• Title/Summary/Keyword: 한국 제4기학회

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Experimental Study on Influence of Flow Rate Ratio in a Dehumidifier with a Solar Desiccant Apparatus (태양열제습장치 중 제습기에서의 유량비 영향에 관한 실험적 연구)

  • Choi, Kwang-Hwan;Rokhman, Fatkhur
    • Journal of the Korean Solar Energy Society
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    • v.31 no.2
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    • pp.8-15
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    • 2011
  • 제습기의 역할은 태양열제습냉방시스템 요소 중에서도 매우 중요하다. 본 논문은 이러한 특성에 맞추어 제작된 장치를 갖고서 제습능력에 영향을 미치는 유량비를 바꾸어 실험한 결과이다. 실험은 크기가 $40m^3$인 항온항습실을 대상으로 이루어졌으며, 향류형 제습기의 수직 높이는 0.4m로 고정되었다. 또한 충진층은 액체흡수제와의 접촉면을 넓게하기 위하여 플라스틱 충진재로 채워져 있으며, 흡수제의 온도는 빠른 변화를 보기 위하여 $15^{\circ}C$로, 농도는 40%로 고정하였다. 액체흡수제의 유량과 습도가 높은 공기의 유량을 각각 3단계로 바꾸어 실험한 결과, 풍량이 높을수록 제습기 효과는 낮아졌으나, 전체적인 제습량에서는 많아졌다. 한편, 제습기에서 액체흡수제 유량이 많을수록 제습되는 수분량이 많아졌으나, 시간의 변화에 따라 제습되는 속도는 현저하게 낮아졌다. 따라서, 향후 실험에서는 유량의 변화 폭을 더욱 확대해서 많은 실험 결과를 확보하고, 이를 모델링화 하여 높은 정확도를 예측할 필요가 있다.

The Zoeal Stages of Pilumnus minutus De Haan, 1835 (Decapoda ; Brachyura: Pilumnidae) in the laboratory (애기털보부채게(갑각강, 단미목, Pilumnidae)의 zoea 유생)

  • Hyun Sook Ko
    • Animal Systematics, Evolution and Diversity
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    • v.10 no.2
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    • pp.145-155
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    • 1994
  • The zoeal development of the pilumnid crab, Pilumnus minutus De Haan, 1835 consisted of 4 zoeal stages. The duration of the zoeal stages was at least 15 days at $25^{\circ}C$. The morphology of the zoeal stage is described in detail, and comparisons are made with the known larvae of other species of the family pilumnidae. The Pilumnus minutus zoea strongly resembles zoeae of other species of the genus Pilumnus in the mouthpart setation and the carapace spines, but shows some differences in the abodominal lateral knobs. the Pilumnus minutus zoea has some affinities with the Parapilumnus trispinosus zoea by having the abodominal lateral knobs on somites 2, 3, 4 and 5.

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Synthesis of Novel Ester Quaternary Ammonium Cationic Surfactants via Michael Addition Reaction (Michael Addition Reaction을 이용한 신규 Ester Quaternary Ammonium Salt 양이온 계면활성제의 합성)

  • Kang, Eun-kyung;Jung, Seon Hwa;Jung, GaYoung;Lee, Byung Min
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.1
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    • pp.142-151
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    • 2017
  • Cationic surfactants have a bactericidal effect and the study for effective development of them became important parts in the industry. There have been increasing researches that focus on the development of products having not only outstanding features but also safety and biodegradability. In this work, novel ester-type cationic surfactants were obtained via Michael addition reaction. Intermediates were quantitatively prepared by the Michael addition reaction between alkyl acrylate and amine compounds under mild conditions without solvent and catalyst. The intermediates were quaternized with dimethyl sulfate. HQ21 with two hydrophobic groups and a hydrophilic group and HQ22 with two hydrophobic groups and two hydrophilic groups were obtained. The structures of the products were characterized by 1H-NMR, HR-MS and FT-IR and biodegradability of the products were tested.

