• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.359-371
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• 2006

In this study, the soil characteristics are analyzed using the result of various soil tests as an object of the soil layer of natural slopes in landslides areas composed with gneiss, granite, and the tertiary sedimentary rock. To investigate the soil characteristics according to landslide and non landslide areas, soils are sampled from Jangheung, Sangju and Pohang. The landslides at three areas are occurred due to heavy rainfall in same time. The geology of Jangheung area, Sangju area and Pohang area is gneiss, granite, and the tertiary sedimentary rock, respectively. On the basis of the landslide data and the result of soil test, the soil characteristics at the landslide area and the differentiation between landslide area and non landslide area are analyzed. However soil characteristics have a little differentiation to geological condition, the uniformity coefficient and the coefficient of gradation of soils at the landslide area is larger than those of soils at the non landslide area. Also, the proportion of fine particle of soils at the landslide area is higher. The plastic limit of soils sampled from the granite and the sedimentary rock regions is larger than that sampled from the gneiss region. However the liquid limit is irrelevant to the geological condition. Also, the consistency of soils at the landslide area is smaller. The natural moisture content of soils in the sedimentary rock regions is larger than that of the granite and gneiss. It is mainly influenced by mineral composition, soil layer structure, weathering condition, and so on. The soils sampled from landslide area have higher porosity and lower density than those from non landslide area. It means that the soils of landslide area have poor particle size distribution and loose density. Therefore, the terrain slope with poor distribution and loose density is vulnerable to occur in landslides. Also, landslides are occurred in the terrain slope with high permeability. The permeability is mainly influenced by the soil characteristics such as particle size distribution, porosity, particle structure, and the geological origins such as weathering, sedimentary environment. Meanwhile, the shear strength of soils is little difference according to the geological condition. But, the internal friction angle of soils sampled from the landslide area is lower than that of soils from the non landslide area. Therefore, the terrain slope with low internal friction angle is more vulnerable to the landslide.

• Neonatal Medicine
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• v.15 no.1
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• pp.32-37
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• 2008

Purpose : Perinatal asphyxia is an important cause of neonatal mortality and subsequent lifelong neurodevelopmental handicaps. Although many treatment strategies have been tested, there is currently no clinically effective treatment to prevent or reduce the harmful effects of hypoxia and ischemia in humans. In the clinical setting, maternal hyperthermia induces adverse effects on the neonatal brain, but recent studies have shown that hyperthermic pretreatment (PT) plays some role in hypoxic-ischemic (HI) injuries of the developing brain. The present study investigated the effect of hyperthermic PT on HI brain injuries in newborn rats. Methods : HI was produced in 7-day-old neonatal rats by unilateral common carotid artery ligation, followed by hypoxia with 8% oxygen at $38^{\circ}C$ for 2 hours. Twenty-four hours before HI, one-half of the pups were exposed to a $40^{\circ}C$ environment for 2 hours. The severity of the brain injury was assessed 7 days after the HI. Results : Hyperthermic PT reduced the gross and histopathologic findings of brain injury from 64.7 to 31.2% (P<0.05). There were no differences in location and severity of injury between the pretreated and control brains. Conclusion : These findings indicate that hyperthermic PT provides neuroprotective benefits on HI in the developing brain. Also, these findings suggest maternal hyperthermia may have protective effect on perinatal HI brain injuries.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.368-380
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• 1999

