• 제목/요약/키워드: Heat retention

검색결과 255건 처리시간 0.047초

십종요통(十種腰痛) 중 식적(食積).습열(濕熱) 요통(腰痛)의 증례보고 (A Case Report of Lumbago due to Retention of Undigested Food(食積) and Damp-heat(濕熱) in Ten Kinds of Lumbago)

  • 박민제;김정욱;황민섭;윤종화;성수민
    • Journal of Acupuncture Research
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    • 제22권4호
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    • pp.143-153
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    • 2005
  • What we want to report is the oriental medical treatment of eleven patients with lumbago. The patients had several features in common. First, the source of the lumbago was related to overdrinking or overeating, which is something like food damage(食傷) in oriental medicine. Second, they had symptoms of digestive trouble as well as lower back pain. Third, the R.O.M of lumbar spine was limited but there was no another special abnormality in physical examination. Fourth, singly they had muscular tenderness of Iliopsoas muscle and symptoms by Myofascial pain of Iliopsoas muscle was appeared. We assumed this sort of lumbago to be one due to retention of undigested food(食積) or damp-heat(濕熱) in oriental medicine, similar to Myofascial pain syndrome of Iliopsoas muscle in western counterpart. Acupuncture treatment was done to improve the digestive trobles according to oriental medical theory, and we saw the improvement in VAS score of lower back pain, degree of lumbar flexion, Iliopsoas muscle's tenderness and also digestive trobles. But an objective researches on the relation of lumbago due to retention of undigested food(食積) or damp-heat(濕熱) and myofascial pain syndrome of Iliopsoas muscle are quite lacking. However we think such a clinical approach could be useful in practices of oriental medicine increase in curative effect.

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Sensitivity Studies on Thermal Margin of Reactor Vessel Lower Head During a Core Melt Accident

  • Kim, Chan-Soo;Kune Y. Suh
    • Nuclear Engineering and Technology
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    • 제32권4호
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    • pp.379-394
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    • 2000
  • As an in-vessel retention (IVR) design concept in coping with a severe accident in the nuclear power plant during which time a considerable amount of core material may melt, external cooling of the reactor vessel has been suggested to protect the lower head from overheating due to relocated material from the core. The efficiency of the ex-vessel management may be estimated by the thermal margin defined as the ratio of the critical heat flux (CHF)to the actual heat flux from the reactor vessel. Principal factors affecting the thermal margin calculation are the amount of heat to be transferred downward from the molten pool, variation of heat flux with the angular position, and the amount of removable heat by external cooling In this paper a thorough literature survey is made and relevant models and correlations are critically reviewed and applied in terms of their capabilities and uncertainties in estimating the thermal margin to potential failure of the vessel on account of the CHF Results of the thermal margin calculation are statistically treated and the associated uncertainties are quantitatively evaluated to shed light on the issues requiring further attention and study in the near term. Our results indicated a higher thermal margin at the bottom than at the top of the vessel accounting for the natural convection within the hemispherical molten debris pool in the lower plenum. The information obtained from this study will serve as the backbone in identifying the maximum heat removal capability and limitations of the IVR technology called the Cerium Attack Syndrome Immunization Structures (COASISO) being developed for next generation reactors.

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Computational Study of the Mixed Cooling Effects on the In-Vessel Retention of a Molten Pool in a Nuclear Reactor

  • Kim, Byung-Seok;Ahn, Kwang-Il;Sohn, Chang-Hyun
    • Journal of Mechanical Science and Technology
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    • 제18권6호
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    • pp.990-1001
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    • 2004
  • The retention of a molten pool vessel cooled by internal vessel reflooding and/or external vessel reactor cavity flooding has been considered as one of severe accident management strategies. The present numerical study investigates the effect of both internal and external vessel mixed cooling on an internally heated molten pool. The molten pool is confined in a hemispherical vessel with reference to the thermal behavior of the vessel wall. In this study, our numerical model used a scaled-down reactor vessel of a KSNP (Korea Standard Nuclear Power) reactor design of 1000 MWe (a Pressurized Water Reactor with a large and dry containment). Well-known temperature-dependent boiling heat transfer curves are applied to the internal and external vessel cooling boundaries. Radiative heat transfer has been considered in the case of dry internal vessel boundary condition. Computational results show that the external cooling vessel boundary conditions have better effectiveness than internal vessel cooling in the retention of the melt pool vessel failure.

