• Title/Summary/Keyword: accumulation phenomena

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Flow Analysis for the Sludge Pneumatic Dehydrator with Cyclone Type (사이클론형 슬러지 공기건조기의 유동해석)

  • Kim, Bong-Hwan;Jung, Dae-Sik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.4
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    • pp.1-6
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    • 2009
  • Air drying technology was developed as an equipment for reducing of moisture content from wastewater treatment and waterworks sludge cake and reproducing it by reusable matter. Advantage of cyclone type pneumatic dehydrator is simple and excellent drying performance. The air drying equipment was composed to the air ejector which made high-speed fluid field, and cyclone which made circling fluid field. Dewatered cake was crushed at the high-speed zone as first step, and formed with dried powder of sphere shape by the collision between particles at the circling fluid zone. In this study, a CFD analysis has been performed to predict air-sludge particles flow in cyclone and ejector of pneumatic dehydrator. The computational results showed typical Rankine vortex structure which was frequently found in swirling flow phenomena. And the conical type wedge in lower part of a cyclone prevented accumulation of the sludge particles in the cyclone. Therefore, this technology was effective in drying of dehydrated cake of waterworks sludge.

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Characteristic Studies on the Stone Cultural Heritage by Shape Reversal Engineerings (석조문화재의 형상역공학적 특성연구)

  • Shon, Ho-Woong;Lee, Kang-Won
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2009.04a
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    • pp.59-63
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    • 2009
  • Structures show the phenomena of deformation and lowering of function with time-lapse by artificial environments and changes of geotechnical conditions or accumulation of initial deformation elements. This study aims the structural assessment of cultural heritage. Non-destructive evaluation techniques were applied to protect it from survey: 3D precise laser scanning surveying system was applied to measure the exact size, displacement and declining angles.

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A Numerical Model for Predicting Shoreline Changes (해안선 변화를 예측하기 위한 수치모델에 관한 연구)

  • 양인태;최한규;최창혁
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.7 no.1
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    • pp.19-26
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    • 1989
  • The quantification of phenomena presented by the shoreline changes and the prediction of future changes of shoreline are investigated by using a numerical model in this study. Shoreline has been sucessively affected by the activities of reclamation to maximize the land use and it also has been changed with cycles of accumulation and erosion of deposits. Many researches were performed on the jetties constructed to protect facilities adjacent to the shore. However, few studies on a seawall of protecting the beach, being very important in terms of land use, were carried out. Therefore, this study is to analyze effects of a straight seawall to shoreline changes.

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Rethinking of Research and Educational Trends in Foreign Studies Field in Korea (한국에서의 해외지역 연구와 교육에 대한 비판적 고찰)

  • Kwon, Se Eun
    • Cross-Cultural Studies
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    • v.22
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    • pp.279-301
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    • 2011
  • This paper is aimed to examine the current research and educational problems of foreign studies in Korean universities and review some alternative ways. Area studies as foreign studies have several characteristics which are different from those of the other research disciplines. It is a research and educational program that promotes comprehensive understanding about political, economic, social, and cultural phenomena of a specific area in the world. For better understand 'others', researchers in the field of area studies must explain the whole mechanism of the area, which could be revealed in terms of the very existence of its reality. Foreign studies are accomplished with joint-research method, collaborating two or more different research disciplines and based on the contemporary system of knowledge accumulation and educational program. Therefore, the critical issue can be gradually taken on a political and social characteristic. At this point, research and educational manner in foreign studies field in Korea should be changed to secure the academic reflections of temporality, sociality, placeness using a new paradigm such as complexity.

Patient-specific pluripotent stem cell-based Parkinson's disease models showing endogenous alpha-synuclein aggregation

  • Oh, Yohan
    • BMB Reports
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    • v.52 no.6
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    • pp.349-359
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    • 2019
  • After the first research declaring the generation of human induced pluripotent stem cells (hiPSCs) in 2007, several attempts have been made to model neurodegenerative disease in vitro during the past decade. Parkinson's disease (PD) is the second most common neurodegenerative disorder, which is mainly characterized by motor dysfunction. The formation of unique and filamentous inclusion bodies called Lewy bodies (LBs) is the hallmark of both PD and dementia with LBs. The key pathology in PD is generally considered to be the alpha-synuclein (${\alpha}$-syn) accumulation, although it is still controversial whether this protein aggregation is a cause or consequence of neurodegeneration. In the present work, the recently published researches which recapitulated the ${\alpha}$-syn aggregation phenomena in sporadic and familial PD hiPSC models were reviewed. Furthermore, the advantages and potentials of using patient-derived PD hiPSC with focus on ${\alpha}$-syn aggregation have been discussed.

