• 한국환경복원기술학회지
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• 제17권5호
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• pp.1-17
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• 2014

Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.) under natural room temperature and to analyze differences between alternative and natural conditions for a practical application. Fifteen cultivars of KB were evaluated in the study. Daily and cumulative germination pattern were measured and analyzed on a daily basis. Differences were observed in germination percentage, germination pattern, days to the first germination and days to 75% germination. Germination percentage was variable with cultivars at the end of study. It was 75.75 to 90.25% under natural condition. There were considerable variations in early germination characteristics and germination pattern among KB cultivars according to germination conditions. The first germination in all entries tested was initiated between 6 and 9 DAS (days after seeding) under ISTA (International Seed Testing Association) condition. But it was observed between 9 and 12 DAS under natural condition, being 3 to 5 days later as compared with ISTA condition. On the first date of a germinating process, the germination rate was 0.25% to 25.00% under ISTA condition, while 0.50% to 13.25% under natural condition. Days to the 75% germination were 15.08 to 28.80 DAS under ISTA condition and 17.78 to 28.75 DAS under natural condition. Midnight II, Excursion and Midnight were the fastest cultivars under ISTA condition, while Odyssey the fastest one under natural condition. Regardless of germination condition, the slowest cultivar was Voyager II, being over 4 weeks to 75% germination percentage. For the most cultivars, days to 75% germination under natural room temperature condition were 1 to 8 days slower than under ISTA condition. From this study information on differences in germination characteristics and pattern among cultivars would be usefully applied for KB establishment such as golf course construction. Prior to on-site seeding, a comprehensive germination test is practically recommended due to a possible decline in germination capability during domestic distribution and storage after import.

• Weed & Turfgrass Science
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• 제2권1호
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• pp.47-54
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• 2013

본 실험은 자연실온 환경에서 세엽형 훼스큐 초종 간 초기 발아특성 및 발아패턴을 조사하고 변온 및 자연실온에서의 그 차이점을 비교 분석해서 실무 시공에 응용할 수 있는 기초자료를 파악하고자 시작하였다. 공시재료는 츄잉스 훼스큐(CF), 크리핑 레드 훼스큐(CRF), 하드 훼스큐(HF) 및 쉽 훼스큐(SF)에서 선정한 6품종 이었으며, 일일 발아패턴 및 누적 발아패턴을 1일 간격으로 조사하였다. 화인 훼스큐 종자의 발아율, 발아패턴 및 발아 특성은 생육환경, 초종 및 품종에 따라 유의한 차이가 크게 나타났다. 자연실온에서 발아력은 ISTA 변온과 다르게 나타났고 최종 발아율은 29.7~80.0% 사이로 다양하였다. 발아패턴은 최초 발아의 경우 ISTA 변온에 비해 3~4일 늦은 치상 후 8~10일 사이에 시작되었다. 발아율 50% 도달한 기간은 최초 발아 후 2~5일 경과 후인 치상 후 11~14일 사이로 ISTA 변온에 비해 3~4일 정도 늦게 나타났다. 또한 실무적으로 요구되는 발아율 60% 도달기간은 ISTA 변온에 비해 초종에 따라 3.0~4.2일 정도 늦은 치상 후 12.1~19.0일 사이로 나타났다. 공시 초종 중 60% 발아율 도달 기간이 가장 빠른 품종은 CF 'Jamestown II' 품종이었고, 반대로 가장 느린 종류는 CRF 'Audubon' 품종이었다. 자연실온 환경에서 화인 훼스큐 초종 간 조성 속도는 CRF < SF < HF < CF 순서로 나타났다. 본 실험을 통해 밝혀진 초종 및 품종 간 이러한 생리생태적 특성 차이 및 비교 자료는 골프장 등 잔디밭 조성 시 실무적인 기초 자료로 유용하게 활용될 수 있을 것이다.

• 한국산학기술학회논문지
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• 제20권8호
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• pp.425-430
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• 2019

아연말 코팅은 친환경성 및 고성능으로 인하여 널리 사용되고 있다. 일반적으로 코팅온도가 코팅층 두께 및 코팅 품질을 결정하는 주요한 요소이며 아연말 코팅의 경우에도 코팅 룸 내 균일하며 적절한 코팅온도가 요구된다. 본 연구에서는 일반적으로 사용하는 자연대류 상태에서의 아연말 스프레이 코팅 룸의 온도 분포를 해석하기 위해 룸 내부의 공기 유동을 포함하는 열 유동 전산 시뮬레이션을 수행하였다. 3차원 CAD 프로그램인 SolidWorks를 이용하여 스프레이 코팅 룸 전체와 예열실과 건조실을 모두 고려한 모델링을 수행하였으며 ANSYS의 FLUENT 프로그램을 이용하여 열 유동연성 해석을 수행하였다. 해석 결과 스프레이 코팅 룸에서의 온도 분포 특성을 파악할 수 있었으며, 현재의 상태로는 목표 온도 값인 $25^{\circ}C$에 미달하고 있었음을 알 수 있었다. 이에 두 가지 다른 경계조건 (히터를 추가하는 방법과 현재 상태에서 Open 부분을 닫는 방법) 에 대해 열 유동 시뮬레이션을 수행하였으며, 시뮬레이션 결과 히터를 추가하기보다는 Open된 부분을 닫는 방법이 더 좋은 결과를 나타내었다.

