• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.12
• /
• pp.983-990
• /
• 2014

This research focused on designing an appropriate thermocouple sensor for a thermal boundary layer with a large temperature gradient. It was designed to minimize the conduction error from a constant temperature wall in a boundary layer. A $79.9-{\mu}m$ thermocouple was chosen, and a five-axis device jig was developed to fabricate a butt-welded thermocouple, which is different from arc-welded junction thermocouples. This was used to minimize the size of the thermocouple junction. In addition to fabricating butt-welded thermocouples, a thorough calibration was conducted to decrease the internal error of a multimeter to ensure that the data from the butt-welded and regular thermocouples were almost the same. Based on this method, a butt-welded thermocouple with a small junction was found to be suitable for measuring the temperature in a thermal boundary layer with very large thermal gradients. Using this thermal boundary layer probe, the thermal boundary layers in a turbine cascade were measured, and the Nusselt numbers were obtained for the turbine endwall.

• Parasites, Hosts and Diseases
• /
• v.34 no.4
• /
• pp.267-278
• /
• 1996

A clinical case of CheMletietlo infestation on a dog born and raised in Korea is reported. A three-year old female Whippet was hospitalized due to a multiple fracture and displacement of the left scapula caused by a recent car accident The mite infestation was not noticed at the time of hospitalization. The dog underwent multiple operations involving internal fixation of the fractured scapula with wire and a plate, followed by extensive chemotherapy with antibiotics and prednisolone. After two months of hospitalization. a pruritic dermatitis near the left scapula developed. Multiple white dandruff-like ilakes were seen on the hair coat. especially over the dorsal spine and neck, and the dog expressed increased pruritus by frequently licking and scratching the affected areas. Local dense accumulations of skin debris that became crusty were also observed. Microscopic examination or a skin scraping revealed a heavy infestation of cheyletiella vnsfuri. as idrntified by the prrsrnce of holes of the palpi and the heart-shaped sensory organ on menu I. Immnosuppression elicited by the extensive administration of prednisolone was suspected for the initiation of the generalized mite infestation.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.3
• /
• pp.179-184
• /
• 2015

In this study, the flap fatigue test of a 48 m long wind turbine blade was performed for 1 million cycles to evaluate the characteristics of acoustic emission signals generated from fatigue damage of the wind blades. As the number of hits and total energy continued to increase during the first 0.6 million cycles, blade damage was constant. The rise-time result showed that the major aspects of damage were initiation and propagation of matrix cracks. In addition, the signal analysis of each channel showed that the most seriously damaged sections were the joint between the skin and spar, 20 m from the connection, and the spot of actual damage was observable by visual inspection. It turned out that the event source location was related to the change in each channel's total energy. It is expected that these findings will be useful for the optimal design of wind turbine blades.

• Journal of Korean Society of Steel Construction
• /
• v.9 no.2 s.31
• /
• pp.237-248
• /
• 1997

Three types of fatigue cracks frequently observed in the crane runway girders are verified experimentally using two testing-purpose girders with the size of $6400{\times}600{\times}300$ in millimeters. The fatigue cracks are observed in the vicinity of load-bearing points, at the end of gusset plates and at the fillet welded joints between the lower flange and the web. The load-bearing-point cracks are initiated at the intersection of the fillet welds between the upper flange and the web, where the vertical stiffener is located. The cracks grow up toward the diagonal direction of the web. The cracks observed at the fillet welded joints grow up perpendicularly to the crane runway girder. Compared with the JSSC fatigue design code, the joint class is classified as follows: E for the vicinity of load-bearing points, G or H for the end of gusset plates and D for the lower fillet welded joints. The tests reveal that the class of joint classification at the end of gusset plates and at the lower flange coincides with the fatigue design code.

