• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.56-61
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• 2012

Fuel-side cold-flow tests were performed on the technology demonstration model of a 75 ton-class liquid rocket engine combustion chamber for the first stage of the Korea space launch vehicle II. Pressure drop in the cooling channels of the combustion chamber was measured by changing fuel mass flow rate through a pressure regulating system. Pressure drop in each segment of the chamber could be obtained and a lot of pressure drop was caused by high flow velocity in the nozzle throat segment. The accuracy of a hydraulic analysis method for calculating a pressure loss in cooling channels could be verified by applying it to the cold-flow test conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.26-37
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• 2011

A 75-tonf-class LRE(liquid rocket engine) thrust chamber with ablative material for technology demonstration was manufactured on the basis of development technologies of 30-tonf-class LRE. Hydraulic characteristics of the thrust chamber were examined through cold flow test and ignition test of low flow condition. Test result showed that hydraulic function was good. Side ignition method with igniter ring also showed a fine function of ignition in operating ways of static condition. But a close review is required to understand the phenomena of generation and extinction of specific frequencies showed in dynamic characteristics ways. To achieve these, a large combustion test facility which is capable of performing combustion test at design condition of the 75-tonf-class thrust chamber should be constructed as soon as possible.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2184-2193
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• 1994

A flow visualization experiment using water-table models was performed. The water-table models simulated the two-dimensional cold flow fields inside the combustion chambers of incinerators. The flow were visualized by small but neutrally bouyant particles photographed by an overhead camera. The experimentally simulated flow fields apparently showed distinct features of two combustion chamber shapes; counter and parallel flow types. The significance of the secondary air injection on the mixing of combustion gases were clearly observed. The effects of the recirculation zones, which were present in the secondary chamber, were discussed by considering the importance of them for optimal combustion.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.84-92
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• 2002

On the cold start of LPG engine, as the engine temperature has not reached its equilibrium temperature, liquid LPG could not be changed perfectly gaseous LPG, although it was passed to the vaporizer. Liquid and gas mixed fuel could influence starting ability and exhaust emission characteristics of LPG engine. In this study, the vaporization characteristic of liquid LPG was investigated with a conventional vaporizer and the vaporizer with heat source(glow plug) installed at preheated chamber inlet, by using the visualization methods and engine test. According to visualization result, even if the engine coolant temperature was $14^{\circ}C$, liquid fuel was supplied to primary chamber over 25 seconds without vaporizing from preheated chamber in such a conventional vaporizer. However, the vaporizer with heat source do not correspond with that, scarcely had been trim on glow plug when LPG began to vaporize. The effectiveness of heat source could be verified by application to the conventional LPG engine.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.06b
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• pp.60-66
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• 1998

The horizontal cold chamber pressure die casting produces a variety of net shape, complicate-geometry castings with desired mechanical properties. dimensional tolerance, and surface finish. However, top quality castings can be achieved only when optimal performance of thecold chamber (shot sleeve )and plunger is maintained druing the molten metla injection phase of the process. Unforturately, inreality , shot sleeves deteriorate fast and sometimes fail catastrophically due to incorrect design. These early and unexpected failures of shot sleeves cost die casters money and productiivity. To prevent promature failures of shoe sleeves major faulure mechanisms were investigated. with the aid of analyticla solutions robust design criteria for shot sleeves have been developed. The data directly obtained from failed shot sleeves in the die casting industry for automotive parts, support a strong correlation between design and filures. by applying these design criterial we expected premature faulures of shot sleeves can be avoided in die casting industry.

• Journal of computational fluids engineering
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• v.20 no.3
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• pp.8-14
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• 2015

More and more, spaces are decreasing which satisfy multiple requirements for wind power plants. However, areas which have excellent wind resources and are free to civil complaints occupy a large space, although they are exposed to the cryogenic environment. This study conducted a thermal-fluid analysis of a cryogenic chamber for testing large wind turbine parts exposed to the cryogenic environment. The position of supply air is placed to the upper area to compare each cooling performance for each location of various outlets in mixing ventilated conditions. The study carried out CFD analysis for the chamber both with and without a test object. For the cases without the test object, the air temperature of the upper supply and down extract type chamber was cooled faster by 5-100% than the others. However, for the cases with the test object, the object temperature of upper supply and center extract on the opposite side type chamber was cooled faster by 33-132% than the others. The cooling performance by the air inside the chamber and the test object did not show the same pattern, which implicates the need to consider the cooling performance by not only the air but also the test object in the large cryogenic chamber design for testing large parts.

