• Journal of the Korean Chemical Society
• /
• v.68 no.4
• /
• pp.205-220
• /
• 2024

This study aims to explore characteristics of pedagogical reasoning and action of beginning science teachers that naturally and spontaneously occurs in a professional learning community. Three novice middle school science teachers who majored chemistry education in A college of education, passed the examination for selecting secondary school chemistry teachers, and had a common goal of designing 8^th grade science lesson plan voluntarily created a professional learning community and had weekly meetings over a year. Main data sources included transcribed audio-recording of 11 meetings of three science teachers in a professional learning community. Data was analyzed using Shulman's pedagogical reasoning model that includes comprehension, transformation, instruction, evaluation, reflection, and new comprehension to identify characteristics and features of pedagogical reasoning in a professional learning community. Data analysis revealed that pedagogical reasoning in a professional learning community comprises not only preparation, representations, instructional selections, and adaptation but also evaluation, reflection, and new comprehension in transformation stage. Reflection in transformation stage leads teachers to be actively engaged in discussion and get new comprehension on each sub-component(preparation, representations, instructional selections, adaptation, and evaluation) of transformation stage.

• 한국유가공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.59-60
• /
• 2002

Edible films such as wax coatings, sugar and chocolate covers, and sausage casings, have been used in food applications for years$^{(1)}$ However, interest in edible films and biodegradable polymers has been renewed due to concerns about the environment, a need to reduce the quantity of disposable packaging, and demand by the consumer for higher quality food products. Edible films can function as secondary packaging materials to enhance food quality and reduce the amount of traditional packaging needed. For example, edible films can serve to enhance food quality by acting as moisture and gas barriers, thus, providing protection to a food product after the primary packaging is opened. Edible films are not meant to replace synthetic packaging materials; instead, they provide the potential as food packagings where traditional synthetic or biodegradable plastics cannot function. For instance, edible films can be used as convenient soluble pouches containing single-servings for products such as instant noodles and soup/seasoning combination. In the food industry, they can be used as ingredient delivery systems for delivering pre-measured ingredients during processing. Edible films also can provide the food processors with a variety of new opportunities for product development and processing. Depends on materials of edible films, they also can be sources of nutritional supplements. Especially, whey proteins have excellent amino acid balance while some edible films resources lack adequate amount of certain amino acids, for example, soy protein is low in methionine and wheat flour is low in lysine$^{(2)}$. Whey proteins have a surplus of the essential amino acid lysine, threonine, methionine and isoleucine. Thus, the idea of using whey protein-based films to individually pack cereal products, which often deficient in these amino acids, become very attractive$^{(3)}$. Whey is a by-product of cheese manufacturing and much of annual production is not utilized$^{(4)}$. Development of edible films from whey protein is one of the ways to recover whey from dairy industry waste. Whey proteins as raw materials of film production can be obtained at inexpensive cost. I hypothesize that it is possible to make whey protein-based edible films with improved moisture barrier properties without significantly altering other properties by producing whey protein/lipid emulsion films and these films will be suitable far food applications. The fellowing are the specific otjectives of this research: 1. Develop whey protein/lipid emulsion edible films and determine their microstructures, barrier (moisture and oxygen) and mechanical (tensile strength and elongation) properties. 2. Study the nature of interactions involved in the formation and stability of the films. 3. Investigate thermal properties, heat sealability, and sealing properties of the films. 4. Demonstrate suitability of their application in foods as packaging materials. Methodologies were developed to produce edible films from whey protein isolate (WPI) and concentrate (WPC), and film-forming procedure was optimized. Lipids, butter fat (BF) and candelilla wax (CW), were added into film-forming solutions to produce whey protein/lipid emulsion edible films. Significant reduction in water vapor and oxygen permeabilities of the films could be achieved upon addition of BF and CW. Mechanical properties were also influenced by the lipid type. Microstructures of the films accounted for the differences in their barrier and mechanical properties. Studies with bond-dissociating agents indicated that disulfide and hydrogen bonds, cooperatively, were the primary forces involved in the formation and stability of whey protein/lipid emulsion films. Contribution of hydrophobic interactions was secondary. Thermal properties of the films were studied using differential scanning calorimetry, and the results were used to optimize heat-sealing conditions for the films. Electron spectroscopy for chemical analysis (ESCA) was used to study the nature of the interfacial interaction of sealed films. All films were heat sealable and showed good seal strengths while the plasticizer type influenced optimum heat-sealing temperatures of the films, 130$^{\circ}$C for sorbitol-plasticized WPI films and 110$^{\circ}$C for glycerol-plasticized WPI films. ESCA spectra showed that the main interactions responsible for the heat-sealed joint of whey protein-based edible films were hydrogen bonds and covalent bonds involving C-0-H and N-C components. Finally, solubility in water, moisture contents, moisture sorption isotherms and sensory attributes (using a trained sensory panel) of the films were determined. Solubility was influenced primarily by the plasticizer in the films, and the higher the plasticizer content, the greater was the solubility of the films in water. Moisture contents of the films showed a strong relationship with moisture sorption isotherm properties of the films. Lower moisture content of the films resulted in lower equilibrium moisture contents at all aw levels. Sensory evaluation of the films revealed that no distinctive odor existed in WPI films. All films tested showed slight sweetness and adhesiveness. Films with lipids were scored as being opaque while films without lipids were scored to be clear. Whey protein/lipid emulsion edible films may be suitable for packaging of powder mix and should be suitable for packaging of non-hygroscopic foods$^{(5,6,7,8,)}$.

