• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.2
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• pp.79-89
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• 1995

Changes of microbial activity and physicochemical environment during composting of papermill sludge(PMS) in the pilot plant equipped with an agitated bed reactor were monitored for establishing the efficient composting system. Microbial activity determined as the evolution of $CO_2$ increased for the first 10 days after introduction of PMS to the reactor and decreased thereafter. Population changes of microorganisms in the reactor-PMS were not typical as in windrow system. The ratio of thermophilic bacteria to mesophilic bacteria, however, increased slowly even 23 days after introduction. Temperature of PMS increased rapidly from the first day and reached $62^{\circ}C$ at 7 days after introduction and decreased slowly thereafter. The acidity of PMS was pH 6.8 initially, increased to pH 8.0 after 7 days and decreased to pH 7.4 after 23 days. Redox potential(Eh) of PMS was -320mV at the beginning of composting, but it was increased with time to reach -15mV after 23 days composting. However, Eh of PMS pre-sterilized before measurement was average 50mV, regardless of composting periods indicating the major role of microorganisms during composting process. Water content of PMS was 67% initially and decreased to about 50% after 23 days composting in the reactor. Less than 13 days-old compost inhibited growth of radish in the container mixture with bed soil. Based on statistical analysis of microbial and physicochemical parameters of PMS during composting, an equation was developed for determining compost maturity. A number of experiments using various organic wastes are required before application of the formular to the practical use.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.777-790
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• 2019

The purpose of this study is to investigate the experience of teachers who apply Smart-technology in elementary school STEAM class and the reasons, difficulties when applying the technology and required support. Semi-structured in-depth interviews were conducted with six elementary school teachers with specialized knowledge in STEAM education who have experienced STEAM lessons several times before. The research findings are as follows: First, research participants utilized a variety of Smart-technology in STEAM class, most of which were experiential or interactive technology. Among the STEAM learning criteria, the Smart-technology in 'Creative Design' course was most often applied. Second, they adopted Smart Technology in STEAM class to encourage students to feel interested, actively participate in the class, enjoy indirect experience, and nurture interest in state-of-the-art technology. They used it to prepare for future societies and organize classes that are suitable for STEAM learning criteria. They also used Smart-technology because it was easy to use. Third, they found it difficult to find, secure, and use suitable Smart-technology when applying Smart-technology in the STEAM class. They also had trouble restructuring the curriculum. In addition, there were difficulties in using Smart-technology in the class such as lack of class hours, increased level of activity, insufficient physical environment and unexpected malfunction of Smart-technology, thus interrupted the class. After the class, it was hard to manage Smart-technology and also, there were difficulties in assessment, record, and negative awareness of surrounding people. Fourth, they mentioned that's suggesting education guidelines, develop, and distribute educational materials are required to enable 'Creative Design,' reduce educational content, provide training, secure Smart-technology equipment and provide Wi-Fi, support teacher's club and communities and create an atmosphere to emotionally support teachers in order to activate using Smart-technology in STEAM class.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.258-292
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• 1996

