5kgf/cm^2$, cement and coal mixed solid is $0.25{\times}10^5kgf/cm^2$, $0.095{\times}10^5kgf/cm^2$. Average seismic velocity of limestone is 5.240m/sec, cement and coal mixed solid is 2,211.3m/sec, 1,447.5m/sec. Average uniaxial compressive strength of limestone was $1,221.3kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $125.22kgf/cm^2$, $35kgf/cm^2$ each other. Average friction angle of limestone was $49.14^{\circ}$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $38.39^{\circ}, 25.83^{\circ}$ each other. Average cohesion of limestone was $137.7kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $23.5kgf/cm^2$, $15.5kgf/cm^2$ each other. Average deformation modulus of limestone was $2.84{\times}10^5kgf/cm^2$ and limestone specimen mixed with cement milk and solid of cement milk mixed with coal were $0.4{\times}10^5kgf/cm^2, 0.12{\times}10^5kgf/cm^2$ each other. It was analyzed that the elasticity and uniaxial compressive strength, seismic velocity of solid of cement milk mixed limestone pieces and coal had an highly interrelation regardless of existence of limestones pieces and coal but it had shown that limestones had an lower interrelation. In case of field seismic velocity and deformation of limestone, SIC solid of cement milk mixed with coal and limestone pieces had an highly interrelation.