• Title/Summary/Keyword: period two solutions

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Deposition Characteristics of Water-soluble Inorganic Ions in the Iksan Ambient Air during Fall, 2004 (가을철 대기환경 중 수용성 이온성분의 침적특성)

  • Kang, Gong-Unn;Kim, Nam-Song;Jeon, Seon-Bok
    • Journal of Environmental Health Sciences
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    • v.32 no.4 s.91
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    • pp.359-372
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    • 2006
  • In order to investigate the daily deposition characteristics of water-soluble inorganic components in airborne deposit on the Iksan, deposition samples were collected using a deposition gauge from October 16 to November 1, 2004. Deposition samples were collected using two different sampling gauges, a dry gauge and a wet gauge, respectively. To get wet the bottom of wet gauge during the sampling period, the volume of $30{\sim}50ml$ distilled ionized water was added in a wet gauge before the beginning of each deposition sampling. Deposition samples were collected twice a day and analyzed for inorganic water-soluble anions ($Cl^-,\;{NO_3}^-,\;{SO_4}^{2-}$) and cations (${NH_4}^+,\;Na^+,\;K^+,\;Mg^{2+},\;Ca^{2+}$) using ion chromatography. Qualify control and quality assurance of analytical data were checked by the data obtained from reinjection of standard solution, Dionex cross check standard solutions, and random several deposition samples, and measured data was estimated to be reliable. Considering the deposition sample volume, the sampling time, the surface area of sampling container, and the ion concentration measured, the daily deposition amounts for measured ions were calculated in $mg/m^2$. The total daily deposition amounts of all measured ions for dry and wet gauge were $7.5{\pm}2.8$ and $17.7{\pm}4.2mg/m^2$, respectively. A significant increase in deposition amount during rainfall days was observed for both wet gauge and dry gauge, having no difference of deposition amount between in wet gauge and in dry gauge. The mean deposition of all ions measured in this study were higher in wet gauge than in dry gauge because of the surface difference of the sampling container, especially for ${NH_4}^+\;and\;{SO_4}^{2-}$. The mean deposition amounts of ${NH_4}^+\;and\;{SO_4}^{2-}$ in wet gauge were found to be about 10 times and 3 times higher than those in dry gauge, while the rest of the chemical species were equal or a little higher in wet gauge than in dry gauge. Dominant species in dry gauge were ${NO_3}^-\;and\;Ca^{2+}$, accounting for 21% and 28% of the total ion deposition, whereas those in wet gauge were ${SO_4}^{2-}\;and\;{NH_4}^+$, accounting for 19% and 41% of the total ion deposition, respectively.

A Study on Methods of Documentary Research on Educational Facilities - Focused on the Utilization of the ERIC - (교육시설(敎育施設)에 관한 문헌연구(文獻硏究) 방법(方法) - 미국 ERIC 자료 활용방법을 중심으로 -)

  • Park, Jae-Youn
    • Journal of the Korean Institute of Educational Facilities
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    • v.1 no.1
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    • pp.33-40
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    • 1994
  • This study was taken to increase efficiency in reviewing documents of school facilities from the network of ERIV(Educational Resources and Information Center, USA). Outline of the ERIC network, and the structure, role, function of the ERIC thesaurus are introduced. A thesaurus have developed for information retrieval purpose provides the filing labels which permit information to be stored by one person and retrieved by another. As an information system grows, its thesaurus is systematically built and refined to the point where it represents, in a very special sense, the vocabulary of subject field. The Thesaurus of ERIC Descriptors represents such a vocabulary for the field education. An understanding of its origins, its function and its limitations, is just as important to the teacher, the student of education or the educational researcher as it is for the indexer or custodian of the information pool it represents. If the Thesaurus is understood and used in an appropriate way, it can give all educators not only insight into the ERIC system but also an increased awareness of the language of their field. A great many terms are necessary to describe the many aspects of education, and the task of relating them in even an approximately consistent way is an enormous one. The undertaking should be managed by people who not only know what they are talking about but who also should be able to predict what people in their field are lilely to be talking about in the near future. It should also enlist people who are willing to pay term to another within the system. To engage a large number of these two kinds of people over a long period of time is very likely to cost a great deal of money. There is very little proprietary value in producing such a list of terms, for it can very easily be copied, adapted, updated, etc. Thus, because of its high cost and low proprietary value, it becomes a task likely to be funded only by a government. A government has many ways of spending its money. However, after the decision has been made to spend money to produce an authority list, one must decide how this authority is to be delegated. The history of the development of the ERIC Thesaurus is the history of how this authority was delegated. Scientific research has thrived on efforts to define terms as precisely as possible. It is difficult to say with certainty, however, that solutions to social problems have thrived on a simple diet of scientific research. Contemporary crises demand new and imaginative ways of conceiving problems and talking about them. If this Thesaurus or any other scheme for normalizing or controlling language inhibits in the slightest measure the creative use of language, it is against it use. Only if the principles and details of the Thesaurus are misunderstood can it be used as a constraint on language in a negative sense. Students of education of every kind should see the The-saurus as an opportunity to become increasingly self-conscious about their language and thus about their assumptions and their approaches to educational problems.

