• Journal of Biosystems Engineering
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• v.33 no.6
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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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• v.27 no.1
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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.

• Journal of Technology Innovation
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• v.19 no.3
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• pp.57-83
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• 2011

We suggested industry-specific priorities of R&D investment with R&D investment elasticity to GDP calculated from the ripple effect of 28 large-sized industry R&D investment, using a Computable General Equilibrium(CGE) Model. Priority orders apply to only 12 industries, because 16 industries with less than 1% of total investment have been excluded. First, R&D investment elasticity to GDP says that priorities are ordered as Basic metal products, Chemicals, drugs and medicines, Food, beverages and tobacco products, Electronic and electrical equipment, Transportation equipment, Precision instruments, Electrictity, gas, steam and water supply, General machinery and equipment, Communications and broadcasting, Construction, Other services, and Real estate and business services. These priorities show the status quo of Korean industry structures well. The GDP growth rate to 2030 year reference equilibrium, which is an auxiliary index, says a similar priority to results from R&D investment elasticity to GDP. In the end, two criteria of priority order can be functioned as a good index for National Science and Technology Commission deciding what industry to invest and what budget to allocate.

• Journal of Korean Library and Information Science Society
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• v.49 no.3
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• pp.429-458
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• 2018

In this study, based on the results of analyzing the facilities and operation of the public libraries in Iksan, several strategies that may contribute to its regional development have been established. The strategies are as follows. The first one is to hire more librarians to perform the role of libraries at the advanced level that are suitable for the ever-growing library facilities. The second is the plan for specialization of the libraries, which was proposed with each subject suitable for each library such as History Culture, Modern and Local Culture, Jewelry and Precious metal, Food Cluster, Female, Administration & Welfare, and Environment & Ecology by matching the urban policies and characteristics of Iksan with these library. The others are the operation of English library in the way suggested in this study and the establishment of youth library to build up the role of the libraries in educational city. Through these strategies, the overall function and role of the public libraries in Iksan can be strengthened and emphasized.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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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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• v.31 no.6
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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.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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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.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.3
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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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• v.3 no.3
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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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• v.60 no.1
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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.