• Analytical Science and Technology
• /
• v.29 no.5
• /
• pp.209-218
• /
• 2016

PM₁₀ and PM_2.5 samples were collected at the 1100 site of Mt. Halla in Jeju Island during 2011~2012, and their ionic and elemental species were analyzed, in order to investigate the characteristics of emission sources as well as aerosol compositions. The mass concentrations of PM₁₀ and PM_2.5 were 22.0±13.1 µg/m³ and 11.3±6.1 µg/m³, respectively, showing 2.4~2.6 times lower than those of the capital city area of Korea. The composition ratios of major secondary pollutants (nss-SO₄²⁻, NH₄⁺, and NO₃⁻) were the highest as 85.5 % for PM₁₀ and 91.3 % for PM_2.5, and followed by the order of marine (Na⁺, Cl⁻, and Mg²⁺), organic acid (HCOO⁻ and CH₃COO⁻), and soil (nss-Ca²⁺) sources. Among the elemental species in PM₁₀, soil-originated components (Al, Fe, and Ca) were consisted of 50.9 %, which was higher proportion than marine and anthropogenic elements. The acidification of the fine particulate matters was found to be influenced mostly by sulfuric and nitric acids, and these acids were mainly neutralized by calcium carbonate in PM₁₀ and by ammonia in PM_2.5. The clustered back trajectories showed that 47 % of total air mass inflows was from the China, and the concentrations of NO₃⁻ and nss-Ca²⁺ were especially high corresponding to the inflows.

• The Korean Journal of Archival Studies
• /
• no.17
• /
• pp.3-37
• /
• 2008

In this article, I outlined the archival management system in Early Joseon Dynasty and examined the characteristics of the system. At first, I explained the three aspects of the archival management; the memory of the past, the documentation of the contemporary, and the vision of the future through the documentation. Secondly, I tried to understand the character of the Veritable Record and its compilation by the concepts of archival science such as 'authenticity', 'reliability'. In the memory of the past, the History of a Dynasty(Koryo-Sa) and the Comprehensive History of Eastern Kingdom were included. The arrangement of the past was accompanied with the systematic study of the domestic and foreign histories. At the beginning of the state building, there was many practical need to the experiences of government and social re-construction. It was also the process of the legitimacy establishment of the new dynasty. And the Bureaucracy promoted the development of the records and archival management system because it needed the continuity and evidence of business. The dualistic structure of the records and archival management system was the most unique character of this age. The management of general administrative records was not different from the modern one. But the historical drafts and the compilation of Veritable record were different. Here, I had to examine the characteristics of these procedures by the concept authenticity, reliability, and custodianship. In doing so, I suggested the need of conceptualization of the historical terms such as 'the primary sources' and 'the secondary sources' in historical study. The archival concepts will be the most useful means to that issue. Through the memory of the past and the documentation of the contemporary, they made visions of the future, new vision of the Literati Governance. In this tradition, in spite of the revision of the Veritable records by the new changed political party, both the orignal and the revised remained as the comparative evidence for the future generation in the name of the Black-Red Revised History.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.8
• /
• pp.574-582
• /
• 2012

