• Journal of Biosystems Engineering
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• 제33권6호
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• pp.404-409
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• 2008

Excessive presence of heavy metals in environment affects plants and fruits grown in the contaminated area. Rapid on-site monitoring of heavy metals can provide useful information for efficiently characterizing heavy metal-contaminated sites and for minimizing the exposure of the contaminated food crops to humans. This study reports on the evaluation of gold and glassy carbon (GC) electrodes with mercury or bismuth as a coating material for simultaneous determination of cadmium (Cd) and lead (Pb) in 0.1 M $HNO_3$ solution by anodic stripping voltammetry (ASV). The use of a square-wave voltammetric potential between a working electrode and a reference electrode caused Cd and Pb ions deposited on the electrode surface to be oxidized, thereby generating electric currents at different potentials. The mercury-coated gold electrode was not sensitive enough to detect the usable range of Cd concentrations (1 to 100 ppb). The GC electrodes with mercury or bismuth displayed well-defined, sharp and separate current peaks for Cd and Pb ions when the square-wave voltammetric potentials were applied. The peak currents measured with both mercury- and bismuth- coated GC electrodes were linearly proportional to Cd and Pb concentrations in the range of 1 to 200 ppb in 0.1 M $HNO_3$ with strong linear relationships between concentration and peak current ($R^2$ > 0.95), indicating that both of Cd and Pb ions could be quantitatively measured.

• The Korean Journal of Ecology
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• 제27권1호
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• pp.15-20
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• 2004

With attention to different human activities around Anzali wetland and introduction of different pollutants containing heavy metals into this water ecosystem and absorption and accumulation of heavy metals in shell and muscle of Astacus leptodactylus which is native benthose of Anzali wetland and enjoys food and economic importance; Sampling of waters and sediments from 18 stations and shell and muscle of Astacus leptodactylus from 5 stations had been conducted. After biometric evaluation of Astacus leptodactylus, the chemical analysis of the samples by using international and standard methods and then their heavy metals content was determined by Atomic Absorpotion Spectrophotometer (AAS), model P.U 9400 philips. Result of the analysis stated that; 1) The mean values of Cr, Zn, Pb, Ni, V in Anzali waters were 6.4, 184.5, 28.8, 28.9, 47.1 ($\mu$ gr/lit) respectively, which comparing to the international standards, is not suitable for drinking, but it can be used for agricultural and aquacultural purposes. Even though the concentration of heavy metals in sediments were high, there are in range of acceptable limit for aquatics organisms; 2) Comparatively, the concentration of heavy metals in shell and muscle of Astacus leptodactylus in Anzali wetland (Cr, Zn, Pb, Ni, V in shell were 3.48, 109.3, 14.13, 7.17, 36.2 and in muscle were 2.98, 131.98, 3.12, 4.77, 9.05 ppm respectively) were more than what is determined for Aras dam (in shell were 1.6, 224.3, 7.8, 7.6, 10.3 and in muscle were 1.4, 60.2, 0.45, 2.7, 4.4 mg/kgr respectively); 3) For all samples, concentration of heavy metals in all Astacus leptodactylus in Anzali wetland and Aras dam, was at tolerance level for human consumption; 4) There was no association with significant difference between weight and size of Astacus leptodactylus with absorption and accumulation of heavy metals; but there was a significant association between heavy metals content in water and in sediments, and in sediments, shell and muscle of Astacus leptodactylus in Anzali wetland.

• 기술혁신연구
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• 제19권3호
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• pp.57-83
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• 2011

본 연구에서는 CGE(Computable General Equilibrium)모형을 이용하여 28개 산업별 R&D투자액의 GDP 파급효과를 추정한 뒤, 그 결과로써 GDP의 R&D투자탄력성을 계산하여 산업별 R&D 투자 우선순위를 제시하였다. 우선순위는 28개 대분류 산업 중 전체 연구 개발투자에서 차지하는 비중이 1% 미만인 16개 산업을 제외한 12개 산업에 대해서만 적용해 보았다. 먼저 GDP의 R&D투자 탄력성에 근거한 우선순위는 제1차 금속제품, 화학제품, 음식료품, 전기 및 전자기기, 수송장비, 금속제품, 정밀기기, 전력 가스 및 수도, 일반기계, 통신 및 방송, 건설, 사회 및 기타 서비스, 부동산 및 사업 서비스 순이었다. GDP의 R&D투자탄력성에 근거한 순위설정은 비교적 우리나라 산업들의 현황을 잘 보여주고 있는 것으로 판단된다. 보조 지표인 2030년 기준 균형 대비 GDP 증가율에 근거한 우선순위 역시 판정기준으로 유사한 결과를 보여주었다. 결국 두 개의 우선순위 기준은 국가과학기술위원회의 R&D예산투자방향 및 기준 설정과 주요 사업별 예산배분 방향에 좋은 판정기준으로 활용될 수 있음을 보여주었다.

