• Clean Technology
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• v.25 no.2
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• pp.147-152
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• 2019

Electrostatic precipitator that shows a good performance for the removal of particulate matter is important for controlling emissions from industrial facilities and power plants. The efficiency of the electrostatic precipitator on the removal of particulate matter is highly affected by the flow pattern inside the electrostatic precipitator. A number of studies have been conducted to obtain uniform flow distribution inside electrostatic precipitators. An electrostatic precipitator (ESP) with a length of 3.5 m and a height of 0.875 m was designed and installed in this study. The ESP included an inlet duct, diffuser, body, and contractor. Three perforated plates were installed in the diffuser of the ESP. Five pitot tubes were installed vertically and used to measure flow distribution in the cross section of the ESP body. Root mean square deviation value (RMS%) was used to examine the flow distribution inside the ESP when the perforated plates were installed in the diffuser. Flow distribution was also investigated in relation to the porosity of the perforated plate. The results showed that the perforated plates improved greatly the flow distribution inside the electrostatic precipitator. In addition, the most uniform flow distribution was found with 40%, 50%, and 50% porous perforated plates located from the inlet of the diffuser.

• Ecology and Resilient Infrastructure
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• v.9 no.4
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• pp.269-281
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• 2022

The prediction of changes regarding the distribution of vegetation and plant species according to climate changes is important for ecosystem management. In this study, we attempted to develop an assessment method to evaluate the possibility of the potential distribution of warm-temperate woody plant species of East Asia in Korea. To begin with, a list of warm-temperate woody plants distributed in China and Japan, but not in Korea, was prepared, and a database consisting their global distribution and bioclimatic variables was constructed. In addition, the warm-temperate vegetation zone in Korea was delineated using the coldness index and relevant bioclimatic data were collected. After the exclusion of multicollinearity among bioclimatic variables using correlation analysis, mean temperature of the coldest quarter, mean temperature diurnal range, and annual precipitation were selected as the major variables that influence the distribution of warm-temperate plants. A multivariate environment similarity surfaces (MESS) analysis was conducted to calculate the similarity scores between the distribution of these three bioclimatic variables in the global distribution sites of the East Asian warm-temperate woody plants and the Korean warm-temperate vegetation zone. Finally, using stepwise variable-selection regression, the mean temperature of the coldest quarter and annual precipitation were selected as the main bioclimatic variables that affect the MESS similarity index. The mean temperature of the coldest quarter accounted for 88% of the total variance. For a total of 319 East Asian warm-temperate woody plant species, the possibility of their potential distribution in Korea was evaluated by applying the constructed multivariate regression model that calculates the MESS similarity index.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.96-109
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• 2024

Background: Khyber Pakhtunkhwa government initiated the Billion Tree Tsunami Afforestation Project including regeneration and afforestation approaches. An effort was made to assess the distribution characteristics of afforested species under present and future climatic scenarios using ecological niche modelling. For sustainable forest management, landscape ecology can play a significant role. A significant change in the potential distribution of tree species is expected globally with changing climate. Ecological niche modeling provides the valuable information about the current and future distribution of species that can play crucial role in deciding the potential sites for afforestation which can be used by government institutes for afforestation programs. In this context, the potential distribution of 8 tree species, Cedrus deodara, Dalbergia sissoo, Juglans regia, Pinus wallichiana, Eucalyptus camaldulensis, Senegalia modesta, Populus ciliata, and Vachellia nilotica was modeled. Results: Maxent species distribution model was used to predict current and future distribution of tree species using bioclimatic variables along with soil type and elevation. Future climate scenarios, shared socio-economic pathways (SSP)2-4.5 and SSP5-8.5 were considered for the years 2041-2060 and 2081-2100. The model predicted high risk of decreasing potential distribution under SSP2-4.5 and SSP5-8.5 climate change scenarios for years 2041-2060 and 2081-2100, respectively. Recent afforestation conservation sites of these 8 tree species do not fall within their predicted potential habitat for SSP2-4.5 and SSP5-8.5 climate scenarios. Conclusions: Each tree species responded independently in terms of its potential habitat to future climatic conditions. Cedrus deodara and P. ciliata are predicted to migrate to higher altitude towards north in present and future climate scenarios. Habitat of D. sissoo, P. wallichiana, J. regia, and V. nilotica is practiced to be declined in future climate scenarios. Eucalyptus camaldulensis is expected to be expanded its suitability area in future with eastward shift. Senegalia modesta habitat increased in the middle of the century but decreased afterwards in later half of the century. The changing and shifting forests create challenges for sustainable landscapes. Therefore, the study is an attempt to provide management tools for monitoring the climate change-driven shifting of forest landscapes.

