• Advances in aircraft and spacecraft science
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• v.10 no.3
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• pp.203-222
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• 2023

The detonation combustion is a supersonic combustion process follows on shock wave oscillations in detonation tube. In this paper numerical studies are carried out combined effect of blockage ratio and spacing of obstacle on detonation wave propagation of hydrogen-air mixture in pulse detonation combustor. The deflagration to detonation transition of stoichiometric (ϕ=1)fuel-air mixture in channel has been analyzed for effect of blockage ratio (BR)=0.39, 0.51, 0.59, 0.71 with spacing of 2D and 3D. The reactive Navier-Stokes equation is used to solve the detonation wave propagation mechanism in Ansys Fluent platform. The result shows that fully developed detonation wave initiation regime is observed near smaller vortex generator ratio of BR=0.39 inside the combustor. The turbulent rate of reaction has also a great significance role for shock wave structure. However, vortices of rapid detonation wave are appears near thin boundary layer of each obstacle. Finally, detonation combustor demonstrates the superiority of pressure gain combustor with turbulent rate of reaction of 0.6 kg mol/m3 -s inside the detonation tube with obstacle spacing of 12 cm, this blockage enhanced the turbulence intensity and propulsive thrust. The successful detonation wave propagation speed is achieved in shortest possible time of 0.031s with a significance magnitude of 2349 m/s, which is higher than Chapman-Jouguet (C-J) velocity of 1848 m/s. Furthermore, stronger propulsive thrust force of 36.82 N is generated in pulse time of 0.031s.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.22-33
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• 1997

The objective of this study is to understand disordered parent-child relationships of Reactive Attachment Disorder(RAD) systematically through the mother’ internal working model of child. In this study, RAD mothers’internal representations of the child were compared with mothers’of control group and association between mothers’ representation classifications and children’ attachment classifications was examined. Also individual differences in mother-child interaction by mothers’representation classifications was observed. The subjects of this study were 40 2-5 year-old children and their mothers, 20 attachment disordered dyads and 20 normal dyads of control group. Mothers were interviewed using the Working Model of the Child(Zeanah, Benoit & Barton 1986) to classify internal representations of child. Children’ attachment patterns were assessed by the Strange Situation Procedure. For observation of motherchild interaction, Each dyad was seen in DPICS devised by Eyberg and Robinson(1983). The results of the study were as follows：1) Among RAD group, 55% of mothers were classified as disengaged and 45% classified as distorted, while all mothers of control group were classified as balanced. In rating scales, there were significant differences in all 3 representation classifications in Intensity of involvement and Coherence. In Intensity of involvement disengaged representations had the lowest score and distorted representations had the lowest score in Coherence. 2) Mothers’representation classifications were related to children’ attachment classifications. All mothers of control group whose children were classified as secure were classified as balanced. Among RAD’ mothers, by contrast, 82% of mothers classified as disengaged had children classified as anxious-avoidant, 56% of mothers classified as distorted had children classified as disorganized / disoriented and 33% of mothers classified as distorted had children classified as anxious-resistant. 3) There were individual differences in mother-child interactions by mothers’representation classifications. In the child-centered play, mothers classified as disengaged used discriptive statement, reflective statement and discriptive-reflective question less than balanced mothers. Mothers classified as distorted used direct command and indirect command more than balanced mothers. In the clean-up task, mothers classified as disengaged and distorted used direct command and indirect command more than balanced mothers. The results of this study suggest that parents’working model of the child is an important factor to understand parent-child attachment relationships and their interactions. The understanding of parents’ working model of the child is thought to enrich our understanding of disordered parent-child relationships and to provide useful informations for specific and successful treatments.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.650-659
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• 1999