• 한국도서관정보학회지
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• 제49권3호
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• pp.429-458
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• 2018

본 연구에서는 익산시 공공도서관의 시설과 운영에 대해 분석하고, 그 결과를 바탕으로 지역발전에 기여하는 도서관 발전 전략을 수립하였다. 지속적으로 확충하고 있는 도서관 시설에 걸맞은 선진국 수준의 도서관 역할을 수행하기 위하여 사서의 충원이 절실하다. 익산시 도시 정책과 특성을 살려 각 도서관에 맞게 '역사문화', '근대 향토문화', '보석 귀금속', '식품클러스터', '여성', '행정 복지', '환경과 생태' 등의 주제로 도서관 특성화 방안을 제시하였다. 본 연구에서 제시하는 방법인 영어도서관 운영과 청소년 도서관 설립으로 교육도시 익산에서 도서관의 역할이 강화될 수 있다. 도서관의 특성화 중심 운영은 익산시 공공도서관의 전반적 기능과 역할을 강화할 수 있는 방안이다.

• Journal of Applied Biological Chemistry
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• 제60권3호
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• pp.257-263
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• 2017

A cellulolytic strain Y2 was isolated from soil obtained in the Canadian Alpine region. The isolate was identified as Paenibacillus sp. Y2 by 16S rRNA sequencing. When grown in LB medium supplemented with carboxymethyl-cellulose (CMC), CMCase production increased to 122.0% of that observed in LB without CMC. Culture supernatant was concentrated by ultrafiltration and 80% ammonium sulfate precipitates were separated by Hi-Trap Q and CHT-II chromatography. The purified enzyme (EG-PY2) showed a homogeneous single band and the molecular mass was estimated to be 38 kDa by SDS-PAGE. Optimum pH and temperature of the enzyme were 4.5 and $30^{\circ}C$, respectively. The half-life of enzyme activity at 50 was 140.7 min, but the enzyme was drastically inactivated within 5 min at $55^{\circ}C$. The enzyme was highly activated to 135.7 and 126.7% by 5.0 mM of $Cu^{2+}$ or $Mg^{2+}$ ions, respectively, and moderately activated by $Ba^{2+}$ and $Ca^{2+}$ ions, whereas it was inhibited to 76.8% by $Fe^{2+}$, and to ${\leq}50%$ by $Mn^{2+}$, $Co^{2+}$, $Zn^{2+}$, and EDTA. The enzyme was activated to 211.5% in the presence of 0.5 M of NaCl and greatly tolerant to 3.15M of NaCl. The enzyme showed 2.98 times higher ${\beta}$-glucanase activity than CMCase activity. Based on these results, it can be concluded that EG-PY2 is an acidophilic, cold-active, and halotolerant endoglucanase. The authors suggest it is considered to be useful for various industrial applications, such as, fruit juice clarification, acidic deinking processes, high-salt food processing, textile and pulp industries, and for biofuel production from seaweeds.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1615-1620
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• 2010

Bis-[dipyrido[3,2-$\alpha$:2',3'-c]phenazine)$_2$(1,10-phenanthroline)$_2Ru_2$]$^{2+}$ complexes (bis-Ru(II) complexes) tethered by linkers of various lengths were synthesized and their binding properties to DNA investigated by normal absorption and linear dichroism spectra, and fluorescence techniques in this study. Upon binding to DNA, the bis-Ru(II) complex with the longest linker (1,3-bis-(4-pyridyl)-propane), exhibited a negative $LD^r$ signal whose intensity was as large as that in the DNA absorption region, followed by a complicate $LD^r$ signal in the metal-to-ligand charge transfer region. The luminescence intensity of this bis-Ru(II) complex was enhanced. The observed $LD^r$ and luminescence results resembled that of the [Ru(1,10-phenanthroline)$_2$ dipyrido[3,2-$\alpha$:2',3'-c]phenazine]$^{2+}$ complex, whose dipyrido[3,2-$\alpha$:2',3'-c]phenazine (dppz) ligand has been known to intercalate between DNA bases. Hence, it is conclusive that both dppz ligands of the bis-Ru(II) complex intercalate. The binding stoichiometry, however, was a single intercalated dppz per ~ 2.3 bases, which violates the "nearest binding site exclusion" model for intercalation. The length between the two Ru(II) complexes may be barely long enough to accommodate one DNA base between the two dppz ligands, but not for two DNA bases. When the linker was shorter (4,4'-bipyridine or 1,2-bis-(4-pyridyl)-ethane), the magnitude of the LD in the dppz absorption region, as well as the luminescence intensity of both bis-Ru(II) complexes, was half that of the bis-Ru(II) complex bearing a long linker. This observation can be elucidated by a model whereby one of the dppz ligands intercalates while the other is exposed to the aqueous environment.

