• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.760-766
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• 1998

This study was carried out far isolation and characterization of ammonia oxidizing bacteria (AOB) from aquacultural place and sludges of waste water collected in Pusan. One autotrophic AOB, Nitrosomonas sp. and 8 heterotrophic AOB (2 strains of Bacillus sp., 2 strains of Acinetobacter sp., Xanthomonas sp., Alcaligenes sp., Pseudomonas sp., Sphingobacterium sp.) were isolated. and identified. Variation of total nmmonia nitrogen (TAN) and $NO_2-N$ in mineral salt media containing 10mg/ $\ell$ of NHCl for 15 days in differents 9 strains was measured in order to examine the ablitity of ammonia oxidation. TAN was started to reduce after 4 days incubation and ca. 2 mg/$\ell$ of TAN was decreased after 15 days incubation by Nitrosomonas sp., At that time, $NO_2-N$ was produced to 0.023$\~$0.036 mg/$\ell$. Heterotrophic AOB showed the low ability of ammonia oxidation, 0.02$\~$0,04 mg/$\ell$ of TAN was decreased and $NO_2-N$ was produced to 0.01$\~$0.51 mg/$\ell$ after 15 days. When each strain of 8 heterotrophs was incubated in mimeral salt media containing 10 mg/$\ell$ $NH_4Cl$ and 50 mg/$\ell$ glucose, and 50 mg/$\ell$ $NH_4Cl$ and 5 g/$\ell$ glucose, the diminution of TAN was 1.12$\~$3.38 mg/$\ell$ and 1$\~$20 mg/$\ell$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.635-640
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• 2001

These studies were carried out to develop sausage using extracts from waste resources. The changes of pH and moisture contents were tended to be a similar to control, respectively ranged in pH 6.0~6.4 and 62~60% in moisture content. However, the water holding capacity of sausage added with chitosan and sesamol gradually were tended to be a little high, compared to control. The treatments using natural resource by-product revealed a low TBARS value, compared to control. This means that sausage added with natural by-product seem to be extend its shelf-life during storage. At the same time, the TBARS values were very similar to sausage added with 0.5% potassium sorbate. The residual nitrite contents of sausage added with natural resource by-product were tended to be a little lower than that of control. As storage time goes by, the nitrite contents of sausage product gradually were a little more decreased during storage at 3$0^{\circ}C$ than those of storage at 1$0^{\circ}C$. The lightness of sausage color gradually were a little more decreased during storage at 3$0^{\circ}C$ than those of storage at 1$0^{\circ}C$. The redness of sausage added with chitosan were a little highter, compared to control Sensory test suggested that the changes of sausage color, flavor, texture and taste were tended to be decreased gradually. In conclusion, sausage added with natural resource by-product was effective on the basis of the reduction in residual nitrite content and lipid oxidation.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.1-17
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• 2003

Populus species have been as a model species in tree breeding and we have enormous varieties resulting from the poplar breeding because of their fast growth performance and short rotation age. New varieties developed in Korea are common italian poplar(P euramericana, I-214, I-476), P euramericana“Eco 28”(Italian poplar No.1) and p. deltoides“Lux”(Italian poplar No.2), which were introduced from foreign countries. As hybrid polars, Hyun-Sasi(p. alba ${\times}$ P. glandulosa No.1, No.2, No.3, No4.), P. nigra x P. maximowiczii and P. koreana x P. nigra val. italica, were developed, and P. davidiana was selected as the result of selection breeding The total plantation areas covered with the new varieties are 935,162ha that include 745,773ha of P. euramericana, 184,636ha of P. alba x P. glandulosa, and other new varieties are 4,735ha. The new poplars are contributed to increase farmer's income as well as bare land tree-planting in Korea. The technologies associated with the poplar species were developed, such as the determination of optimum site for new the poplar species, the crossing method between incompatible poplar species, and the vegetative mass propagation. In the future, poplar species will be considered for phytoremediation species at contaminated areas such as landfill sites or with lives stock's waste water as well as wood production, a shade tree like road-side tree and public park tree.