• BMB Reports
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• v.40 no.5
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• pp.617-624
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• 2007

Protein arginine methylation is a posttranslational modification involved in various cellular functions including cell signaling, protein subcellular localization and transcriptional regulation. We analyze the protein arginine methyltransferases (PRMTs) that catalyze the formation of methylarginines in porcine brain. We fractionated the brain extracts and determined the PRMT activities as well as the distribution of different PRMT proteins in subcellular fractions of porcine brain. The majority of the type I methyltransferase activities that catalyze the formation of asymmetric dimethylarginines was in the cytosolic S3 fraction. High specific activity of the methyltransferase was detected in the S4 fraction (high-salt stripping of the ultracentrifugation precipitant P3 fraction), indicating that part of the PRMT was peripherally associated with membrane and ribosomal fractions. The amount and distribution of PRMT1 are consistent with the catalytic activity. The elution patterns from gel filtration and anion exchange chromatography also indicate that the type I activity in S3 and S4 are mostly from PRMT1. Our results suggest that part of the type I arginine methyltransferases in brains, mainly PRMT1, are sequestered in an inactive form as they associated with membranes or large subcellular complexes. Our biochemical analyses confirmed the complex distribution of different PRMTs and implicate their regulation and catalytic activities in brain.

• The korean journal of orthodontics
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• v.41 no.3
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• pp.191-199
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• 2011

Objective: The purpose of this study was to investigate the stress distribution on the orthodontic mini-implant (OMI) surface and periodontal ligament of the maxillary first and second molars as well as the tooth displacement according to the OMI position in the dragon helix appliance during scissors-bite correction. Methods: OMIs were placed at two maxillary positions, between the first and the second premolars (group 1) and between the second premolar and the first molar (group 2). The stress distribution area (SDA) was analyzed by three-dimensional finite element analysis. Results: The maximal SDA of the OMI did not differ between the groups. It was located at the cervical area and palatal root apex of the maxillary first molar in groups 1 and 2, respectively, indicating less tipping in group 2. The minimal SDA was located at the root and furcation area of the maxillary second molar in groups 1 and 2, respectively, indicating greater palatal crown displacement in group 2. Conclusions: Placement of the OMI between the maxillary second premolar and the maxillary first molar to serve as an indirect anchor in the dragon helix appliance minimizes anchorage loss while maximizing the effect on scissors-bite correction.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.2
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• pp.113-119
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• 2017

Background: The purpose of this study was to investigate the distribution of systemic diseases and medications in patients older than 65 years of age who visited the hospital for implant treatment, as well as to investigate basic information about surgical complications that may occur after insured implant treatment. Method: A total of 126 patients over 65 years of age were treated for implant surgery from October 1, 2013 to October 30, 2016. Electronic chart review was conducted to obtain medical records, which included sex, age, systemic diseases, medication(s) being taken, and control of the medications. Five patients were excluded due to lack of medical records giving information about systemic disease. Results: Of the 126 patients, 112 (88.9%) were taking medication due to systemic disease and 9 patients (7.1%) were not. The sex distribution was 71 women and 55 men and the highest proportion of patients were between 65 and 69 years old. The most common diseases were, from most to least frequent, hypertension, cardiovascular disease, diabetes, and osteoporosis. The drug groups that can cause major complications after dental treatment were classified as hemorrhagic, osteoporotic, and immunosuppressive agents, and were taken by 45 (35.7%), 22 (17.5%) and 4 (3.2%) patients, respectively. Conclusion: Given that 88.9% of the elderly patients who were eligible for insurance implant treatment had systemic disease, it is necessary to carefully evaluate patients' medical histories and their general conditions in order to prevent emergencies during implant surgery.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.243-247
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• 1986

174 patients who visited in the Department of Dentistry, College of Medicine, Yeungnam University from 1983. 7. 15 to 1986. 11. 30 were surveyed on the tendency of patient distribution and the state of Angle's classification. The results were as follows : 1. There was increased visiting rate of patient per year. Female outnumbered male by a ratio of 1.3 : 1. 2. 8-15 age group was 74% in total visiting in the most frequency. The average visiting numbers of each month were higher among the vacation and was about 74% in that period. 3. As showed the living distribution, Nam Gu and Su Sung Gu's patients were 53% of the total. 4. As the motive of visiting in Dental Department, patients of 30% in total patients visited for themself to receive orthodontic treatment and others was introduced patients. 5. By classification, Class I malocclusion was 63% in total visiting patient, Class II malocclusion 17%, ClassIII malocclusion 20%. Crowding among Class I malocclusion was 60%.

