• 대한기계학회논문집
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• 제8권5호
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• pp.442-449
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• 1984

본 연구에서는 두 분류가 교우되어 배합이 이루어지는 유동역에서 3차원 방향 에 대하여 평균속도분포, 난류강도분포, 난류전단응력분포, 상관계수의 분포 및 난류 운동에너지와 운동량의 변화 등을 측정 분석하였다.

• Molecular & Cellular Toxicology
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• 제1권2호
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• pp.73-77
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• 2005

Nickel is the one of potent environmental, the occupational pollutants and the classified human carcinogens. It is a serious hazard to human health, when the metal exposure. To prevent human diseases from the heavy metals, it is seemingly important that understanding of how nickel exerts their toxicity and carcinogenic effect at a molecular and a genomic level. The process of nickel absorption has been demonstrated as phagocytosis, iron channel and diffusion. Uptaked nickel has been suggested to induce carcinogenesis via two pathways, a direct DNA damaging pathway and an indirect DNA damaging pathway. The former was originated from the ability of metal to generate Reactive Oxygen Species (ROS) and the reactive intermediates to interact with DNA directly. Ni-generated ROS or Nickel itself, interacts with DNAs and histones to cause DNA damage and chromosomal abnormality. The latter was originated from an indirect DNA damage via inhibition of DNA repair, or condensation and methylation of DNA. Cells have ability to protect from the genotoxic stresses by changing gene expression. Microarray analysis of the cells treated with nickel or nickel compounds, show the specific altered gene expression profile. For example, HIF-I (Hypoxia-Inducible Factor I) and p53 were well known as transcription factors, which are upregulated in response to stress and activated by both soluble and insoluble nickel compounds. The induction of these important transcription factors exert potent selective pressure and leading to cell transformation. Genes of metallothionein and family of heat shock proteins which have been known to play role in protection and damage control, were also induced by nickel treatment. These gene expressions may give us a clue to understand of the carcinogenesis mechanism of nickel. Further discussions on molecular and genomic, are need in order to understand the specific mechanism of nickel toxicity and carcinogenicity.

• The Journal of Korean Physical Therapy
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• 제13권3호
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• pp.509-527
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• 2001

The Sun's ray is composed of Infrared(49%), Visible light(40%) and Ultra violet(11%), however the ray getting to the earth is FIR(Far infrared; 60%), IR(Infrared; 20%), and UV(Ultra Violet; 20%). Human beings has utilized FIR already from time immemorial. Hershel found out Infrared for the first time. in the Industrial Revolution the Infrared and FIR had been begun to use making products. In these days, with contemporary science FIR would be begun to clear up the implication in the human body and organic compound. IR classified by wavelength three parts NlR, MIR, FIR. There is FIR which is radiated from healthy human body the wave length is 8-l4m. The human body is composed of proteins which get easily changed by a thermal factor (about 42 $^{\circ}$C over). FIR with low temperature can deeply penetrate on the human body composed things without troublesomes, since FIR has effectively operated on the human body at low temperature (35-40 $^{\circ}$C). When FlR penetrated on the human body. it would inhibit the abnormal genes and cells expression, and then information of DNA and RNA would be reexpressed for arranging DNA and RNA abnormal state. As FlR's receptors in the body, it could be presumed that N-glycosyl linkage of purine and deoxyribose, RNA splicing process, and Heat shock protein. To take the FIR which was a optimized wavewlength and strength, at first, we induced the characteristic algorithm and the computerized programing. Then we formed that the formular of optimized FIR with physical, mathematical logic and theory. especially, Plank, Kirchhoff, Wien, Stefan-Boltzmann's logic and law. In the long run, the formular was induced with integration mathematical, since we had to know the molecular wavelength. Based on the induced formular as above, we programmed the optimized FlR radiating computerized program. In this research, we designed the eletronic circuit f3r interfacing with human body to diagnosis and treatment with FIR sensor which radiated FIR wavelength optimized.

• Asian-Australasian Journal of Animal Sciences
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• 제15권1호
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• pp.16-18
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• 2002

