• Journal of the Society of Naval Architects of Korea
• /
• v.41 no.2
• /
• pp.55-60
• /
• 2004

This paper describes the estimation method of hull girder response of ships due to springing. To this aim, nonlinear springing effect on the hull girder is evaluated including vertical, horizontal, and torsional deformation of the hull. The Timoshenko beam model is used to calculate the stress distribution on the hull girder. The quadratic strip method is employed to calculate the hydrodynamic forces and moments on the hull. In order to remove the irregular frequencies, 'rigid lid'is adopted on the hull free surface level and hydrodynamic coefficients are interpolated for asymptotic values. The results of example calculation show a reasonable agreement with previous results for both symmetric and anti-symmetric responses.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.283-289
• /
• 2004

Rail defects(Corrugation, shelling, etc) are occurred by the Rail with wheel contact stress. Rail grinding is maintaining of optimal rail profile to use special rail grinding machine to remove rail defect. The benefits of rail grinding enforcement, improve track safety, improve track steering and rail life, improve ride comfort and reduce noise, etc. Actually when rail grinding plan apply to field track, we should consider a lot of function before determination, such as grinding method, grinding pass number, removing metal volume, etc. because each track has various characteristics. Therefore it is important that the determination of rail grinding strategy for optimum and economic before enforcement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.631-635
• /
• 2000

Recently, the epoxy molded type PT for indoor and applied 25.8kV was often distroyed by degradation of insulation that effected many electric stress and defect of manufactured goods. therefore In this work, We can present a method of solution in the process of produce the PT through analysis of experiments. In order to reduce the PD (Partial Discharge) which was occurred at the insulation material of epoxy resin, we has many tried to remove faults In the process of the products,

• Molecules and Cells
• /
• v.39 no.1
• /
• pp.72-76
• /
• 2016

Cell death pathways such as apoptosis can be activated in response to oxidative stress, enabling the disposal of damaged cells. In contrast, controlled intracellular redox events are proposed to be a significant event during apoptosis signaling, regardless of the initiating stimulus. In this scenario oxidants act as second messengers, mediating the post-translational modification of specific regulatory proteins. The exact mechanism of this signaling is unclear, but increased understanding offers the potential to promote or inhibit apoptosis through modulating the redox environment of cells. Peroxiredoxins are thiol peroxidases that remove hydroperoxides, and are also emerging as important players in cellular redox signaling. This review discusses the potential role of peroxiredoxins in the regulation of apoptosis, and also their ability to act as biomarkers of redox changes during the initiation and progression of cell death.

• Biomolecules & Therapeutics
• /
• v.31 no.4
• /
• pp.395-401
• /
• 2023

Innate immunity is a first line defence system in the body which is for sensing signals of danger such as pathogenic microbes or host-derived signals of cellular stress. Pattern recognition receptors (PRR's), which present in the cell memebrane, are suspect the infection through pathogen-associated molecular patterns (PAMP), and activate innate immunity with response to promote inflammation via inflammatory cells such as macrophages and neutrophils, and cytokines. Inflammasome are protein complexes which are part of innate immunity in inflammation to remove pathogens and repair damaged tissues. What is the important role of inflammation in disease? In this review, we are focused on the action mechanism of NLRP3 inflammasome in inflammatory diseases such as asthma, atopic dermatitis, and sepsis.

• Journal of Photoscience
• /
• v.5 no.4
• /
• pp.157-162
• /
• 1998

The effect of heat treatment in the light on the subsequent CO2 fixation was studied with isolated spinach chloroplasts to define the role of light during heat stress. The degree of inhibition in CO2 fixation after heat treatment at 35$^{\circ}C$ under full light intensity (600W/$m^2$) was same as that in the dark. However, heat treatment of isolated chloroplasts in the light manifested thylakoidal damage, which did not occur in the dark. Under weak light (10~30 W/$m^2$ ) where no thylakoidal damage occurred, the inhibition was substantially alleviated , showing protective effect of light . The inhibition caused by heat treatment in the dark or light is prevented by the addition of a few combined compounds to the medium prior to treatment. Fructose-1-6- bisphosphate(with aldolase)and ribose-5-phosphate, known to be effective combined with oxaloacetate in preventing inhibition after heat treatment in the dark were equally effective in the light even without oxaloacetate. Addition of sugar phosphate reduced the Mehler reaction, which may occur in fast rae under high light. However, the addition of bicarbnate and catalase that would remove Mehler reaction did not provide any protection, indicating that protective role of sugar phosphate is elsewhere. Furghermore, in whole plants rapid recovery from heat stress was observed in the light. The apparently lesser or equal inhibition in spite of additional thylakoidal damage under heat stres in the light and less requirement for the protection against heat treatment suggest that the inhibitory effect of heat stress is alleviated by light treatment.

