• Transactions of the Korean hydrogen and new energy society
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• v.24 no.5
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• pp.461-466
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• 2013

In this research, the diesel cycle was thermodynamically interpreted to evaluate the possibility of high efficiency by converting diesel engine to the atkinson cycle, and general cycle features were analyzed after comparing these two cycles. That an experimental single cylinder and a long stroke diesel-atkinson engine, of which S/B ratio was more than 3, were manufactured. After evaluating the engine through basic experiments, a diesel engine was converted into the atkinson cycle by constituent VCR (variable compression ratio) device and VVT (variable valve timing) system. The experimental method was to observe compression work reduction effects due to low compression effects from delayed intake valve closing of the early stage atkinson engine. The result, the possibility of increasing compression ratio about each engine load was confirmation by constructing compensate expansion-compression ratio in accordance with the delayed intake valve close.

• The Korean Journal of Zoology
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• v.33 no.2
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• pp.183-190
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• 1990

The present study exarnines the physiological alteradons in prolactin (PRL) messenger ribonucleic acid (mRNA) and serum PRL levels during the rat estrous cycle and the effed of naloxone, an endogenous oploid peptide receptor antagonist, on PRL gene expression during the rat estrous cycle. Adult female rats exhibiting at least two consecutive 4-day estrous cycles were used in this study. A single injection of naloxone (2mg/kg b.w.) or saline was given sc 30 mm prior to decapitation. Animals were sacrificed at 10:00 h of each stage of the estrous cycle, and at 2-h intervals from 10:00 h to 20:00 h during the proestrus. PRL mRNA and serum PRL levels were determined by a RNA-blot hybridization with the rat PRL cDNA probe and by a PRL radjoimmunoassay, respectively. PRL mRNA and serum PRL levels were not dramatically altered in the morning of each stage of diestrus I, II and proestrus, and naloxone failed to modify the two parameters. During estrus naloxone clearly suppressed serum PRL levels, but it was unable to modify PRL mRNA levels. A more detailed examination of the proestrus stage revealed that PRL mRNA and serum PRL levels were fluctuated as a function of time: PRL mRNA levels reached a maximum level at 12:00 h and gradually decreased until 18:00 h. PRL mRNA levels then rose at 20:00 h. No difference of PRL mRNA levels between the control and naloxone-treated groups was observed. Changes in serum PRL levek during proestrus were conversely related to changes in PRL mRNA: serum PRL levels were low from 10:00 h to 14:00 h, then increased and reached a maximum level at 16:00-18:00 h. Following then, serum PRL levels were decreased. Naloxone was effective in suppressing the charaderistic afternoon surge of PRL from 16:00 h to 20:00 h. These data clearly showed that alterations in PRL mRNA levels were conversely correlated with changes mn serum PRL levels on proestrus, indicating a differential regulation of PRL gene expression and secretion.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.128-137
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• 2015

Going through rapid changes, the field of information technology (IT) has launched many innovative products. Some of those products have spread, forming a stable market, whereas others have disappeared. The purpose of the study is to purpose a theoretical model to show changes in the importance of competition factors over the three stages. Our study applied the innovation adoption stage model of the Innovation Diffusion Theory (IDT) to the industry life cycle of the Industry Life Cycle (ILC) Theory resulting in three stage of introduction, growth, and maturity, and defined a model of market characteristics according to time. By using the model, we analyzed the case of notebook computers and tablet and checked the fitness of the model. Results show that five competition factors worked differently according to time. In the introduction stage, relative functionality and relative playfulness are important competition factors. In the growth stage, compatibility is added to those two factors. In the last maturity stage, compatibility, complexity, and cost level are important competition factors.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.494-500
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• 2006

Life Cycle Assessment(LCA) is an environmental assessment tool for evaluating environmental burdens associated with products, processes and activities from the raw material acquisition stage to the end-of-life stage. End-of-life stage as well as other processes requires a reliant database in order to increase the confidence in the LCA results. In this study, the flow of Personal Computer(as PC) in the end-of-life stage was examined and the database of two scenarios has been established, i.e. one is part reuse and the other is no part reuse, in the end-of-life phase of PC. Also, key environmental issues were identified by carrying out LCA on a PC in the end-of-life phase for eight environmental impact categories. The 'ozone layer depletion' contributes the highest environmental impact due to generation of $Cl_2$ gas during the incineration of waste plastics. In addition, the scenario 1(part reuse) is more environmentally sound than the scenario 2(no part reuse) when comparing two scenarios.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.56-66
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• 2013

Weight reduction of the VTHL / TSTO type of the reusable launch vehicles using RBCC engines are investigated. To predict weight and thrust of the vehicles, equations of motion are analyzed. Analysis results are compared with specifications of existing launch vehicles for validations. For the mission of inserting 2.5 ton payload to 200 km circular orbit, the case A, which uses the RBCC engine in the 1st stage shows smaller weight than the case B, which uses the RBCC engine in the 2nd stage. The weight of the case A shows only 25.8% of a existing rocket launch vehicle's weight.

