• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.4
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• pp.174-181
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• 2016

Objectives: This retrospective study aims to evaluate the prevalence of maxillofacial trauma in a developing country, along with its pattern, etiology and management. Data for the present study were collected from the Department of Dentistry, ESIC Medical College and Post Graduate Institute of Medical Sciences and Research, Chennai in India. Materials and Methods: The medical records of patients treated for maxillofacial injuries between May 2014 and November 2015 were retrospectively retrieved and analyzed for prevalence, pattern, etiology, and management of maxillofacial trauma. SPSS software version 16.0 was used for the data analysis. Results: Maxillofacial fractures accounts for 93.3% of total injuries. The mean and standard deviation for the age of the patients were $35.0{\pm}11.8$ years and with a minimum age of 5 years and maximum age of 75 years. Adults from 20 to 40 years age groups were more commonly involved, with a male to female ratio of 3:1. There was a statistically significantly higher proportion of males more commonly involved in accident and injuries (P <0.001). Conclusion: The most common etiology of maxillofacial injury was road traffic accidents (RTA) followed by falls and assaults, the sports injuries seem to be very less. In RTA, motorized two-wheelers (MTW) were the most common cause of incidents. The majority of victims of RTA were young adult males between the ages of 20 to 40 years. The malar bone and maxilla were the most common sites of fracture, followed by the mandible. The right side of the zygomatic complex was the predominant side of MTW injury. The majority of the zygomatic complex fractures were treated by conservative management. Open reduction and internal fixation were performed for indicated fracture patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.1
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• pp.31-34
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• 2009

Purpose: This study compared the frequency of postoperative infections in patients for a closed mandibular fracture with that without the postoperative antibiotic prophylaxis. Patients and Methods: 48 patients without any specific medical history were divided into two groups depending on whether or not antibiotics had been applied after the surgery. The 24 patients in group 1 received only a second-generation cephalosporin ($Cefotetan^{(R)}$) intravenously from admission to immediate after the surgery. Likewise, 24 patients in group 2 received 1.0g of $Cefotetan^{(R)}$ twice daily longer than the third day after surgery. The mean (SD) duration of antibiotics administration after surgery was 6.9 (${\pm}3.56$). The patients were evaluated after surgery for any postoperative infections according to the criteria: purulent drainage from a wound, spontaneous wound dehiscence accompanied by swelling, pain, and fever around the wound. Results: Postoperative infections were encountered in 2 out of 24 patients in group 1, who received antibiotic medication until shortly after surgery, and in 3 out of the 24 patients in group 2, in whom the medication was continued even after the surgery. There was no sig nificant difference in the incidence of postoperative infections between the two groups. Conclusion: From this study, postoperative use of antibiotics seems to be unnecessary with view of the little significance of the factors that could affect the wound infection.

• Corrosion Science and Technology
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• v.16 no.3
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• pp.100-108
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• 2017

In this investigation corrosion behavior of newly developed high-pressure die cast Al-Ni (N15) and Al-Ni-Ca (NX1503) alloys was studied in 3.5% NaCl solution. The electrochemical corrosion behavior was evaluated using open circuit potential (OCP) measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization results validated that NX1503 alloy exhibited lower corrosion current density ($i_{corr}$) value ($5.969{\mu}A/cm^2$) compared to N15 ($7.387{\mu}A/cm^2$). EIS-Bode plots revealed a higher impedance (${\mid}Z{\mid}$) value and maximum phase angle value for NX1503 than N15 alloy. Equivalent circuit curve fitting analysis revealed that surface layer ($R_1$) and charge transfer resistance ($R_{ct}$) values of NX1503 alloy was higher compared to N15 alloy. Immersion corrosion studies were also conducted for alloys using fishing line specimen arrangement to simultaneously measure corrosion rates from weight loss ($P_W$) and hydrogen volume ($P_H$) after 72 hours and NX1503 alloy had lower corrosion rate compared to N15 alloy. The addition of Ca to N15 alloy significantly reduced the Al3Ni intermetallic phase and further grain refinement may be attributed for reduction in the corrosion rate.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.457-464
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• 2014

Recently, interests in space information data are increasing due to the initiation of spatial information open platform service by the Ministry of Land, Infrastructure and Transport. The purpose of this study is optimizing management and storing of the texture data, one kinds of 3D-spatial data. First, extract 3D-spatial data through the aerial triangulation and 3D-writing using raw image taken with the Multi-directional aerial camera and the vertical aerial camera. And develop the method to create single texture data and related technique by align and place corresponding 3D-spatial data to optimal storage space. Through experiment, the results show effect of 8 times of storage capacity reduction compared to existing single-file storage method, additionally, new method can improve file management efficiency in comparison with multiple file storage method. The results of this study can be cornerstone of three-dimensional space information management when dealing with bulk data, and utilizations will be enhanced through the further studies and algorithm improvement.