Background/Aims: It is well recognized that all aerobic cells have the protective mechanisms in order to minimize the tissue damage induced by various reactive oxygen species(ROS). Thioredoxin peroxidase(TPX) which has been recently identified and characterized functions to convert peroxide to water. The protein is also found in various subtypes(TPX-A & B, MER5, HS22 and HORF-06) and is known to be ubiquitous in most human cells. Especially, ischemic brain injuries, partial hepatectomy and radiation induced DNA damages. In treating lung cancer, radiation therapy has a major place in the local control and the relief of symptoms, but radiation induced free radical injury and resulting pulmonary fibrosis has been the major drawback of the therapy. However, little is known about the protective mechanisms and biologic modulations against radiation-induced tissue damages. Methods: Eighteen mice were divided into six groups, 3 in each group, and fifteen had received 900cGy of radiation. The mice were sacrificed according to the pre determined time schedule; immediate, 1, 2, 3 and 6 weeks after irradiation. Extracts were made from the lungs of each mice, Western blot analysis of various subtypes of TPX were done after SDS-P AGE. Examination of H & E stained slides from the same irradiated specimens and the control specimens were also performed. Results: No difference in the intensity of the immunoreactive bands in the irradiated lung samples of the mice compared to the unirradiated control was observed regardless of the time intervals, although H & E examination of the sample specimens demonstrated progressive fibrotic changes of the irradiated lung samples. Conclusion: In conclusion, according to our data, it is suggested that various thioredoxin peroxidase subtypes and catalase which are known to be increased in many repair processes may not be involved in the repair of the radiation injury to the lung and subsequent fibrosis.

• Journal of Life Science
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• v.19 no.5
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• pp.598-606
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• 2009

Oxidative stress by free radicals is a major cause of neuronal cell death. Excitotoxicity in hypoxia/ischemia causes an increase in reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP), resulting in dysfunction of the mitochondria and cell death. Pinelliae Rhizoma (PR) is a traditional medicine for incipient stroke. We investigated the effects of PR Water-Extract on the modulation of ROS and MMP in a hypoxic model using cultured rat cortical cells. PR Water-Extract was added to the culture medium at various concentrations (0.25${\sim}$5, 5.0 ${\mu}g/ml$) on day in vitro 12(DIV12), given a hypoxic shock (2% $O_2$/5% $CO_2$, $37^{\circ}C$, 3 hr), and cell viability was assessed on DIV15 by Lactate Dehydrogenase Assay (LDH assays). PR Water-Extract showed a statistically significant effect on neuroprotection (10${\sim}$15% increase in viability; p<0.01) at 1.0 and 2.5 ${\mu}g/ml$ in normoxia and hypoxia. Measurement of ROS production by $H_2DCF-DA$ stainings showed that PR Water-Extract efficiently reduced the number and intensity of ROS-producing neurons, especially at 1 hr post shock and DIV15. When MMP was measured by JC-1 stainings, PR Water-Extract efficiently maintained high-energy charged mitochondria. These results indicate that PR Water-Extract protects neurons in hypoxia by preventing ROS production and preserving the cellular energy level.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.107-112
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• 1999

The ZnSe/GaAs epilayers were grown by RF reactive sputtering. In order to obtain the optimum condition of the growth, we have studied the dependence of Ar pressure, input power of sputter, temperature of substrate, and the distande between substrate and target. Through the observation of the grown epilayer via electronic microscope, we confirmed that the layer's surface was uniform and the boundary of the substrate and the layer was well defined. The defotmation of lattice distortion and the distortion ratio were obtained by DCRC measurements. From mrasurements of photoluminescence, in the ZnSe/GaAs sample without injection of $N_2$gas, we found that the intensity of bound exciton $I_2$is stronger than that of $I_1$and the bound exiton $I_1$represents the deep acceptor level, $I_1\;^d$. On the other hand, in the ZnSe/GaAs sample with injection of$N_2$gas, the peak of$I_1$ was much higher than that of the $I_2$and the half width appeared to be narrow. We concluded that the p-type of ZnSe/GaAs epilayer was grown successfully, because of stronger peak of the bound exciton $I_1$due to the $N_2$dopping.