• Tuberculosis and Respiratory Diseases
• /
• v.44 no.3
• /
• pp.534-546
• /
• 1997

Background : The p53 and retinoblastoma(Rb) tumor suppressor genes are associated with the pathogenesis of several types of human cancer. Substantial proportion of the primary lung cancers or cell lines have been reported to have the p53 and/or the Rb gene mutations. But, so far there is no report on the analysis of the Rb gene polymorphism as one of the genetic susceptibility marker. This study was undertaken to establish the gene frequencies of the polymorphic genotypes of the p53 and Rb genes in Koreans to evaluate the possible involvement of these genotypes as a risk factor of lung cancer. Methods : In this study 145 controls without previous and present tumor history and 128 lung cancer patients were subjected to analysis. The two intragenic polymorphisms of the p53 gene(exon 4/ AccII, intron 6/MspI) and one intron 17/XbaI polymorphism of the Rb gene were analysed by the method of polymersae chain reaction- restriction fragment length polymorphisms(PCR-RFLPs). The genotype of the intron 3/16 bp repeat polymorphism of p53 was determined by PCR and direct gel electrophoresis. Results : There were no significant differences in the genotype distributions of the p53 gene between lung cancer patients and controls. But heterozygotes(Arg/Pro) of the exon 4/AccII polymorphisms were slightly over-represented than controls, especially in the Kreyberg type I cancer, which was known to be associated with smoking. The intron 3/16 bp duplication and the intron 6/MspI polymorphisms were in complete linkage disequilibrium. About 95% of the individuals were homozygotes of the common alleles both in the 16 duplication and MspI polymorphisms, and no differences were deteced in the genotype distributions between lung cancer patients and controls. Overall genotype distributions of the Rb gene polymorphisms between lung cancer patients and controls were not significantly different However, the genotype distributions in the Kreyberg type I cancer were significantly different from those of controls(p = 0.0297) or adenocarcinomas(p = 0.0008). It was noticeable that 73.4% of the patients with adenocarcinomas were heterozygotes(r1/r2) whereas 39.2% of the Kreyberg type I cancer were heterozygous at this polymorphisms. In the lung cancer patients, significant differences were also noted between the high dose smokers and low dose smokers including non-smokers(p = 0.0258). The relative risk to Kreyberg type I cancer was significantly reduced in the individuals with the genotype of r1/r2(odds ratio = 0.46, 95% C.I. = 0.25-0.86, p = 0.0124). The combined genotype distribution of the exon 4 AccII of the p53 and the intron 17 Rb gene polymorphisms in Kreyberg type I cancers were significantly different from dose of controls or adenocarcinomas. The highest odds ratio were observed in the individuals with the genotypes of Arg/Pro and r2/r2(odds ratio = 1.97,95% C.I. = 0.84-4.59) and lowest one was in the patients with Arg/Arg, r1/r2 genotype(odds ratio = 0.54, 95% C.I. = 0.25-1.14). Conclusion : The p53 and the Rb gene polymorphisms modulate the risk of smoking induced lung cancer development in Koeans. However, the exact mechanism of risk modulation by these polymorphism remains to be determined. For more discrete clarification of associations between specific genotypes and lung cancer risk, the evaluations of these polymorphisms in other ethnics and more number of patients will be needed.

• Journal of the Korean Society of Radiology
• /
• v.10 no.1
• /
• pp.21-28
• /
• 2016

This study tries to evaluate the usefulness CSI treatment. Compare the standard technique and simple technique, using the volume region of a high dose of Field joints (hot spot) or low dose regions (cold Spot). In patients who agreed to this study, obtain CT image using CT simulator skull to pelvis region. Standard Technique were performed on the movement of the joint radiation field range and simple technique has set a treatment plan to secure the radiation field range and analyzed treatment planning. Under analysis standard technique occurred the area of the high dose(Hot Spot) for the area overlapping the field and simple technique showing a uniform doses. CI indices of standard technique and simple technique was 1.6~3, 1.6~1.87, CN indices was 0.32~0.53, 0.46~0.51 and HI indices was 0.11~0.33, 0.2~0.26. Therefore, adjacent to part of the dose distribution junction more equally than simple technique compared to the Standard Technique. Compare the dose distribution patterns using CI, CN, HI indices, showed a uniform dose distribution in the simple technique. so, simple technique was determined appropriate treatment the CSI.

