• Structural Engineering and Mechanics
• /
• 제9권4호
• /
• pp.339-347
• /
• 2000

The creep deformation of pure bending (hold constant moment for a period of time) tests were conducted in this paper. Thin-walled tubes of 304 stainless steel were used in this investigation. The curvature-ovalization measurement apparatus, designed by Pan et al. (1998), was used for conducting the present experiments. It has been found that as soon as the creep deformation is started, the magnitudes of the tube curvature and ovalization of tube cross-section quickly increase. The magnitudes of the creep curvature and ovalization of tube cross-section increase fast with a higher hold moment than that with a lower one. Owing to the continuously increasing curvature during the creep deformation, the tube specimen buckles eventually.

• 동의생리병리학회지
• /
• 제22권4호
• /
• pp.914-917
• /
• 2008

Primary carcinoma of the fallopian tube is exceedingly rare, accounting for 0.3 percent of female genital tract cancer. It is usually unilateral, but 20 percent of cases are bilateral. It occurs most commonly in women between 40 and 60 years old. Approximately 50 percent of the patients are nulliparous. Because of variable presenting symptoms and rarely incidence, preoperative diagnosis of fallopian tube carcinoma is seldom made. Evaluation and treatment are also essentially the same at that of ovarian carcinoma. We experienced a case of bilateral primary fallopian tube carcinoma in women presented with vaginal bleeding and pelvic mass, postoperatively pathologic examination of resected specimen after laparatomy and reported with brief review of literature.

• 한국전기전자재료학회논문지
• /
• 제14권7호
• /
• pp.606-610
• /
• 2001

Bi-2212 HTS tube was fabricated by centrifugal forming and partial melting processes. Bi-2212 bulk tube has been optimized to achieve smooth surface and uniform thickness. The slurry was prepared in the mixing ratio of 10:1 between Bi-2212 powder and binder and initially charged into the rotating mold under the speed of 300~450 rpm. Heat-treatment was performed at the temperature ranges of 860~89$0^{\circ}C$ in air for partial melting. the HTS tube fabricated by centrifugal forming process at 89$0^{\circ}C$ under the rotating speed of 450 rpm was highly densified and the plate-like grains with more than 20${\mu}{\textrm}{m}$ were well oriented along the rotating axis. The measured Tc and J$_{c}$ at 10K on specimen heat treated at 89$0^{\circ}C$ was around 85 K and 1,200 A/$\textrm{cm}^2$ respectively.y.

• Architectural research
• /
• 제23권1호
• /
• pp.11-17
• /
• 2021

A concrete-filled circular steel tube beam was fabricated, and a bending test was performed to analyze its failure modes, displacement ductility, bending-shear strength, and load-central deflection relationship. For the bending test, the installation position of the shape memory alloy (SMA) inside and outside the double-skin steel tube was used, and the rebar installation position, the concrete strength, the mixing of fibers, and the inner-outer diameter ratio as the main parameters. The test results showed that the installation positions of the reinforcements inside and outside the double-skin steel tube and the inner-outer diameter ratio of the steel tube affected the ductility, maximum load, and failure mode. In general, the specimen made of general concrete with SMA installed outside and inside (OI) the double-skin steel tube showed the best results.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.166-169
• /
• 2006

A new bridge system described in this paper uses concrete-filled steel tube (CFT) girders as a replacement for conventional girders. Experimental investigations were carried out to comprehend the flexural behavior of CFT girder-slab deck composite section. The experimental investigation consisted of designing and constructing a test specimen and loading it to collapse in bending to check the applicability of the system. The test results showed that concrete filled steel tube girders have good ductility and maintain its strength up to the end of the loading. In the test, the flexural behavior of each specimen of CFT girder-deck composite section is identified.