• The Korea Journal of Herbology
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• v.29 no.5
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• pp.39-43
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• 2014

Objectives : The purpose of this sutdy was finding out the origin and daily dose of Allii Fistulosi Bulbus in Treatise on Cold Damage Diseases. Methods : In order to estimate the origin and daily dose of Allii Fistulosi Bulbus, I researched the Treatise on Cold Damage Diseases, Synopsis of Prescription of the Golden Chamber, Classified Emergency Materia Medica, Compendium of Materia Medica, and Huangdi's Internal Classic. Results : According to some important herbal textbooks, Allii Fistulosi Bulbus had no seed, was reproduced by rhizome, and its leaves were soft. Chongbaek in Treatise on Cold Damage Diseases did not include word 'raw'. The unit of the dose of it was the number of article. So Allii Fistulosi Bulbus in Treatise on Cold Damage Diseases was not Daepa but Jokpa, and was dried, and was round shaped bulb bigger than bean. The daily dose was 4, 9, 14 articles in Treatise on Cold Damage Diseases and Synopsis of Prescription of the Golden Chamber. These were estimated equal to 1, 2, 3 Ryang. 1 Ryang equals to 6.5 g in Treatise on Cold Damage Diseases, so the daily dose of Allii Fistulosi Bulbus was estimated 6.5 g, 13.0 g, and 19.5 g. I weighed the middle-sized Allii Fistulosi Bulbuses, the result was remarkably consistent with the estimated numerical value. Conclusions : In Treatise on Cold Damage Diseases, Allii Fistulosi Bulbus was dried bulb of Jokpa of Allium fistulosum Linn$\acute{e}$ and the daily dose was 4 or 9 articles, respectively equaled to 1 Ryang, 2 Ryang and 6.5 g, 13 g.

• Journal of Korean Medical classics
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• v.19 no.2 s.33
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• pp.138-162
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• 2006

'On the Morbid Pulse of Abdominal Fullness, Cold Mounting, and Abiding Food' in the Chapter 10 of Synopsis of Golden Chamber that enunciates Abdominal Fullness, Cold Mounting, and Abiding Food is related to the stomach and intestines respectively, and is similar to the region and symptom of disease in the light of both abdominal fullness and symptoms of pain. This chapter was united into one because the formula mentioned in this chapter can be applied to three disease patterns. Abdominal fullness shows the symptoms of distention and unease, but judging from the text as well as a specific formula and symptoms, it follows pain. Accordingly Abdominal fullness dealt with in this chapter is the first consideration and it is a kind of a disease pattern attendant on abdominal pain. Cold Mounting does not mean mounting gi disease but means the abdominal pain. The cause of cold mounting is mainly due to insufficiency of yang gi and oversufficiency of cold evil. And the main symptoms of cold mounting follow the severe pain around the naval and sweating, cold of the extremities, pulse deep and tight. Abiding food is of the same meaning such as damage of food today. Abiding food is now referred to as damage of food. Principles which have set forth in this chapter are put to use of the method of ejection in case that abiding food places in the upper part, precipitation in the lower part. The symptoms of abiding food show that the pulse is slight and slippery and the wrist pulse is both superficial and large and rough in applying the pressure, and the cubit pulse is also slight and superficial as well, and that have diarrhea and have little appetite.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.137-141
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• 2007

The startup behaviour of PEM fuel cells at subfreeze zero is one of the most challenging tasks to be solved before PEM fuel cell vehicle is commercialized. Automotive companies are trying to increase cold statup capability of fuel cell. In this study, we found out the design factor of the stack to increase cold startup capability using 4kW stack and then cold startup test was performed at the various shutdown condition and the various current. In order to test the cold startup possibility and capability in vehicle, we installed 80kW stack in the vehicle and this 80kW fuel cell vehicle was housed in an environmental chamber to investigate the characteristics of cold startup and driving. We found that it is possible for fuel cell vehicle with 80kW stack to self-heated cold startup and drive at $-15^{\circ}C$.

• The Journal of Korean Medical History
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• v.22 no.2
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• pp.43-62
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• 2009

Yoshimasi Todo (吉益東洞), who thought that the books on herbal medicines are the reason for the complicated explanation of the effects of herbs, thought that the articles from Treatise on Cold Damage Diseases (傷寒論) and Synopsis of Prescriptions of the Golden Chamber (金匱要略) are the only books that can identify the effects of herbs. He also thought that the practitioners from the later period have added too much on the original text, which led to his thought that the original text of Treatise on Cold Damage Diseases (傷寒論) and Synopsis of Prescriptions of the Golden Chamber (金匱要略) did not have the explanation that involves the theory of yin-yang(陰陽), the five phases(五行), and three yin and three yang(三陰三陽). From this, he investigated the standards of using the herbs in the Synopsis of Prescriptions of the Golden Chamber (金匱要略) by comparing the articles. In this point of view, Yoshimasi Todo (吉益東洞) said that Poria Scleotium (茯笭) treats palpitations (悸) and 肉瞤筋惕. This meant the symptom of unvoluntary palpitations and the trembling of muscles with wrenching pain. Also, he thought that the symptom of Poria Scleotium (茯笭) in the formula of decoction is shown by the symptoms of dizziness, palpatations, vomiting, trembling of muscles, and cramps. This paper studies on the symptoms that seems close to the meaning of the symptom of Poria Scleotium (茯笭) that Yoshimasi Todo (吉益東洞) meant, which can be summarized to palpatations and trembling of muscles. I wish this paper is of help to those who study Treatise on Cold Damage Diseases (傷寒論), Synopsis of Prescriptions of the Golden Chamber (金匱要略), and the medicine of Yoshimasi Todo (吉益東洞).