• Journal of Korean Neurosurgical Society
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• v.58 no.2
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• pp.112-118
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• 2015

Objective : Thoracic ossification of the ligamentum flavum (OLF) is a relatively rare disease. Because of ambiguous clinical symptom, it is difficult for early diagnosis of OLF and subsequent treatment can be delayed or missed. Therefore, the purpose of this study is to comprehensively assess the prevalence and distribution of thoracic OLF by magnetic resonance imaging (MRI) and coexisting spinal disease in Korean patients with back pain or leg pain. Methods : The sample included 2134 Korean patients who underwent MRI evaluation for back pain. The prevalence and distribution of thoracic OLF were assessed using lumbar MRI with whole spine sagittal images. Additionally, we examined the presence of coexisting lumbar and cervical diseases. The presence of thoracic OLF as well as clinical parameters such as age, sex, and surgery were retrospectively reviewed. Results : The prevalence of thoracic OLF in total patients was 16.9% (360/2134). The prevalence tended to increase with aging and was higher in women than in men. The lower thoracic segment of T10-11 was the most frequently affected segment. Of the 360 patients with OLF, 31.9% had coexisting herniated thoracic discs at the same level. Approximately 74% of the patients with OLF had coexisting lumbar and cervical disease. Nine (2.5%) of 360 OLF patients underwent surgery for thoracic lesion. Conclusion : The prevalenceof thoracic OLF was relatively higher than those of previous reports. And coexisting lumbar and cervical disease were very frequent. Therefore, we should check coexisting spinal diseases and the exact diagnostic localization of ossification besides lumbar disease.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.117-125
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• 2011

There are many studies reporting the average carbon dioxide levels in various indoor spaces. However, there have been a few studies showing how carbon dioxide concentration varied at many measurement points in one indoor space. In this study, the changes of indoor carbon dioxide concentration at classroom, library, and kindergarten were reported to find its carbon dioxide distribution change at various locations and altitudes. The maximum carbon dioxide concentration of the 3 sites were measured as 2,684, 2,295, and 1,526 ppm, respectively. These values exceeded the guideline concentration of 1,000 ppm for public places. The concentration of carbon dioxide was higher at upper area than lower area, and this is probably due to the rise of warm breathing air generated from students. In the upper area, the carbon dioxide concentration was higher at center area than four corners. However, in the lower area, the carbon dioxide concentration was higher at four corners than center area. Therefore, it could be concluded that the center of upper area is the best place for the installation of ventilation or carbon dioxide removal system.

• Korean Journal of Materials Research
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• v.20 no.9
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• pp.457-462
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• 2010

Adsorption of a water molecule on a Si (001) surface and its dissociation were studied using density functional theory to study the distribution of -OH fragments on the Si surface. The Si (001) surface was composed of Si dimers, which buckle in a zigzag pattern below the order-disorder transition temperature to reduce the surface energy. When a water molecule approached the Si surface, the O atom of the water molecule favored the down-buckled Si atom, and the H atom of the water molecule favored the up-buckled Si atom. This is explained by the attractions between the negatively charged O of the water and the positively charged down-buckled Si atom and between the positively charged H of the water and the negatively charged up-buckled Si atom. Following the adsorption of the first water molecule on the surface, a second water molecule adsorbed on either the inter-dimer or intra-dimer site of the Si dimer. The dipole-dipole interaction of the two adsorbed water molecules led to the formation of the water dimer, and the dissociation of the water molecules occurred easily below the order-disorder transition temperature. Therefore, the 1/2 monolayer of -OH on the water-terminated Si (001) surface shows a regular distribution. The results shed light on the atomic layer deposition process of alternate gate dielectric materials, such as $HfO_2$.