• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.99-102
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• 2009

Inflammatory pseudotumor is an uncommon lesion with unknown etiology characterized by sclerosing inflammation which clinically and radiographically mimics a neoplastic lesion. A 47-year-old man presented with sudden headache and dysarthria. Brain CT scan revealed a $2.6{\times}2.2\;cm$ sized, round, and hyperdense mass in the anterolateral wall of the left lateral ventricular trigone. On MR imaging studies, the mass showed low signal intensity in the wall of the trigone on T2-weighted image, central mixed (iso- and high-) signal intensity with peripheral low-signal intensity on T1-weighted image. Subtle staining of left choroid plexus with irregular shaped distal branch of anterior choroidal artery was found on the cerebral angiography. These findings suggested a small tumorous lesion originated from the left choroid plexus. During the hospital days, the mass manifested as repeated hemorrhages. The mass was successfully removed via left occipital transcortical approach. The histopathological report of the specimen was hemorrhage and fibrosis, with dense lymphoplasma cell infiltration, suggestive of an inflammatory pseudotumor.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.537-539
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• 2009

A 47-year old woman was admitted to our hospital for removal of a known mass that was located on the suprasternal notch; specifically, the mass was located on the supero-anterior mediastinuum. The mass was removed by a cervical incision and the histopathologic diagnosis of the resected specimen was hererotopic thyroid tissue with nodular hyperplasia. Mediastinal hererotopic thyroid tissue is a rare malady, so we report here diastinal hererotopic thyroid tissue and we review the relevant medical literature.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.61-66
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• 2003

In this paper, the effect of binder additive on the fracture toughness was metal matrix composite produced by squeeze casting method. In this study using the matrix is AC4CH and reinforcement used Aluminum borate whisker. Each MMC was produced by add inanimate binder ($SiO_2,\;Al2O_3,\;TiO_2$) to whiskers for increase the binding together of whiskers. Fracture toughness test were carry out in accordance with the ASTM E-399 standard test method, W=25mm, b=12.5mm CT(half size) specimen. However Base metal AC4CH was not meet the qualification of $P_m/P_Q<1.1$, so that test were performed $J_{IC}$ test. $K_{J_{IC}}$ value was measuring by $J_{IC}$ value change into $K_{IC}$. $J_{IC}$ test was carry out in accordance with the ASTM 1820.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.1024-1027
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• 2002

Epiploic appendages are small, 0.5-5 cm long, peritoneal pouches containing small vessels and fat, located on the serous surface of the colon, from the cecum to the rectosigmoid junction. Pathologic states are rare in these appendages, the most frequent being is infarction either due to torsion or spontaneous. As a result of subsequent inflammatory reaction, the condition has been termed primary epiploic appendagitis. The condition is manifested by localized abdominal pain, which is often mistaken for appendicitis or diverticulitis and is usually diagnosed at surgery. With the aid of comtemporary imaging modalities, however, the diagnosis of epiploic appendagitis need no longer hinge on the pathologic specimen but may be established by the clinician. As this disorder recently has been demonstrated to be predominantly self-limited, laparotomy is no longer considered necessary. Conservative management has been shown to be safe. We report a 5-year-old male patient with epiploic appendagitis who presented with acute abdominal pain.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.1
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• pp.108-111
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• 2004

Tuberculosis is not a common cause of liver abscess and it is rarely considered in the differential diagnosis of a patient with hepatic mass. We report a case of tuberculous abscess of liver and spleen in a 15-year-old boy who presented with abdominal pain, fever and weight loss. The ultrasonographic and computed tomographic scan of the abdomen revealed multiple cystic lesions in the liver and spleen. Mycobacterium tuberculosis was cultured from the ascitic fluid and biopsy specimen of lymph node. Follow up CT scan of the abdomen after anti-tuberculosis medication for eighteen months showed complete resolution of the cystic lesions with calcified nodules.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.73-80
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• 2011

The experimental investigation focuses on an influence of artificial aging time in longitudinal butt welded Al 6013-T4 aluminum alloy on the fatigue crack growth resistance. The preferred welding processes for this alloy are frequently tungsten inert gas welding (TIG) process due to its comparatively easier applicability and better weldability than other gas metal arc welding. Fatigue crack growth tests were carried out on compact tension specimens (CT) in longitudinal butt TIG welded after T82 heat treatment was varied in three artificial aging times of 6 hours, 18 hours and 24 hours. Of the three artificial aging times, 24 hours of artificial aging time are offering better resistance against the growing fatigue cracks. The superior fatigue crack growth resistance preferred spatial variation of materials within each specimen in the Paris equation based on reliability theory and fatigue crack growth rate by crack length are found to be the reasons for superior fatigue resistance of 24 hours of artificial aging time was compared to other joints. The highest of crack propagation resistance occurs in artificial aging times of 24 hours due to the increase in grain size (fine grained microstructures).