In the last year great interest appears to YBCO thin films preparation on different substrate materials. Preparation of epitaxial film is a very difficult problem. There are many requirements to substrate materials that must be fullfilled. Main problems are lattice mismatch (misfit) and similarity of structure. From paper [1] or follows that difference in interatomic distances and angles of substrate and film is mire important problem than similarity of structure. In this work we present interatomic distances and angle relations between substrate materials belonging to ABCO4 group (where A-Sr or Ca, B-rare earth element, C-Al or Ga) of different orientations and YBCO thin films. There are many materials used as substrates for HTsC thin films. ABCO4 group of compounds is characterized by small dielectric constants (it is necessary for microwave applications of HTsC films), absence of twins and small misfit [2]. There most interesting compounds CaNdAlO4, SrLaAlO4 and SrLaGaO4 were investigated. All these compounds are of pseudo-perovskite structure with space group 14/mmm. This structure is very similar to structure of YBCO. SLG substrate has the lowest misfit (0.3%) and dielectric constant. For preparation of then films of substrates of this group of compound plane of <100> orientation are mainly used. Good quality films of <001> orientations are obtained [3]. In this case not only a-a misfit play role, but c-3b misfit is very important too. Sometimes, for preparation of thin films substrates of <001> and <110> orientations were manufactured [3]. Different misfits for different YBCO faces have been analyzed. It has been found that the mismatching factor for (100) face is very similar to that for (001) face so there is possibility of preparation of thin films on both orientations. SrLaAlO4(SLA) and SrLaGaO4(SLG) crystals of general formula ABCO4 have been grown by the Czochralski method. The quality of SLA and SLG crystals strongly depends on axial gradient of temperature and growth and rotation rates. High quality crystals were obtained at axial gradient of temperature near crystal-melt interface lower than 50℃/cm, growth rate 1-3 mm/h and the rotation rate changing from 10-20pm[4]. Strong anisotropy in morphology of SLA and SLG single crystals grown by the Czochralski method is clearly visible. On the basics of our considerations for ABCO4 type of the tetragonal crystals there can appear {001}, {101}, and {110} faces for ionic type model [5]. Morphology of these crystals depend on ionic-covalent character of bonding and crystal growth parameters. Point defects are observed in crystals and they are reflected in color changes (colorless, yellow, green). Point defects are detected in directions perpendicular to oxide planes and are connected with instability of oxygen position in lattice. To investigate facets formations crystals were doped with Cr3+, Er3+, Pr3+, Ba2+. Chromium greater size ion which is substituted for Al3+ clearly induces faceting. There appear easy {110} faces and SLA crystals crack even then the amount of Cr is below 0.3at.% SLG single crystals are not so sensitive to the content of chromium ions. It was also found that if {110} face appears at the beginning of growth process the crystal changes its color on the plane {110} but it happens only on the shoulder part. The projection of {110} face has a great amount of oxygen positions which can be easy defected. Pure and doped SLA and SLG crystals measured by EPR in the<110> direction show more intensive lines than in other directions which allows to suggest that the amount of oxygen defects on the {110} plane is higher. In order to find the origin of colors and their relation with the crystal stability, a set of SLA and SLG crystals were investigated using optical spectroscopy. The colored samples exhibit an absorption band stretching from the UV absorption edge of the crystal, from about 240 nm to about 550 m. In the case of colorless sample, the absorption spectrum consists of a relatively weak band in the UV region. The spectral position and intensities of absorption bands of SLA are typical for imperfection similar to color centers which may be created in most of oxide crystals by UV and X-radiation. It is pointed out that crystal growth process of polycomponent oxide crystals by Czochralski method depends on the preparation of melt and its stoichiometry, orientation of seed, gradient of temperature at crystal-melt interface, parameters of growth (rotation and pulling rate) and control of red-ox atmosphere during seeding and growth (rotation and pulling rate) and control of red-ox atmosphere during seeding and growth. Growth parameters have an influence on the morphology of crystal-melt interface, type and concentration of defects.

• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.811-817
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• 2006

The primary purpose of this study is to estimate the guaranteed strength and construction quality of the combined high flowing concrete which is used in the slurry wall of underground LNG storage tank. The required compressive strength of this type of concrete become generally known as a non economical value because it is applied the high addition factor for variation coefficients and low reduction factor under water concrete. Therefore, after estimation of the construction quality and guaranteed strength in actual site work, this study is to propose a suitable equation to calculate the required compressive strength in order to improve its difference. Application results in actual site work are shown as followings. The optimum nix design proportion is selected that has water-cement ratio 51%, sand-aggregate ratio 48.8%, and replacement ratio 42.6% of lime stone powder by cement weight. Test results of slump flow as construction quality give average 616~634mm. 500mm flowing time and air content are satisfied with specifications in the rage of 6.3 seconds and 4.0% respectively. Results of strength test by standard curing mold show that average compressive strength is 49.9MPa, standard deviation and variation coefficients are low as 1.66MPa and 3.36%. Also test results by cored cylinder show that average compressive strength is 66.4MPa, standard deviation and variation coefficients are low as 3.64MPa and 5.48%. The guaranteed strength ratio between standard curing mold and cored cylinder show 1.23 and 1.32 in the flanks. It is shown that applied addition factor for variation coefficients and reduction factor under water concrete to calculate the required compressive strength is proved very conservative. Therefore, based on these results, it is proposed new equation having variation coefficients 7%, addition factor 1.13 and reduction factor 0.98 under water connote.

• Journal of The Korean Association For Science Education
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• v.19 no.3
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• pp.428-440
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• 1999