• 한국정밀공학회지
• /
• 제25권4호
• /
• pp.53-60
• /
• 2008

Electron detectors used in scanning electron microscope accept electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. Electron detector is one of the key components dominating the performance of scanning electron microscope so that the development of electron detectors having high performance is indispensable to acquire high quality images using scanning electron microscope. In this paper, we designed and manufactured an electron detector and conducted a couple of image capture experiments using it. In particular, scintillator which generates light photons when it is struck by high-energy electrons was manufactured and experimental studies on the optimization of manufacturing condition was carried out. From experiments to evaluate the performance of our detector, it was verified that the performance of our detector is equivalent to or better than that of the conventional one.

• 한국공간구조학회논문집
• /
• 제22권3호
• /
• pp.73-80
• /
• 2022

Unlike the CFT retrofit method, The EPFT retrofit method, which fills the steel tube with engineering plastic, does not require a separate concrete forming work and is a lightweight seismic Retrofit Method. In this study, an prototype model of the EPFT was proposed, and to analyze the seismic performance, an independent specimens and a reinforced concrete column were fabricated to conduct a seismic performance test. As a result of loading test of the independent specimens, the strength was increased compared to the steel tube column without internal filling, and the ductility ratio did not significantly increase due to the falling off of the weld. As a result of loading test of the concrete reinforcement specimen, the strength, ductility ratio, and energy dissipation were increased, and the number of cracks by loading step decreased compared to the non-reinforced specimen.

• KCI Concrete Journal
• /
• 제11권3호
• /
• pp.127-140
• /
• 1999

In this paper, a microscopic analysis of prefinitelv strained cement paste specimen was carried out. The microscopic behavior of concrete under triaxial stress must be fully understood in order to explain the additional ductilitv that comes from lateral confinement and to get microstructural information in large deformed and large strained concrete. The so-called "tube-squash" test was applied to achieve enormously high shear and deviatoric strain of concrete under extremly high pressure without fracture. Then, microscopic analyses by focusing on hydration and microstructure of Prefinitely strained cement paste were carried out on cored-out deformed and virgin (undeformed) cement paste specimens : the first specimen being 40 days old, the second one being one year old. The microscopic analysis bv Field Emission Scanning Electronic Microscope (FESEM) was carried out for comparison between the specimens after 40 days and those arter one year. For one year old specimens, X-Ray Diffractometer (XRD) analysis, Energy Dispersive x-rav Spectrometer (EDS) analysis, and Differential Thermal Analysis/Thermo-Gravitv (DTA/TG) analysis were also carried out to study the hydration and the microstructures of prefinitely strained cement paste specimen by focusing on the methodologies of their microscopic analyses. analyses.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권3호
• /
• pp.240-249
• /
• 2018

Purpose: The purpose of this research is to find which technique, between the PAUT (Phased array ultrasonic test) that has been used widely in practice and RT (Radiographic test) that was used widely in the past, has the higher reliability as a non-destructive testing of welding points in water wall tubes. Methods: To evaluated the reliability of non-destructive testing, eleven test pieces that were fabricated intentionally, which have the most frequently occurred defect types in water wall tubes and then both the PAUT and RT were performed on those eleven test pieces to compare their reliability. Results: The differences of type of defect, length are occurred due to the characteristics of nondestructive testing. The RT could not detect the lack of fusion defect type in specimen #4 and #8 while PAUT could not detect the lateral crack and 1 mm size small porosity in specimen #11. Conclusion: It is concluded that applying both the RT and PAUT result the best reliability rather than applying only one test method, if it is possible, in nondestructive testing of weld water wall tube in thermal power plant boiler case.

• 한국군사과학기술학회지
• /
• 제13권6호
• /
• pp.1051-1057
• /
• 2010

Database for the damage reference by armor piercing bullet test was established for both tube and plate specimens having a range of thickness. As the inclined angles of hit are increasing, it has been found that penetration damage diameter tends to increases accordingly in both specimen of the tube and plate, and such penetration damage diameter on the rear side becomes bigger than those on the front side. The tube specimen showed that the damage becomes bigger when central areas rather than the peripheral were hit. Through the plate test, it also has been found that the penetration ballistic limit for Al alloy is about 25.4mm and that of stainless steel about 12.7mm. From the fatigue analysis results using the database for damage reference, it has been identified whether the safety requirements of military aircraft could be met.