• Horticulture, Environment, and Biotechnology : HEB
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• 제59권6호
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• pp.835-845
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• 2018

We studied the role of ethylene control in regulating energy metabolism, antioxidant enzyme activity, and vase life of cut rose Rosa hybrida 'Carola'. Rose flowers at stage II were sprayed with one of the following solutions: water (control), $10{\mu}L\;L^{-1}$ 1-methylcyclopropene (1-MCP), or $0.5g\;L^{-1}$ 2-chloroethanephosphonic acid (ethephon). After harvest, ethylene production rate, respiration intensity, energy charge (EC), activities of energy metabolism-related and antioxidant enzymes, and malondialdehyde (MDA) content were measured. Results showed that 1-MCP enhanced the activities of superoxide dismutase, $H^+$-adenosine triphosphatase, $Ca^{2+}$-adenosine triphosphatase, succinic dehydrogenase, and cytochrome c oxidase, increased adenosine triphosphate (ATP) content, maintained high EC levels, inhibited respiration intensity, reduced peroxidase (POD) and polyphenol oxidase (PPO) activity and MDA accumulation, and prolonged vase life. Ethephon promoted ethylene production and respiration intensity, increased POD and PPO activity, reduced ATP content and EC levels, and accelerated senescence. Our results support a novel role for ethylene control in regulating senescence of 'Carola'.

• Steel and Composite Structures
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• 제44권6호
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• pp.817-828
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• 2022

In this study, considering dissipated energy in fracture process zone (FPZ), a novel criterion based on maximum strain energy release rate (SER) for orthotropic materials is presented. General case of in-plane loading for cracks along the fibers is assumed. According to the experimental observations, crack propagation is supposed along the fibers and the reinforcement isotropic solid (RIS) concept is employed as a superior model for orthotropic materials. SER in crack initiation and propagation phases is investigated. Elastic properties of FPZ are extracted as a function of undamaged matrix media and micro-crack density. This criterion meaningfully links between dissipated energy due to toughening mechanisms of FPZ and the macroscopic fracture by defining stress intensity factors of the damaged zone. These coefficients are used in equations of maximum SER criterion. The effect of crack initiation angle and the damaged zone is considered simultaneously in this criterion and mode II stress intensity factor is extracted in terms of stress intensity factors of damage zone and crack initiation angle. This criterion can evaluate the effects of FPZ on the fracture behavior of orthotropic material. Good agreement between extracted fracture limit curves (FLC's) and available experimental data proves the ability of the new proposed criterion.

• 자원ㆍ환경경제연구
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• 제19권1호
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• pp.129-157
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• 2010

본 연구는 최종에너지 가정부문의 에너지 효율 개선 여부를 검토하는 실증분석이다. 타부문과 달리 가정부문의 최종에너지는 그 완만한 증가 추세를 보이고 있으나, 에너지 효율 정책을 평가하는 주요 잣대의 하나이므로 효율분석의 대상으로 하였다. 자료는 1990년부터 2006년까지의 연간자료를 이용하였으며, 분석 방법으로는 요인분해 방법 중 가장 광범위하게 사용하고 있는 LMDI 방법을 사용하였다. 기온효과를 제거한 후 실증분석 결과를 살펴보면, 동 기간 중 가정부문 에너지 효율은 연간 1%씩 개선효과를 보이고 있다. 용도별로는 전기기기의 에너지 원단위는 오히려 악화된 것으로 나타나고 있다. 가정부문 전체의 에너지 효율의 개선은 유사한 기간을 대상으로 선진국들의 자료와 비교하여 볼 때, 효율 개선의 방향과 크기가 유사함을 확인할 수 있다. 시기별로 나누어 볼 때, 1990년대에 에너지 효율 개선이 뚜렷이 나타났으나, 2000년대는 그 효율의 개선이 크지 않은 것으로 결과가 나타났다. 이는 가정부문에서 에너지 사용에 대한 행태의 변화에 그 원인이 있는 것으로 보인다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.111-116
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• 2000

A semi-infinite interfacial crack propagated with constant velocity in two bonded anisotropic strip under out-of-plane clamped displacements is analyzed. The asymptotic stress and displacement fields near the crack tip are obtained, where the results get more general expressions applicable not only to isotropic/orthotropic materials but also to the extent of the anisotropic material having one plane of elastic symmetry for the interfacial crack. The dynamic stress intensity factor is obtained as a closed form, which is decreased as the velocity of crack propagation increases. The critical velocity where the stress intensity factor comes to zero is obtained, which agrees with the lower value between the critical values of parallel crack merged in the material 1 and 2 adjacent to the interface. The dynamic energy release rate is also obtained as a form related to the stress intensity factor.

• 한국기후변화학회지
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• 제9권4호
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• pp.407-421
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• 2018

In this paper, I analyze the GHG (greenhouse gas) emission factor of the domestic railway transportation sector using the LMDI (Log Mean Divisia Index) methodology. These GHG factors are the emission factor effect, energy intensity effect, transportation intensity effect, and economic activity effect. The analysis period was from 2011 to 2016, and the analysis objects were an intercity railway, wide area railway, and urban railway. The results show that the GHG emission of railway transportation sector decreased during these 6 years. The factors decreasing the GHG emission are the emission factor effect, energy intensity effect, and transportation intensity effect, while the factor increasing the GHG emission is the economic activity effect.

