• Journal of the Korean association of regional geographers
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• v.5 no.1
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• pp.163-185
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• 1999

The purpose of this study is to develop the model of constructivist multimedia-assisted instruction(CMAI) and to analyze the effect of it in the secondary school geography. The main results are as follows : (1) The conceptual model of CMAI can be defined as an instruction aiming at making a person who has self-directed learning ability through constructivism and multimedia. The procedural model of CMAI based on PIDA instructional strategy is divided into four stages : prediction & explanation, inquiry activity, discussion & fixation, application & synthesis stage. (2) CMAI is typed by offline CMAI and online CMAI. that is, O/WCMAI(online CMAI by web-based courseware). Offline CMAI is subdivided into P/TCMAI(offline CMAI by presentation-based courseware) and C/RCMAI(offline CMAI by cd-rom based courseware) according to authoring tool and function. (3) Offline constructivist multimedia course-ware(offline courseware) was developed for 2 periods as the material to analyze the effect of CMAI. Offline courseware is received development level of it. (4) After offline courseware being applied to the class, the effect of it according the types of the CMAI instruction(lecture instruction, whole teaching, individualized learning, cooperative learning) was analyzed. As the result of analyzing the descriptive statistics of the level of learning achievement and instruction response, there isn't big relationship between them. As the result of analyzing the inferential statistics of the level of learning achievement, there wasn't significant difference between the types of CMAI instruction in whole student of the classes and certain students who improved their grades. But as the result of analyzing of the level of instruction response, there was significant difference between lecture instruction and other types of the CMAI instruction(whole teaching, individualized learning, cooperative learning).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.2
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• pp.106-117
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• 2006

We measured the concentrations of organic matter and metallic elements (Al, Fe, Cr, Mn, Ni, Cu, Zn, As, Cd, Pb and Hg) in the surface sediments of Masan Harbor (in the southern sea, Korea) to evaluate the geochemical characters of sediment and the pollutions by organic matter and metallic elements. The mean grain size of the surface sediments in the study area ranged from $5.6{\phi}$ to $7.8{\phi}$, indicating silt sediment. The water content of the surface sediments exceeded 60% except at some stations. The contents of ignition loss (IL), total organic carbon (TOC) and total nitrogen (TN) ranged from 7.2-14.3%, 1.2-3.2%, and 0.10-0.28%, respectively. Based on the C/N ratios, the organic matter in the surface sediments of Masan Harbor may originate from terrigenous sources including fluvial inputs (mainly sewage in urban areas). The chemical oxygen demand (COD) and acid volatile sulfide (AVS) ranged from $11.3-29.9\;mgO_2/g\;dry$ and 0.20-4.47 mgS/g dry, respectively, and low concentrations were observed near a shipping route. In addition, the concentrations of metallic elements showed large spatial variations in Masan Harbor and the distributions of metallic elements were also comparable to those of organic matter. This implies that the distributions of organic matter and metallic elements in the surface sediments of Masan Harbor are mainly controlled by biogenic matter and artificial action (mainly dredging). In addition, we calculated the enrichment facto. (EF) and geoaccumulation index (Igeo) in order to evaluate pollution by metallic elements. The enrichment of metallic elements relative to Al was three to eighteen times higher at the study sites, compared to levels in the Earth's crust except for Fe, Ni and Mn. In addition, the Igeo class indicated that the surface sediments in the study area were moderately to strongly polluted in terms of metallic elements.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.295-304
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• 2003

The Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of arsenic and other toxic elements in soils and crop plants in areas covered with black shales. Rock and soil samples digested in 4-acid solution (HCI+HNO$_3$+HF+HC1O$_4$) were analyzed fer arsenic and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg/kg As is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Duk-pyung (28.2 mg/kg) and the Chubu areas (32.6 mg/kg). Arsenic is highly elevated in rice stalks and leaves from the Dukpyung (1.14 mg/kg) and the Chubu areas (1.35 mg/kg). The biological absorption coefficient (BAC) of As in plant species decreases in the order of rice leaves>com leaves>red pepper>soybean leaves=sesame leaves>corn stalks>corn grains.