• 한국환경복원기술학회지
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• 제18권3호
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• pp.23-38
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• 2015

The study was initiated with Kentucky bluegrass (KB, Poa pratensis L.) to investigate germination and early establishment characteristics of new cultivars for a practical application to turfgrass establishment such as parks, athletic field and golf course etc. Fifteen cultivars were evaluated in different experiments. An alternative condition for a KB germination test required by International Seed Testing Association (ISTA) was applied in Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$ (natural conditions). Seed germinating vigor, germination speed and germination peak time were measured in both experiments. Significant differences were observed in seed germinating vigor, germination speed and germination peak time. Seed germinating vigor was variable with different environments and cultivars. It was 75.25 to 89.50% under ISTA conditions and 75.75 to 90.25% under natural conditions. There were considerable variations in early germination characteristics among KB cultivars according to different environments. Early germination characteristics showed that all cultivars were 3 to 5 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 50% to 80%, was much faster with 'Midnight II', 'Excursion' and 'Midnight' under ISTA conditions. But it was faster with 'Midnight II', 'Excursion' and 'Odyssey' under natural conditions. Differences was also observed in germination peak time with cultivars and growing conditions. It ranged 5.94 to 14.88 days under ISTA conditions and 4.71 to 13.06 days under natural conditions. Regardless of the environment conditions, the shortest cultivars were 'Odyssey' and 'Midnight II'. The longest ones were 'Nuglade' under ISTA condition and 'Moonlight' under natural conditions. Considering germinating vigor, germination speed and germination peak time, 'Midnight II', 'Excursion', 'Midnight', and 'Odyssey' were regarded as excellent cultivars under ISTA conditions in terms of early establishment characteristics, while 'Midnight II', 'Excursion', 'Odyssey', and 'Courtyard' under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for investigating the early germinating vigor, germination speed and germination peak time. Also, a proper cultivar selection and comprehensive site analysis for the growing environmental conditions should be done before turfgrass establishment such as golf course construction.

• KIEAE Journal
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• 제6권1호
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• pp.57-62
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• 2006

Korean Traditional houses has been evolved and developed in many years, adopting the natural environment to control exterior conditions. These control method are various passive system of using natural materials, considering micro climate, building lay out, and these system are more natural and ecological to make the comfortable indoor climate than active systems of the present houses. This study aims to analyzed control performance of outdoor environment of five Korean traditional houses during the summer and winter. These houses are varied with lay out and floor plan to reflect the way of control for environmental condition, surveyed the reverberation time and sound level difference between rooms of the main living room and other main floored room, master room and kitchen. Especially air temperature and humidity have been measured simultaneously in each rooms to compare with outdoor condition. As a result, the variation of air temperature and humidity of most rooms are considerably static while condition of outdoors are much varied, it is showed that indoor climate has been controled with traditional soiled walls.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2251-2254
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• 2012

A rapid and practical green route for N-formylation of primary and secondary amines with formic acid at room temperature under the solvent-free conditions using HEU zeolite as a heterogeneous, reusable and highly efficient catalyst is described. The process is remarkably simple and environmentally benign. Excellent chemoselectivity was observed for the conversion of primary amines in the presence of secondary amines.

• Advances in nano research
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• 제6권1호
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• pp.57-80
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• 2018

In this study, the thermal loading effect on free vibration characteristics of carbon nanotubes (CNTs) with multiple cracks is studied. Various boundary conditions for nanotube are taken in to account. In order to take the small scale effect, the nonlocal elasticity of Eringen is employed in the framework of Euler-Bernoulli beam theory. This theory states that the stress at a reference point is a function of strains at all points in the continuum. A cracked nanotube is assumed to be consisted of two segments that are connected by a rotational spring which is located in the position of the cracked section. Hamilton's principle is used to achieve the governing equations. Influences of the nonlocal parameter, crack severity, temperature change and the number of cracks on the system frequencies are investigated. Also, it is found that at room or lower temperature the natural frequency for CNT decreases as the value of temperature change increases, while at temperature higher than room temperature the natural frequency of CNT increases as the value of temperature change increases. Various boundary conditions have been applied to the nanotube.