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A Study on Developing the Classification Scheme of Library Goods (도서관용품 분류체계 개발에 관한 연구)

  • Noh, Young-Hee;Ahn, In-Ja;Park, Mi-Young;Joung, Hyun-Tae
    • Journal of the Korean Society for Library and Information Science
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    • v.45 no.1
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    • pp.125-147
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    • 2011
  • Recently, with a high demand for the construction and remodeling of libraries, and the rapid increase in the number of libraries during the last two years, the concern and need for library goods is also increasing sharply. The purpose of this study is to develop a new classification scheme of library goods by clarifying the terminology which could provide an accurate information on library goods and allow for their smooth circulation. In this study, library goods are defined as all kinds of products required for effectively collecting, organizing and providing services with library materials, and classified into library equipments and library supplies. The term, library equipment is principally used for those things that do not wear out within a certain time period, such as furniture and machinery. Library supplies refer to those things that are expendable. As the terminology is clarified, the classification scheme can be further refined. Library equipment, for example, can be classified as furniture, library system solutions, and computers and multi-media tools. Library supplies can be classified into library organization and repair supplies, sign systems, and miscellaneous articles. Finally, six major categories which include 117 different items are presented.

Potential Impact of Timber Supply and Fuel-Wood on the Atmospheric Carbon Mitigation : A Carbon Cycle Modeling Approach (목재공급과 연료용 목재가 대기에 축적된 탄소저감에 미치는 잠재적 영향 : 탄소순환모형 접근법)

  • Lyon, Kenneth S.;Lee, Dug Man
    • Environmental and Resource Economics Review
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    • v.19 no.3
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    • pp.597-632
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    • 2010
  • There is general agreement that global warming is occurring and that the main contributor to this probably is the buildup of green house gasses, GHG, in the atmosphere. Two main contributors are the utilization of fossil fuels and the deforestation of many regions of the world. The burning of fossil fuels increases atmospheric carbon while the burning of fuel-wood reducing fossil fuel consumption along with its forest source maintain an atmospheric carbon level. The standing timber in the forests is a carbon sink, as are wood buildings and structures, and fossil fuel in the ground. This paper is designed to examine a number of current issues related to mitigating the global warming problem through forestry. For this purpose, we develop a modeling approach by integrating timber market, fossil fuel market and carbon cycling model. We use discrete time optimal control theory to identify optimal time paths, the laws of motion, and stationary stats solutions of endogenous variables in the model. On the basis of these results, we identify the optimal amounts of subsidies to be provided or taxes to be imposed by the regulatory agency to mitigate atmospheric carbon accumulation. We also present a numerical example to help illustrate the characteristics of variables in the model when the social cost for atmospheric carbon incrementally shifts upward. A surprising result is that the social cost function for atmospheric carbon has a very smaller impact on the optimal rotation period than previous literature suggested.

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Effects of Phytoncide Treatment on the Physicochemical, Microbiological, and Sensory Characteristics of Fresh-cut Lettuce (Phytoncide 처리가 신선편이 양상추의 저장 중 이화학적, 미생물학적 및 관능적 특성에 미치는 영향)