• Clean Technology
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• v.19 no.4
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• pp.416-422
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• 2013

In environmental friendly aspects, the synthesis of glycerol carbonate from glycerol using carbon monoxide and oxygen gases which were produced in petrochemical plants was studied. The oxidative carbonylation of glycerol under batch reaction system was performed on parameter conditions such as effect of various metals (Cu, Pd, Fe, Sn, Zn, Cr), oxidizing agents, mole ratio of carbon monoxide to oxygen, catalyst amount, solvent types, reaction temperature and time and dehydrating agents. In particular copper chloride catalysts showed the excellent activities, and the glycerol carbonate yields over CuCl and $CuCl_2$ catalysts were the maximum of 44% and 64%, respectively at the following reaction conditions: solvent as nitrobenzene, mole ratio of 1:3:0.15 (glycerol:carbon monoxide:catalyst), mole ratio of 2:1 (carbon monoxide:oxygen), the total pressure of 30 bar at 413 K for 4 hr. It was found that reactivity were significantly different depending on the oxidation number of Cu catalysts, and oxygen plays an important role as oxidizing agents in producing H2O during oxidation reaction after carbonylation of glycerol.

• Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.27.1-27.8
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• 2016

Apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, energy, essential amino acids, and fatty acids in extruded pellets containing various fish meals were determined for olive flounder (Paralichthys olivaceus). Eight extruded pellet diets were prepared to contain different fish meals (herring fish meal, anchovy fish meal, mackerel fish meal, sardine fish meal-A, sardine fish meal-B, tuna fish meal, pollock fish meal-A, and pollock fish meal-B) designated as HM, AM, MM, SM-A, SM-B, TM, PM-A, and PM-B, respectively. Chromic oxide ($Cr_2O_3$) was used as an inert indicator at a concentration of 0.5 % in the diet. Feces were collected from triplicate groups of fish ($151{\pm}4.0g$) using a fecal collection column attached to the fish rearing tank for 4 weeks. Dry matter ADCs of the MM, SM-A, SM-B, and PM-A diets were higher than those of all the other dietary groups, and the lowest digestibility of dry matter was observed in the PM-B diet. Fish fed the MM, SM-A, and PM-A diets showed significantly higher ADC of protein than those fed the AM, SM-B, TM, and PM-B diets. Lipid ADC of PM-B was significantly lower than that of the other diets. Energy ADCs of fish fed the MM, SM-A, and PM-A diets were significantly higher than those of the other diets. The availability of essential amino acids in the MM, SM-A, and PM-A diets were generally higher than that of the other fish meal diets, while TM showed the lowest values among all the experimental diets. ADCs of fatty acids in the AM, MM, SM-A, and PM-A diets were generally higher than those of fatty acids in the other diets, and the lowest values were recorded for the PM-B diet. These results provide information on the bioavailability of nutrients and energy in various fish meals which can be used to properly formulate practical extruded feeds for olive flounder.

• Journal of Chest Surgery
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• v.27 no.2
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• pp.99-113
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• 1994

Pentastarch is a new synthetic hydroxyethyl starch similar to hetastarch. We report on the clinical comparisons the clinical efficacy and safety of 10% pentastarch in prime solutions for CPB in cardiac operations with that of 20% serum albumin. During CPB, group P [n = 20] received 500ml of 10% pentastarch and group A [n = 20] received 100ml of 20% albumin in prime solutions The postoperative time of ICU stay in group P and the day and amount of chest drain, hospital stay in group A were longer [p<0.05]. Fresh whole blood and PRBC were added only in group A and a higher amount of hartman solution was added in group A during CPB [p<0.05]. Prothrombin time was prolonged preoperatively and 2 days postoperatively in group A and 7 days postoperatively in group P [p<0.05] but there were no significant differences in bleeding time or fibrinogen level. Platelet count was higher immediately postoperatively in group A and preoperatively and 1, 2, and 7 days postoperatively in group P [p<0.05].Total protein and albumin level were higher 1 day postoperatively in group A and 2 and 7 days postoperatively in group P [p<0.05]. BUN was increased 2 days postoperatively in group A and Cr was increased 1 day postoperatively in group P [p<0.05]. CPK was higher preoperatively and 1, 2, and 7 days postoperatively in group A and plasma hemoglobin level was also higher 2 and 7 days postoperatively in group A [p<0.05]. There were no significant differences in arterial blood gas analysis but higher pO2 and lower pCO2 levels were maintained in group P and ejection fraction was higher 7 days postoperatively in group P [p<0.05]. Both groups were improved postoperatively in NYHA class and the hemodynamic parameters such as MAP, CO, CI, SV, LVSWI were well maintained in group P [p<0.05]. The amount of blood products used was higher in group A and urine output was higher immediately postoperatively in group A and 1, 2 days postoperatively in group P and the chest output was higher in group A. The complications were developed in 7 patients in group A and 5 patients in group P and mortality was not present in both groups.In conclusion, 10% pentastarch is as safe and effective as 20% albumin in prime solutions for cardiopulmonary bypass in cardiac operations.