• Journal of Life Science
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• v.22 no.6
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• pp.744-750
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• 2012

The aim of the present study is to investigate the effects of 12 weeks-moderate aerobic exercise training on body composition, adiponectin, retinol-binding protein-4 (RBP-4), and vascular inflammation factors in obese children. The subjects were classified into two groups, one of which was an exercise group (n=15) practicing moderate aerobic exercise training for 12 weeks, and the other group, the control group (n=13), was not in that program. The exercise group participants performed on the treadmill running at heart rate reserve (HRR) 50% of exercise intensity for 300 kcal of the consumed time. The results of all the studies and inspections are as follows: Weight, body mass index, body fat, and systolic and diastolic blood pressure were significantly lower, while $VO_2$ max was higher in the exercise group than in the control group (p<0.05, respectively). Fasting glucose, insulin, and HOMA-IR levels in the exercise group were significantly decreased (p<0.05), whereas adiponectin levels in the exercise group were significantly increased after 12 weeks' exercise training (p<0.05). In addition, our results showed that RBP4, C-reactive protein (CRP), and interleukin-6 (IL-6) concentrations in the exercise group were significantly lower than those of the control group (p<0.05). This investigation has shown that a 12 weeks-regular aerobic exercise program offers useful effects such as an amelioration of inflammation and body indices in obese children.

• Journal of Digital Convergence
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• v.12 no.12
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• pp.643-650
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• 2014

The purpose of this study is to research the effect of walking exercise with acaiberry ingestion for 8 weeks on inflammatory markers of middle age women. The participators were aging from 40 to 50 aging healthy women. The first group is classified to ingest acaiberry(AB), the second group is classified to walking exercise with acaiberry ingestion(WE+AB), and third group is classified to just walking exercise(WE). The program was doing walking exercise 3 times per week for 8 weeks. Acaiberry ingestion is after walking exercise for 8 weeks. The amount of the acaiberry is 5g acaiberry dilutes with 100mg water to inhale before breakfast and dinner to monitor CRP of each group before ingest acaiberry and 8 weeks later how to change CRP and cardiovascular disease. Consequently, all of three groups such as: acaiberry ingestion group, walking exercise with acaiberry ingestion group, and just walking exercise group, has positive effect with WBC(white blood cell), Albumin, ESR(erythrocyte sedimentation rate), CRP(C-reactive protein), but Albumin increases very small amount of gaze. Therefore, this study has no longer period time for research, and in the future there should be more concrete and various studies, such as adding more exercise of method, intensity, and measure of ingestion for supporting this study.

• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.761-772
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• 2023

The purpose of this study is to help a recovery of fatigue through the effect of cold immersion treatment after rowing ergometer on blood fatigue substance, MDA and SOD in rowing athletes. For this, 10 subjects participated in this study and we divided them into cold water immersion group (CWI, n=10), non-cold immersion group (NCI, n=10). The exercise program was performed to 2000 m rowing ergometer for maintaining high intensity. The data was collected with regard to the interaction effect of the group and time among the CWI and NCI, ANOVA was used. As the post-hoc test, Bonferroni test was used. The significance was set at .05 and the following conclusions were deduced. For lactic acid, there were the main effect of time (p<.001) and significant difference in the both group (p<.001). Also, LDH were significant difference in the each group (p<.05). For MDA, there were the interaction between group and time (p<.05) and the main effect of group (p<.05) and time (p<.001). SOD were indicated main effect of group and time (p<.05), there was significant difference between each group in the after 30 min recovery (p<.05). Collectively, The results of this study suggest that positive effect on blood fatigue substances, reactive oxygen species and anti-oxidation enzyme through cold water immersion intervention. Therefore, we strongly recommend that performing the cold immersion intervention would be beneficial after high intervention exercise.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.495-504
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• 2015