  • Kim, Do-Hee;Kim, Han-Bit;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.20 no.2
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    • pp.166-172
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    • 2013
  • The effect of phytoncide solution treatment on the browning and quality of fresh-cut iceberg lettuce during storage was studied. The treatments were applied as four solutions adjusted at $10^{\circ}C$: distilled water (DW) as the control; edible ethanol (EE); 1% (v/v) phytoncide essential oil from pine needle diluted with distilled water (DP); and 1% (v/v) phytoncide essential oil diluted with edible ethanol (EP). Fresh-cut lettuce was dipped in each solution for 60 sec, was rinsed with distilled water, was packaged with an OPP film bag, and was then stored at $4^{\circ}C$ for 12 days. The EP group had a significantly high level of total soluble solids, titratable acidity, and carbon dioxide, and low total bacteria counts, pH, and oxygen. The sensory score of color in the EP group recorded a high value, but the EE and EP groups recorded low scores in aroma and taste during the storage period. Alcohol and phytoncide were vaporized by opening the package for two hours, and the score of the aroma and taste of EP showed no differences from those of the other groups. Based on the above results, it was determined that the phytoncide essential oil diluted in edible alcohol with 1% solution inhibited the browning of and microbial growth in fresh-cut lettuce, and will be a useful natural compound in maintaining the quality of fresh-cut produce.

Kinetic Study of Cadmium Adsorption by Sewage Sludge (하수오니에 의한 Cd 흡착의 속도론적 연구)

  • Lee, Sang-Mo;Goh, Tee-Boon
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.1
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    • pp.32-39
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    • 2000
  • To investigate the adsorption-desorption reaction of Cd by sewage sludge, the adsorption of Cd from $Cd(NO_3)_2$ solutions of concentrations ranging from 5 to $50{\mu}g\;Cd\;mL^{-1}$ by sewage sludge was examined for reaction periods up to 48 hours. The amount of Cd adsorbed as a function of time was measured. The adsorption between Cd in solution and the solid phase could be described by two stages. The initial adsorption of Cd was very rapid, that is, approximately 95% of the added Cd was removed from solution within the first 30 minutes. Further, the greater the concentration of Cd added, the greater was the amount of Cd adsorbed. After the rapid initial decrease of Cd, a slower decline in the Cd concentration resulted which followed first order reversible kinetics. The equilibrium concentrations for the reactions, as well as the time period for the equilibrium reactions were dependent on the initial Cd concentrations. If equilibrium is reached, the amount of Cd remaining in solution is greater when the amount adsorbed is higher, although the percentage of Cd in solution is constant relative to the initial concentration of Cd. Some of the adsorbed Cd was released back to solution since the concentration of Cd after 48 hours was higher than the equilibrium concentration of Cd. However, despite the increased amount of Cd measured, the overall net reaction was a significant adsorption of Cd from solution by sewage sludge.

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The Study on the South-North Sudan Conflict (남북 수단 분쟁 연구)

  • Cho, Sang-Hyun;Kum, Sang-Moon
    • International Area Studies Review
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    • v.17 no.4
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    • pp.155-179
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    • 2013
  • Becoming independent in 1956, Sudan has since experienced a number of coups $d^{\prime}{\acute{e}}tat$, religious conflicts between the Islamic north and the Christian south, conflicts between the north-south population composition and races, two civil wars for nearly 40 years due to a clash of interests over resources and others, and the Darfur crisis in which hundreds of thousands died. In 1983, as the Sudanese government forced Islamic laws on the southern region where many Christians lived, the civil war resumed and suffered heavy casualties. Although a brief period of tranquility is maintained at the present moment as South Sudan seceded, military conflicts continue to arise. The objective of this research is to understand the North-South Sudan conflict by examining its history and course. For this purpose, chapter 2 will make a theoretical and reality approach for conflict items and solutions. Chapter 3 will discuss the historical background and reasons for the Sudanese conflict by considering Sudan before 19th century, the Egyptian conquest of Sudan and the diverging North and South, Sudanese independence and other divisions yet again, and finally the North-South conflicts over religion and resources. In Chapter 4, there will be an analysis of the course of the Sudan Civil War by separating it into the First and Second Civil War. In Chapter 5, the consequences and future prospect will be presented in lieu of the conclusion.

A Study on Loading Method of Large Scaffolding Module for LNG Carriers Using TRIZ (TRIZ를 이용한 LNG 운반선 대형 비계 모듈의 탑재 방안 연구)

  • Park, Myeong-Chul;Shin, Sang-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.94-100
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    • 2021
  • To improve the productivity of cargo containment construction for a membrane LNG carrier, it is important to shorten the installation period and process of the scaffolding system, which is a construction workbench of a cargo containment for a membrane LNG carrier. As an effective method, opinions are being gathered to enlarge the lifting unit from the existing two stages to eight stages. On the other hand, the stresses around the pin and hole will increase significantly because of the increase in lifting load according to the large size of the module. The purpose of this study was to establish a new large module-lifting plan by introducing TRIZ to solve these problems. This study adopted a method to utilize 40 inventive principles, which is one of the various problem-solving tools of TRIZ. First, technical contradictions were derived, the engineering parameters were selected. Second, efficient inventive principles were selected to overcome the technical contradictions using a contradiction matrix. Finally, the general and specific solutions were derived through the selected inventive principle, and structural analysis confirmed that the stress generated in the structure was low. The utility of TRIZ was confirmed by the successful lifting of large modules using the established lifting method.