• Journal of the Mineralogical Society of Korea
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• v.18 no.1
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• pp.33-43
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• 2005

Three types of clinopyroxenes in alkali basaltic rocks from Jeju Island can be identified on the basis of geochemical and textural data. Type Ⅰ is Cr-rich diopside in spinel peridotites from the upper mantle. Type Ⅱ is augite in fine-grained pyroxenites which are possibly either magmatic vein or metamorphic segregations owing to anatexis of the upper mantle. The augite of Type Ⅱ contains high Ca and Mg and relatively low Ti. Type Ⅲ is thought to be either cumulates or cognate phenocrysts and can be subdivided into Ⅲa, Ⅲb, and Ⅲc based on their occurrence mode. Clinopyroxenes of Type Ⅰ have the highest Mg# and Si and the lowest Ti, whereas those of Type Ⅲhave lower Mg#와 Si and higher Ti. These geochemical characteristics indicate that (Ti+Al/sup Ⅵ/)/Si and Al/sup Ⅵ//Al/sup Ⅵ/ increase from Type Ⅰ to Type Ⅲ. It is possibly interpreted that Type Ⅰ is of the highest pressure origin and Type Ⅲ of the lowest. Fractionation of high-pressure clinopyroxenes would result in evolved undersaturated alkali-enriched liquids, probably producing the alkali-enriched host basaltic rocks in Jeju Island.

• Journal of the Mineralogical Society of Korea
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• v.32 no.2
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• pp.87-102
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• 2019

Pallancata Ag mine is located at the Ayacucho region 520 km southeast of Lima. The geology of mine area consists of mainly Cenozoic volcanic-intrusive rocks, which are composed of tuff, andesitic lava, andesitic tuff, pyroclastic flow, volcano clasts, rhyolite and quartz monzonite. This mine have about 100 quartz veins in tuff filling regional faults orienting NW, NE and EW directions. The Ag grades in quartz veins are from 40 to 1,000 g/t. Quartz veins vary from 0.1 m to 25 m in thickness and extend to about 3,000 m in strike length. Quartz veins show following textures including zonation, cavity, massive, breccia, crustiform, colloform and comb textures. Wallrock alteration features including silicification, sericitization, pyritization, chloritization and argillitization are obvious. The quartz veins contain calcite, chalcedony, adularia, fluorite, rutile, zircon, apatite, Fe oxide, REE mineral, Cr oxide, Al-Si-O mineral, pyrite, sphalerite, chalcopyrite, galena, electrum, proustite-pyrargyrite, pearceite-polybasite and acanthite. The temperature and sulfur fugacity ($f_{s2}$) of the Ag mineralization estimated from the mineral assemblages and mineral compositions are ranging from 118 to $222^{\circ}C$ and from $10^{-20.8}$ to $10^{-13.2}atm$, respectively. The relatively low temperature and sulfur-oxygen fugacities in the hydrothermal fluids during the Ag mineralization in Pallancata might be due to cooling and/or boiling of Ag-bearing fluids by mixing of meteoric water in the relatively shallow hydrothermal environment. The hydrothermal condition may be corresponding to an intermediate sulfidation epithermal mineralization.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.265-277
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• 2000