The colorful overhead projector films, named as Bio-cosmos II, including photographs, pictures, concept maps, and diagrams, were developed and manufactured as audio-visual teaching aids and teaching resources for students' biology learning in high school, and the CD-ROM and web sites for their application to the school were also constructed. The content of the films was organized based upon the analysis of seven different biology textbooks approved by the Ministry of Education. The films were designated based on various instructional strategies and manufactured using multimedia with various educational softwares. The CD-ROM was composed of the scenes as logo, initial main, chapters list, contents, and quit. Initial main scene indicated various chapters according to the texts of biology areas in General Science, Biology I, and II. Each chapters linked with the scenes for detailed concept maps, the downstream real subjects, and contents. The subject screens were composed of various types of summarized diagrams including lesson contents, figures, pictures, photographs, and their explanation, experimental procedures and results, tables for summarized contents, and additional animation with video captures, explanations, glossary, etc. Most files were manufactured in software Adobe Photoshop by scanning the pictures, figures and photographs, and then the explanation, modification, storing with PICT or PSD files, and transformation with JPG files, were processed in the aspect of high quality in terms of instructional strategies and graphic skills on gracefulness, clearness, colorfulness, brightness, and distinctness. A 14 films for biology areas in General Science, 80 for Biology I, and 142 for Biology II were manufactured and loaded to the CD-ROM and web site, and the files had been attempted to opened with an internet home-page of http://gic.kyungpook.ac.kr/biocosmos.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1279-1283
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• 2009

In order to investigate the potential characteristics of horseweed (Erigeron canadensis L.) recognized with weeds for the application to food industry, the antioxidative properties of horseweed were measured with total polyphenol, flavonoid, tannin, chlorophyll contests and antioxidant activities. Total polyphenol, flavonoid, tannin, and chlorophyll content were 63.32, 27.71, 161.19, and 428.85 mg/g in the extracts of fresh horseweed (FHE), respectively. The extracts of dry horseweed (DHE) on $40^{\circ}C$ for 48 hr were 89.25, 33.44, 210.44, and 229.29 mg/g, and the extracts of dry horseweed after blanching (BDHE) were 115.49, 45.51, 252.54, and 283.07 mg/g, respectively. $IC_{50}$ of EDA (electron donating ability, %) and AEAC (L-ascorbic acid equivalent antioxidant capacity) were 5.5527 mg/mL and 192.78 mg AA eq/g sample in the FHE, respectively. The DHE were 0.4710 mg/mL and 194.05 mg AA eq/g sample, and the BDHE were 0.4135 mg/mL and 242.40 mg AA eq/g sample, respectively. Horseweed, where the antioxidant activity is excellent, is thought to be potentially useful with foodstuffs.

• Communications of Mathematical Education
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• v.27 no.1
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• pp.39-62
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• 2013

On the standards or elements of teaching evaluation, the Korea Institute of Curriculum and Evaluation(KICE) has carried out the following research such as : 1) development of the standards on teaching evaluation between 2004 and 2006, and 2) investigation on the elements of Teacher Knowledge. The purposes of development of evaluation standards for mathematics teaching through those studies were to improve not only mathematics teachers' professionalism but also their own teaching methods or strategies. In this study, the standards were revised and modified by analyzing the results of those studies focused on the knowledge of subject matter knowledge, knowledge of learners' understanding, teaching and learning methods and assessments, and teaching contexts. For this purpose, according to those evaluation domains of each teacher knowledge, elements on teaching evaluation focused on the teacher's knowledge were established using the instructional evaluation framework, which is developed in this study, including the four areas of knowledge obtaining, instructional planning, instructional implementation, and instructional reflection. In this study, 1st and 2nd pilot studies was accomplished for revising evaluation standards and as a result, the procedure for implementing mathematics teaching using evaluation standards was changed to evaluate teachers own teaching using the standards focused on instructional reflection and according to the degree of satisfaction on reflecting their own teaching, standards on knowledge obtaining, instructional planning, instructional implementation would be utilized. Teacher survey is accomplished two times, by the subject of seven teachers. According ot the result of the first teacher questionnaire which was consisted of the essay type of questions on the degree of understanding the content of standards, the evaluation standards were revised. According ot the result of the second teacher questionnaire which was consisted of the essay type of questions on the application of standards, the evaluation standards were revised finally and the way of how to use the standards efficiently was suggested.

• Korean Journal of Organic Agriculture
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• v.22 no.1
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• pp.97-113
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• 2014

An actual proof experiment was carried out to establish the production of high quality organic rice at farm household in Gwangjin, Junnam, Korea 2011. Experimental plot was designed with conventional organic cultivation and manual organic cultivation in both Hopeongbyeo and Onnuri varities. Experimental field was consisted with suitable drainage loam soil, anryong series, and normal paddy field. Chemical characteristics of the soil were investigated from initial soil and soil after harvest in experimental sites. Seed disinfection was treated with hot water dipping method at $60^{\circ}C$ for 10 min. Rice transplanting was carried out at 17 June with 25 days seedling using machine transplanting. Golden apple snail was used to prevent weed growth as middle size (1.5~1.7 kg/10a) at one week after rice transplanting. Amount of applied fertilizer in experimental plot was supplied with organic fertilizer for the shortage after harvest of hairy vetch (1,100 kg/10a). Bordeaux mixture was used to control of sheath blight and neck blast disease in all experimental plot at 19 Aug. Application of chitin culture solution was treated in manual organic cultivation at 2 and 15 Aug. At late growth stage, incidence rate of neck blast was the highest level at Hopyeongbyeo in conventional organic cultivation. Incidence rate of sheath blight in both Hopyeongbyeo and Onnuri was higher in conventional organic cultivation than in manual organic cultivation. Incidence of rice leaf folder was the highest level at Onnuri in conventional organic cultivation. Yield index in manual organic cultivation was increased by 13% and 38% at Onnuri and Hopyeongbyeo, respectively, compared with conventional organic cultivation. Head rice percentage in both Hopyeongbyeo and Onnuri was slightly increased in manual organic cultivation. These results indicate that high quality production of rice organic cultivation could be depending on management of safe fertilization with nutrient content in soil.

