• 한국대기환경학회지
• /
• 제7권3호
• /
• pp.219-226
• /
• 1991

Results from study on physiological responses to $SO_2$ of Quercus spp. selected for restoration of vegetation damaged by air pollution in the field study were as follows. Tolerance of Quercus aliena, Q. acutissima and Q. mongolica used in this study to $SO_2$ was higher in that order and tolerance of these plants to $SO_2$ was high comparatively among trees composing of major forest vegetation of Korea including natural forests and plantations. Stomatal resistance of these plants was increased after exposure to $SO_2$ and range of increase was different among species. From discrepancy between order of tolerance to $SO_2$ and range of increase in stomatal resistance, we were estimated that resistance mechanisms of Quercus spp. were different among species as mechanism originated in avoidance and resistance, respectively. Water potential of plant leaves reduced after exposure to $SO_2$, degree of reduction accorded with order of tolerance to $SO_2$. Reduction of water potential of plants after exposure to $SO_2$ was initiated before appearance of visible damage in plant leaves and water potential of plants exposed to $SO_2$ of low concentration, in which plants were not showed viaible damage was also reduced.

• Animal cells and systems
• /
• 제4권4호
• /
• pp.337-340
• /
• 2000

The photosynthetic and stomatal responses of several woody plants (Powlonia coreana, Firmiana simplex, Quercus acutissima Q. variabilis and Q. serrata) to SO$_2$ were investigated in order to understand their ecophysiological tolerance to $SO_2$ Of the plants, P, coreana showed the largest reduction in its photosynthesis in response to exposure of 0.4 ppm $SO_2$ for 20 h. Fumigation of 0.7 ppm $SO_2$ for 20 h caused complete leaf necrosis of P. coreana and f simplex, which made them unavailable for the measurement of photosynthesis. Q. variabilis exhibited the smallest reduction in photosynthesis following exposure of 0.7 ppm $SO_2$ for 20 h. Both stomatal- and non-stomatal inhibition of the plants by $SO_2$ were determined according to equations by lkeda et at. (1992). When exposed to 0.4 ppm $SO_2$ for 20 h, F. simplex and P. coreana showed the lowest stomatal and non-stomatal inhibition, respectively, while Q. variabilis and Q. serrata exhibited the lowest stomatal and non-stomatal inhibition, respectively, in response to 0.7 ppm $SO_2$ for 20 h. The data are discussed with regard to resistance mechanisms of other plants to $SO_2$ exposure and implications for restoration of declined Korean forests.

• 한국환경농학회지
• /
• 제15권4호
• /
• pp.479-487
• /
• 1996

$SO_2$에 대한 양버즘나무의 내성을 증대시키고자 생장왜화제인 uniconazole을 토양주입하고, 그 내성 기작을 superoxide dismutase와 peroxidase의 역할과 관련하여 조사했던 바 다음과 같은 결과를 얻었다. Uniconazole은 농도가 높아질 수록 간장, 엽면적 및 T/R율(率)을 현저하게 감소시키고, 엽록소 농도와 superoxide dismutase 및 peroxidase활성을 현저하게 증가시켜 $SO_2$ 처리에 의한 가시피해를 유의성있게 경감시켰다. Diethyldithiocarbamate를 엽면살포하였을때, superoxide dismutase와 peroxidase 활성이 현저하게 불활성화되어 $SO_2$ 처리에 의한 가시피해(可視被害)가 증가되었으며 uniconazole 처리에 의해 증대되었던 $SO_2$ 내성은 diethyldithiocabamate 처리에 의하여 다시 감소되었다. 이상과 같이 uniconazole은 식물생장의 왜화(矮化)에 의한 조직의 치밀화 이외에 SOD와 POD의 활성증대를 통해 $SO_2$에 대한 내성을 증대시킨 것으로 판단된다.

• Journal of Microbiology and Biotechnology
• /
• 제10권3호
• /
• pp.338-343
• /
• 2000

The growth capabilities of three $highly-CO_2-tolerant$ microalgae under high concentrations of $CO_2$ were compared for their tolerance to $SO_2$ and NO, the major inhibitory compounds present in flue gases. Although all strains showed good growth with 15% $CO_2$, Chlorella KR-1 exhibited the most desirable properties for $CO_2$ fixation among the strains compared. While Chlorella sp. HA-1 exhibited the best tolerance to NO among the other strains tested, Chlorella sp. KR-1 showed higher tolerance to $SO_2$ than the other two strains tested.

• 대한산업공학회지
• /
• 제24권2호
• /
• pp.175-183
• /
• 1998

When a product is designed, tolerances must be given to the product so that required functions are guaranteed and production costs are minimized. In this research, a model is suggested which allocates tolerances to components optimally according to the STA(Statistical Tolerance Allocation) method. Taking into account the concept that dimensional errors have characteristics of statistical distributions, this model presents the discrete pseudo-boolean approach for the tolerance optimization by minimizing the tolerance cost and the quality loss cost. In this approach, two methods are proposed for the reduction of the problem scale; 1) a method for converting the minimization model for casts into the maximization model for cost savings, and 2) procedures to reduce the number of constraints and variables.