• Journal of Ocean Engineering and Technology
• /
• v.24 no.2
• /
• pp.57-61
• /
• 2010

At present, welding technology is not only emphasized in the development of manufacturing technology but its application is also expanding. In these systems, attempts have been made to use SUS as a high-temperature material for special applications, and in improvements in manufacturing technologies bear watching, together with an increase in the use rate. Specifically, three-dimensional wings are often used for fasteners with the purpose of decreasing the weight (정해용, 2007). However, due to developments in welding technology, there has been a recent tendency to replace existing assembly methods with welding. Specifically, if laser welding techniques are applied, the heat-affected zone can be minimized compared toother welding techniques. However, in the case of these special welding techniques, there is an increase in residual stress, which fatally affects the fatigue life. In order to remove the residual stress and its effect on fatigue life, shot-peening is executed. The intention of this study was to obtain the optimal conditions for shot-peening.

• Journal of the Korean Society of Safety
• /
• v.20 no.1 s.69
• /
• pp.36-41
• /
• 2005

PCV(Positive Crankcase Ventilation) valve acts as a flow control valve to get a re-combustion of blow-by gas by having it flow from a crankcase to an inlet manifold suction tube. The blow-by gas of the crankcase should be eliminated or taken properly because it cause corrosion to critical parts, and contributes to increase crankcase pressure that can cause a drop in efficiency. The excessive stress and strain on the PCV valve that remove these harmful gas would be bring the difficult on the flow rate control and failure of the valve. Those condition inevitably induce the accident. Therefore, this study purpose is FEM evaluation of the stresses and deformation in the X3 PCV model according to the change of the differential pressure between inlet and outlet. From results, the maximum equivalent stresses increased linearly according to the increase of the differential pressure at the about 50mm from the inlet position and were under the yield strength of the valve. And the deformations were relatively small regardless of the in-outlet differential pressure variation.

• Korean Journal of Occupational Health Nursing
• /
• v.15 no.2
• /
• pp.83-93
• /
• 2006

Purpose: This study purposed on investigating how the emotional labor affects the physical uncomfortable feeling of the workers in the department store. Method: The method of data collection was used of questionnaire for 574 workers of one department store located in Seoul. The period of data collection was done from November 1, 2004 to November 30 for about one month. The working career of the participants was over one month at that department. Result: The degree of emotional labor for participants, men were $3.21{\pm}0.53$ for the total point of 5.0 point, and the degree of the physical uncomfortable feeling was $3.07{\pm}0.48$ for total of 5.0 point. The degree of emotional labor for participants, women were $3.22{\pm}0.42$ for the total point of 5.0 point, and the degree of the physical uncomfortable feeling was $3.13{\pm}0.42$ for total of 5.0 point. In order to analyze the factors that affected the emotional labor and physical uncomfortable feeling, the multi-level reflecting analysis was used. As a result, men were insecurity of job influenced the emotional labor feeling in remarkable degree, women were the responsibility of job influenced the emotional labor. Men were insecurity and responsibility of job influenced physical uncomfortable feeling in remarkable degree, women were responsibility of job and emotional labor influenced the physical uncomfortable feeling in remarkable degree. Conclusion: The results of this study show that various strategies to remove the factors of job insecurity in order to reduce the level of emotional labor of the workers at the department store should be devised. In addition, the special way to minimize the physical insecurity should be contrived and carried out. Since the workers of the department stores had higher emotional labor, the factors of stress need to be analyzed and should be removed.

• YAKHAK HOEJI
• /
• v.49 no.1
• /
• pp.30-37
• /
• 2005

Xuesaitong Ruanjiaonang (XR), a soft capsule containing Panax notoginseng saponins as main ingredients, is believed to remove extravasated blood and increase cerebral blood flow by improving blood circulation, and therefore, has been used in China to treat ischemic stroke or hemiplegia caused by cerebral thrombosis. To characterize pharmacological actions of XR, the present study evaluated its effects on neuronal cell damage induced by various oxidative insults or excitotoxic amino acids in primary cultured rat cortical cells. The neuronal cell viability was not affected by XR with the exposure for 2 h at the concentrations tested in this study ($10{\sim}1000\;{\mu}g/ml$). However, significant reduction of the cell viability was observed when the cultured cells were exposed to XR at $1000\;{\mu}g/ml$ for 24 h. XR was found to concentration-dependently inhibit the oxidative neuronal damage induced by $H_{2}O_2$, xanthine/xanthine oxidase or $Fe^{2+}$/ascorbic acid. In addition, it dramatically inhibited the excitotoxic damage induced by glutamate or N-methyl-D-aspartate (NMDA). We found that the NMDA-induced neurotoxicity was inhibited more effectively and potently than the glutamate-induced toxicity. Moreover, XR was found to exert mild inhibition of lipid peroxidation induced by $Fe^{2+}$/ascorbic acid in rat brain homogenates and some 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. Taken together, these results demonstrate neuroprotective and antioxidant effects of XR, showing inhibition of oxidative and excitotoxic damage in the cultured cortical neurons, as well as inhibition of lipid peroxidation and its radical scavenging activity. Considering that excitotoxicity and oxidative stress pl ay crucial roles in neuronal cell damage during ischemia and reperfusion, these results may provide pharmacological basis for its clinical usage to treat ischemic stroke.