• 한국환경복원기술학회지
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• 제11권5호
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• pp.79-91
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• 2008

Research was initiated to investigate germination characteristics of creeping bentgrass (CB, Agrostis palustris Huds.). Seven varieties of CB were evaluated with different experiments. An alternative environment condition requiring for a CB germination test by International Seed Testing Association (ISTA) was applied in the Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$(ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$(natural conditions). In each experiment, data such as seed germinating vigor, early germination characteristics, germination speed and germination peak time were measured. Significant differences were observed in seed germinating vigor, early germination characteristics, germination speed and germination peak time. Seed germinating vigor was variable with different environments and varieties. It was 61.50 to 98.25% under ISTA conditions and 55.00 to 98.50% under natural conditions. There were considerable variations in early germination characteristics among CB varieties according to different conditions. Early germination characteristics indicated that all varieties were 1 to 4 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 70% and 90%, was much faster with Penn A-1, Penn A-4 and Penncross under ISTA conditions. But it was even faster with L-93 and Penncross when grown under natural conditions. Differences were also observed in germination peak time with varieties and growing conditions. It was 0.57 to 2.86 days under ISTA conditions and 0.74 to 1.74 days under natural conditions. Regardless of the environment conditions, the shortest variety was L-93 and the longest one T-1. Considering germinating vigor, early germination characteristics, germination speed and germination peak time, Penn A-1, Penn A-4 and Penncross were regarded as excellent varieties under ISTA conditions in terms of early establishment characteristics, while L-93, Penn A-1 and Penncross under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for the early germinating vigor, germination speed and germination peak time. Also, a proper variety selection and comprehensive site analysis for the growing environmental conditions should be done before golf course construction.

• 아시안잔디학회지
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• 제25권1호
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• pp.1-10
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• 2011

본 실험은 자연 실온 환경에서 크리핑 벤트그래스 신품종의 초기 발아특성 및 발아패턴을 조사하고, 그리고 변온 및 자연실은 환경에서의 그 차이점을 비교 분석해서 실무 시공에 응용할 수 있는 기초자료를 파악하고자 시작하였다. 공시재료는 크리핑 벤트그래스 7품종이었으며, 일일 발아패턴 및 누적 발아패턴을 1일 간격으로 조사하였다. 크리핑 벤트그래스 종자의 발아율, 발아패턴 및 발아특성은 온도 조건 및 품종에 따라 차이가 크게 나타났다. 공시 품종 모두 최초 발아는 ISTA 변온환경 에서 치상 후 4-5 일 사이에 시작되었지만, 자연 실온 환경에서는 대부분 품종이 ISTA 변온보다 2~3일 늦은 6~8일 사이에 시작되었다. 최초 발아 시 발아율은 ISTA 변온에서 일반적으로 5~25% 정도였고, 'Penn A-1', 'Penncross' 및 'Penn A-4' 품종의 최초 발아율은 50~70% 정도로 초기 발아가 대단히 왕성하였다. 하지만 자연 실온 환경에서 최초 발아율은 일반적으로 5~10% 정도였으며, 'Penncross', 'L-93' 및 'Penn A-4' 품종은 20~50% 정도로 초기 발아 특성이 대단히 왕성하였다. 크리핑 벤트그래스에서 발아율 50% 도달 기간은 ISTA 변온에서는 치상 후 4~10일 사이에 나타났고, 자연 실온에서는 품종에 따라 ISTA 변온보다 2~5일 정도 늦은 치상 후 6~15일 사이에 나타났다. 발아율 85% 도달 기간은 ISTA 변온에서는 치상 후 5.90~11.75일 사이였으며, 가장 빠른 종류는 'Penn A-1' 품종이었다. 하지만 자연 실온에서는 ISTA 변온보다 다소 늦은 치상 후 7.95~12.50일 사이였고, 가장 빠른 종류는 'L-93' 품종이었다. 그리고 온도 조건에 관계없이 기준 발아율 도달 기간이 가장 느린 품종은 ISTA 변온 및 자연 실온에서 각각 11.75일 및 12.50일로 나타난 'T-1' 품종이었다. 본 실험 결과 나타난 이러한 발아특성 비교 데이터는 골프장 등 잔디밭 조성 시 실무적인 기초 자료로 유용하게 활용될 수 있을 것이다.

• 설비공학논문집
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• 제16권2호
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• pp.111-120
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• 2004

The optimal design method of indoor thermal environment using CFD coupled simulation and genetic algorithms (GA) is developed in this study. CFD could analyze the thermal environment considering the distribution of temperature, velocity, etc. in a room. Therefore, It would be appropriate to use CFD for the optimal design method considering their distribution. In this paper, the optimal design means the most appropriate boundary conditions of the room among the conditions where the design target of indoor therm environment is achieved. Two step optimal indoor thermal environment design method is proposed. It includes the GA for searching the optimal indoor thermal environment design. To examine the performance of this method, the optimal design of hybrid ventilation system, which uses the natural cross ventilation and the radiation-cooling panel is conducted. The optimal design which satisfies the design target (thermal comfort, minimum cooling load, minimum vertical temperature difference) is found using two step optimal design method.