This study presents the concentrations of the polycyclic aromatic hydrocarbons (PAHs) listed as priority pollutants by United States Environmental Protection Agency (US EPA), in 98 sludges from 54 industrial wastewater treatment facilities of South Korea. The mean concentrations of ${\Sigma}_{16}PAHs$ were ranged from 32.5 ${\mu}g/kg-dw$ to 1189.3 ${\mu}g/kg-dw$ by industries, and the highest content was found in the petrochemical industry, followed by chemical, clothing manufacturing and dying, pulp and papermaking, secondary wastewater treatment, and food/beverage producing industries. Comparisons to the EU and Danish standards of ${\Sigma}_{16}PAHs$ in sewage sludge for land application showed only two samples (one from petrochemical, and the other from chemical industry) exceeded the limits. ANOVA test with PAH concentrations as variables revealed no statistically significant influences by industrial types and sampling time (i.e., seasonal variations). Pearson correlations between individual PAHs showed strong relationships (r>0.7) among 4-ring PAHs. Concentrations of acenaphthylene, anthracene, fluoranthene, benzo(a)anthracene, benzo(f)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene presented strong correlations to ${\Sigma}_{16}PAHs$. Principal component analysis discriminated entire samples into three groups by two principal components (PC1 and PC2) with 70% of data variations, in which industrial types were not of importance, but a dominance of certain PAHs. Samples in group-I, which is high PC1 and low PC2, were characterized by a dominance of 2-ring PAHs, and in group-II, PC1 and PC2 showed a linear relation, was dominant 4-ring PAHs. Group-III with low PC1 and high PC2 includes 17 samples showing a noticeably high contribution of 3-ring PAHs to ${\Sigma}_{16}PAHs$. This study provides concentrations of PAHs in industrial sludges collected from a wide variety of sources (six industrial types) and two seasons of sampling events, and the comparison of ${\Sigma}_{16}PAHs$ with other studies are also discussed.

• Journal of the Korean earth science society
• /
• v.32 no.7
• /
• pp.832-859
• /
• 2011

The importance of scientific education on accurate oceanic currents and circulation has been increasingly addressed because the currents have played a significant role in climate change and global energy balance. The objectives of this study are to analyze errors of the oceanic current maps in the textbooks, to discuss a variety of error sources, to suggest how to produce a unified oceanic current map of the East Sea for the students. Twenty-seven textbooks based on the 7th National Curriculum were analyzed and quantitatively investigated on the characteristics of the current maps by comparing with both the previous literature and up-to-date scientific knowledge. All the maps in the textbooks with different mappings were converted to digitalized image data with Mercator mapping using geolocation information. Detailed analysis were performed to investigate the patterns of the Tsushima Warm Current (TWC) in the Korea Strait, to examine how closely the nearshore branch of the TWC flows along the Japanese coast, to scrutinize the features of the offshore branch of the TWC south of the subpolar front in the East Sea, to quantitatively investigate the northern range of the northward-propagating East Korea Warm Current and its latitude turning to the east, and lastly to examine the outflow of the TWC near the Tsugaru Strait and the Soya Strait. In addition, the origins, southern limits, and distances from the coast of the Liman Current and the North Korea Cold Current were analyzed. Other erroneous expressions of the currents in the textbooks were presented. These analyses revealed the problems in the present current maps of the textbooks, which might lead the students to misconception. This study also addressed a necessity in a bridge between scientists with up-to-date scientific results and educators who needed educational materials.