• 임산에너지
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• 제19권1호
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• pp.20-29
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• 2000

본 연구는 피음이 층층나무 1년생 유묘의 생장에 미치는 영향을 구명하기 위하여 수행되었다. 실험은 자연전광의 100, 50, 30, 17, 9, 및 1%로 조절된 야외피음 포지에서 이루어졌으며 다음과 같은 결과를 얻을 수 있었다. 묘고생장은 상대광도 100%와 50%에서 가장 높았으며 상대생장율에서는 100%구보다는 50%구에서 높게 나타났다. 상대광도 9%구 이하에서는 생장을 하지 못했다. 근원경생장은 묘고생장과 유사한 결과를 보였다. 엽면적은 상대광도 50%구에서 가장 높았으며 그이하의 광도에서는 대구조에 비해 작게 나타났다. SLA와 LAI는 광도가 감소함에 따라 증가하였다. LAR과 LWR은 광도가 감소함에 따라 증가하였으나 상대광도 9%이하의 광도에서 LWR은 다시 감소하였다. 상대광도가 낮아짐에 따라 유묘의 뿌리, 줄기, 잎의 biomass 생산 및 가지와 잎 수는 감소되었다. T/R율은 17%와 30%구에서 가장 높았다. 또한 측근은 50%구를 제외하고 광도가 감소함에 따라 감소하였다.

• 한국환경과학회지
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• 제22권12호
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• pp.1661-1669
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• 2013

This study conducted a laboratory simulation using artificial and natural rainfall in order to investigate the runoff characteristics of livestock resources through the analysis of the surface runoff water and infiltration water by rainfall intensity and fertilization level. Cattle manure and pig liquid fertilizer was used as livestock resource. As a result of this study, it was observed that the surface runoff occurred over 32 mm/hr rainfall intensity, and flow rate of the surface runoff water and the runoff ratio of contaminant parameters from livestock resource was increased, as rainfall intensity was stronger. With doubled fertilization level, T-N increased in compost and the amount of $COD_{Mn}$ runoff also considerably increased in liquefied fertilizer. In the case of natural rainfall, the runoff ratio of T-P clearly increased in compost and the T-N of final surface runoff ratio in compost and liquefied fertilizer was ranged from 0.13047 to 0.13623 with stronger rainfall intensity.

• 대한기계학회논문집
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• 제17권2호
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• pp.331-341
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• 1993

The propagating crack problems under dynamic antiplane mode in orthotropic material is studied in this paper. To analyze the dynamic fracture problems by theoretical method or experimental method in orthotropic material, it is important to know the dynamic stress intensity factor in the vicinity of crack tip. Therefore the dynamic stress field and dynamic displacement field with dynamic stress intensity factor of orthotropic material in mode III were derived. When the crack propagation speed approachs to zero, the dynamic stress components and dynamic displacement components derived in this paper are identical to the those of static state. In addition, the relationships between dynamic stress intensity factor and dynamic energy release rate are determined by using the concept of crack closure energy with the dynamic stresses and dynamic displacements derived in this paper. Finally, the characteristics of crack propagation are studied with the properties of orthotropic material and crack speed. The variation of angle .alpha. between fiber direction and crack propagating direction and crack propagation speed fairly effect on stress component and displacement component in crack tip. The influence of crack propagation speed on the speed on the stress and displacement is greater in the case of .alpha.=90.deg. than in the case of .alpha.=0.deg. and the faster the crack propagation speed, the greater the stress value and displacement value.

• 산업융합연구
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• 제22권1호
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• pp.85-93
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• 2024

본 연구의 목적은 한국인에서 고강도 신체활동(일)과 음료수 섭취 빈도와의 관계성를 알아보고자 하였다. 본 연구 대상자는 2021년 제8차 국민건강영양조사(KNHANES)의 데이터를 활용하였다. 데이터 자료 분석은 집단 간 평균 차이, χ²-test, 이분형 로지스틱 회귀분석을 실시하여 분석하였다(p<0.05). 탄산음료는 그룹 중 63.6%가 일주일에 한 번 이하로 섭취하였고, 에너지 드링크는 68.6%가 일주일에 한 번 이하로 섭취하였다. 이러한 결과는 고강도 신체활동(일)을 하는 그룹에서 탄산음료와 에너지 드링크가 더 자주 소비되었으며, 대부분의 음료수가 일주일에 한 번 이하로 섭취되었다는 것을 알 수 있었다. 본 연구의 결과를 토대로, 고강도 신체활동(일)을 할 때 탄산음료와 에너지 드링크를 대체할 만큼 건강에 이로운 음료의 개발을 위한 기초 자료로 활용되기를 바라며, 음료수 섭취보다는 건강에 이로운 새로운 접근 방식을 탐구하고 건강증진을 위한 중재 프로그램을 개발의 필요성을 제안하고자 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.560-563
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• 1997

Sound intensity method is well known as a visualization technique of sound field and sound propagation in noise control. Sound intensity is a vector quantity that describes the magnitude and the direction of net flow of acoustic energy at a given position. The current measuring method is expensive and difficult to identify the noise source exactly. In this paper, we have studied the noise source identification and the characteristics of noise source of rotary compressor for air conditioner using complex sound intensity method. The new method for instantaneous sound intensity is also proposed and it is useful for transient state and steady state. The criteria of these states select auto correlation coefficient. The advantage, simplicity and economic attribution of this method are verified by analyzing the characteristics of noise source with instantaneous sound intensity compared to mean sound intensity.