• 한국토양비료학회지
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• 제47권3호
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• pp.213-216
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• 2014

Arsenic is a known hazardous metalloid not only to the animals but also to plants. With high concentrations, it can impede normal plant growth and cause even death of plants at extremely high levels. A known plant response to stress conditions such as toxic levels of metal (loids) is the production of stress ethylene, causing inhibitory effect on root growth in plants. When the effect of various arsenic concentrations was tested to maize plant, the stress ethylene emission proportionately increased with increasing concentration of As(V). The inoculation of two arsenic tolerant bacteria; Pseudomonas grimonti JS126 and Pseudomonas taiwanensis JS238 having respective high and low 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity reduced stress ethylene emission by 59% and 30% in maize grown in arsenic polluted soils. The result suggested the possible use of Pseudomonas grimonti JS126 for phytoremediation of arsenic polluted soils.

• 대한예방한의학회지
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• 제16권3호
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• pp.167-183
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• 2012

Objective : Average, lowest, highest concentration and exceeding value of legal allowance of As, Cd, Pb, Co, Cr in frequently using 16 oriental herbal medicines in korea(Astragali Radix, Ginseng, Citri Unshii Pericarpium, Aurantii Fructus Immaturus, Angelicae Gigantis Radix, Cnidii Rhizoma, Paeoniae Radix, Rehmanniae Radix Preparata, Zingiberis Rhizoma Crudus, Zizyphi Fructus, Atractylodis Rhizoma Alba, Hoelen, Dioscoreae Rhizoma, Corni Fructus, Schisandrae Fructus, Lycii Fructus) was evaluated according to their origines (korea, china) and property was also discussed according to the medicinally active part and individuals regardless origines. Method : Korean and Chinese herbal medicines were evenly sampled from corresponding country nationwide. Pre-treatment was executed according to the KFDA(Korea Food and Drug Administration) regulation and analysis was performed according to the Korean Environmental Analysis QA/QC. Result : Not much difference was observed according to their origines. However, lowest, highest and percent exceeding value of legal allowance was showed some consistent differences according to the medicinally active part and individuals. Co and Cr was can not be evaluated since their legal regulation was not established yet. Conclusion : The average concentration of As, Cd, Pb, Co, Cr in frequently using 16 oriental herbal medicines in korea showed no noticeable difference according to their origines. Regardless the origin, some consistent differences were observed according to the individuals and medicinally active parts.

• Advances in environmental research
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• 제3권3호
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• pp.207-216
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• 2014

A study was conducted to determine the phytotoxic effect of mercury on seed germination and seedling growth of an important arid legume tree Albizia lebbeck. The seeds germination and seedling growth performance of A. lebbeck responded differently to mercuric chloride treatment (1 mM, 3 mM, 5 mM and 7 mM) as compared to control. Seed germination of A. lebbeck was significantly (p < 0.05) affected by mercury treatment at 1 mM. Root growth of A. lebbeck was not significantly affected by mercury treatment at 1 mM, and 3 mM. Shoot and root length of A. lebbeck were significantly (p < 0.05) affected by 5 mM concentration of mercury treatment. Increase in concentration of mercury treatment at 5 mM and 7 mM significantly (p < 0.05) reduced seedling dry weight of A. lebbeck. The treatment of mercury at 1 mM decreased high percentage of seed germination (22%), seedling length (10%), root length (21.85%) and seedling dry weight (9%). Highest decrease in seed germination (51%), seedling (34%), root length (48%) and seedling dry weight (41%) of A. lebbeck occurred at 7 mM mercury treatment. A. lebbeck showed high percentage of tolerance (78.14%) to mercury at 1 mM. However, 7 mM concentration of mercury produced lowest percentage of tolerance (51.65%) in A. lebbeck. The seed germination potential and seedling vigor index (SVI) clearly decreased with the higher level of mercury. Plantation of A. lebbeck in mercury-polluted area will help in reducing the burden of mercury pollution. A. lebbeck can serve better in coordinating in land management programs in metal contaminated areas. The identification of the toxic concentration of metals and tolerance indices of A. lebbeck would also be helpful for the establishment of air quality standard.

• Korean Chemical Engineering Research
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• 제60권1호
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• pp.70-79
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• 2022

Biodiesel production has attracted attention as a sustainable source of fuel and is a competitive alternate to diesel engines. The glycerol that is produced as a by-product is generally discarded as waste and can be converted to green chemicals such as acetins to increase bio-diesel profitability. Acetins find application in fuel, food, pharmaceutical and leather industries. Batch experiments and analysis have been previously conducted for synthesis of acetins using glycerol esterification reaction aided by sulfated metal oxide catalysts (SO₄^2-/CeO₂-ZrO₂). The aim of this study was to optimize process parameters: effects of mole ratio of reactants (glycerol and acetic acid), catalyst concentration and reaction temperature to maximize glycerol conversion/acetin selectivity. The optimum conditions for this reaction were determined using response surface methodology (RSM) designed as per a five-level-three-factor central composite design (CCD). Statistica software 10 was used to analyze the experimental data obtained. The optimized conditions obtained were molar ratio - 1:12, catalyst concentration - 6 wt.% and temperature -90 ℃. A packed bed reactor was fabricated and column studies were performed using the optimized conditions. The breakthrough curve was analyzed.