Studies on Damage Properties of MgO-C Refractories through Hertzian Indentation at Room and High Temperatures

  • Cho, Geun-Ho;Byeun, Yunki;Jung, Yeon-Gil
    • Journal of the Korean Ceramic Society
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    • v.56 no.1
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    • pp.77-83
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    • 2019
  • MgO-C refractories are used in basic furnaces and steel ladles due to their many desirable properties, such as excellent thermal shock resistance via low thermal expansion, and high thermal conductivity. However, the mechanical and thermal properties of the refractory continuously deteriorate by spalling phenomena and pore generation due to the oxidation of graphite, used as a carbon source, indicating that the characteristics and performance of MgO-C refractories need to be improved by using a new material or composition. In this study, the use of a Hertzian indentation test as a method for determining the damage and fracture behavior of an MgO-C refractory is described. The results highlight that Hertzain indentation tests can be one of the important evaluation tools for quasi-plastic damage accumulation of MgO-C refractories during falling process of scrap metal.

Studies on the Nitrogen Metabolism of Soybeans -II. Variation of Free Amino acids during the Growth of Younger Plants (대두(大豆)의 질소대사(窒素代謝)에 관(關)한 연구(硏究) -II. 유(幼) 식물시기(植物時期)에서의 유리(遊離)아미노산(酸)의 소장(消長))

  • Kang, Y.H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.3 no.1
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    • pp.49-54
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    • 1970
  • In an effort of determine the metabolism and bio-synthesis of nitrogen, was studied at variance of souble nitrogens, free amino acids and total alcohol soluble amino acids during the growth of younger soybean plants, and saybean divides into cotyledon and embryonic organ (shoot and root system) in this experiment. 1. In the soluble nitrogen of soybean, ratio of increase and decrease in the amino acids of them was displayed the near phenomena both cotyledon and embryonic organ of soybean. But, in the 17th days after seed germination, that is the developmeatal stage of adult leaf of soybeans, was appear the maximum value. It has been suggested that the stage of first half period of growth as boundary the stage of adult leaf development which indicated clear morphologically, at the younger soybean plants, is the step that nitrogen assimilation. 2. It was investigated the amino acids of seventeen kinds in the seed state, but at the third days after seed germination, was investigated the amino acids of nineteen kinds. Ultimately, it appears the translocation from cotyledon to embryonic organ in the distribution of amino acid, the nineth day which differentiation begining day of embryonic organ, then after, it happen the variation of number of inspected amino acid in the cotyledon and embryonic organ but only the variance changes in the distribution and quantitative aspects. Especially, the most conspicuous fact was indicated the accumulation of Asparagine, that is the phenomena of Asparagine-accumulation was constitute, not with standing no fertilization from outside. It may be concluded from the results of this investigation that the difference of special phenomena of soybean from the embryo of other plans. 3. In the initial stage of differentiation at embryonic organ number of inspected amino acid was very few, and then, it was slightly appeared the increase-phenomena in the number of them. It was that the amino acid inspecting the initial stage was translocated from the cotyledon. It is suggested that the intermediate-metabolism of amino acid was constituted on the basis of above the result. 4. The phenomena of increase and decrease of total alcohol soluble amino acid were essentially identical to the water soluble amino acid of soybean, but it was appeared the severe difference of amounts in both of them.