• Journal of Agricultural Extension & Community Development
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• v.16 no.2
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• pp.363-384
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• 2009

This study aimed at finding directions for Korean agriculture to establish a new paradigm of sustainable development. Various problematic issues and concerns in the environment necessitate the transformation of Korea's development paradigm from unconditional growth to "Green Growth" through new policies on green value and review of various advanced researches. In this research, the environment-friendly agriculture's problems, particularly in agribusiness were analyzed. Drawing from Michael Porter's Value Chain Analysis, this research developed a value chain model in agriculture that reflects the environment and the present situations. Future directions in the agriculture sector were also discussed. Korea realized food self-sufficiency through the green revolution in the early 1970s. However, a lot of problems have also occurred, including ground and water pollution and the destruction of ecosystems as a result of the overuse of pesticides and chemical fertilizers. In the late 1970s, the growing interest on environment-friendly agriculture led to the introduction of sustainable methods and techniques. Unfortunately however, these were not innovative enough to foster environment-friendly agriculture. Thereafter, the consumers' distrust on agricultural products has worsened and concerns about health have increased. In view of this, the Ministry of Food, Agriculture, Forestry and Fisheries introduced in December 1993 a system of Quality-Certified Products for organic and pesticide-free agri-foods. Although a fundamental step toward the sustainability of the global environment, this system was not enough to promote environment-friendly agriculture. In 2008, Korea's vision is for "Low Carbon Green Growth" to move forward while also coping with climate change. But primary sectors in a typical value chain do not consider the green value of their operations nor look at production from an environmental perspective. In order to attain sustainable development, there is a need to use less resources and energy than what is presently used in Korean agricultural and value production. The typical value chain should be transformed into a "closed-loop" such that the beginning and the end of the chain are linked together. Such structure allows the flow of materials, products and even wastes among participants in the chain in a sustained cycle. This may result in a zero-waste sustainable production without destroying the ecosystem.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.23-31
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• 2006

carbon modified methods were used for the preconcentration and determination of copper in some real samples using the flame atomic absorption spectrometry. The copper ions was adsorbed quantitatively on the activated carbon due to their complexation with 4- amino-2, 3-dimethyl-1-phenyl-3-pyrazoline (ADMPP) or 4-(4- methoxybenzylidenimin) thiophenole (MBITP). The adsorbed copper on solid phase was eluted quantitatively using small amount of nitric acid. The influence of important parameters including pH, amount of carrier, flow rate, amount of activated carbon and type and concentration of eluting agent for obtaining maximum recovery were investigated. The methods based on ADMPP and MBITP at optimum conditions is linear over concentration range of 0.05-1.5 g mL-1 and 0.05-1.2 g mL-1 of copper with correlation coefficient of 0.9997 and 0.9994 and both detection limit of 1.4 ng mL-1, respectively. The preconcentration leads to enrichment factor of 310 and break through volume of 1550 mL for both ligands. The method has a good tolerance limit of interfering ion and a selectivity that has been successfully applied for the determination of copper content in real sample such as tap, spring, river and waste water.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.123-130
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• 2010

In this study, mixed recycled coarse aggregate (RCA) was produced by mixing RCA from waste concrete in order to evaluate a new method of RCA production. Bond strength between reinforcing bars and RCA concrete was qualitatively evaluated as a part of continuous studies to establish design code of reinforced concrete structural members using recycled aggregate. For practical application, specimens were manufactured with the ready mix RCA concrete. Parameters investigated include: concrete compressive strength (i.e 21, 27 and 40 MPa), replacement levels (i.e 0, 30, 60 and 100%), bar position (i.e vertical and horizontal) and bar location (75 and 225 mm). For the pull-out test, each specimen was in the form of a cube, with each side of 150 mm in length and a deformed bar, 16 mm in diameter, was embedded in the center of each specimen. From the test results, the most of HT type specimen with compressive strength of 21 and 27 MPa showed lower bond strength than the ones provided in CEB-FIP and considered in reinforcement location factor ($\alpha\;=\;1.3$). It was reasoned that bonded area of top bar specimen was reduced at the soffit of reinforcement because of bleed water of fresh concrete. Therefore the reinforcement location factor in current KCI design code should be reviewed and modified.

