• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.93.1-93
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• 2003

A growth chamber fumigation was conducted to evaluate the ozone (O3) on the physiology of three hot pepper, Capsicum annuum L. cultivars, 'dabotab', 'buchon' and 'pochungchun'. Thirty-day old plants were exposed to O3 of 120 nl 1-1 in the chambers for 8 h d-1 for 3 days. Foliar damage due to O3 was different from the varieties, 'dabotab'was most sensitive to O3, 'pochungchun' was medium, and 'buchon' was resistant. Ozone symptom on the leaves was bifacial necorsis. Photosynthesis and stomatal conductance were decreased due to O3 treatment, but they were not much different from the variety. Decreases of net photosynthesis by O3 were 56％, 40％ and 35％ on 'dabotab', 'buchon' and 'pochungchun', respectively Decreases of stomatal conductance by O3 were 66％, 63％, and 50％ on each varieties. Ozone closed the stomata and decrease net photosynthesis on hot peppers regardless of the variety. Light curves on the three varieties were showing similar patterns that O3 damage on net photosynthesis were started at the low levels of light with or without the visible injury, Assimilation-internal CO2 concentration curves of the three cultivars were not different due to the treatment. It means there was not significant biochemical damage Inside the leaves by O3. In conclusion, ozone closed the stomata and damaged light capturing system of the pepper leaves with or without the visible damage. Although visible damage of the leaves could be a good indicator of O3 resistance, the ecophysiological change by O3 were not proportional to the amout of visible injuries

• 한국해양공학회지
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• 제33권3호
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• pp.259-271
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• 2019

It is important to obtain reasonable predictions of the extent of the damage during maritime accidents such as ship collisions and groundings. Many fracture models based on different mechanical backgrounds have been proposed and can be used to estimate the extent of damage involving ductile fracture. The goal of this study was to compare the damage extents provided by some selected fracture models. Instead of performing a new series of material constant calibration tests, the fracture test results for the ship building steel EH36 obtained by Park et al. (2019) were used which included specimens with different geometries such as central hole, pure shear, and notched tensile specimens. The test results were compared with seven ductile fracture surfaces: Johnson-Cook, Cockcroft-Latham-Oh, Bai-Wierzbicki, Modified Mohr-Coulomb, Lou-Huh, Maximum shear stress, and Hosford-Coulomb. The linear damage accumulation law was applied to consider the effect of the loading path on each fracture surface. The Swift-Voce combined constitutive model was used to accurately define the flow stress in a large strain region. The reliability of these simulations was verified by the good agreement between the axial tension force elongation relations captured from the tests and simulations without fracture assignment. The material constants corresponding to each fracture surface were calibrated using an optimization technique with the minimized object function of the residual sum of errors between the simulated and predicted stress triaxiality and load angle parameter values to fracture initiation. The reliabilities of the calibrated material constants of B-W, MMC, L-H, and HC were the best, whereas there was a high residual sum of errors in the case of the MMS, C-L-O, and J-C models. The most accurate fracture predictions for the fracture specimens were made by the B-W, MMC, L-H, and HC models.

• 대한화장품학회지
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• 제48권1호
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• pp.33-38
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• 2022

자외선인 ultraviolet B (UVB)는 피부각질세포의 DNA 잔기에 손상을 준다. 특히, DNA의 pyrimidine 잔기 손상인 cyclobutane pyrimidine dimers (CPD)의 형성은 피부 광노화의 대표적인 지표로 여겨진다. 본 연구에서는 피부 각질세포에서 UVB에 의한 DNA 손상을 완화 시키는 소재로 감초추출물(Glycyrrhiza glabra extract, G. glabra extract)의 효능을 확인하였다. 먼저 피부각질세포에서 UVB 의존적으로 CPD형성이 증가하는 것을 확인하였다. 이후 감초추출물에 의해 UVB 유발 CPD 형성이 유의하게 줄어드는 것을 확인할 수 있었다. 추가로 DNA 손상회복 인자의 mRNA 발현이 감초추출물에 의해 증가하는 것도 확인하였다. 결론적으로 본 연구를 통해 감초추출물의 피부각질세포에서의 DNA 보호 효과를 확인할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.609-612
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• 2007

