• Corrosion Science and Technology
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• v.2 no.4
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• pp.197-201
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• 2003

In this study, Ni-P layers were electroplated on the surface of stainless steel in order to investigate the effects of an additive and agitation on their mechanical properties and microstructure. The concentration of the additive in the plating solution increased, the pores formed in the layer decreased, while the residual stress developed in the layers during electroplating increased. Agitation of the solution during electroplating was observed to force to increase local pores in the layer, which lowers its tensile properties. Grain growth was suppressed due to very fine $Ni_3P$ precipitates formed at its grain boundaries during heat treatment at $343^{\circ}C$ for 1 hr in air.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.179-182
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• 1998

It is widely recognized that conventional means for determining the minimum ignition energy(MIE) of powder are time-consuming and require operational skill. As a variety of new fine powders are being produced day by day in industry, there is an urgent need to a quicker and more economical means to measure MIE. To meet this requirement, we have developed a measurement system which employs a novel method to create an air/dust mixture in a miniature combustion box. In this system, the powder to be tested input into a hopper made of metal mesh, and successively fed downward to form a thin, curtain-like dust/air mixture by vibration. With this new apparatus, three type of powders -Lycopodium, Anthraquinone, and Polyacrylonitrile-were tested and the MIE data were compared with those taken with a conventional apparatus(the Hartmann tube). Two of them agreed satisfactory, but the other, anthraquinone, showed quite different values supposedly due to the agglomeration of the powder particles by static-charge.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.250-252
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• 2005

T/P92 steels are created for using USC boiler tube and header in next generation power plant. SP-Creep test and tensile creep test are performed to characterize creep for local structures of T/P92 steel weldment. The results are shown that P92 steel weldment is clearly superior than that of X20CrMoV121 steel weldment, which is widely used in supercritical power Plant. while fine gram HAZ is most weakest in X20 steel weldment, coarse grain HAZ is most weakest in P92.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.4
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• pp.576-581
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• 2010

As a super high speed small-sized centrifugal separator which is operated by the center inputting method has solved two difficulty problems, it can be made use of developing the new composition through the making of Nano particle (50~100nm) by high speed revolution and alleviation of unbalanced shapes inside the disk continuously throwing slurry in the central part. Uses the air spindle and the centrifugal machine production will be able to manufacture the Roh class fine particle under boil.

• Journal of the Korean institute of surface engineering
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• v.34 no.4
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• pp.289-296
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• 2001

Ni-P electroformed layers were investigated for developing a steam generator tube repair technology in PWRs. The effects of an additive, RPP (Reagent over Pitting Protection) and agitation on mechanical properties and microstructure of the layer were evaluated. The addition of the RPP showed to inhibit the formation of pores, to refine the grain size, and to increase the residual stress in the layer. However, the agitation of the solution during electroforming was observed to increase pores in local regions of the electroformed layer, resulting in decreasing its mechanical properties. The heat treatment of the layer at $343^{\circ}C$ for 1 hr. precipitated the very fine particles of Ni3P in the layer, which inhibited grain growth and increased microhardness.

• Journal of Veterinary Clinics
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• v.40 no.2
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• pp.124-129
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• 2023

A 5-year-old neutered male domestic short-haired cat presented with acute dyspnea characterized by open-mouth breathing and stridor for 2 days. Direct visualization via laryngoscopy revealed diffuse laryngeal swelling and severe thickening of the vocal folds bilaterally; thus, the upper respiratory tract was obstructed owing to severe edema. Neutrophil infiltration was found on fine needle aspiration of the larynx cytology, and no discrete mass with polyp or neoplasia was identified on diagnostic imaging. The cat was diagnosed with acute obstructive laryngitis, and a tracheostomy tube was immediately installed. After 17 days of treatment with steroids, doxycycline and azithromycin, the swollen larynx gradually improved, and there was no recurrence of laryngitis or respiratory obstruction. A feline upper respiratory polymerase chain reaction panel revealed Mycoplasma felis infection; however, it could not be determined whether it was pathogenic or opportunistic. Herein, we report a case of obstructive laryngitis in a cat. When respiratory obstruction due to acute laryngitis is identified, a good prognosis is expected with rapid and appropriate treatment.

