• Journal of Conservation Science
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• v.30 no.4
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• pp.335-343
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• 2014

This study classified the result of non-metallic inclusion analysis and result of microstructure investigation on the ironware excavated in the Baekje region into Han River, Geum River, and Yeongsan River to estimate the iron making temperature and study the characteristics of regional and temporal characteristics of the heat treatment technology and steel making technology. Regardless of era, bloom iron and sponge iron are judged to be the major method for making as a directreduction process in all three regions. The result of the reinterpretation of the non-metallic inclusion by the oxide ternary constitutional diagram suggest that the temperature inside of the furnace is estimated to be between $1,100{\sim}1,300^{\circ}C$ while making the steel. The magnetic iron ores are the major raw material of steel ore and irons with high $TiO_2$ are estimated to use iron sands. Ironware with $CaO/SiO_2$ rate higher than 0.4% are considered to have artificially added the flux of calcareous materials. It was found that the iron making method is the solid caburizing-steel which caburizes low-carbon steels by the CO gas and $CO_2$ gas created when heating the forging furnace with charcoal. Also, the ironware manufacturers in the Baekje during 3rd century recognized the heat treatment technology as they performed carburizing process and quenching to intentionally increase the strength of necessary parts.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.1
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• pp.31-36
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• 2008

This work was performed to evaluate the effect of membrane material and structure on fouling in a submerged membrane bioreactor(MBR). Three types of microfiltration membranes with the same pore size of 0.1 $\mu$m but different materials, polytetrafluoroethylene (PTFE), polycarbonate(PCTE) and polyester(PETE), were used. While PETE membrane exhibited the most rapid flux decline throughout the operation, PCTE and PTFE had a similar tendency with regard to permeability. Difference in permeability between PETE and the other membranes gradually decreased with time, which was probably due to chemical cleaning. The higher TOC rejection of PETE membrane could be attributable to its faster fouling, resulting from a larger amount of foulants to get attached to the membrane in a shorter time. DOC fractionation using a DAX-8 resin showed that the composition of each fraction between the supernatant and permeates did not change significantly with operation time, indicating that membrane hydrophilicity/hydrophobicity was not a dominant factor affecting to MBR fouling in this study. Compared to other membranes, the fouling of PETE membrane was more influenced by pore clogging (irreversible fouling), which would probably contribute to a higher organic rejection of the PETE membrane.

• Resources Recycling
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• v.9 no.1
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• pp.52-62
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• 2000

In order to maximize the recycling of converter slag to the more valuable fields, such as high quality aggregates for construction, cement industry and flux for ion making. It will be very important to control the compositions and properties of converter slag to suit the purpose of utilizastion. In this study, converter slag (STELCO, CANADA) was mixed with 5%~30% $SiO_2$and 7% carbon, and then reduced at $1650^{\circ}C$. After the reduction was completed, the reformed slags were cooled to room temperature in the furnace. All of the slags were then characterized using SEM-EDX, XRD and chemical analysis. Also the compressive strengths and densities of the reformed slags were measured to compare with natural aggregates. XRD analysis shows that th phases of reformed slags are changed from bredigite+merwinite mixed phases of 10% $SiO_2$added reduction to akermanite phases of 20% and 30% $SiO_2$ added reduction. But the SEM-EDX analysis revealed that the phase distribution of the reformed slags was changed very sensitively and complicately depends on the change of slag compositions. And also the properties of reformed slags are changed very much depend on the phase distribution. About one third of Cadmium and on fifth of Vanadium are remained in reduction reformed converter slag. Another heavy metal elements such as cobalt, zinc, lead are removed up to more than 90-95% of original slag. The compressive strength and density of 25% $SiO_2$ added and reformed slag is very near to natural granite. This is superior more than 10% to Thyssen's $SiO_2$ added and oxidized converter slag aggregates.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.559-569
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• 2007

