• 한국패류학회지
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• 제28권1호
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• pp.29-35
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• 2012

Growth patterns of the Manila clam, Ruditapes philippinarum in each tidal level were studied in the intertidal zone in Tae-an on the west coast of South Korea from April to August 2009. Environmental factors and the specimens of R. philippinarum were monthly collected at three intertidal locations: low intertidal zone, low-middle intertidal zone and middle intertidal zone. Temperature of sediment in low intertidal zone were lower than those in other intertidal locations. Concentrations of Chl-${\alpha}$ were not significantly different between in each tidal level. Exposure hours in low intertidal zone were shorter than those in other intertidal locations. Density of each year class in low intertidal zone were higher than those in low-middle intertidal zone and middle intertidal zone. Growth factors of R. philippinarum in low intertidal zone were better than those in other intertidal locations. The growth rate of under one year class individuals of low intertidal zone were higher than those in low-middle intertidal zone and middle intertidal zone, before the main recruitment period of R. pilippinarum. Although the growth patterns of R. philippinarum may be affected by various environmental factors, we suggests that the exposure duration is the main affect in the growth patterns of R. philippinarum in intertidal zone.

• 생물환경조절학회지
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• 제32권4호
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• pp.449-455
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• 2023

본 연구에서는 한 온실 내에서 딸기 재배 베드를 관부 난방 적용 베드, 관행 베드 2처리로 나누고 동일 환경에서 관부 난방이 딸기 재배 환경, 출뢰, 개화 및 수확량에 미치는 영향을 분석하였다. 관부 난방 전 두 처리에서 딸기 관부 온도 및 배지 온도는 큰 차이 없었으며, 외기온이 낮은 12월, 1월, 2월에는 시험구의 주간 평균 딸기 관부 온도는 대조구에 비해 1.3℃ 높았으며, 야간 평균 딸기 관부 온도는 대조구에 비해 2.7℃ 높게 나타났다. 주간 배지 온도는 시험구가 대조구보다 평균 1.7℃ 높았으며, 야간 배지 온도는 시험구가 대조구보다 평균 2.4℃ 높게 나타났다. 딸기 관부 온도와 출뢰 기간에 대한 상관분석 및 회귀분석을 수행한 결과 상관계수는 -0.86으로 높은 음의 상관관계를 보여 관부 온도가 높을수록 출뢰 기간이 짧아지는 경향이 있었으며, 결정계수는 0.74로 높은 설명력을 보였다. 딸기 화아분화는 10-20℃에서 촉진되고, 5-10℃, 25-30℃에서는 효과가 없으며, 5℃ 이하 및 30℃ 이상일 때는 저해되는데, 대조구 온실이 외기온이 낮은 12월, 1월, 2월에, 특히 야간의 딸기 관부 온도가 월별로 각각7.3℃, 7.6℃, 8.8℃로 나타나 10℃ 이하로 유지되면서 화아분화가 촉진되지 않았고, 시험구에 비해 출뢰, 개화가 늦은 것으로 판단된다. 3월 말까지의 딸기 수확량은 시험구 392.6g/plant, 대조구 346.0g/plant로 관부 온돡 높았던 시험구에서 약 13.5% 높게 나타났으며, 딸기의 품질은 2L 등급과 L 등급의 비율이 시험구 62.4%, 대조구 58.5%로 시험구에서 높은 등급의 딸기 비율이 더 많은 것으로 나타났다. 딸기의 화아분화의 주요인은 온도이고, 2차적 요인은 일장이므로 추후 연구를 통해 관부 온도뿐만 아니라 일장 등 다양한 요소를 고려하여 딸기 생육, 수확량의 변화를 분석해보는 연구도 필요하다고 판단된다.