• Journal of Life Science
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• v.21 no.8
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• pp.1149-1155
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• 2011

Myostatin (MSTN) belongs to the transforming growth factor-${\beta}$ superfamily or growth and differentiation factor 8 (GDF-8), and functions as a negative regulator of skeletal muscle development and growth. Previous studies in mammals have suggested that myostatin knock-out increased muscle mass and decreased fat content compared to those of the wide type. Recently, several studies on myostatin have beenconducted on the block myostatin signal pathway with myostatin antagonists and the MSTN regulation with RNAi to control myostatin function. This study was performed to analyze growth and muscle alteration of Oncorhychus masou by treatment with recombinant myostatin prodomains derived from fish. We designed myostatin prodomains derived from P. olivaceus (pMALc2x-poMSTNpro) and S. schlegeli (pMALc2x-sMSTNpro) in a pMALc2x expression vector, and then purified the recombinant proteins using affinity chromatography. The purified recombinant proteins were treated in O. masou through an immersion method. Recombinant protein treated groups did not show a significant difference in weight, protein, or lipid composition compared to the control. However, there was a difference in the average number and area for histological analyses in the muscle fiber. At twelve and twenty-two weeks from the initial treatment, there were differences in averagefiber number and area between the 0.05 mg/l treated-group and the control, but the numbers were similar to those of the control during the same time period. At twelve weeks, however, 0.2 mg/l treated-group had an increase in average fiber number and decrease in average fiber area compared to the control. At twenty-two weeks, the pMALc2x-sMSTNpro 0.2 mg/l treated-group was induced and showed a decrease in average fiber number and increase in average fiber area. The results between twelve and twenty-two weeks showed that the fiber numbers had decreased, whereas average fiberarea had increased due to sMSTNpro. It is understood that the sMSTNpro induced only hyperplasia at twelve weeks, after which it induced hypertrophy. Recombinant myostatin prodomains derived from fish may induce hyperplasia and hypertrophy in O. masou depending upon the time that has elapsed.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.33-40
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• 2006

Many soil amendments have been used nowadays to improve physical and chmical condition of turf soil, which might ultimately optimize turfgrass growth in golf courses. This study was carried out to Investigate the effects of new organic soil amendment containing pig excreta 50% and sawdust 50% on growth of zoysiagrass (Zoysia japonica L.) and kentucky bluegrass (Poa pratensis L.) in greenhouse. Three applicable treatments with soil mixtures of 10, 20, and 30% (v/v) animal organic soil amendment (AOSA) with sand, were tested for chemical property, physical property, visual quality and root length of zoysiagrass and Kentucky bluegrass. As results, application of $10{\sim}30%$ AOSA mixtures were proper to grow turfgrass in soil nutrition. Especially, the treatment with 20% AOSA mixtures showed 0.7% in organic matter, which meets to green standard of USGA. Also, 30% AOSA mixtures was 1.1% in organic matter, which might be desirable for zoysiagrass-planted golf courses in Korea. It was turned out that addition of AOSA decreased the hydraulic conductivity in soil physical property Because the sand possess high hydraulic conductivity, it is recommended to combine $10{\sim}30%$ AOSA with sand in order to sustain soil balance. The treatment with $10{\sim}30%$ AOSA noticeably increased visual quality of both zoysiagras and Kentucky bluegrass during 90 days. However, treatments with either 20% or 30% AOSA were effective to develop root length of zoysiagrass but treatments with 20% AOSA were more effective than that of 30% AOSA mixtures to promote root length of Kentucky bluegrass at 60 days. In conclusion, considering all vital factors such as visible quality, root growth, organic matter content, and economical efficiency, was taken, it is recommended that a $20{\sim}30%$ mixture of AOSA with sand is good for the growth of zoysiagrass and 20% mixture for Kentucky bluegrass.