The purposes of this study were to find the main foulant of membrane and the optimal chemical cleaning method for MF(microfiltration) drinking water treatment system using D dam water as water source. The MF pilot plant which can treat maximum $500m^3/d$ consisted of 3 racks and was operated for 10 months under various operation conditions. After 10 months operation, $1^{st}$ and $2^{nd}$ rack of membrane pilot plant system were cleaned chemically and the degree of the restoration of the fouled membrane in terms of the pure water flux was detemnined. Inorganic compounds which contained in chemical cleaning waste was analyzed by Inductively Coupled Plasma (ICP). One membrane module for 3rd rack was disjointed and membrane fouling materials, especially inorganic compounds were investigated by Electron Probe Microanlysis (EPMA) to elucidate the reason of TMP increase. And also, the various chemical reagents (1N HCl or $H_2SO_4$, oxalic acid as acid and 0.3% NaOCl as alkali) were tested by combination of acid and alkali to determine the optimal chemical cleaning method for the MF system using micro-modules manufactured using the disjointed module. It was verified that the inside and outside of membrane module was colorized with black. As a result of the quantitative and semi-qualitative analysis of membrane foulant by ICP, most of inorganic foulant was manganese which is hard to remove by inorganic acid such as HCI. Especially, it was observed by EPMA that Mn was attached more seriously in inside surface of membrane than in outside surface of that. It was supposed that Mn fouling in inside surface of membrane might be caused by the oxidation of soluble manganese (Mn(II)) to insoluble manganese ($MnO_2$) by chlorine containing in backwashing water. The optimal cleaning method for the removal of manganese fouling was consecutive cleaning with the mixture of 1N HCl and 1% of oxalic acid, 0.3% NaOCl, and 1N HCl showing 91% of the restoration of the fouled membrane.

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.154-161
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• 2015

For efficiently designing neutron induced gamma spectroscopy sonde, Monte Carlo simulation is employed to understand a dominant location of thermal neutron and classify the formation elements from the energy peak of capture gamma spectrum. A pulsed neutron generator emitting 14 MeV neutron particles was used as a source, and flux of thermal neutron was calculated from the twelve detectors arranged at each 10 cm intervals from the source. Design for reducing borehole effects using shielding materials was also applied to numerical sonde model. Moreover, principal elements and quantities of numerical earth models were verified through the energy spectrum analysis of capture gamma detected from a gamma detector. These results can help to enhance the signal-to-noise ratio, and determine an optimal placement of capture gamma detectors of neutron induced gamma spectroscopy sonde.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.320-327
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• 2016

Allium hookeri is used for food and medical materials in Asia. This study was carried out to elucidate the effects of shading rates on growth and quality of A. hookeri cultivation in greenhouse. Treatments were given with 35%, 55%, 75% and 95% shading rates and non-shading (Control). Photosynthesis photon flux density (PPFD) of control, 35%, 55%, 75%, and 95% shading were 792, 515, 351, 182, and $78.2{\mu}mol{\cdot}m{\cdot}s^{-1}$ respectively. The emergence ratio was 98% under non-shading, 35% and 75% shading condition, and it was 100% under 55% and 95% shading condition on April 20, 2016. These results showed no correlation between emergence rate and shading treatment. When shading net was set up inside at greenhouse, fresh weights in control, 35%, 55%, 75%, and 95% shading treatments were 1,142, 3,511, 5,936, 6,408 and 3,779kg/10a, respectively. When shading net was set up outside at greenhouse, fresh weights in control, 55%, 75%, and 95% shading treatments were 1,372, 5,442, 6,238 and 3,595kg/10a, respectively. Dry weight, percentage of dry matter, number of leavesand branches, plant height and root length in 75% shading treatment were higher than other shading treatments. From these results, we suggested that the proper shading rate in a greenhouse is 75% for A. hookeri cultivation in middle area of Korea.

• Journal of Plant Biotechnology
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• v.41 no.3
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• pp.107-115
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• 2014

Vegetable oils (triacylglycerols) produced mainly in seeds of plants are used for valuable foods that supply essential fatty acids for humans as well as industrial raw materials and biofuel production. As the demanding for vegetable oils has increased, plant metabolic engineering to produce triacylglycerols in biomass such as leaves has been considered and explored for alternative source of vegetable oils. Leaves are genetically programmed to supply the fixed carbon by photosynthesis to other organs for plant development and growth. Therefore, in order to produce and accumulate triacylglycerols in leaves, one should take account of multiple metabolic pathways such as carbon flux, competition of carbohydrate and fatty acid biosynthesis, and triacylglycerols turnover in leaves. The recent metabolic engineering strategy has showed potential in which the co-expression of three genes WRINKLED1, DGAT1, and OLEOSIN involved in the critical step for increasing the fatty acid synthesis, accumulating triacylglycerols, and protecting triacylglycerols, respectively produced higher amount of vegetable oils in leaves. Developing of genetically engineered plants producing vegetable oil in biomass at non-agricultural lands will be promising to the future success of the field.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.215-217
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• 2016