The HDD (hard disk drive) using Load/Unload (L/UL) technology includes the benefits which are increased areal density, reduced power consumption and improved shock resistance than those of contact-start-stop (CSS). Dynamic L/UL has been widely used in portable hard disk drive and will become the key technology for developing the small form factor hard disk drive. The main design objectives of the L/UL mechanisms are no slider-disk contact or no media damage even with contact during L/UL, and a smooth and short unloading process. In this paper, we focus on lift-off force, pitch static attitude (PSA), roll static attitude (RSA) and dimple point. The "lift-off" force, defined as the minimum air bearing force, is another very important indicator of unloading performance. A large amplitude of lift-off force increases the ramp force, the unloading time, the slider oscillation and contact-possibility. PSA and RSA are also very important parameters in L/UL system and stability of slider is mainly determined by PSA and RSA. Dimple point by PSA and RSA is also important indicator. Therefore we find the optimal dimple point of SFF HDD suspension for improving the unloading performance.

• Journal of Chest Surgery
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• 제17권3호
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• pp.418-423
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• 1984

Appreciation of the large volume deficits which may occur in surgical or trauma patients due to blood loss has led to vigorous transfusion techniques designed to overt hypovolemic shock and ischemic damage to vital organs which may develop in minutes during the hypovolemic state. In a significant proportion of patients treated with massive rapid blood or fluid transfusion, hypervolemia occurs and life threatening pulmonary edema may develop. Especially, hypervolemia may occur during transfusion for preventing development of the so-called low output syndrome following cardiac surgery. However, the most effective indicator which reveals the adequate level of transfusion is not settled yet. The present study was aimed to compare the effectiveness of the indicators suggested thus far and to determine the most sensitive one. Eight dogs were experimentally studied in terms of left atrial pressure, pulmonary arterial systolic pressure, central venous pressure, mean systemic arterial pressure and heart rate before and after induced hypervolemia with infusion of 600ml heparinized homologous blood. Immediately after induced overtransfusion of the blood, pulmonary arterial systolic pressure increased 75.0%, in omparison with the control before transfusion, left atrial pressure 58.8%, central venous pressure 44.6%, and mean systemic arterial pressure 10.1%, one hour after transfusion, pulmonary arterial systolic pressure 40.0%, left atrial pressure 21.2%, central venous pressure 14.5%, and mean systemic arterial pressure 3.2%, central venous pressure 14.5%, and mean systemic arterial pressure 3.2%, respectively. Heart rate showed no significant change throughout the experiment. These result suggested that the changes of the pulmonary arterial systolic pressure is the most sensitive indicator for detection of hypervolemia during blood transfusion.

• 한국축산식품학회지
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• 제32권5호
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• pp.540-544
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• 2012

During heat treatment and storage of milk, deteriorative reaction takes place, which consequently influence on the milk quality. In this study, formation of lactulose and furosine under different thermal conditions and storage conditions, and the ratio of lactulose and furosine (LU/FU) in presence of reconstituted milk powder were determined to establish chemical indicators for heat damages of milk and the adulteration of fresh milk in dairy field. The lactulose and furosine contents linearly increased with increased heating temperature and heating time. It showed high correlation between the formation of lactulose and furosine, and the treatment temperature and time (p<0.05). The lactulose and furosine concentration of HTST milk and UHT milk noticeably increased during storage at $30^{\circ}C$, but there was no noticeable increase of lactulose and furosine concentration at lower storage temperature. In the raw milk, the lactulose and furosine contents greatly increased with the addition of reconstituted milk. The increase level of furosine was much higher than that of lactulose, which consequently resulted in the lower LU/FU ratio in milk as increase of added reconstituted milk amounts. As comparing with raw milk, there was more than twice reduction in LU/FU ratios after the addition of reconstituted milk (p<0.05). It can be concluded that lactulose and furosine are suitable milk quality indicators of heat damage and for demonstrating improper addition of reconstituted milk powder.

• 한국안전학회지
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• 제33권6호
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• pp.93-101
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• 2018

Various leading indicators of safety culture have been advocated for proactive actions as lagging indicators have limitations in reflecting the attitudes and behaviors due to their reactivity and low sensitivity. This study proposes a model of incident-reporting culture (IRC) and determines the influence of the components on incident-reporting rate (IRR) in order to develop proactive indicators of safety culture. A questionnaire survey was administered to 614 workers at a chemical company in Korea, and the internal psychological aspects were explored by using perceptions, attitude, and backgrounds. The relationship between these factors and IRR was quantitatively confirmed. The workers are more reluctant to report injury than property damage, the perception of severity is the most influencing factor, and most property damages are reported regardless of worker's willingness. These features should be prioritized when improving IRC, and the criteria of IRC need to be aligned with safety culture.