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The Effect of Regulatory Focus on the Link Between Purchase Behavior and Redemption Behavior

  • Kim, Ji Yoon
    • Asia Marketing Journal
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    • v.15 no.4
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    • pp.51-60
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    • 2014
  • Previous research on loyalty program has verified the factors that influence redemption behavior and the understanding of the mechanism of redemption behavior with academic and practical implications. However, these research has not proven boundary conditions in which the phenomena can be strengthened or weakened- that is, the moderating effect remains unclear. The inclusion of moderating variables can provide a more extensive understanding of the mechanism of this behavior from academic and managerial perspectives alike. Therefore, this current research proposes regulatory focus as a moderating variable, which has received scarce attention in the study of loyalty program behavior, especially individual characteristic variables that, in turn, affect the consumers' purchasing behavior in various ways. Previous research on consumer decision making investigates the differential role of regulatory focus as a series of stages. Regulatory focus theory posits that people depend on the two types of regulatory focus when pursuing goals: promotion focus vs. prevention focus. The former induces tendencies to recognize a goal as a hope and ideal, as something that satisfies the need for accomplishment, and to be sensitive to the presence of a positive outcome of the match and to match the pursuit of goals. On the other hand, the latter tends to regard a goal as the responsibility or obligation to achieve the goal, has a tendency to avoid failure to meet a target, and is sensitive to the presence of the negative consequences that do not reach the target. The following propositions are suggested: 1) The effect of higher accumulation effort level on delaying point redemption speed will be relatively more pronounced for customers with prevention focus. 2) The effect of higher accumulation effort level on large redemption unit size will be relatively more pronounced for customers with prevention focus. 3) The effect of higher accumulation effort level on hedonic redemption ratio will be relatively more pronounced for customers with promotion focus. Therefore, this research provides a moderating variable that has the potential to be used as a reference for market segmentation and affects the relationship between point accumulation effort and three sides of point redemption behavior. On this basis, the direction for the future research on this issue is recommended. Future research could verify these propositions conducting a survey of customers' propensity of regulatory focus in conjunction with the history of the loyalty program of data. This would provide a more realistic effect on the usage behavior of loyalty program consumers by providing useful implications for both marketing practitioners and researchers.

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Phytoremediation of Organophosphorus and Organochlorine Pesticides by Acorus gramineus

  • Chuluun, Buyan;Iamchaturapatr, Janjit;Rhee, Jae-Seong
    • Environmental Engineering Research
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    • v.14 no.4
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    • pp.226-236
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    • 2009
  • The performance of phytoremediation has proven effective in the removal of nutrients and metals from aqueous systems. However, little information is available regarding the behavior of pesticides and their removal pathways in aquatic environments involving plant-uptake. A detailed understanding of the kinetics of pesticide removal by plants and information on compound/plant partition coefficients can lead to an effective design of the phytoremediation process for anthropogenic pesticide reduction. It was determined that the reduction rates of four organophosphorus (OP) and two organochlorine (OC) pesticides (diazinon, fenitrothion, malathion, parathion, dieldrin, hexachlorobenzene [HCB]) could be simulated by first-order reaction kinetics. The magnitude of k was dependent on the pesticide species and found within the range of 0.409 - 0.580 $d^{-1}$. Analytical results obtained by mass balances suggested that differential chemical stability, including diversity of molecular structure, half-lives, and water solubility, would greatly influence the removal mechanisms and pathways of OPs and OCs in a phytoreactor (PR). In the case of OP pesticides, plant accumulation was an important pathway for the removal of fenitrothion and parathion from water, while pesticide sorption in suspended matter (SM) was an important pathway for removal of dieldrin and HCB. The magnitude of the pesticide migration factor (${\Large M}_p^{pesticide}$) is a good indication of determining the tendency of pesticide movement from below- to above-ground biomass. The uncertainties related to the different phenomena involved in the laboratory phyto-experiment are also discussed.

Runoff Estimation with Consideration of Land-Use Distribution (토지이용 분포를 고려한 유출량 산정기법)

  • Son, Kwang-Ik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.1
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    • pp.97-102
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    • 2008
  • The Natural Resource Conservation Service Curve Number(NRCS-CN) method is one of the widely used methods for computation of runoff from a basin. However, NRCS-CN method has a weak point in that the spatial land use distribution characteristics are ignored by using area-weighted CN value. This study developed a runoff estimation algorithm which can reflect the spatial land-use distribution. The algorithm consists of Moglen's theory and a developed flow accumulation estimation program in FORTRAN. Comparisons between the results from area-weighted CN method and this study showed reasonably good agreement with measured data of experimental watersheds. The developed program predicted lower runoff than the conventional NRCS-CN method. As a conclusion, this study proposes a new design direction which can simulate real runoff phenomena. And the developed program could be applied into runoff minimization design for a basin development.