• Economic and Environmental Geology
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• v.46 no.5
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• pp.445-453
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• 2013

The Uiseong Tapriri Five-Storied Stone Pagoda (National Treasure No. 77) is typical stone cultural heritage in Unified Silla Dynasty, Korea. The pagoda has been occurred black, brown discoloration and microcrack, exfoliation, granularity decomposition with white discoloration because of continuous weathering. As the results of analysis for the contaminants, chemical weatherings are generated that black contaminant by manganese oxide, brown contaminant by iron oxide, white contaminants by gypsum and taranakite. And physical weatherings, such as microcrack, exfoliation, are occurred by salt(gypsum) crystallization. Therefore, these need to remove the contaminants according to the conservation treatment manual, and regular monitoring using P-XRF to preserve long-term the Five-Storied Stone Pagoda at Tapri-ri, Uiseong.

• Mycobiology
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• v.42 no.3
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• pp.262-268
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• 2014

Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as $0^{\circ}C$. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of fruits, including table grapes and oranges, has received much attention in European countries. However, to the best of our knowledge there has been no report of the use of thymol fumigation to control gray mold in table grapes in Korea. Thymol ($30{\mu}g/mL$) and linalool ($120{\mu}g/mL$) significantly inhibited mycelial growth and conidia germination of B. cinerea. The occurrence rate of gray mold rot of B. cinerea and other unknown fungi was significantly reduced by fumigation with $30{\mu}g/mL$ thymol in several table grape cultivars, such as Campbell early, Muscat Bailey A, Sheridan, and Geobong. In this study, fumigation with $30{\mu}g/mL$ thymol, had no influence on the sugar content and hardness of grapes, but reduced fungal infection significantly. This suggests that $30{\mu}g/mL$ thymol could be utilized to reduce deterioration of grapes due to gray mold and other fungal infections during long-term storage.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.232-238
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• 2001

Effects of atmospheric nitrogen deposition on terrestrial ecosystems were reviewed and discussed in this paper. The amount of nitrogen deposition has increased rapidly in Europe, North America and Korean due to industrialization, increase in fossil fuel combustion(automobiles in particular), and intensive agricultural activities. Nitrogen input through such deposition may enhance primary productivity at early stage, but it could cause nitrogen saturation and hence deterioration of forests of disturbance of systems in the long term. Mechanisms of the deterioration of forests by nitrogen deposition include nutrients imbalance, soil acidification, and immobilization of toxic ions. In addition, nitrogen deposition may impede the decomposition rates of soil organic matter, and induce eutrophication in aquatic ecosystems by enhanced leaching of nitrate. Finally, I propose several topics in relation to nitrogen deposition, which warrant further studies in Korea.

• Journal of Korean Neurosurgical Society
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• v.63 no.3
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• pp.346-357
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• 2020

During the follow-up period after surgery for spinal dysraphism, a certain portion of patients show neurological deterioration and its secondary phenomena, such as motor, sensory or sphincter changes, foot and spinal deformities, pain, and spasticity. These clinical manifestations are caused by tethering effects on the neural structures at the site of previous operation. The widespread recognition of retethering drew the attention of medical professionals of various specialties because of its incidence, which is not low when surveillance is adequate, and its progressive nature. This article reviews the literature on the incidence and timing of deterioration, predisposing factors for retethering, clinical manifestations, diagnosis, surgical treatment and its complications, clinical outcomes, prognostic factors after retethering surgery and preventive measures of retethering. Current practice and opinions of Seoul National University Children's Hospital team were added in some parts. The literature shows a wide range of data regarding the incidence, rate and degree of surgical complications and long-term outcomes. The method of prevention is still one of the main topics of this entity. Although alternatives such as spinal column shortening were introduced, re-untethering by conventional surgical methods remains the current main management tool. Re-untethering surgery is a much more difficult task than primary untethering surgery. Updated publications include strong skepticism on re-untethering surgery in a certain group of patients, though it is from a minority of research groups. For all of the abovementioned reasons, new information and ideas on the early diagnosis, treatment and prevention of retethering are critically necessary in this era.

• Journal of Conservation Science
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• v.17 s.17
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• pp.5-18
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• 2005

Rock materials of the Stone Lantern in the Gwanchoksa temple was composed of dark grey granodiorite. This Stone Lantern is partly structural distortion as S-shape, especially, rocks of the upper supports and under the roof materials were highly deterioration due to the surface exfoliation, and strong secondary contaminations owing to the discoloration by oxidation of inserted iron plates between the rock properties, and white grey to dark black contaminants along the rain path way. Rock surface of the Stone Lantern occurred as partly green patches because of coated by algae, lichen and moss. This biological problems are need for cleaning and treatments. The Stone Lantern have to be considered to conservation method that can reduce weathering factors with long-term monitoring about environmental change for structural stability, surface degradation and mechanical weathering. Materials of the Stone Lantern and basement rocks of the area are consisted of same petrogenetic granodiotite based on occurrences, petrological and geochemical characteristics.

