• Journal of the Microelectronics and Packaging Society
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• v.11 no.3 s.32
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• pp.1-7
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• 2004

Tin plating on component finishes may grow whiskers under certain conditions, which may cause failures in electronics equipment. To protect the environment, 'lead-free' among component finishes is being promoted worldwide. This paper presents the evaluation results of whiskers on two kinds of lead-free plating materials at the plating temperature and under the reliability test. The rising plating temperature caused increasing the size of plating grain and shorting the growth of whisker. The whisker was grown under the temperature cycling the bent type in matt Sn plating and striated type in malt Sn-Bi. The whisker growth in Sn-Bi plating was shorter than that in Sn plating. In FeNi42 leadframe, the $7.0{\~}10.0{\mu}m$ diameter and the $25.0{\~}45.0{\mu}m$ long whisker was grown under 300 cycles. In the 300 cycles of Cu leadframe, only the nodule(nuclear state) grew on the surface, and in the 600 cycles, a $3.0{\~}4.0{\mu}m$ short whisker grew. After 600 cycles, the ${\~}0.34{\mu}m$ thin $Ni_3Sn_4$ formed on the Sn-plated FeNi42. However, we observed the amount of $0.76{\~}1.14{\mu}m$ thick $Cu_6Sn_5$ and ${\~}0.27{\mu}m$ thin $Cu_3Sn$ intermetallics were observed between the Sn and Cu interfaces. Therefore, the main growth factor of a whisker is the intermetallic compound in the Cu leadframe, and the coefficient of thermal expansion mismatch in FeNi42.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.297-308
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• 1989

These are two case reports of recurrent ossifying and cemento-ossifying fibroma in a year or 5 months following conservative treatment. Ossifying fibroma or cemento-ossifying is a relatively uncommon benign fibro-osseous tumor of the jaws, and is generally believed to originate from periodontal ligaments. In recent, it is not demanded more differentiation of ossifying, cementifying and cemento-ossifying fibroma due to the thought that these lesions represent a spectrum of the same disease process rather than separate entities. The tumor commonly presents as an asymptomatic mass lesion and is usually well-circumscribed clinically so that conservative surgical excision has been the treatment of choice, but on occasion extended surgical procedures may become necessary, especially for those tumors which demonstrate rapid expansions and are poorly encapsulated (either initially or when recurrent) and when tumor growth is progressed aggressively or recurrent. En-bloc resection of mandible with iliac bone and inferior alveolar nerve graft was performed in case 1, recurrent cemento-ossifying fibroma of 32-year old male patient, and extended surgical enucleation of mass including normal marginal bone was done in case 2, recurrent ossifying fibroma of 72-year old female patient. By follow-up check of the patients, we obtained good result without any sings of recurrence.

• Applied Microscopy
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• v.32 no.4
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• pp.399-410
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• 2002

This study was performed to investigate the effects of Bambusae Caulis in Liquamen (bamboo extract) on the changes of antioxidant enzymes and histopathological changes of liver and kidney in mice when administered in different dosages. The experimental groups were divided into four. For control group, 0.9％ NaCl (0.2 ml/25 g B.W.) and for experimental groups, 5% (H1 group), 10% (H2 group), and 20%(H3 group) bamboo extract diluted with 0.9％ NaCl, were administered (0.2 ml/25 g B.W.) respectively for 28 days at an interval of 48 hours. MnSOD activities were increased in H1 group (46%, P<0.05), H2 group (40%, P<0.05), and H3 group (34%, P<0.05) as compared to the control group. CuZnSOD activities were increased in H1 group (11%, P<0.05), but were decreased in H3 group (13%, P<0.05). The activities of catalase were decreased in H1 group (39%, P<0.05), H2 group (34%, P<0.05), and H3 group (31%, P<0.05) as compared to the control group. Histopathological observation revealed ballooned hepatocytes in the pericentral and periportal veins of H1 group. More ballooned and injured hepatocytes than in H1 group were observed in the H2 and H3 groups. Detachment of endothelial cells of the central vein was observed in the H2 and H3 groups. These results indicated that bamboo extract developed dose-dependent changes in antioxidant enzyme activities and developed histopathological changes of liver and kidney.