Purpose: The purpose of this study was to evaluate and compare the scintigraphic findings and diagnostic accuracy of double-phase Tc-99m sestamibi scan in primary and secondary hyperparathyroidism (HPT). Materials and Methods: We retrospectively reviewed 16 cases of primary (18 lesions) and 11 cases of secondary HPT (44 lesions) who underwent Tc-99m-sestamibi scan before the surgical intervention. Scan was performed using LEM camera (Siemens, Germany) after the injection of 740MBq of Tc-99m sestamibi. Routine image consisted of baseline and 3-hour delayed images and each image was obtained using both parallel and pine hole collimator. The study population was 27 patients (male/female=5/22, age: $49.1{\pm}10.8$). Results: Eighteen lesions of primary HPT consisted of 13 adenomas and S hyperplasias, while all lesions of secondary HPT were hyperplasias. Among the case of primary HPT, we could detect all the lesions of 13 adenomas but only 2 lesions of 5 hyperplasias (40%) could be detected by double phase scintigraphy. Three cases of primary lesion showed decreased uptake in delayed images compared with baseline. The sensitivity, specificity, positive predictive value and accuracy of primary and secondary HPT were 58.8% (10/17), 83.3% (10/12), 83.3% (10/12), 75.9% (22/29), and 37.5% (15/40), 50% (2/4), 88.2% (15/17), 38.6% (17/44), respectively. Overall sensitivity, specificity, positive predictive value and accuracy were 43.9% (25/57), 75% (12/16), 86.2% (25/29), and 53.4% (39/73). There were no statistical difference between the weight of primary and secondary HPT lesion (p>0.05). Conclusion: Tc-99m sestamibi scan is fairly good modality to detect parathyroid lesion in patient with primary HPT before the surgical intervention. However, since some of cases may reveal decreased uptake in delayed image, a careful attention to the findings of baseline images may be helpful. Still the low accuracy of sestamibi scan in diagnosis of secondary HPT prohibits routine use of it for this disease.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.87-94
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• 1986

This study was performed in order to contemplate their correlations between physical and mechanical properties of the marine clays which were collected from main harbors in Korea. The results obtained are as follows: 1. Most of the soils in experimental districts consist of CH. CL. and ML. and they are considered to be still proceeding. 2. The equations of the relationship between compression index and liquid limit are as, follows: CH : $C_c=0.0137$ (LL-22.60) CL : $C_c=0.0123$ (LL-14.64) 3. The relationship between compression index and initial void ratio appears that the higher the plasticity, the easier the slope of the regression line. The equations are as follows : CH : $C_c=0.431$ ($e_o-0.504$) CH : $C_c=0.471$ ($e_o-0.235$) ML : $C_c=0.641$ ($e_o-0.393$) 4. The equations of the relationship between compression index and natural water content are as follows: CH : $C_c=0.0133$ ($W_n-28.27$) CL : $C_c=0.0225$ ($W_n-23.56$) ML : $C_c=0.0106$ ($W_n-16.42$) 5. The relationship between initial void ratio and natural water content, and compression index is highly positive correlation and the equations are as follows : CH : $C_c=0.301$ ($e_o+0.017W_n-1.05$) CL : $C_c=0.141$ ($e_o+0.0567W_n-1.054$) ML : $C_c=0.421$ ($e_o+0.0214W_n-1.121$) 6. The equations of the relationship between initial void ratio and liquid limit, and compression index are as follows : CH : $C_c=0.36$ ($e_o+0.08LL-0.819$) CL : $C_c=0.269$ ($e_o+0.026LL-0.929$) 7. The cohesion of marine clays is no concerned with the increment of depth. The equations of relationship between cohesion and unconfined compression strength are as follows. CH : qu=1.896C+0.0107 CL : qu=1.849C+0.04.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.164-179
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• 2014

The Buddhas of the Three Words in a form of arranging Bhaiṣajyaguru and $Amit{\bar{a}}bha$ at its side based on ${\acute{S}}{\bar{a}}kyamuni$ at the center is enshrined in Daeungbojeon Hall of Daeheungsa Temple located at Haenam. So far, this Buddhas of the Three Words has been known as a wooden Buddha statue. However, as a result of X-ray screening, in left/right Buddha statues excepting main Buddha, wood and molding clay layer were observed at the same time. Therefore, this study intended to observe its internal structure, grafting method and to clarify making technique of Buddha statue during Joseon era based on image information being obtained through X-ray screening of The Buddhas of the Three Words of Daeheungsa Temple. As its result, it was revealed that form of ${\acute{S}}{\bar{a}}kyamuni$ was completed by mainly grafting 5 pieces of timber and this statue shows a typical wood grafted Buddha statue during Joseon era. Form of Bhaiṣajyaguru and $Amit{\bar{a}}bha$ were completed based on molding technique by applying clay on sculpture similar to its appearance after sculpturing more than 10 pieces of timber through its grafting. In other words, internal timber is considered to play a role of its core and grafting method of timber is more close to a technique of molding Buddha statue than to that of wooden Buddha statue during Joseon era. However, clay was directly applied on timber thinly, not applying clay thickly on it after winding straw rope on wooden core and its characteristic is that its facial area was completely composed of wooden construction only. Therefore, it is hard to rule out a possibility that the original sculpturing intention of an artist might be a wooden Buddha statue but in view of the fact that a word, 'molding' was used in a record of relics buried in statue, it could be seen that this Buddha statue might have been recognized as a molding statue at the time when creation of this statue was completed. It is considered that number of case of making statue based on this technique would be more increased when more results of X-ray screening should be accumulated and if more data should be collected, it would provide a significant evidence for identifying chronological, regional aspects of making technique of Buddha statue.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.40-52
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• 2023