• 한국어병학회지
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• 제36권2호
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• pp.361-368
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• 2023

Juveniles of the white leg shrimp Litopenaeus vannamei (Weight 0.18±0.08 g) were exposed to nitrite-N at 0, 25, 50, 100, 200 and 400 mg/L for 72 hours, and the lethal concentration, heamolymph and genes regulation were evaluated. The lethal concentration 50 (LC₅₀) of L. vannamei exposed to nitrite-N was 141.2 mg/L at 25℃ and 33 psu. In Total protein, total cholesterol, and BUN in heamolymph temporarily increased after the start of the experiment and then stabilized, but glucose, an indicator of stress, decreased over time in the entire experimental group, and creatines, an indicator of tissue damage, decreased with nitrite concentration until the first 12 hours. The genes of immune-related showed that masquerade-like serine proteinase(Mas) increased at 50 and 400 ppm for 24 hours, and then gradually decreased depending on concentration. In the case of prophenoloxidase, it was highest at 400 ppm for 40 hours, and other genes(Ras-related nuclear protein, Masquerade-like serine proteinase, proPO-activating enzyme) showed a response for 48 hours and then gradually decreased. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of L. vannamei.

• Smart Structures and Systems
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• 제33권1호
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• pp.41-53
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• 2024

Grouting sleeves are an essential connecting component of prefabricated components, and the quality of grouting has a significant influence on structural integrity and seismic performance. The embedded grouting sleeve (EGS)'s grouting defects are highly undetectable and random, and no effective monitoring method exists. This paper proposes an ultrasonic guided wave method and provides a set of guidelines for selecting the optimal frequency and suitable period for the EGS. The optimal frequency was determined by considering the group velocity, wave structure, and wave attenuation of the selected mode. Guided waves are prone to multi-modality, modal conversion, energy leakage, and dispersion in the EGS, which is a multi-layer structure. Therefore, a time-reversal (TR)-based multi-mode focusing and dispersion automatic compensation technology is introduced to eliminate the multi-mode phase difference in the EGS. First, the influence of defects on guided waves is analyzed according to the TR coefficient. Second, two major types of damage indicators, namely, the time domain and the wavelet packet energy, are constructed according to the influence method. The constructed wavelet packet energy indicator is more sensitive to the changes of defecting than the conventional time-domain similarity indicator. Both numerical and experimental results show that the proposed method is feasible and beneficial for the detection and quantitative estimation of the grouting defects of the EGS.

• 한국산림과학회지
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• 제102권4호
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• pp.530-536
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• 2013

본 연구는 산림환경이 인체 내 과산화지질 농도 변화에 영향을 줄 수 있는지 확인하고, 산림치유 효과 측정을 위한 생리적 지표로써 과산화지질의 활용가능성을 검토하고자 하였다. 피험자 29명을 대상으로 도시지역인 제주도의 제주시청 앞 인도와 산림지역인 삼나무 숲길에서 심리적 지표인 기분상태척도와 생리적 지표인 과산화지질수준 변화를 걷기 전후에 분석하였다. 도시지역에 비해 산림지역에서 기분상태척도의 총기분장애점수가 유의하게 낮아져 심리적으로 안정되는 효과를 보였다. 또한 과산화지질 수준은 도시지역에서 2.9에서 3.5 수준(5점 수준, 만점)으로 유의하게 높아졌고, 산림지역에서는 2.4에서 1.9 수준으로 낮아지는 경향을 보였는데, 위와 같은 결과는 과산화지질이 단기간 환경노출에 의한 인체에 미치는 영향을 파악하는데 적합한 지표라는 것을 보여준다. 산림과 도시에서 대기환경 및 심리적 안정도가 달라 과산화지질 수준의 변화 경향도 서로 다르게 나타난 것으로 보인다. 향후 연구에서는 장기간의 환경노출이 인체에 미치는 영향을 파악하기 위한 생리적 지표로써 과산화지질의 적합성을 분석하고, 새로운 생리적 지표를 지속적으로 발굴하는 것이 필요하다.