• Resources Recycling
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• v.5 no.4
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• pp.25-31
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• 1996

The wastes ot l~mestone mines have been cause the extrar.ngance of the valuablz m e r a l s and destruction of the environment. Therefore, \\-c tied ta separation of calcite illid clay from the limestone mine wastes by rotntmg screen type separator made by ourselves in order to recyding such us a raw matcriala for cement maimfacture. CaO amtents in the separated coarse products increased from 37.36 wt% to 42+2 wt% at the condition ihat water content in wastes was lzss than 6wt%, the passing time of specimen in &amber was 15 semnds and the rotation speed was 6OLl qm. A process in order lo separate wastes effectively to having wide range aI part~dcs ize was cstablishcd and CaO contents of coarsc products through this process increased to 46.85 wt%. Tbis rcsult is insuEiicient to directly rcusing as a raw malerials for cement. However, it is supposed that coarse products would be able to be reuscd as a raw materials uf cement, if only it rs sclected dolomite in wastes, and really it may be possible in fields Othenvise, undcrsize products(less than 20 mm) would be able to recycling as a raw of cement bccause chcmicrl campasitions of thosc is kept almost constant v&cs on the overall process.

• KSBB Journal
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• v.11 no.6
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• pp.681-688
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• 1996

In the removal of phenolic precipitates formed by horseradish peroxidase (HRP) and $H_2O_2$ from waste water, the effects of the concentrations of phenolic compounds and $H_2O_2$ on the removal efficiency of various phenols were studied. More than 90% of various phenolic compounds were removed from the aqueous solutions (pH 5-7) by HRP and H2O2. The removal efficiency of phenolic compounds by HRP was reduced to a great extent when the initial concentration of $H_2O_2$ was over 10mM. Furthermore, no phenolic compounds were removed when 50mM of $H_2O_2$ was used. The HRP's turnover number, which indicates the number of phenolic molecules removed per one molecule of HRP, was the largest as 18047 for p-ethoxyphenol while it was the smallest as 1244 for m-chlorophenol when the initial concentrations of phenolic compounds and H2O2 were the same at 1mM. HRP which was separated from the aqueous solution containing phenol and $H_2O_2$ after 24hr of reaction revealed structural changes and diminished activity. The Soret absorbance near 404nm of this HRP sample was decreased to 48% of that of fresh HRP. The values of kcat and kcat/Km of this HRP sample for the oxidation of guaiacol were also reduced to 41% and 51% of those of fresh HRP, respectively. The removals of nonphenolic aromatic compounds such as benzene, ethylbenzene, and toluene (BET) by HRP and $H_2O_2$ were enhanced when phenols were coexisting in the aqueous solutions of BET.

• Clean Technology
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• v.18 no.1
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• pp.76-82
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• 2012

The paper includes utlization of zeolite as potential adsorbent to remove a hazardous malachite green from waste water. The adsorption studies were carried out at 298, 308 and 318 K and effects of temperature, contact time, initial concentration on the adsorption were measured. On the basis of adsorption data Langmuir and Freundlich adsorption isotherm model were also confirmed. The equilibrium process was described well by Freundlich isotherm model, showing a selective adsorption by irregular energy of zeolite surface. From determined isotherm constants, zeolite could be employed as effective treatment for removal of malachite green. From kinetic experiments, the adsorption process followed the pseudo second order model, and the adsorption rate constant ($k_2$) decreased with increasing initial concentration of malachite green. Thermodynamic parameters like activation energy, change of free energy, enthalpy, and entropy were also calculated to predict the nature adsorption. The activation energy calculated from Arrhenius equation indicated that the adsorption of malachite green on the zeolite was physical process. The negative free energy change (${\Delta}G^{\circ}$ =-6.47~-9.07 kJ/mol) and the positive enthalpy change (${\Delta}H^{\circ}$ = +32.414 kJ/mol) indicated the spontaneous and endothermic nature of the adsorption in the temperature range 298~318 K.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.119-125
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• 2015

A concentration meter is widely used at purification plants, sewage treatment plants and waste water treatment plants to sort and transfer high concentration sludge and to control the amount of chemical dosage. When the strange substance is contained in the sludge, however, the attenuation of ultrasonic wave could be increased or not be transmitted to the receiver. At that case, the value of concentration meter is higher than the actual density value or vibrated up and down. It has also been difficult to automate the residuals treatment process according to the problems as sludge attachment or damage of a sensor. Multi-beam ultrasonic concentration meter has been developed to solve these problems, but the failure of the ultrasonic beam of a specific concentration measurement value degrade the performance of the entire system. This paper proposes the method to improve the accuracy of sludge concentration rate by choosing reliable sensor values and learning them by proposed algorithm. The prediction algorithm is chosen as neuro-fuzzy model, which is tested by the various experiments.