• The Journal of the Petrological Society of Korea
• /
• v.21 no.2
• /
• pp.235-247
• /
• 2012

Peridotite xenoliths hosted by alkali basalts from South Korea occur in Baengnyeong Island, Jeju Island, Boeun, Asan, Pyeongtaek and Ganseong areas. K-Ar whole-rock ages of the basaltic rocks range from 0.1 to 18.9 Ma. The peridotites are dominantly lherzolites and magnesian harzburgites, and the constituent minerals are Fo-rich olivine ($Fo_{88.4-92.0}$), En-rich orthopyroxene, Di-rich clinopyroxene, and Cr-rich spinel (Cr# = 7.8-53.6). Hydrous minerals, such as pargasite and phlogopite, or garnet have not been reported yet. The Korean peridotites are residues after variable degree of partial melting (up to 26%) and melt extraction from fertile MORB mantle. However, some samples (usually refractory harzburgites) exhibit metasomatic enrichment of the highly incompatible elements, such as LREE. Equilibration temperatures estimated using two-pyroxene geothermometry range from ca. 850 to $1050^{\circ}C$. Sr and Nd isotopic compositions in clinopyroxene separates from the Korean peridotites show trends between depleted MORB-like mantle (DMM) and bulk silicate earth (BSE), which can be explained by secondary metasomatic overprinting of a precursor time-integrated depleted mantle. The Korean peridotite clinopyroxenes define mixing trends between DMM and EM2 end members on Sr-Pb and Nd-Pb isotopic correlation diagrams, without any corresponding changes in the basement. This is contrary to what we observe in late Cenozoic intraplate volcanism in East Asia which shows two distinct mantle sources such as a DMM-EM1 array for NE China including Baengnyeong Island and a DMM-EM2 array for Southeast Asia including Jeju Island. This observation suggests the existence of large-scale two distinct mantle domains in the shallow asthenosphere beneath East Asia. The Re-Os model ages on Korean peridotites indicate that they have been isolated from convecting mantle between ca. 1.8 and 1.9 Ga.

• Journal of Technology Innovation
• /
• v.25 no.2
• /
• pp.89-125
• /
• 2017

Complex product systems (CoPs) is a engineering-intensive products with high-ended design technology, which are closely linked with national economic growth and development of social infrastructures. Accordingly, in order to understand the technological evolution of CoPs, it is necessary to identify the macro-environmental drivers surrounding the CoPs and their impact on the technological evolution of the CoPS. Therefore, we investigate the effect of policy, economic and social drivers on the technological evolution of CoPS by implementing the longitudinal case study on nuclear power plant during the periods between 1950 and 2010s. Based on the analysis of various sources of secondary data and primary data through interviews, we found that the technological evolution of nuclear power plant is progressed as "Phase 1: Application research for peaceful utilization of nuclear energy" between 1950s and 1960s, "Phase 2: The first renaissance of nuclear energy" during 1970s, "Phase 3: Enhancement of safety and the catch-up of latecomers in nuclear energy" between 1990s and 2000s, and "Phase 4: Top prioritization of safety and the development of next generation reactors for the second renaissance of nuclear energy" since 2010s. We also found that various kinds of policy, economic and social drivers, such as energy policy, investment in technology development, economic growth and energy demand, social acceptability and environmental concern, have affected the technology evolution of nuclear power plant at each phase. We emphasize the role of macroenvironmental drivers in the technological evolution of CoPS. We also suggest that countries that endeavor to develop CoPs need to utilize those drivers for enhancing competitiveness and sustaining leadership.