• Journal of radiological science and technology
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• v.3 no.1
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• pp.107-113
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• 1980

The concentration of total protein during the metamorphosis of the Indian meal moth, Plodia interpunctella $H\ddot{u}bner$ was measured using micro-Kjeldahl method by Oser(1965). Healthy specimens were chosen as samples at each developmental stages: the 1st instar larva, the 3rd inster larva, final instar larva, pupae 2, 6, 10 days and the adult 1 day. The total protein concentration decreased gradually until the two day pupal stage and increased at the six day pupal stage. In the one day dault stage, the concentration reached a maximum. In conclusion, changes of total protein concentation through the course of the physiological cycle form a U-shaped curve when graphed against the histolysis of larval organs and the histogenesis of adult organs. In view of controlling pest, the U-shaped pattern of physiological activity indicates that control will be the most effective at the time of the most physiological weakness manifested at the two day pupal stage.

• Molecules and Cells
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• v.20 no.1
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• pp.136-141
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• 2005

Mild stresses such as high temperature ($30^{\circ}C$) or a low $H_2O_2$ concentration induced transient cell cycle arrest at G1/S or G2/M depending on the cell cycle stage at which the stress was applied. When stresses were introduced during G0 or G1, the G1/S checkpoint was mainly used; when stresses were introduced after S phase, G2/M was the primary checkpoint. The slowing of cell cycle progression was associated with transient delays in expression of A-, B-, and D-type cyclins. The delay in expression of NtcycA13, one of the A-type cyclins, was most pronounced. The levels of expression of Ntcyc29 (a cyclin B gene) and of CycD3-1 differed most depending on the applied stress, suggesting that different cellular adjustments to mild heat and a low concentration of $H_2O_2$ are reflected in the expression of these two cyclins.

• Progress in Superconductivity and Cryogenics
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• v.15 no.2
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• pp.1-8
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• 2013

This paper reviews the development status of magnetic refrigeration system for hydrogen liquefaction. There is no doubt that hydrogen is one of most important energy sources in the near future. In particular, liquid hydrogen can be utilized for infrastructure construction consisting of storage and transportation. Liquid hydrogen is in cryogenic temperatures and therefore high efficient liquefaction method must be studied. Magnetic refrigeration which uses the magneto-caloric effect has potential to realize not only the higher liquefaction efficiency > 50 %, but also to be environmentally friendly and cost effective. Our hydrogen magnetic refrigeration system consists of Carnot cycle for liquefaction stage and AMR (active magnetic regenerator) cycle for precooling stages. For the Carnot cycle, we develop the high efficient system > 80 % liquefaction efficiency by using the heat pipe. For the AMR cycle, we studied two kinds of displacer systems, which transferred the working fluid. We confirmed the AMR effect with the cooling temperature span of 12 K for 1.8 T of the magnetic field and 6 second of the cycle. By using the simulation, we estimate the total efficiency of the hydrogen liquefaction plant for 10 kg/day. A FOM of 0.47 is obtained in the magnetic refrigeration system operation temperature between 20 K and 77 K including LN2 work input.

• Journal of Chest Surgery
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• v.25 no.9
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• pp.962-967
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• 1992

Eight patients with proven clinical stage Ill lung carcinoma of which six were epidermoid cell carcinoma and two were small cell carcinoma underwent concomitant radiation therapy and chemotherapy before surgical resection from March 1990 to February 1992 at the thoracic surgical department, Yongdong Severance Hospital, Yonsei University College Medicine The therapy consisted of more than one cycle of chemotherapy every 4 weeks and concomitant irradiation. Three to four weeks after chemotherapy and radiation therapy, the patient were reevaluated for thoracotomy and pulmonary resection. Two patients were found to have unresectable lesions and, radiosotopes were implanted to the remaining tumors. Three patients had complete pneumonectomies and two patients had pericardial penumonectomyo. Only one patient had complete pneumonectomy & concomitant resection of ribs attached to tumors with reconstruction of chest wall with Marlex mesh. Complete sterilization of lung tumor and mediastinal nodes proven histologically was achieved in 2 patients, without operative mortality. The median survival of all patients was eight months, but the median survival of survivors which lung tumor were completely resected completely and whose pathologic reports showed stage I or 0, was about 18 months to now. The overall result indicates some benefit from this preoperative chemotherapy and radiation therapeutic regimen in patients with advanced unresectable lung cancer.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.626-632
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• 2015

The International Maritime Organization (IMO) has adopted several regulations for the prevention of air pollution from ships. In addition, there is a requirement for shipping liners to reduce greenhouse gas emissions. Accordingly, we need to take measurements to ensure that the steps taken are both efficient and environmentally friendly. It has been determined that the application of the Miller cycle in diesel engines has the effect of both reducing the amount of NOx and improving thermal efficiency. However, this method requires a considerably larger charge air pressure. Therefore, we consider a two-stage turbo-charging system, which not only results in a high charging pressure, but also improves the part load performance with an exhaust-gas bypass system or the application of the Miller cycle. Because of complications associated with the two-stage turbo-charging system, it is complex and difficult to realize a design that optimizes matching between diesel engine and turbo-chargers. Accordingly, it is necessary to perform a quantitative analysis to determine the effects and optimal conditions of these different systems in the early stage of system design. In this paper, we develop a simulation program to model these systems, and we verify that the results of this program are reliable. Further, we discuss methods that can be employed to improve its efficiency.