• Journal of Conservation Science
• /
• v.26 no.4
• /
• pp.371-376
• /
• 2010

The great jar estimated in Proto-Three Kingdoms period was found at the site from Pyeongtaek Daechuri and the bonding traces from pieces destroyed when they were excavated are observed. Therefore this study would figure out the components of bonding material used in great jars by optical microscope, FT-IR, py-GC/MS and the kind of textile attaching to great jar by transmitted light microscope. As a result of optical microscope for the cross-section, black material is uniformly applied between a piece of jar and the part of bonding and the textile line are observed. Black bonding material is resulted in korean rhus lacquer by FT-IR and py-GC/MS and the kind of textile is identified as hemp by transmitted light microscope. Materials for repairing archaeological objects are hardly known causing little information, but this study proves that the bonding material had used lacquer for great jars before Proto-Three Kingdoms period. Therefore if ancient bonding materials are systematically analysed in the further studies, it would be significant help for studying bonding and restoration materials of ancient objects.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.10
• /
• pp.379-385
• /
• 2020

This paper presents a design for preventing coolant leaks in the core part of a heater mounted in a combat vehicle. The heater is a device that makes heated coolant flow through the heater core in the crew room. A problem with coolant leaks in the heater core area during the operation of a combat vehicle was identified. This problem is caused mainly by high pressure at the junction of the tank and tube due to the vulnerability of this area. To solve this problem, an improved core was made by improving the welding method and changing the end region of the heater core to a structure that can withstand high pressure. When pressure was applied sequentially to the existing core and improved core, a leak occurred at 7.0 kgf/㎠ in the existing core while the improved core maintained its structure up to 17.0 kgf/㎠, highlighting the improvement. Finally, performance tests and environment tests were conducted to demonstrate the suitability of the improved structure. The improved heater will be applied to combat vehicles. This paper is expected to serve as a reference for improving defense capabilities by securing reliability as well as the design and analysis of failures of similar equipment.nse capabilities through securing reliability as well as the design and analysis of failures of similar equipment.

• The Journal of Korean Society for Radiation Therapy
• /
• v.33
• /
• pp.9-14
• /
• 2021

This study examined dose change depending on the reposition error of the junction at the time of treatment with multi-isocenter volumetric modulated arc therapy. This study selected a random treatment region in the Arccheck Phantom and established the treatment plan for multi-isocenter volumetric modulated arc therapy. Then, after setting the error of the junction at 0 ~ 4 mm in the X (left), Y (upper), and Z (inner and outer) directions, the area was irradiated using a linear accelerator; the point doses and gamma indexes obtained through the Phantom were subsequently analyzed. It was found that when errors of 2 and 4 mm took place in the X and Y directions, the gamma pass rates (point doses) were 99.3% (2.085) and 98% (2.079 Gy) in the former direction and 98.5% (2.088) and 95.5% (2.093 Gy) in the latter direction, respectively. In addition, when errors of 1, 2, and 4 mm occurred in the inner and outer parts of the Z direction, the gamma pass rates (point doses) were found to be 94.8% (2.131), 82.6% (2.164), and 72.8% (2.22 Gy) in the former part and 93.4% (2.069), 90.6% (2.047), and 79.7% (1.962 Gy) in the latter part, respectively. In the X and Y directions, errors up to 4 mm were tolerable; however, in the Z direction, error values exceeding 1 mm were beyond the tolerance level. This suggests that for high and low dose areas, errors in the direction same as the progress direction in the treatment region have a more sensitive dose distribution. If the guidelines for set-up errors are established at the institutional level through continuous research in the future, it will be possible to provide good quality treatment using junctions.

• Journal of Welding and Joining
• /
• v.13 no.2
• /
• pp.1-11
• /
• 1995

고온설비에 사용되고 있는 고온재료의 재료특성 변화와 이의 평가방법에 대하여 극히 제한된 범 위에서 개략적으로 기술하였다. 이러한 고온설비의 재질열화에 대한 대책은 초임계압 화력발 전설비 등을 비교적 조기에 도입한 선진국은 물론 최근 발전설비의 보일러 및 터빈을 비롯하여 석유화학 설비의 압력용기 등과 같이 고온.고압 하에서 장시간의 운전이력을 갖는 고온기기의 수가 증가하는 상태에 있는 우리나라에 있어서도 이들 설비의 정확한 수명진단과 장수명화 기 술의 개발은 시급히 해결해야할 과제로 되고 있다. 또 이러한 문제들은 대부분 용접 부위가 문제점으로 제시되고 있다. 따라서 이를 원활히 해결하고 확실한 진단과 잔여수명예측에 대한 기술의 개발을 위해서는 산.학.연의 공동연구를 통하여 종합적이고 체계적인 연구가 절실하게 요구되며, 상호 습득하고 있는 정보교환도 중요하다.