• Applied Microscopy
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• v.40 no.1
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• pp.1-8
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• 2010

The ultrastructure of spermatogenesis and sperm in Chinese minnow, Rhynchocypris oxycephalus belonging to Leuciscinae was investigated by light and electron microscopes. The whitish testis was located between intestine and air bladder. The size of testis was major axis 2.3 cm, minor axis 6 mm. The testis contained numerous testicular cysts, and spermatogenesis was non-synchronized in these testicular cysts. In the case of spermatogonium, the nucleus was comparatively large ellipsoidal, and mitochondria showed a marked development. The size of primary spermatocyte was smaller than that of spermatogonia, and secondary spermatocyte was smaller than primary spermatocyte. The chromatin of spermatocyte was highly condensed according to their development. The nucleus with electron-dense was round shape. In spermiogenesis, flagella started to be formed and chromatin was more condensed. The mitochondria were rearranged in a middle piece. The sperm was formed by loss of cytoplasm. The head of mature sperm was a spherical shape and have not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have not lateral fins.

• Economic and Environmental Geology
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• v.45 no.2
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• pp.79-88
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• 2012

The increased brightness and focused X-ray beams now available from laboratory X-ray sources facilitates a variety of powder diffraction experiments not practical using conventional in-house sources. Furthermore, the increased availability of 2-dimensional area detectors, along with implementation of improved software and customized sample environmental cells, makes possible new classes of in-situ and time-resolved diffraction experiments. These include phase transitions under variable pressure- and temperature conditions and ion-exchange reactions. Examples of in-situ and time-resolved studies which are presented here include: (1) time-resolved data to evaluate the kinetics and mechanism of ion exchange in mineral natrolite; (2) in-situ dehydration and thermal expansion behaviors of ion-exchanged natrolite; and (3) observations of the phases forming under controlled hydrostatic pressure conditions in ion-exchanged natrolite. Both the quantity and quality of the in-situ diffraction data are such to allow evaluation of the reaction pathway and Rietveld analysis on selected dataset. These laboratory-based in-situ studies will increase the predictability of the follow-up experiments at more specialized beamlines at the synchrotron.

• Journal of fish pathology
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• v.24 no.3
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• pp.225-236
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• 2011

This study was aimed to determine the fish physical status according to the gross and histopathological findings of liver in cultured black rock fish, Sebastes schlegeli. All 47 fish submitted had no marked abnormalities in the external findings. 42.55% of fish showed normal liver, 25.53% yellow liver, 25.53% atrophic brown liver, 4.26% yellowish-green liver and 2.13% fatty liver in gross examination. Grossly normal liver showed no remarkable change in lobular structure but many vacuoles were found in hepatic cell. Hepatic cells took normal roundish, polygonal shapes containing spherical nuclei. In group of yellow-brown liver, many brown pigments were seen in hepatic cells, MMCs and brown-colored hyaline droplets within cytoplasm of hepatocytes. Yellowish green pigments were seen in hepatic cells and MMCs of yellow green liver and green colored hyaline droplets within hepatocytes. The dilated central veins are highlighted with atrophy of hepatic cells. Outline of atrophic hepatocyte became ambiguous and nucleus frequently become small and pyknotic. Fatty liver showed prominent vacuolar structures in cells as clear spaces or foamy cytoplasm with degenerative nuclei. From these results, it was strongly suggested that hepatic gross and histological findings could be used as important and critical health parameters of fish prior to progression to substantial manifestation as clinical disease.