During the process of freezing, spermatozoa suffer cold shock which increases their susceptibility to lipid peroxidation which plays an important role in ageing of spermatozoa, shortening their life span and affecting the preservation of semen. An experiment was therefore conducted to study the effect of addition of natural antioxidants into semen diluents on the preservability of buffalo semen. Split semen samples were extended in milk egg yolk diluents fortified with vitamin E (MYE), vitamin C (MYC) and control group (MYO); Tris-egg yolk diluents fortified with vitamin E (TYE), vitamin C (TYC) and control group (TYO) and evaluated for their preservabilities at 4-7$^{\circ}C$ and $37^{\circ}C$. Overall least squares mean of percent motility observed after 0, 24, 48, 72 and 96 h of preservation at 4-7$^{\circ}C$ were 66.70, 54.00, 36.80, 21.90 and 12.50, respectively while the estimates for semen extended in MYE, MYC, MYO, TYE, TYC and TYO were 44.80, 42.70, 38.70, 36.00, 35.20 and 33.00 percent, respectively. The results showed that motility was significantly (p<0.01) affected by extender (extender-antioxidant combination) and preservation interval. Overall least squares mean percent motility observed after 0, 4, 8, 12 and 24 h of preservation at $37^{\circ}C$ were 68.50, 58.90, 45.00, 38.10 and 18.10 percent, respectively, while the estimates for semen extended in MYE, MYC, MYO, TYE, TYC and TYO were 48.20, 49.30, 46.80, 45.30, 42.30 and 42.50 percent, respectively. Extender and storage interval were found to be significantly (p<0.01) affecting spermatozoa motility on room temperature preservation. The results indicated that the incorporation of antioxidants, especially vitamin E, had beneficial effect on preservability of buffalo semen.

• 약학회지
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• 제48권2호
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• pp.159-164
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• 2004

Primary pro-inflammatory cytokines are a trio: tumor necrosis- $\alpha$ (TNF-$\alpha$), interleukine-$\beta$ (IL-$\beta$), and interleukine-6 (IL-6). These cytokines initiate and regulate the acute-phase inflammatory response during infection, trauma, or stress and appear to play an important role in the immune process. Nitric oxide (NO) is a multi-functional mediator, which plays an important role in regulating various biological functions in vivo. NO production by inducible nitric oxide synthase (iNOS) in macrophages is essential for the defense mechanisms against microorganisms and tumor cells. However, over-expression of iNOS by various stimuli, resulting in over-production of NO, contributes to the pathogenesis of septic shock and some inflammatory and auto-immune disease. Solvent fractions of sage ( Salvia officinalis L.), which is cultivated in Jeju-Do, was assayed for their effects on TNF-$\alpha$ and IL-6 production in LPS-stimulated RAW 264.7 macrophages. Hexane and ethylacetate (EtOAc) fraction of sage inhibited the protein and mRNA expression of TNF-$\alpha$ and IL-6 in LPS stimulated RAW 264.7 cells at the concentration of 100 $\mu\textrm{g}$/$m\ell$. Also, incubation of RAW 264.7 cells with the fraction of hexane or EtOAc (50 $\mu\textrm{g}$/$m\ell$) inhibited the LPS induced nitrite accumulation and the LPS/IFN-${\gamma}$ induced iNOS protein. And this inhibition of iNOS protein is concordant with the inhibition of iNOS mRNA expression. Above results suggest that extract of sage may have anti-inflammatory activity through the inhibition of pro-inflammatory cytokines (TNF-$\alpha$, IL-1$\beta$, IL-6), iNOS and NO.

• Journal of Trauma and Injury
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• 제30권3호
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• pp.80-86
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• 2017

Purpose: To analyze the data of patients who suffered trauma in a cultivator accident and visited the trauma center in rural Gyeongbuk Province. Methods: We retrospectively reviewed the medical records and Korean Trauma Data Bank data of 120 patients who suffered cultivator-related traumas and visited the rural regional trauma center in Gyeongbuk Province from January to December 2015. Results: The age of the patients ranged from 35 to 96 years (mean, 70 years). Ninety-one (75.8%) patients were men, and twenty-nine (24.2%) were women. Most of the patients were in their 70s (46 men [50.5%] and 13 women [44.8%]). In total, 113 patients (94.1%) arrived at the regional trauma center by ground transport and 7 (5.9%) arrived by air transport. Ninety-eight patients (81.7%) were transported to the regional trauma center directly from the scene of the accident, and twenty-two (18.3%) were transferred from another medical institute. The mean time from the accident to arrival at the emergency department was 139 minutes, and only 46 patients (38.3%) arrived within 1 hour. Twelve (10.0%) patients died, including two deaths on arrival and two post- cardiopulmonary resuscitation deaths in the emergency department. All deaths were of male cultivator operators. The causes of death were shock (hypovolemic, traumatic, or septic), subdural hematoma (open), hemothorax, rhabdomyolysis, and pneumonia. Conclusions: As the government - led regional trauma center project is on process, it would be clinically important to summarize the initial outcome of cultivator injuries, which are characteristically found more in regional trauma centers in the rural area, and have high mortality. Based on this study, in the future, it will be necessary to follow up and analyze more number of patients and to construct accurate database about trauma cases related to cultivator in Gyeongbuk region.