• Journal of Power System Engineering
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• v.18 no.1
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• pp.91-98
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• 2014

In this investigation, the effect of crack orientation on spatial randomness of fatigue crack growth rate (FCGR) in friction stir welded (FSWed) 7075-T651 aluminum alloy joints has been statistically analyzed by Weibull distribution. The fatigue crack growth tests are conducted under three different constant stress intensity factor range (SIFR) control at room temperature with R = 0.1 and frequency 10Hz on compact tension (CT) specimen machined at base metal (BM) and weld metal (WM). The experimental fatigue crack growth rate data were obtained for two types of specimens having LT and TL orientations. LT specimens both base metal and weld metal showed higher fatigue crack growth rate as compared to TL specimens. In the lower SIFR region, FCGR were found to be almost 3 times higher in higher SIFR region. The shape parameter of Weibull both LT and TL orientation for FCGR was increased with increasing SIFR, the scale parameter was also increased with increasing SIFR. The smallest value of the shape parameter was shown in weld metal specimens having LT orientation at lower SIFR region.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.116-123
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• 2006

During the last two decades, many researchers investigated influences of stress triaxiality on ductile fracture for various specimens and structures. With respect to a transferability issue, the local approach reflecting micro-mechanical specifics is one of effective methods to predict constraint effects. In this paper, the applicability of the local approach was examined through a series of finite element analyses incorporating modified GTN (Gurson-Tvergaard-Needleman) and Rousselier models as well as fracture toughness tests. To achieve this goal, fracture resistance (J-R) curves of several types of compact tension (CT) specimens with various crack length, with various thickness and with/without 20% side- grooves were estimated. Then. the constraint effects were examined by comparing the numerically estimated J-R curves with experimentally determined ones. The assessment results showed that the damage models might be used as useful tool for fracture toughness estimation and both the crack length and thickness effects should be considered for realistic structural integrity evaluation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.8 s.239
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• pp.1118-1122
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• 2005

The direct current potential drop (DCPD) method and the unloading compliance (UC) method with a crack opening displacement gauge were applied simultaneously to the Zr-2.5Nb curved compact tension (CCT) specimens to determine which of the two methods can precisely determine the crack initiation point and hence the crack length for evaluation of their fracture toughness. The DCPD method detected the crack initiation at a smaller load-line displacement compared to the UC method. As a verification, a direct observation of the fracture surfaces on the curved compact tension specimens was made on the CCT specimens experiencing either 0.8 to 1.0 mm load line displacement or various loads from $50\%\;to\;80\%$ of the maximum peak load, or $P_{max}$. The DCPD method is concluded to be more precise in determining the crack initiation and fracture toughness, J in Zr-2.5Nb CCT specimens than the UC method.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.167-172
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• 2008

This study is to evaluate the fatigue crack growth characteristics for base metals and welded metal of 9% Ni steels. Since this material has very excellent fracture toughness at low temperature, it has been widely used for inner walls of LNG storage tank. These materials to compare fatigue crack growth (FCG) behaviour are treated with heat by the method of quenching and tempering (QT), and quenching, lamellarizing and tempering (QLT). FCG tests using compact temsion (CT) specimen under stress ratio R=0.1, 0.5, and constant load are carried out. K-increasing tests are conducted by the standard test method described in ASTM E 647. To investigate the effect of welded metal on the crack growth rate, the locations of notch tip were chosen at the center of welded metal and heat affected zone (HAZ). Form the results, FCG rate has almost same tendency according to stress ratio, base and welded metal, the locations of welded metal. FCG rate of welded metal is somewhat faster than base metal. Also scanning electron microscope (SEM) is used to observe the striation of the fractured surface after fatigue crack tests.