• 대한인간공학회지
• /
• 제36권5호
• /
• pp.535-543
• /
• 2017

Objective: This study was designed to identify factors affecting pilots' +Gz tolerance recovery from +Gz induced exhaustion. Background: +Gz tolerance of pilots has been considered as a crucial factor to fly the modern high performance fighter aircrafts. However, the factors affecting pilots' G-tolerance recovery from +Gz induced exhaustion have not been examined in the acceleration research community. Method: A centrifuge profile consisting of a high +Gz run for pilot's exhaustion and a low +Gz run for pilot's recovery and another high +Gz runs for pilot's second exhaustion was designed. The subjects' +Gz tolerance recovery ratio was measured by ratio of second high +Gz run time to the first high +Gz run time. The subjects' +Gz tolerance recovery rate was measured by dividing the subjects' +Gz tolerance recovery ratio by the low +Gz run time. The subjects' G-tolerance recovery rate was analyzed with respect to the subjects' personal factors including subjects' anthropometric and physiologic characteristics, flight time, flying aircraft type and so on. Results: The subjects' previous three-month flight hours (r=-0.336, p=0.039), six-month flight hours (r=-0.403, p=0.012) and one-year flight hours (r=-0.329, p= 0.044) correlated with the subjects' G-tolerance recovery rate. Conclusion: The subjects' G-tolerance recovery rate is clearly related to the subjects' previous flight hours. However, the subjects' anthropometric and physiologic characteristics do not show any statistically significant correlation with the subjects' G-tolerance recovery rate. Application: This research provides a safety critical insight to aviation community by identifying the factors to affect the gravity-induced loss of consciousness (GLOC) of pilots.

• Archives of Pharmacal Research
• /
• 제21권6호
• /
• pp.769-773
• /
• 1998

Brazilin was examined for its effects on the induction of immunological tolerance. Brazilin was administered to C57BL/6 female mice for 2 consecutive days before the immunization with high dose SRBC (109 cells) which can produce immunological tolerance. Delayed type hypersensitivity, IgM plaque forming cells, ConA induced IL-2 production and mitogen- or antigen-induced proliferation of lymphocytes were measured as evaluation parameters. Administration of brazilin prior to immunization could keep the DTH and IL-2 production almost optimaly immunized levels. Brazilin also inhibited the elevation of non-specific suppressor cell activity. ConA induced proliferation of splenocytes in high dose SRBC immunized mice was significantly decreased by pretreatment of brazilin. And this might be one of the reason for augmentation of DTH by brazilin. However, IgM plaque forming cells were not affected by the treatment of brazilin. These results indicate that brazilin prevents the induction of mmunological tolerance caused by high dose SRBC by suppressing the elevation of suppressor cell activity and by inhibiting the decrease in IL-2 production in C57BL/6 female mice.

• 대한전기학회논문지:전력기술부문A
• /
• 제54권2호
• /
• pp.73-78
• /
• 2005

The management of technological systems will become increasingly complex. Safe and reliable software operation is a significant requirement for many types of system. So, with software fault tolerance, we want to prevent failures by tolerating faults whose occurrences are known when errors are detected. This paper presents a fault location algorithm for single-phase-to-ground faults on the teed circuit of a parallel transmission line using software fault tolerance technique. To find the fault location of transmission line, we have to solve the 3rd order transmission line equation. A significant improvement in the identification of the fault location was accomplished using the N-Version Programming (NVP) design paradigm. The delivered new algorithm has been tested with the simulation data obtained from the versatile EMTP simulator.

• Food Science and Biotechnology
• /
• 제17권2호
• /
• pp.257-261
• /
• 2008

Previous studies have suggested a possible correlation between cell surface hydrophobicity (CSH) and stress tolerance in Bifidobacterium. In this study, the relationship was examined between CSH and environmental stress tolerance in Lactobacillus spp. By measuring the adhesion to hexadecane, 2 Lactobacillus fermentum strains- KLB 261 and KLB 231 were found to have high and low CSH, respectively. To measure their tolerance to various stresses, cells were subjected to salt (2 M NaCl), acid (pH 2), $H_2O_2$ (0.01 %, v/v), ethanol (20%, v/v), heat ($60^{\circ}C$), and cold ($-20^{\circ}C$). Compared with KLB 231, the hydrophobic KLB 261 was found to be much more resistant to the various stresses examined. After being subjected to different stresses for a period of time, KLB 261 and KLB 231 showed 50 and 0% survivability in 2 M NaCl, 108.2 and 0.6% in 0.01 %(v/v) $H_2O_2$, 40.2%(v/v), and 3.7% at $60^{\circ}C$ incubation, 4 and 0.6% at $-20^{\circ}C$, 12.9 and 0.1 % in pH 2, 33.8 and 0.2% in 20%(v/v) ethanol, respectively. Autoaggregation test and morphological observation were also conducted in an attempt to explain these differences. These results suggested that high CSH could strengthen the stress tolerance of lactobacilli.

• Journal of Ginseng Research
• /
• 제29권2호
• /
• pp.86-93
• /
• 2005

This study was undertaken to determine the antagonism of the ginseng total saponin (GTS) on the development of nalbuphine-induced tolerance and physical dependence. GTS is blown to have antinarcotic action with a dose of 100mg/kg (i.p.) in rats. STS significantly inhibits the development of nalbuphine-induced physical dependence as well as the tolerance. The level of pCREB was elevated in the striatum by the chronic treatment with nalbuphine or GTS, how-ever, the elevation of pCREB was inhibited by the GTS co-treatment. It has been suggested that NMDA receptor and/or NO is involved in the penomena of opioid dependence and withdrawal. However, the level of nNOS and NR1 was not modulated by the treatment with nalbuphine or GTS on the cortex, hippocampus and striatum in the rat brain. These results suggest that the GTS could be used to ameliorate the nalbuphine tolerance and withdrawal symptoms.