Laboratory experiments were conducted to investigate characteristics for removing ammonia-nitrogens by electrolysis methods. A stainless steel plate is used as the cathode and either $IrO_2{\backslash}Ti$ plate serves as the anode. Experiments were conducted to examine the effects of the operating conditions, such as the current density, retention time, electrode gap, $Cl^-/NH_4{^+}-N$ on the $NH_4{^+}-N$ removal efficiency. Possible optimum range for these operating variables are experimentally determined. The $NH_4{^+}-N$ removal efficiencies between plate type anode and net type anode were about same effect, but electrolytic power using net type anode is low than plate type anode. The $Cl^-/NH_4{^+}-N$ ratio was about $20.0kgCl^-/kgNH_4{^+}-N$ when $NH_4{^+}-N$ removal obtained 73 %, $Cl^-/NH_4{^+}-N$ ratio needs $27.6kgCl^-/kgNH_4{^+}-N$ so as to $NH_4{^+}-N$ completely remove. The removal efficiency of $NH_4{^+}-N$ increase with current density, retention time and $Cl^-/NH_4{^+}-N$ ratio, but decreased with increasing electrode gap. The relationship of operating conditions and $NH_4{^+}-N$ removal efficiencies are $$NH_4{^+}-N_{re}(%)=14.5364(Current\;density)^{0.7093}{\times}(HRT)^{1.0060}{\times}(Gap)^{-0.9926}{\times}(Cl^-/NH_4{^+}-N)^{1.0024}$$ With adding COD or/and alkalinity, relationships are $$NH_4{^+}-N_{re}(%)=9.8408(Current\;density)^{0.6232}{\times}(HRT)^{1.0534}$$ There existed a competition between the removals for $NH_4{^+}-N$ and $COD_{Cr}$ during electrolysis, the removal of $NH_4{^+}-N$ was shown to be dominant. $NH_4{^+}-N$ removal was high as addition of glucose and alkalinity.

• Journal of the Korean earth science society
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• v.22 no.5
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• pp.405-414
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• 2001

Jecheon granite can be divided into two types; porphyritic granite (K-feldspar megacryst bearing) and medium-grained biotite granite. Porphyritic granite, host body of feldspar deposits, is 8${\sim}$11 km in diameter and about 80 $km^{2}$ in area. It mainly contains K-feldspar, plagioclase, biotite and quartz, and magnetite, zircon, sphene and apatite are accessary minerals. Enclosed minerals in K-feldspar megacryst with 3${\sim}$10 cm in diameter are hornblende, plagioclase, quartz, magnetite, apatite, sphene and zircon. Mafic enclaves mainly consisting of hornblende, plagioclase and quartz are frequently observed in porphrytic granite. Medium-grained biotite granite consists of K-feldspar, plagioclase, biotite and hornblende as main, and hematite, muscovite, apatite and zircon as accessary minerals. Core and rim An contents of plagioclase from porphyritic granite, medium biotite granite, K-feldspar megacryst, and mafic enclave are 36 and 21, 40 and 32, 37 and 32, and 43 and 36, respectively. $X_{Fe}$ values of hornblende are 0.57 at biotite granite, 0.51 at K-feldspar mehacryst and 0.45 at mafic enclave. $X_{Fe}$ values of biotite and hornblende are homogeneous without chemical zonation. K-feldspar megacryst shows end member of pure composition with exsolved thin lamellar pure albites. Characteristics of mineral compositions and petrography indicate porphyritic granite is igneous origin and medium-grained biotite granite comes from the same source of magma; biotite granite is initiated to solidly and from residual melt porphyritic granite can be formed. Possibly K-feldspar megacrysts are formde under H$_{2}$O undersaturation condition and near K-feldspar solidus curve temperature; growth rate is faster than nucleation rate. Mafic enclaves are thought to be mingled mafic magma in felsic magma, which is formed from compositional stratigraphy. Estimated equilibrium temperature and pressure for medium-grained biotite granite are about $800^{\circ}C$ and 4.83${\sim}$5.27 Kb, respectively.