• Journal of Conservation Science
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• v.30 no.4
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• pp.439-446
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• 2014

We carried out monitoring of deterioration condition for the Rock-carved Buddha Triad in Seosan after dismantlement of protective facilities and conservation treatment. As the results of ultrasonic velocity measurement, physical properties of rock were evaluated to maintain similar the past. Result of digital image analysis, white discoloration was reoccured after four years of conservation treatments. And biodeterioration of unknown in the past was generated left side on the Rock-carved Buddha. Phenomenon of biodeterioration on the surface rocks was estimated by variation of sunshine and water contents according to topography condition.

• Structural Monitoring and Maintenance
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• v.2 no.1
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• pp.35-48
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• 2015

The main objective of this study is to evaluate the long-term performance of various concrete composites in natural marine environment prevailing in the Gulf region. Durability assessment studies of such nature are usually carried out under aggressive environments that constitute seawater, chloride and sulfate laden soils and wind, and groundwater conditions. These studies are very vital for sustainable development of marine and off shore reinforced concrete structures of industrial design such as petroleum installations. First round of testing and evaluation, which is presented in this paper, were performed by standard tests under laboratory conditions. Laboratory results presented in this paper will be corroborated with test outcome of ongoing three years field exposure conditions. The field study will include different parameters of investigation for high performance concrete including corrosion inhibitors, type of reinforcement, natural and industrial pozzolanic additives, water to cement ratio, water type, cover thickness, curing conditions, and concrete coatings. Like the laboratory specimens, samples in the field will be monitored for corrosion induced deterioration signs and for any signs of failureover initial period ofthree years. In this paper, laboratory results pertaining to microsilica (SF), ground granulated blast furnace slag (GGBS), epoxy coated rebars and calcium nitrite corrosion inhibitor are very conclusive. Results affirmed that the supplementary cementing materials such as GGBS and SF significantly impacted and enhanced concrete resistivity to chloride ions penetration and hence decrease the corrosion activities on steel bars protected by such concretes. As for epoxy coated rebars applications under high chloride laden conditions, results showed great concern to integrity of the epoxy coating layer on the bar and its stability. On the other hand corrosion inhibiting admixtures such as calcium nitrite proved to be more effective when used in combination with the pozzolanic additives such as GGBS and microsilica.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3271-3276
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• 2016

Background: Intracranial nonvestibular schwannomas arising from various cranial nerves excluding CN VIII are uncommon. Recently, stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) have been widely reported as effective treatment modalities for nonvestibular schwannomas. The purpose of this study was to study the long term clinical outcome for nonvestibular schwannomas treated with both X-Knife and CyberKnife (CK) radiosurgery at one institution. Materials and Methods: From 2004 to 2013, fifty-two nonvestibular schwannoma patients were included in this study, 33 patients (63%) were treated with CK, and 19 (37%) were treated with X-Knife. The majority of the tumors were jugular foramen schwannomas (38%) and trigeminal schwannomas (27%). HSRT was given for 45 patients (86%), whereas CSRT was for 6 (12%) and SRS for 1 (2%). Results: The median pretreatment volume was $9.4cm^3$ (range, $0.57-52cm^3$). With the median follow up time of 36 months (range, 3-135), the 3 and 5 year progression free survival was 94 % and 88%, respectively. Tumor size was decreased in 13 (25%), stable in 29 (56%), and increased in 10 (19%). Among the latter, 3 (30%) required additional treatment because of neurologic deterioration. No patient was found to develop any new cranial nerve deficit after SRS/SRT. Conclusions: These data confirmed that SRS/SRT provide high tumor control rates with low complications. Large volume tumors and cystic expansion after radiation should be carefully followed up with neurological examination and MRI, because it may frequently cause neurological deterioration requiring further surgery.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.10-20
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• 2013

Because of the defect in design, damage in using period, and deterioration in long term exposure to severe environmental condition, degradation of performance in RC (Reinforced Concrete) structures has occurred. This paper contains durability performance evaluation in railway bridges which covers eight districts through field investigation. For the target structures, durability performance is evaluated and the critical problems in use are derived. Additionally, service lifes for the deteriorated structures are evaluated through Durability-Environment index method based on the results from field investigation, and the results are compared with those from the condition assuming the structures without defect, damage, and deterioration. The target structures which consist of RC T girder, PSC girder, RC box, and Rahmen are investigated and the critical damage patterns are derived. They are evaluated to be cracks in PSC girder end, flexural cracks in PSC girder, crack around EPT anchor, and flexural cracks in RC T girder and RC box. The reasons for the critical patterns are also investigated. This study can be utilized for the repair planning considering the different district and the structure types.

• Journal of Conservation Science
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• v.29 no.4
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• pp.321-332
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• 2013

Namwon Singyeri Maaeyeoraejwasang (Rock-Carved Seated Buddha Statue) is composed mainly foliated granite and is different metamorphic grade and weathering degree on rock location. As the results of deterioration evaluation, upper part of the buddha statue was estimated that granularity decomposition was serious and rock strength was lower than lower part. Furthermore organism assessed most effect of among weathering factors. Chl. a amount of organism species were calculated $0.2{\mu}g/cm^2$ of crustaceous lichen, $1.1{\mu}g/cm^2$ of foliose lichen, $2.3{\mu}g/cm^2$ of bryophyte. Organism was taken treatment in order of amount of Chl. a and pre-cleaning, dry cleaning, wet cleaning in sequence. It should be establish conservation plan that strengthening in consideration of lithology characteristics and setting in good condition environment to conserve long-term of Maaeyeoraejwasang.