• 암석학회지
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• 제23권2호
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• pp.61-73
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• 2014

소백산육괴의 중앙부에 위치하는 경상북도 북후면-평은면 지역에서 주 구성암류인 선캠브리아기 변성퇴적암류와 중생대 화강암에 대한 변형된 암석 및 미구조 연구를 통하여 (동)북동-(서)남서 방향으로 발달하는 우수 주향 이동성 예천전단대의 상대적인 형성시기, 변형온도, 초압쇄암대의 분포 등을 파악하였다. 연성 변형된 주요 암석구조는 전단변형에 의해 형성된 압쇄구조면과 신장선구조 그리고 편마구조면 내지 압쇄구조면이 습곡되어 형성된 (동)남동-버전스의 완침강-중경사 밀착습곡 등이 있다. 연성전단변형 동안에 형성된 장석들의 특징적인 미구조는 플레임 퍼어사이트, 밀메카이트, 미세단열, 미세킹크, 킹크대, 파동소광 등이 인지된다. 재결정된 석영집합체의 c-축 배열은 rhomb와 basal가 탁월한 미끄럼계로 작용하여 형성된 single girdle과 Type I crossed girdle 형태를 보여준다. 전단운동감각 결정면상에서 인지되는 전단운동감각은 우세한 방향성인 북서-경사와 부수적인 방향성인 남동-경사 압쇄구조면상에서 상부-북동-이동과 상부-남서-이동을 각각 보여준다. 이러한 특징적인 암석 및 미구조로부터 예천전단운동은 밀착습곡이 형성된 이후 발생하였으며, 예천전단운동이 발생할 당시의 변형온도는 $350{\sim}450^{\circ}C$이었음을 알 수 있다. 선캠브리아기 변성퇴적암류의 대상 분포와 변형된 선캠브리아기 변성퇴적암류의 장석과 중생대 화강암의 석영의 입도 분포로부터 불노봉과 박달산 북부를 통과하는 (동)북동 방향의 예천전단대의 초압쇄암대가 설정된다.

• 대한기계학회논문집
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• 제11권1호
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• pp.145-153
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• 1987

본 논문에서는 예혼합동축분류화염에 있어서 재순환역 안으로의 기체(공기, 연료, 혼합기) 주입과 2차공기의 족회가 화염안정성, 화염형상 및 재순환역에 미치는 영향을 명확히 하였다.

• 환경영향평가
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• 제8권2호
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• pp.73-82
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• 1999

This study analyzed the relationship between NDVI(Normalized Difference Vegetation Index) and urban heat island in three cities: Daegu, Kyungju, and Pohang for understanding the degree of nature conservation concentrating in the transition zone of them. Daegu city is the third city in Korea which has a dense population. Kyungju is a traditional city which has good nature. Pohang is an industrial city which has those of characters of Daegu and Kyungju. Landsat 1M data in May 17, 1997 were used for the analysis of heat island. There were about four theoretical models to estimate the surface temperature from TM data: Two-point linear model, Linear regression model, Quadratic regression model, and Cubic regression model. In this study, Linear regression model had been utilized to analyze the urban heat island. On the resultant images, the transition zone of Daegu was urbanized more extremely than those of other two cities. It is thought that the analysis of relationship between NDVI and surface temperature, used in this study, is regarded as one of effective methodologies for urban-environmental detection from satellite imageries.

• 자원환경지질
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• 제33권5호
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• pp.417-424
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• 2000

We applied SP monitoring and resistivity surveys using the pole-pole electrode array to seawater leakage problems in the Youngsan estuary dam and the Eoeun embankment to estimate and detect the zone of seawater leakage. The embankment is generally affected by tidal variation and has low resistivity characteristics due to the high saturation of seawater. For this reason, SP monitoring and the pole-pole array resistivity surveys, which are relatively more effective to the conductive media, were carried out to delineate the leakage zones of sea water through the embankment. We checked out electrical conductivity (EC) and temperature variations along the inner part of Youngsan estuary dam to detect the zone of seawater leakage and found that the measured EC value agreed to that of seawater in the leakage zone and the temperature was lower than that of the vicinity of leakage zone. SP monitoring results were coincided with tidal variations at each embankment. At the leakage zones in the Youngsan estuary dam and the Eoeun embankment, SP anomalies are in the range of -60~-85 mV and -20~-50 mV, respectively, and true resistivity values obtained by 2-D inversion are 3~15 ohm-m and below 0.3 ohm-m, respectively. Both SP monitoring and the pole-pole array resistivity method are found to be quite effective for investigation of seawater leakage zones in the embankment.