• Journal of Yeungnam Medical Science
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• v.9 no.1
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• pp.137-148
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• 1992

The purpose of this study was to evaluate the influence of phenobarbital(PB) on hepatotoxic effect of carbon tetrachloride($CCl_4$) which induces centrilobular necrosis in liver. Rats were injected intraperitoneally $CCl_4$ dissolved in olive oil by a dose of 0.4mg/kg. For change related to PB pretreatment, rats were injected $CCl_4$ 0.4mg/kg after PB pretreatment. The liver samples were taken in 6, 12, 24, 48, 72, and 120 hours after $CCl_4$ and/or FB injection. Extracted liver tissue was examined with light and electron microscopes. The results were sumarized as follows : 1. Light microscopic findings : In $CCl_4$ group, centrilobular necrosis developed from 6 hours after injection, was the most severe in 48 hours, and recovered after 72 hours. In addition to necrosis, fatty change and pale cell change were accompanied. In PB-$CCl_4$ group, necrosis occurred from 6 hours after $CCl_4$ injection and continued to 72 hours, and the degree of necrosis was more severe than that of $CCl_4$ group and pale cell change was decreased. 2. Electron microscopic findings: In $CCl_4$ group, the early principal change was clumping and vesicular dilatation of endoplasmic reticulum. In PB-$CCl_4$ group, the degenerative change of endoplasmic reticulum was aggrevated and the mitochondria also revealed severe degenerative change. According to the results, it was revealed that $CCl_4$ hepatotoxicity primarily began with the damage of endoplasimic reticulum, then damage of other cell organelles and cell necrosis followed, and these cytotoxic effects were aggrevated by PB pretreatment.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.81-91
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• 2011

This study was conducted to evaluate the necessity of the anchor lug system in continuously reinforced concrete pavement(CRCP) by comparing longitudinal displacements of CRCPs with and without anchor lugs, and to investigate the effect of horizontal cracking on CRCP performance by measuring the vertical displacements. The measurements before and after the anchor lug section was separated were conducted for 12 days in June, and for 14 days in August after the abrupt displacements according to cutting disappeared, respectively. This short term measurement results showed that when anchor lugs were installed, a daily displacement variation at any location was less than 0.1mm; therefore, longitudinal movements were negligibly small. When there were no anchor lugs, longitudinal displacements mainly occurred near the free end and the displacement variation was small; therefore, an expansion joint system seems to be employed at a CRCP terminus without installing anchor lugs. However, further studies are needed to verify the terminus behavior due to annual temperature changes. The horizontal crack width variation was ignorable and did not affect the vertical displacement of the slab. Therefore, the horizontal crack did not delaminate the slab and did not seem to reduce the structural capacity and performance of CRCP.

• Korean Security Journal
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• no.12
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• pp.271-289
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• 2006

Private security industry in South Korea has rapidly been growing in recent years. However, such a rapid growth is being criticized for its focus on external results, which has produced a number of problems. The continued growth of private security industry can be only based upon substantive and qualitative development. In this aspect, it is necessary to consider the global trends of the private security industry, particularly the recent trends of the U. S. security industry which has led the global security industry. This is because the recent trends of the U. S. private security industry would guide the future direction of the private security industry in South Korea. The U. S. private security industry has been replacing the role of law enforcement agencies including the police, from crime prevention to investigation and disaster management, not to mention asset protection and loss prevention. The recent trends of the U. S. security industry appears to be summarized by such characteristics as variety, specialty, and integration, which might account for the structural problem of the private security industry in South Korea. In short, the substantive and qualitative development of the private security industry in South Korea should be accomplished by strengthening its specialty and integration, and also widening its variety.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.1
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• pp.37-43
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• 2013

Conductivity of LSGMC materials were affected by secondary phase segregation, composition and synthetic route. $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.1}Co_{0.1}O_{3-{\delta}}$ (LSGMC) powders were prepared using the glycine nitrate process to produce high surface area and compositionally homogeneous powders. The powders were synthesized with different 0.5, 1, 1.5, 2, 2.5 of glycine/cation molar ratios. A single perovskite phase from the synthesized powders was characterized with X-ray diffraction patterns. The obtained sintered pellets showed the dense grain microstructure. In case of 1.5 molar ratio, its density was higher than the others. The electrical conductivity measured at $800^{\circ}C$ was observed to be 0.131 $Scm^{-1}$. In addition, the linear thermal expansion behavior was indicated between $25^{\circ}C$ and $800^{\circ}C$.