Background: Chronic lymphocytic leukemia (CLL) is the most frequent form of leukemia in Europe and North America, and it mainly affects older individuals. Many approaches are implemented in the management of CLL from a watch and wait (W&W) strategy to chemotherapeutic regimens. We here reviewed our clinical practice for the relevance of the W&W strategy in Lebanese CLL patients. Materials and Methods: A total of 95 patients with CLL diagnosed in four institutions in Lebanon, between 1992 and 2013, were selected and their files were reviewed. Characteristics of these patients were noted including age, sex, RAI and Binet scores, CBC values, presence of hepatomegaly or splenomegaly, performance of bone marrow biopsy or peripheral blood flux cytometry for diagnosis, adoption of W&W strategy, different chemotherapeutic regimens and the indications for treatment. Results: Some 38 patients (40%) diagnosed with CLL were women and 57 (60%) were men with a mean age of 65.1 years [36-89]. Of the total, 50.5%, 17.2%, 14%, 7.5% and 10.8% had an RAI score at diagnosis of 0, 1, 2, 3 and 4, respectively, while 65.6%, 17.2% and 17.2% had Binet scores of I, II and III. The mean lymphocyte count at diagnosis was $39885/mm^3$ [1596-290000], the mean hemoglobin level was 12.7 g/dl [6.2-17] and the mean platelet count was $191255/mm^3$ [14000-458000]. While 26.3% of patients with CLL had splenomegaly, only 7.4% had hepatomegaly. Some 33.7% had undergone a bone marrow biopsy, 66.3% flow cytometry of circulating blood and 5.3% a lymph node biopsy. Overall, the W&W was adopted in 62.4% (58) of patients with a mean duration of 37.7 months [3-216]. The W&W was used in 82.6%, 73.3%, 46.2%, 14.3% and 0% of patients having RAI scores of 0, 1, 2, 3 and 4, respectively, and, it was used in 80%, 46.7% and 6.25% with Binet scores of I, II and III. The most frequent indication for treatment was anemia and thrombocytopenia, accounting for 32.7% of cases. The most frequently used chemotherapeutical regimens were chlorambucil until the end of the last century and flufarabine-cyclophosphamide-rituximab during the last decade. Conclusions: This retrospective review of CLL clinical practice showed an important implementation of the W&W strategy with a long duration, especially in early stage cases with low RAI or Binet scores.

• Membrane Journal
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• v.18 no.1
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• pp.65-74
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• 2008

NOM and fine particles are the main target materials in water treatment using membranes. Particularly, humic substances extracted from soils are frequently used in many fundamental studies representing natural organic matter in raw water for drinking water treatment. In this study, ultrafiltration (UF) of artificial humic water and natural river water was conducted and the characteristics of removal efficiency and permeability were compared. In the UF of river water, the transmembrane pressure increased in the same pattern with that of 5 mg/L humic water. For the removal of organic matter and fine particles, however, two types of feed water had shown different trends. Kaolin particles and humic acids added to artificial water were better removed, while colloids and organics in natural water were relatively poorly removed. From the $UV_{254}$ and GPC analyses, it seemed that the hydrophobicity and size of humic substances contributed to the greater removal of organic matter. The UF membrane applied for humic water also showed a higher flux recovery by caustic chemical cleaning than that for river water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.715-722
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• 2010

The effects of temperature, salinity and irradiance on the growth of the harmful red tide dinoflagellate Cochlodinium polykrikoides Margelef isolated from the South Sea of Korea were examined in the laboratory. Growth was examined under the following combinations of temperature and salinity: 15, 20, 25 and $30^{\circ}C$, and 15, 20, 25, 30 and 35 psu at a constant irradiance of $180\;{\mu}mol/m^2/s$. No growth was observed with a temperature of $15^{\circ}C$ and a salinitiy of 15 psu. Moderate growth rates of more than 0.30 /day were obtained at $25^{\circ}C$ with salinities of 25.35 psu. These values are similar to in situ observations for this species. The maximum growth rate, 0.35 /day, was obtained at $25^{\circ}C$ and 30 psu. In light experiments, cell growth of C. polykrikoides was conducted with constant temperature ($20^{\circ}C$) and salinity (30 psu) under light photon flux densities (PFD) of 10, 25, 50, 70, 100, 150, 250 and $350\;{\mu}mol/m^2/s$. C. polykrikoides did not grow at $10\;{\mu}mol/m^2/s$. Cell growth was observed at irradiance values of $25\;{\mu}mol/m^2/s$ and above. The irradiance-growth curve was described as ${\mu}=0.30{\cdot}(I-15.27)/(I+27.22)$, (r=0.99). This suggests a compensation PFD of $15.27\;{\mu}mol/m^2/s$ and a maximum growth rate of 0.30 /day. In conclusion, C. polykrikoides prefers high salinity, temperature and irradiance in summer in Korea. These results provide important information for understanding the mechanism of C. polykrikoides blooms and developing technology to predict blooms of this organism in the field.