Two- and three-dimensional experiments for oxide pool in in-vessel retention of core melts

  • Kim, Su-Hyeon;Park, Hae-Kyun;Chung, Bum-Jin
    • Nuclear Engineering and Technology
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    • 제49권7호
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    • pp.1405-1413
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    • 2017
  • To investigate the heat loads imposed on a reactor vessel through the natural convection of core melts in severe accidents, mass transfer experiments were performed based on the heat transfer/mass transfer analogy, using two- (2-D) and three-dimensional (3-D) facilities of various heights. The modified Rayleigh numbers ranged from $10^{12}$ to $10^{15}$, with a fixed Prandtl number of 2,014. The measured Nusselt numbers showed a trend similar to those of existing studies, but the absolute values showed discrepancies owing to the high Prandtl number of this system. The measured angle-dependent Nusselt numbers were analyzed for 2-D and 3-D geometries, and a multiplier was developed that enables the extrapolation of 2-D data into 3-D data. The definition of $Ra^{\prime}_H$ was specified for 2-D geometries, so that results could be extrapolated for 3-D geometries; also, heat transfer correlations were developed.

淸肌散加減을 응용한 한포진 환자 치험 1례 (A Clinical Study about the Effect of Chunggisangagam on a Dyshidrotic Eczema Patient.)

  • 심상희;정동환;김종한;최정화;박수연
    • 한방안이비인후피부과학회지
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    • 제16권3호
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    • pp.268-273
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    • 2003
  • Dyshidrotic eczema is a eczema making vesicles at the hand and foot with pruritus, tend to chronically recurred. It is caused to retention of Damp-heat in interior(濕熱蘊積), interior heat due to Yin deficiency(陰虛內熱) in Oriental medicine. We treated a patient who suffered from recurred dyshidrotic eczema differentiated with retention of Damp-heat in interior(濕熱蘊積) with Chunggisangagam(淸肌散加減). After about 30 days of treatment with Chunggisangagam(淸肌散加減), acupunture and aroma therapy, we observed an improvement. Based on this experience, it is considered that the Oriental medicine can be applied to the treatment of dyshidrotic eczema.

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Thermodynamic Study of Sequential Chlorination for Spent Fuel Partitioning

  • Jinmok Hur;Yung-Zun Cho;Chang Hwa Lee
    • 방사성폐기물학회지
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    • 제21권3호
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    • pp.397-410
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    • 2023
  • This study examined the efficacy of various chlorinating agents in partitioning light water reactor spent fuel, with the aim of optimizing the chlorination process. Through thermodynamic equilibrium calculations, we assessed the outcomes of employing MgCl2, NH4Cl, and Cl2 as chlorinating agents. A comparison was drawn between using a single agent and a sequential approach involving all three agents (MgCl2, NH4Cl, and Cl2). Following heat treatment, the utilization of MgCl2 as the sole chlorinating agent resulted in a moderate separation. Specifically, this method yielded a solid separation with 96.9% mass retention, 31.7% radioactivity, and 44.2% decay heat, relative to the initial spent fuel. In contrast, the sequential application of the chlorinating agents following heat treatment led to a final solid separation characterized by 93.1% mass retention, 5.1% radioactivity, and 15.4% decay heat, relative to the original spent fuel. The findings underscore the potential effectiveness of a sequential chlorination strategy for partitioning spent fuel. This approach holds promise as a standalone technique or as a complementary process alongside other partitioning processes such as pyroprocessing. Overall, our findings contribute to the advancement of spent fuel management strategies.

에탄올에 의한 TMA- 포접화합물의 과냉각 개선에 대한 연구 (A Study on the Supercooling Improvement of TMA -Clathrate Compound by Ethanol)

  • 김진흥;정낙규;김창오
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2005년도 동계학술발표대회 논문집
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    • pp.392-397
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    • 2005
  • This study is investigated the supercooling improvement and the phase change temperature of the TMA clathrate compound including TMA(Tri-Methyl-Amine, ($(CH_3)_3N$) of 25 wt% with additive as a low temperature storage material at $6^{\circ}C$ and $-7^{\circ}C$ of heat source. The additive is ethanol of 0.1, 0.3 wt% and 0.5 wt%. The results showed that as the concentration of ethanol is increased, the phase change temperature, the degree of supercooling and the retention time of liquid phase are decreased. Especially, TMA 25 wt% clathrate compound with ethanol of 0.5wt% has the average of phase change temperature of $3.8^{\circ}C$, degree of supercooling of $0.9^{\circ}C$, $0.8^{\circ}C$ and retention time of liquid phase for 6, 5 minutes at $-6^{\circ}C$, $-7^{\circ}C$ of heat source. From the results of this study, TMA 25wt% clathrate compound with ethanol 0.5wt% showed supercooling repression effect.