Prediction of Kimchi Aging Using Electronic Nose System (전자코를 이용한 배추김치의 숙성도 예측)

  • Shin Jung-Ah;Choi Sang-Won;Lee Ki-Teak
    • Food Science and Preservation
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    • v.12 no.6
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    • pp.613-616
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    • 2005
  • The aging degree of Kimchi fermented at $4^{\circ}C$ for 29 days was evaluated by the correlation between the flavor and the acidity analysis. The Kimchi fermentation induced a gradual reduction in pH and an increase in acidity from $0.26\%$ (initial) to $1.15\%$ (29th day). Flavor pattern of the fermented Kimchi was obtained by the electronic nose system with 12 metal oxide sensors. Electronic nose analysis could differentiate the flavor profiles of Kimchi according to the fermentation periods, making 5 group in the principal component analysis (PCA) plot Therefore, aging degree of Kimchi could be differentiated by flavor patterns analysed by electronic nose.

The Sea Level Change and Human Activities at Sejuk-Ri, Ulsan City, Southeastern Coast of Korea during the Early Neolitic Period

  • Hwang, Sang-Ill;Yoon, Soon-Ock
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.75-86
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    • 2004
  • The sea level curve and environmental change were reconstructed at Sejuk-ri during the early Neolitic Age, based on the sedimentary facies, the distribution of remains and carbon datings. Before 6,500 years BP, the sea-level experienced one oscillation. The Neolitic men utilized geomorphic environment which formed according to the sea-level change. They might be occupied in gathering, fishing and hunting including whales hunting. The Neolitic men made acom hollows in order to remove tannin. Besides, they remained shell mounds which were formed from 6,500 years BP to around 6,000 years BP. They left the living place about 6,000 years BP because of transgression.

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Lakes and Palaeolakes in Mongolia and Northwestern China

  • Michael, Walther;Bernd, Wunnemann;Altangerel, Tshimeksaichan
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.17-17
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    • 2004
  • The Pleistocene lake level and climate development is described by proxies from sediment, pollen and diatom records in Mongolia and Northwest-China. It could be proved that higher lake levels seem to have existed during the old and mid Pleistocene period interpreted on the base of geomorphological and sedimentological reords. They are dated in a relativ time scale. The lake basins are filled up to 300 m by limnic deposits, which foused on a constant water balance of more than 700.000 years. Late Glacial and Holocene lake level fluctuations and climate changes can be proved by biostratigraphic records pointing to dry and wet phases. Only for the youngest history desiccation of some lakes are related to human impact.

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Biogeography of the Alpine Plants at Hallasan, Jeju Island, Korea

  • Kong, Woo-Seok
    • The Korean Journal of Quaternary Research
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    • v.19 no.2
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    • pp.40-43
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    • 2005
  • The island alpine biogeography of Mt. Halla (Hallasan), Jeju Island (Jejudo), Korea is discussed. The presence of numerous species of alpine flora on Mt. Halla, the southernmost distributional limit for certain species, may primarily be attributed to palaeo-environmental factors, since it can not be wholly explained by reference to current environmental conditions. The alpine flora on the peak of Mt. Halla, mainly above 1,500m a.s.l, is evidently descended from immigrants from NE Asia via the Korean Peninsula during the epochs of the Ice Age. These plants, which are very intolerant of competition with temperate vegetation, have been able to persist in alpine belts thanks to their harsh climatic conditions, sterile soil, rugged topography and cryoturbation. The alpine plants on Hallasan are in a stage or process of retreat toward the mountaintop, most likely due to recent climatic amelioration. The lower limit of some species seems to coincide with maximum summer isotherms. The continued survival of arctic-alpine and alpine plants on the summit of Hallasan, Jejudo, the Korean Peninsula, however, is in danger, if global warming associated with the greenhouse effect continues.

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