• 한국재료학회지
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• 제12권4호
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• pp.290-295
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• 2002

Microstructure and electrical properties of $In_2O_3$ transparent thin films are analyzed on the basis of Structure Zone Model (SZM) proposed by Thornton. Thin films are deposited on glass substrate by RF magnetron sputtering with variation of substrate temperature $(T_s)$ and argon gas pressure $(P_{Ar})$. Microstructure of Zone I of SZM is observed with lowering of substrate temperature or increasing of argon pressure. The higher electrical resistivity of those specimens is due to micro-pores or voids between columnar grains. At the conditions of $T_s=450^{\circ}C$ and $P_{Ar}$=4.2mTorr, the Zone II structure of SZM and the lowest electrical resistivity $(2.1{\times}10^{-2}{\Omega}cm)$ are observed. The dense structure of columnar grains with faceting on growing surface and preferred orientation of (100) plane are observed in those specimens.

• 한국태양에너지학회 논문집
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• 제37권5호
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• pp.27-37
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• 2017

In this study, an artificial solar simulator composed of a 2.5 kW Xe-Arc lamp and mirror reflector was used to carry out the solar thermal two step thermochemical water decomposition cycle which can produce high efficiency continuous hydrogen production. Through various operating conditions, the change of hydrogen production due to the possibility of a dual-zone reactor and heat recovery were experimentally analyzed. Based on the reaction temperature of Thermal-Reduction step and Water-Decomposition step at $1,400^{\circ}C$ and $1,000^{\circ}C$ respectively, the hydrogen production decreased by 23.2% under the power off condition, and as a result of experiments using heat recovery technology, the hydrogen production increased by 33.8%. Therefore, when a thermochemical two-step water decomposition cycle is conducted using a dual-zone reactor with heat recovery, it is expected that the cycle can be operated twice over a certain period of time and the hydrogen production amount is increased by at least 53.5% compared to a single reactor.

• 대한기계학회논문집B
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• 제24권11호
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• pp.1464-1469
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• 2000

The effects of SiCl$_4$addition on flame structures have been studied in flame hydrolysis deposition (FHD) processes using Coherent anti-Stokes Raman spectroscopy (CARS) and planar laser induced fluorescence (PLIF) to measure temperatures and OH concentrations, respectively. The results demonstrate that even a small amount of SiCl$_4$ addition can change thermal and chemical structures of H$_2$/O$_2$ diffusion flames. When SiCl$_4$ is added to a flame temperature decreases in non-reacting zone due to the increases in both specific heat and density of the gas mixture, while flame temperature increase in particle formation zone due to the heat release through hydrolysis and oxidation reactions of SiCl$_4$. It is also found that OH concentration decreases dramatically in particle formation zone where temperatures increase. This can be attributed to consumption of oxidative species and generation of HCl during silica formation.

• 한국환경과학회지
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• 제27권6호
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• pp.359-369
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• 2018

A model has been developed to predict natural ventilation in a single zone building with large openings. This study first presents pressure-based equations on natural ventilation, that include the combined effect of wind and thermal buoyancy. Moreover, the concept of neutral pressure level(NPL) is introduced to consider the two-way flow through a large opening. The total pressure differences across the opening and the NPL are calculated, and nonlinear equations are solved to find the zonal pressure to satisfy mass conservation. For this analysis, an iterative technique of successively approximating the zonal pressure is used. The results of applying this study model to several simple cases are as follows. When there is no wind and only the stack effect is caused, a one-way flow occurs in both the top and bottom openings in the case of two openings of equal-area, and a one-way flow occurs in the top opening; however, a two-way flow occurs in the bottom opening in the case of two openings of unequal-area. When there is a wind effect, regardless of whether the outside air temperature is lower or higher than the indoor air temperature, air flows into the room through the bottom opening and out of the room through the top opening. As the wind velocity increases, the wind effect appears to be more influential than the stack effect owing to the temperature difference.