The basic purpose of building material called tiles is waterproofing and damp proofing, and they were restricted to use on important buildings to symbolize authority. This is especially true during the Three Kingdoms period, although unearthed examples are rare. Most of these tiles are found in ruins in the Silla and Baekje regions. Tiles were excavated from the Buwon-dong ruins that show the oldest manufacturing technique in the Gaya region to date, and tiles from the early Three Kingdoms period were recently excavated from the Gimhae Bonghwang-dong ruins, which is presumed to be the site of the royal palace of Geumgwan Gaya. These are important materials that show the appearance of tiles from the early days of Gimhae, the ancient capital of Geumgwan Gaya. The tiles excavated from the Bonghwang-dong ruins are reddish-yellow because a small amount of sand was mixed in the tile material and baked at a low temperature. The tiles are thin, no traces of fabric were identified, but traces of clay bands were identified. Tapping tool marks and traces of an anvil used in pottery production are clearly observed on the inside and outside, indicating that the tiles were made in the same way as earthenware manufacturing methods. If this is connected to the genealogy of the potters who made Gaya earthenware, it is estimated that tiles and earthenware were produced together as in the Songrim-ri ruins in Bulo-dong, Incheon, Songgok-dong ruins in Gyeongju, and Mulcheon-ri ruins. To date, tiles excavated from the Gimhae area have been identified only in places believed to be the Geumgwan Gaya City Wall (Royal Palace) in the Gimhae Basin. Considering what has been recorded so far and the geographical scenery, the Bonghwang-dong remains are the only city wall candidate site, and this is clearly revealed through the existence of the excavated tiles, which proves this. Considering that a small number of tiles were excavated during this time, it is estimated that the role of tiles as a luxury product with a symbolic meaning was greater than that of roofing materials, and there were strict restrictions and controls on its use.

• Journal of the Korea Institute of Building Construction
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• v.24 no.2
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• pp.181-191
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• 2024

In the realm of cement manufacturing, concerted efforts are underway to mitigate the emission of greenhouse gases. A significant portion, approximately 60%, of these emissions during the cement clinker sintering process is attributed to the decarbonation of limestone, which serves as a fundamental ingredient in cement production. Prompted by these environmental concerns, there is an active pursuit of alternative technologies and admixtures for cement that can substitute for limestone. Concurrently, initiatives are being explored to harness technology within the cement industry for the capture of carbon dioxide from industrial emissions, facilitating its conversion into carbonate minerals via chemical processes. Parallel to these technological advances, economic growth has precipitated a surge in construction activities, culminating in a steady escalation of construction waste, notably waste concrete. This study is anchored in the innovative production of calcium silicate cement clinkers, utilizing finely powdered waste concrete, followed by a thorough analysis of their mineral phases. Through X-ray diffraction(XRD) analysis, it was observed that increasing the substitution level of waste concrete powder and the molar ratio of SiO₂ to (CaO+SiO₂) leads to a decrease in Belite and γ-Belite, whereas minerals associated with carbonation, such as wollastonite and rankinite, exhibited an upsurge. Furthermore, the formation of gehlenite in cement clinkers, especially at higher substitution levels of waste concrete powder and the aforementioned molar ratio, is attributed to a synthetic reaction with Al₂O₃ present in the waste concrete powder. Analysis of free-CaO content revealed a decrement with increasing substitution rate of waste concrete powder and the molar ratio of SiO₂/(CaO+SiO₂). The outcomes of this study substantiate the viability of fabricating calcium silicate cement clinkers employing waste concrete powder.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.464-470
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• 2009