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의치상의 종류에 따른 상악 의치상의 유지력에 관한 임상적 연구 (A CLINICAL STUDY ON THE RETENTION OF MAXILLARY COMPLETE DENTURE WITH DIFFERENT DENTURE BASE MATERIALS)

  • 이종혁;임주환;조인호
    • 대한치과보철학회지
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    • 제39권1호
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    • pp.58-70
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    • 2001
  • For the successful treatment of complete denture, obtaining a good retention is essential. There are lots of factors affecting denture retention. Denture material, one of those factors affecting denture retention, was the subject of this study, and internal surface treatment also considered for the method of enhancing denture retention. Two resin(Lucitone $199^{(R)}$(heat cured resin) Vertex $CP^{(R)}$(self cured resin)) and two metal($Biosil^{(R)}$(Co-Cr alloy), $Vitallium^{(R)}$(Co-Cr alloy)) denture base materials were used for making test denture base. Newly developed device was used for measuring denture retention. After the retention was measured. We treated internal surface of test denture base with $50{\mu}m\;Al_2O_3$ powder, under 90psi, for 1 minute. Then the retention was measured again. The result was analyzed with K-S test, one-way ANOVA test and independent t-test to deter mine the significant differences as the 95% level of confidence. The results are as follows : In cases of without internal surface treatment, the retention was increased in order of $Vitallium^{(R)},\;Biosil^{(R)},\;Vertex CP^{(R)}$ and Lucitone $199^{(R)}$. Except between Vertex $CP^{(R)}$ and $Biosil^{(R)}$, retention of the other materials was significantly different (p<0.05). After the treatment of internal surface, the retention was increased in order of $Vitallium^{(R)},\;Biosil^{(R)},\;Lucno\;199^{(R)},\;Vertex\;CP^{(R)}$. Except between Lucitone $199^{(R)}$ and Vertex $CP^{(R)}$, $Vitallium^{(R)}$ and $Biosil^{(R)}$ the retention of remaining groups was significantly different each other (p<0.05). In the matter of each material, after the internal surface treatment the retention was increased with Vertex $CP^{(R)},\;Biosil^{(R)}\;and\;Vitallium^{(R)}$ and the value of differences were statistically significant. When we compare the retention of resin and metal denture base, the retention of both denture bases increased significantly with internal surface treatment, and resin denture base showed better retention. As the results show, selecting denture base material could be an important choice of complete denture treatment. To increase denture retention, internal surface treatment can be considered as a possible method.

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고기능성 침낭형 온수매트 제작 (The Production of High Functional Hot Mat with Sleeping Type)

  • 이상헌;강정욱;원우연
    • 한국전기전자재료학회논문지
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    • 제28권6호
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    • pp.400-402
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    • 2015
  • The typical winter heating unit heating mat. The product is to be found in the development of new water heating mat today. The product that circulates the water through the hose inside the mat with your existing heating mat electric heated mat is different from boiling water. However, no clear standards for noise and safety, consumer choice is giving confusing information about the product is low. We were to develop a high heat retention and stability than conventional sleeping mats to produce creative than traditional hot mats, heated mats general comparison with experimental results is a more efficient heat retention mat is produced.

Comparisons of 2-D and 3-D IVR experiments for oxide layer in the three-layer configuration

  • Bae, Ji-Won;Chung, Bum-Jin
    • Nuclear Engineering and Technology
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    • 제52권11호
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    • pp.2499-2510
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    • 2020
  • We performed 3-D (3-dimensional) IVR (In-Vessel Retention) natural convection experiments simulating the oxide layer in the three-layer configuration, varying the aspect ratio (H/R). Mass transfer experiment was conducted based on the analogy to achieve high RaH's of 1.99 × 1012-6.90 × 1013 with compact facilities. Comparisons with 2-D (2-dimensional) experiments revealed different local heat transfer characteristics on upper and lower boundaries of the oxide layer depending on the H/R. For the 3-D shallow oxide layer, the multi-cell flow patterns appeared and the number of cells was considerably increased with the H/R decreases, which differs with the 2-D experiments that the number of cells was independent on H/R. Thus, the enhancement of the downward heat transfer and the mitigation of the focusing effect were more noticeable in the 3-D experiments.