This work investigated the characteristics of a packed-bed plasma reactor system and the performances of the plasma reactors connected in series or in parallel for the decomposition of ethylene. Before the discharge ignition, the effective capacitance of the ${\gamma}$-alumina packed-bed plasma reactor was larger than that of the reactor without any packing, but after the ignition the effective capacitance was similar to each other, regardless of the packing. The energy of electrons created by plasma depends mainly on the electric field intensity, and was not significantly affected by the gas composition in the range of 0~20% (v/v) oxygen (nitrogen : 80~100% (v/v)). Among the various reactive species generated by plasma, ground-state atomic oxygen and ozone are understood to be primarily involved in oxidation reactions, and as the electric field intensity increases, the amount of ground-state atomic oxygen relatively decreases while that of nitrogen atom increases. Even though there are many parameters affecting the performance of the plasma reactor such as a voltage, discharge power, gas flow rate and residence time, all parameters can be integrated into a single parameter, namely, specific input energy (SIE). It was experimentally confirmed that the performances of the plasma reactors connected in series or in parallel could be treated as a function of SIE alone, which simplifies the scale-up design procedure. Besides, the ethylene decomposition results can be predicted by the calculation using the rate constant expressed as a function of SIE.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.103-103
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• 1997

일시적인 국소 뇌허혈 rat model에서 중대뇌동맥의 폐쇄시간에 따른 뇌조직의 손상정도를 비교 조사하였다. 웅성 Wistar rats를 isoflurane 홉입마취하에서 우측 내경동맥내로 17 mm의 silicone-coated 4-0 nylon monofilament를 삽입하여, 중대뇌동맥의 기저부를 30분, 60분 또는 90분동안 폐쇄한 후 이 monofilament를 다시 밖으로 뽑아내므로써 23 시간동안 recirculation 시키는 일시적 국소 뇌허혈 rat model을 사용한 결과, 수술 후 거의 모든 rats에서 left hemiparesis 또는 좌측으로의 circling과 같은 신경학적 결손이 나타나므로써 높은 성공률을 가지고서 비교적 용이하게 뇌허혈을 유발시킬 수 있었으며, 2 mm 두께의 fresh brain coronal slices에 대하여 2,3,5-triphenyltetrazolium chloride (TTC) 염색법을 시행하여 slice surface의 사진을 찍고 computerized 영상분석법을 이용하여 필요한 면적을 측정하므로써, coronal slice의 infarction size (%)는 총 면적에 대한 infarction 면적의 %로서, 부종율 (%)은 대조측 대뇌반구 면적의 2배에 대한 동측 대뇌반구와 대조측 대뇌반구 면적 차이의 %로서 산정되어졌다. 30분 허혈군에서는 본 염색법으로는 infarction이 거의 확인되지 않았으나 60분 허혈군 (n=13)에서는 우측 somatosensory frontoparietal cortex와 striatum 양자 모두 또는 일부 rats에서는 striatum에만 국한된 ulfarction이 확인되어졌으며 90분 허혈군 (n=12)에서는 거의 대부분의 rats에서 위 두 지역 모두에서 infarction이 확인되어졌다. Infarction size (%)는 60분과 90분 허혈군 각각에서, frontal pole로부터 5 mm되는 slice에서는 11.9$\pm$1.2 (평균치$\pm$표준오차), 13.7$\pm$1.9이었으며 7 mm되는 slice에서는 19.1$\pm$1.8, 21.9$\pm$2.1이었으며 9 mm되는 slice에서는 14.7$\pm$2.4, 19.7$\pm$2.2이었다. 또한 부종율 (%)은 60분과 90분 허혈군 각각에서, frontal pole로부터 5 mm되는 slice에서는 3.1$\pm$0.6, 3.8$\pm$0.7이었으며 7 mm되는 slice에서는 3.5$\pm$0.3, 5.7$\pm$1.0이었으며 9 $\pm$되는 slice에서는 3.4$\pm$0.5, 5.7$\pm$0.9이었다. 한편 90분 동안의 중대뇌동맥 폐쇄에 따른 뇌조직 손상을 cresyl violet 염색법, NADPH-diaphorase histochemistry, GFAP immunohistochemistry를 사용하여 일부 측정한 결과, 위의 손상지역에서는 뇌신경세포체들의 shrinkage 내지는 소실됨을 확인할 수 있었으며, NADPH-diaphorase-positive neuron들도 대부분 dendrite와 axon같은 cell process들의 fragmentation, shrinkage 내지는 소실되므로써 intensity의 감소현상이 나타났으며, reactive gliosis로 말미암아 GFAP immunoreactive intensity의 증가현상이 나타났다.