• 천문학회보
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• 제43권1호
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• pp.53.1-53.1
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• 2018

During a major solar eruption, the erupting plasma is possibly out of the equilibrium ionization state because of its rapid heating or cooling. The non-equilibrium ionization process is important in a rapidly evolving system where the thermodynamical time scale is shorter than the ionization or recombination time scales. We investigate the effects of non-equilibrium ionization on EUV and X-ray observations by the Atmospheric Imaging Assembly (AIA) on board Solar Dynamic Observatory and X-ray Telescope (XRT) on board Hinode. For the investigation, first, we find the emissivities for all the lines of ions of elements using CHIANTI 8.07, and then we find the temperature responses multiplying the emissivities by the effective area for each AIA and XRT passband. Second, we obtain the ion fractions using a time-dependent ionization model (Shen et al. 2015), which uses an eigenvalue method, for all the lines of ion, as a function of temperature, and a characteristic time scale, $n_et$, where $n_e$ and t are density and time, respectively. Lastly, the ion fractions are multiplied to the temperature response for each passband, which results in a 2D grid for each combination of temperature and the characteristic time scale. This is the set of passband responses for plasma that is rapidly ionized in a current sheet or a shock. We investigate an observed event which has a relatively large uncertainty in an analysis using a differential emission measure method assuming equilibrium ionization state. We verify whether the observed coronal plasmas are in non-equilibrium or equilibrium ionization state using the passband responses.

• 대한기계학회논문집A
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• 제39권6호
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• pp.611-615
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• 2015

비행기 방어용 대공포는 저고도 방어체계로 사용되고 있으며, 방어능력 극대화를 위해 대부분 고발사율 대공포를 두개 이상 탑재하여 교전 시 명중률을 높이고 있다. 고 발사율 대공포의 경우, 포열진동 및 탄의 불균형 분산은 정확한 조준사격 및 명중률에 아주 결정적인 영향을 미치게 된다. 따라서 사격 진동 및 충격량을 감소하는 구조는 대공포 체계에서는 주요 설계 대상이다. 본 연구에서는 차량의 현가장치 특성에 따라 고발사율 대공포 체계에서 발사시스템의 진동충격으로부터 차단하는 능력을 향상시키고, Recurdyn 과 Adams 를 이용한 동적 거동해석과 실 사격 시험결과를 비교하여 명중률에 영향을 미치는 현가 형태, 위치 및 수량에 따른 체계 자세 흔들림을 예측하였다. 본 연구를 통하여 대공포에 적합한 현가장치와 포 스프링 등과 같은 구성품을 선정할 수 있는 기초연구를 수행하였다.

• 대한기계학회논문집B
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• 제36권12호
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• pp.1171-1176
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• 2012

실리콘 기판 위에 플라즈마 기상층착법을 이용하여 합성된 탄소나노튜브를 화학적인 방법이나 전자빔 혹은 이온빔과 같은 진공 챔버 내에서의 공정없이 펨토초레이저를 이용하여 선택적으로 패터닝 하는 방법을 구현하였다. 플라즈마 기상층착법으로 합성된 탄소나노튜브는 수직성장이 가능하며 탄소나노튜브 간의 간격을 조절하여 성장이 가능하다. 이러한 장점으로 전계방출소자, 바이오센서 등의 응용을 위하여 이용되는 합성 방법이다. 이러한 응용을 위하여 선택적으로 나노튜브를 제거하고 탄소나노튜브 끝의 촉매금속을 제거하는 것이 응용의 효율을 높이는데 매우 중요하다. 본 연구에서는 탄소나노튜브의 전기적, 구조적 특성에 영향을 줄 수 있는 화학적인 방법을 사용하지 않고 펨토초레이저를 사용하여 패터닝과 촉매금속을 제거하는 방법을 구현하였다.

• 한국산학기술학회논문지
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• 제17권2호
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• pp.378-385
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• 2016

전기 분 배전반의 내부 회로 인 부스 바는 충전부의 노출로 인해 전기 사고의 원인이 되며 이로 인한 감전 사고와 단락 사고가 발생된다. 또한 동물 및 이물질 침투로 인한 전기 화재 사고가 발생되는 원인이 되기도 한다. 또한 확장이 불가능한 구조로 무리하게 연결하여 사용하므로 접촉 저항 증가 발생으로 과열 사고를 유발시키기도 하며, 절단과 절곡 등의 제조 공정상의 어려움을 가지고 있기 때문에 주문생산방식을 택할 수밖에 없는 현실이며, 긴급전기 사고 발생시 복구하는데 지연되는 원인이 되기도 한다. 본 논문에서는 이와 같은 문제점을 개선하기 위해서 분 배전반의 모선을 절단하여 개별 블록으로 절연 난연 케이스와 격벽 구조화로 안전성을 높여 모듈 블록화 하였으며, 확장성과 유연성을 구현하였으며, 쉽게 확장이 가능한 구조이며, 또한 쉽게 분 배전반을 조립할 수 있다는 것이며, 이와 같이 전기적 위험 요소를 제거한 전기 분 배전반의 내부 구조는 블록형 부스 바 구조를 가지고 메인차단기와 분기차단기간의 회로 형성 구현 방식의 분 배전반를 제안하고 공인시험기관의 시험을 통해 그 유용성을 입증 하였다.