Varietal Responses of Soybean Germination and Seedling Elongation to Temperature and Polyethylene Glycol Solution (온도와 PEG에 대한 대두품종의 발아 및 묘신장 반응)

  • Seong, Rak-Chun;Chung, Hae-Joon;Hong, Eun-Hi
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.1
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    • pp.31-37
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    • 1988
  • Germination and seedling elongation of soybeans [Glycine max. (L.) Merr., cults. Bangsakong, Hill, Paldalkong, Danyupkong, Baegwun-kong. Kwangkyokong, Changyupkong and Hwangkeumkong] were measured at two temperatures (15 and 30$^{\circ}C$) and four polyethylene glycol 10,000 (PEG) solutions (0, 20, 30 and 35g/100g-H$_2$O). Adjustments of PEG solution were based on water potentials of 0.0, -0.5, -1.1 and -1.5 MPa at room temperature. Observations were made at 3, 6, 9 and 12 days for 15$^{\circ}C$ and 1, 2, 3 and 4 days for 30$^{\circ}C$. Fifteen seeds of each cultivar were placed on Whatman No. 1 (9cm) filter paper in plastic pertridishes, and adjusted to 15 ml of the proper PEG solution supplemented with 0.2 percent thiram using automatic syringe. The dishes were covered with cap. The seeds were germinated at a continuous temperature of 15 or 30$^{\circ}C$ under dark conditions for programmed period. Seedling moisture content and seedling length of eight soybean cultivars decreased as PEG concentration increased both at 15 and 30$^{\circ}C$. Cultivar differences in seedling moisture content and seedling length were found among eight soybean cultivars at temperatures of 15 and 30$^{\circ}C$. Larger sized cultivar absorbed more moisture than samller sized cultivar. However, reverse results were obtained on the seedling moisture content of each of eight soybean cultivars. Cultiver Hill and Paldalkong showed greater seedling length than the other six cultivars from 20 to 30g/100g water of PEG concentrations both at 15 and 30$^{\circ}C$. The results of this study indicated that germination test of soybean seeds in aqueous solutions of PEG has potential for screening soybean cultivars for improved emergence during moisture stress.

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Study of Volcanic Gases and Hot Spring Water to Evaluate the Volcanic Activity of Mt. Baekdu (백두산 화산활동 평가를 위한 화산가스 및 온천수에 대한 연구)

  • Lee, Sangchul;Yun, Sung-Hyo
    • Economic and Environmental Geology
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    • v.50 no.2
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    • pp.171-180
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    • 2017
  • This study performed the analysis on the volcanic gases and hot spring waters from the Julong hot spring at Mt. Baekdu during the period from July 2015 to August 2016. Also, we confirmed the errors that $HCO_3{^-}$ concentrations of hot spring waters in the previous study (Lee et al. 2014) and tried to improve the problem. Dissolved $CO_2$ in hot spring waters was analyzed using gas chromatograph in Lee et al. (2014). Improving this, from 2015, we used TOC-IC to analysis dissolved $CO_2$. Also, we analyzed the $Na_2CO_3$ standard solutions of different concentrations using GC, and confirmed the correlation between the analytical concentrations and the real concentrations. However, because the analytical results of Julong hot spring water were in discord with the estimated values based on this correlation, we can't estimate the $HCO_3{^-}$ concentrations of 2014 samples. During the period of study, $CO_2/CH_4$ in volcanic gases are gradually decreased, and this can be interpreted in two different ways. The first interpretation is that the conditions inside the volcanic edifice are changing into more reduction conditions, and carbon in volcanic gases become more favorable to distribute into $CH_4$ or CO than $CO_2$. The second interpretation is that the interaction between volcanic gases and water becomes greater than past, and the concentrations of $CO_2$ which have much higher solubility in water decreased, relatively. In general, the effect of scrubbing of volcanic gas is strengthened during the quiet periods of volcanic activity rather than active periods. Meanwhile, the analysis of hot spring waters was done on the anion of acidic gases species, the major cation, and some trace elements (As, Cd, Re).