• Journal of the Korean Ceramic Society
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• v.50 no.2
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• pp.122-126
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• 2013

The surface roughness of the inner and outer surfaces of a tube is an important requirement for nuclear fuel cladding. When an inner SiC clad tube, which is considered as an advanced Pressurized Water Cooled Reactor (PWR) clad with a three-layered structure, is fabricated by Chemical Vapor Deposition (CVD), the surface roughness of the substrate, graphite, is an important process parameter. The surface character of the graphite substrate could directly affect the roughness of the inner surface of SiC deposits, which is in contact with a substrate. To evaluate the effects of the surface roughness changes of a substrate, SiC deposits were fabricated using different types of graphite substrates prepared by the following four polishing paths and heat-treatment for purification: (1) polishing with #220 abrasive paper (PP) without heat treatment (HT), (2) polishing with #220 PP with HT, (3) #2400 PP without HT, (4) polishing with #2400 PP with HT. The average surface roughnesses (Ra) of each deposited SiC layer are 4.273, 6.599, 3.069, and $6.401{\mu}m$, respectively. In the low pressure SiC CVD process with a graphite substrate, the removal of graphite particles on the graphite surface during the purification and the temperature increasing process for CVD seemed to affect the surface roughness of SiC deposits. For the lower surface roughness of the as-deposited interlayer of SiC on the graphite substrate, the fine controlled processing with the completed removal of rough scratches and cleaning at each polishing and heat treating step was important.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.191-191
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• 1999

Extended X-ray Absorption Fine Structure (EXAFS)는 일반적으로 널리 사용하는 X선 회절분광기로 분석하기 힘든 chemical 또는 biological system의 structural analyses에 매우 유용한 분석방법이다. 특히 세라믹이나 유전체 비정질 재료의 미세 원자 구조에 관한 정보를 얻는데는 가장 강력한 분석방법중의 하나로 알려져 있다. 현재까지 대부분의 EXAFS 실험은 방사광 가속기를 이용하여 수행하였다. 그런데 신제품 개발의 순환주기가 급속하게 단축되는 현실적인 문제에 부응하기 위하여 실험실에서 EXAFS 실험을 수행할 수 있는 system을 개발하게 되었다. 개발한 XIEES 장비는 rotating anode 형의 18kW X-ray source, Optical system, Detection system, Stepping motor control system, vacuum system, Utility 등으로 구성하였다. Optical system에서의 6개의 Johanson type monochromator를 사용하여 분석가능한 x-ray energy range를 480eV에서 41keV까지 구현하였다. 이는 산소에서 우라늄까지 분석이 가능함을 의미하는 것으로, 산화물 연구에 많이 활용할 것으로 기대한다. XIEES는 투과 및 형광 X-ray를 검출할 수 있는 기능과 X-ray에 의해 여기 되는 모든(광전자, Aiger 전자, 이차전자)들을 검출할 수 있는 기능을 갖추고 있는데 이를 Total Electron Yield 측정이라고 한다. Total Electron Yield 측정은 박막 시료와 같이 투과가 되지 않는 시료를 분석할 뿐만 아니라, 경원소 분석, 낮은 에너지에서 흡수 edge가 나타나는 L-edge 측정을 통한 전자 구조 분석 등에 유용한다. 실험실용 XIEES 장비는 방사광가속기에 비해 x-ray flux가 크게 뒤지는 문제와 Total Electron Yield를 측정하는 데 있어서 source에서 나오는 x-ray beam이 진공용기 안에서 산란되어 이차전자를 여기하고 이 이차전자들이 전자검출기에 유입되어 측정에 영향을 미치는 background 문제 등이 있다. 이 두 가지 문제를 해결하기 위하여 Capillary tube를 사용하였다. 본 연구에서는 실험실용 XIEES 장비를 소개하고 이를 이용하여 Cu standard 시료에서 측정한 EXAFS 결과와 Capillary tube를 사용하여 얻은 x-ray flux 증진 및 background 제거 효과에 대해서 발표한다.

• Journal of Internet of Things and Convergence
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• v.5 no.1
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• pp.29-34
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• 2019

A bag filter collector is a kind of air purifier that organizes several or dozens of filters to purify fine dust and release clean air into the atmosphere. If the bag filter length is less than 5m, the dust and fume attached to the bag filter could be effectively removed by passing the compressed air generated by the diaphragm valve through the venturi. Injectors that are more efficient and economical are urgently needed to achieve satisfactory results for long-bag exhaustion of more than 7 meters. In the case of existing domestic and foreign injectors, a number of blow tubes were dismantled during maintenance, and the injector and blow tube were combined to pose a number of problems, including inconvenience of work due to weight increase. In this study, injector flow for the development of the best use of interpretation of the coanda effect and the fourth round of industrial technology Intelligent automation of exhaustion, have been engineered energy than standard equipment. lowering costs and filter life to radically improve the commercial studies.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.261-269
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• 2002

The objectives of this paper are to study the use of geotextile tribes for dewatering high water content sludges and sediments and to evaluate their feasibility and affecting fsctors. To accomplish these objectives, pressure filtration tests were conducted on woven geotextile (Geotex$\circledR$ 46T and 1212T) fir high water content materials with a modified experimental apparatus. Test results indicate that 1) the filter cake formed on the inside of the geotextile tube is the major contributor to the retention of fine particles, but also causes a decrease in permeability, 2) controlling the formation of the filter cake and thus achieving a balance between soil retention and permeability is vital to a successful project, and 3) geotextiles, sludge properties, and filtration pressures have some effects on the dewatering efficiency and dewatering rate.