Purpose : This study assessed the incidence and outcome of congenital anomalies of the kidney and urinary tract (CAKUT) detected by prenatal ultrasonography Methods : There were 906 cases of CAKUT detected by prenatal ultrasonography and postnatally confirmed at the Asan Medical Center from October 1989 to October 2007. We investigated the incidence and outcome of these cases by reviewing medical records retrospectively. Results : The order of incidence was hydronephrosis, multicystic dysplastic kidney (MCDK), duplex kidney, vesico-ureteral reflux (VUR), single kidney, hydroureteronephrosis, ectopic kidney, polycystic kidney, ureterocele, and posterior urethral valve (PUV). There were 520 cases (57.4%) of hydronephrosis, and 20% of these needed an operation due to significant obstruction. MCDK was associated with other CAKUT in 25.4% of all cases. Approximately 57.9% of duplex kidney cases needed surgical treatment due to ureterocele and VUR. VUR had a male: female ratio of 10:1. Two out of seven cases of autosomal recessive polycystic kidney had progressed to chronic renal failure. Patients with PUV were relatively uncommon, and one out of nine cases progressed to end-stage renal disease. Conclusion : CAKUTs detected by prenatal ultrasonography were composed of various anomalies, and almost all of them had a good outcome without any intervention. However, in some cases, recurrent urinary tract infection or renal failure occurred, especially in bilateral cases. For further management, a long-term multicenter study is needed to investigate the precise incidence and outcome of each anomaly in the general population.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.62-67
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• 2014

A glomerular filtration rate (GFR) study is a test that uses radioactive materials or tracers (radiopharmaceuticals) and a computer to see how well the kidneys are working. Asan Medical Center analyzed and compared data between kidney depth, acquired from kidney donors' CT image and acquired from Gates method's GFR value that are calculated by Tonnesen equation. This study was able to confirm that kidney depth measured from CT image was higher than the Gates Method's GFR value, which was calculated by Tonnessen equation; the direct relationship among pathologic results is confirmed. Particularly, kidney donor whose kidney was at the pelvic area had direct relationship with other clinical results. During the GFR test, it is necessary to confirm the location of kidney has no change with reference of CT image. If kidney depth is manually corrected using CT image when we measures GFR of deformed or horse-shoe kidney, it would be possible to acquire the compatible value which is equivalent to clinical result. There would be a possible issue of appropriateness that whether the applied GFR using CT image's kidney depth has clinical validity. In case of a pediatric patient, the GFR derived from Tonnesen was quiet underestimated while manual method and Gordon stay in normal range. Which results may be correct among them? There have been many reports about kidney depth, to be an accurate index of GFR in children. As one of the study performers, we should contemplate what the best option for pediatric patients would be.

• Journal of Chest Surgery
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• v.35 no.8
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• pp.573-579
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• 2002

Background: In this study, the role and the surgical outcome of the modified Blalock-Taussig shunt in the treatment of the infants with cyanotic complex congenital heart diseases were investigated. Material and Method: Over the last 12 years, 105 modified BT shunts were performed in 100 infants. Postoperative course, shunt patency rate, complications, mortality and its risk factors were reviewed restrospectively. Result: The mean age at operation was 43.0$\pm$36.6 days. Sex ratio was 60:40(M:F). The postoperative oxygen saturations were lowest after mean duration of 11 hours after the shunt procedure. The operative mortality was 8%(8) with 3 late deaths. Causes of operative death included failure of maintenance of minimum oxygenation during the procedure(2), immediate postoperative shunt occlusion(2), respiratory failure(2), low cardiac output due to heart failure and pericardial effusion(2) and sepsis(2). Late deaths resulted from acute cardiac arrest during the follow up cardiac catheterization, hypoxic myocardial failure, and arrhythmia. Year of surgery, shunt size, age at operation, and complexity of the anomalies were not the risk factors for mortality. Six month shunt patency rate was 97% and overall patency rate was 96%. Postoperative complications comprised of shunt occlusion(6), phrenic nerve palsy(3), and wound infection(2). Conclusion: We demonstrated that modified Blalock-Taussig shunt was a useful tool to palliate the infants with complex cyanotic heart disease in whom early complete repair was not feasible with acceptable mortality and patency rate. An adequate postoperative management and a meticulous surgical technique may be key factors for the better results.