• Korean Journal of Remote Sensing
• /
• v.36 no.5_3
• /
• pp.1053-1066
• /
• 2020

Sulfur dioxide (SO₂) is primarily released through industrial, residential, and transportation activities, and creates secondary air pollutants through chemical reactions in the atmosphere. Long-term exposure to SO₂ can result in a negative effect on the human body causing respiratory or cardiovascular disease, which makes the effective and continuous monitoring of SO₂ crucial. In South Korea, SO₂ monitoring at ground stations has been performed, but this does not provide spatially continuous information of SO₂ concentrations. Thus, this research estimated spatially continuous ground-level SO₂ concentrations at 1 km resolution over South Korea through the synergistic use of satellite data and numerical models. A stacking ensemble approach, fusing multiple machine learning algorithms at two levels (i.e., base and meta), was adopted for ground-level SO₂ estimation using data from January 2015 to April 2019. Random forest and extreme gradient boosting were used as based models and multiple linear regression was adopted for the meta-model. The cross-validation results showed that the meta-model produced the improved performance by 25% compared to the base models, resulting in the correlation coefficient of 0.48 and root-mean-square-error of 0.0032 ppm. In addition, the temporal transferability of the approach was evaluated for one-year data which were not used in the model development. The spatial distribution of ground-level SO₂ concentrations based on the proposed model agreed with the general seasonality of SO₂ and the temporal patterns of emission sources.

• Journal of Preventive Medicine and Public Health
• /
• v.14 no.1
• /
• pp.65-74
• /
• 1981

This survey was made to determine the overall health situation on (1) the status of sickness; (2) the medical care utilization; (3) the medical cost in Mi-Kum Myun, Nam Yang Ju Gun, Kyung-Gi Do. The survey with questionnaire was carried out with 2,840 peoples in 560 households from August 9th to 16th, 1979. The findings from the survey were as follows; 1. Annual morbidity rate of the prolonged ill cases was 97.2 per 1,000 population (male 94.7, female 99.6), The highest age specific morbidity rate was 274.5 of the 45-to 64-year group and the lowest was 21.9 of the 5-to 14-year group. 2. Annual morbidity rate of the new patients was 777.5 per 1,000 population(male 644.5, female 909.5). 3. The chief complaints distribution of the prolonged ill cases was: local pain 36.6%, indigestion 22.4%, and coughing 7.3%, respectively, In terms of age and sex distribution, a large number of female of the 45-to 64-year group complained of local pain or general pain and a large number of both sexes of the 25-to 44-year group complaned of indigestion. 4. The major diseases of the new patients which classified with International Classfication of Diseases (I.C.D.) were disease of the respiratory system, disease of the digestive system, and disease of the musculo-skeletal system and connective tissue for male, disease of the respiratory system, disease of the digestive system, and accident, poisoning, violence for female. 5. Total ill days of the 92 new patients were 536 days and average ill days per case were $6{\pm}38.3$ days. 6. The rate of receiving treatment in the prolonged ill cases was 82.2%(medical facilities 46.4%, drug stores 27.5%, herb medicine 8.3%). 7. The rate of receiving treatment by first choice of the new patients was 88.0% (drug stores 57.%, medical facilities 28.2%, and herb medicine 2.2%), and the rate of receiving treatment by second choice was 30.9% of first treatment cases (medical facilities 44.0%, drug store 44.0% and herb meicine 12.0%). 8. Annual hospitalization rate per 1,000 population was 12.0 (male 12.0, female 11.9). 9. The locations of medical facilities utilized by out-patients were: in the prolonged ill cases Seoul or other places 66.4%, Nam Yang Ju Gun 33.6%, in cases of the new patients Seoul or other places 35.1% and Nam Yang Ju Gun 64.9% respectively. 10. The satisfaction rate of the new patients by mode of receiving treatment was: in cases of primary utilization by first choice herb medicine 100.0%, medical facilities 88.5%, and drug stores 69.8%, in cases of secondary utilization medical facilities 100.0%, herb medicine 100.0%, and drug stores 72.7% respectively. 11. The medical cost per utilized facilities was as follows; in average medical fee per case out-patient 8.947 won, in-patient 266,000 won, drug stores 1,532 won, and herb medicine 15,607 won, in average medical fee per day out-patient 4,829 won, in patient 14,178 won, drug stores 891 won, and herb medicine 4,906 won respectively. 12. The sources of the hospital charges paid out were: there own expense 50.0%, debt 35.3%, and security of medical care 14.7% respectively.