• Architectural research
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• v.22 no.1
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• pp.13-21
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• 2020

The purpose of this study was to evaluate the variation in building energy predictions caused by simulation settings related to building envelop thickness. The study assessed the ceiling depth impact on skylight energy performance through OpenStudio integrated Radiance and EnergyPlus simulation programs. A ceiling as deep as 1.5 to 3m was analyzed for skylight to roof ratios from 1% to 25%. The results indicated that the building ceiling depth negatively affected the capability of skylights to significantly reduce building energy consumption. Through a parametric analysis, the study concluded that 8%, 9%, 10% and 11% skylight to roof ratio were optimal in terms of total building energy consumption for a ceiling depth of 1.5m, 2m, 2.5m and 3m, respectively. In addition, the results showed that the usually recommended 5% skylight to roof ratio was only efficient when no ceiling depth was included in the simulation model. Furthermore, the study indicated that the building energy saved by the optimal skylight of each ceiling depth decreased as the ceiling depth deepened. The highest total building energy reduction was 9%, 7%, 5% and 3% for a ceiling depth of 1.5m, 2m, 2.5m and 3m, respectively. This study induced that the solar heat gains and daylight visible transmittance by ceiling depth were crucial in the predictions of skylight energy performance and should not be neglected through building simulation simplifications as it is commonly done in most simulation programs' settings.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.177-180
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• 2003

A glassy carbon electrode(GCE) modified with nafion-DTPA-glycerol was used for the highly selective and sensitive determination of a trace amount of Cu$\^$2+/. Various experimental parameters, which influenced the response of nafion-DTPA-glycerol modified electrode to Cu$\^$2+/, were optimized. The copper(II) was accumulated on the electrode surface by the formation of the complex in an open circuit, and the resulting surface was characterized by medium exchange, electrochemical reduction, and differential pulse voltammetry, A linear range was obtained in the concentration range 1.0${\times}$10$\^$-8/M∼1.0${\times}$10$\^$-6/M Cu(II) with 7 min preconcentration. Further, when an approximate amount of lead(II) is added to the test solution, nafion-DTPA-glycerol modified glassy carbon electrode has a dynamic range of 2 orders magnitude(1.0${\times}$10$\^$-9/M∼1.0${\times}$10$\^$-7/M). The detection limit(3 $\sigma$) was as low as 5.0${\times}$10$\^$-6/M(0.032ppb). The interferences from other metal ions could be reduced by adding KCN into the sample solutions. This method was applied to the determination of coppe,(II) in certified reference material(3.23${\times}$10$\^$-7/M, 21ppb), sea water(9.50${\times}$10/sup-7/M, 60ppb). The result agrees satisfactorily with the value measured by Korea Research Institute of Standard and Science.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.170-183
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• 2020

Objectives: This study was conducted to estimate a technology to reduce hydrogen sulfide (H₂S) in sewage odor using microbial deodorant. Methods: After injecting five commercially available microbial deodorants into fresh sewage, the concentration of hydrogen sulfide over time was measured using the headspace method. H₂S concentration in odor samples was measured using gas chromatograph/FPD. Calculated odor concentration and calculated odor intensity by H₂S concentration remaining after treatment with microbial deodorant were evaluated theoretically. Results: The rate of H₂S abatement by microbial deodorant differed depending on the experimental conditions and the type of deodorant, but it was found to range from 63 to 82%. Especially, two deodorants showed high H₂S reduction rates of over 80% on average. However, based on the best deodorant, the theoretically calculated odor concentration by H₂S after microbial deodorant treatment was 4,400 OU_k, and the theoretical odor intensity was also rated at 4 degrees or higher. Conclusions: In conclusion, microbial deodorant is considered to have a relatively high effect on reducing H₂S in sewage odor. However, even after treatment with microbial deodorant, calculated odor concentration and calculated odor intensity were relatively high. This is thought to be caused by other odorous substances besides H₂S.

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.105-109
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• 2005

Purpose: We compared the clinical features of the ankle fractures treated by operation between the elderly and the young, and reviewed the principles of treatment of the ankle fractures in the elderly. Materials and Methods: We reviewed 49 cases of the ankle fractures, which were treated by open reduction from August 1991 to July 2002. Patients aged more than 60 were designated as the elderly, and patients aged between 15 and 33 were designated as the young. The average follow-up period was 13.2 months. Using the Lauge-Hansen classification, We defined stage I or II fractures as low stage and stage III or IV fractures as high stage fractures. Results: There were 15 cases of high stage fractures (78.9%) in the elderly and 11 cases (36.7%) in the young. High stage fracture rate was significantly higher in the elderly (P=0.004). Hospital day, period between primary injury and operation, and union time were significantly longer in the elderly (P<0.001). However, there was no statistical difference in immobilization time between the two groups. The results of treatment were satisfactory clinically and radiologically by the Meyer's criteria in both groups. Conclusion: In the elderly, high stage fractures were more common and longer hospitalization and union time were needed than the young. However, the result of surgical treatment was satisfactory.

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.94-98
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• 2005

Purpose: To compare the radiographic evaluations between two radiographic views (AP and lateral views) and four radiographic views (AP, lateral and both oblique views) in ankle fractures. Materials and Methods: From January 2000 to June 2002, 60 cases of ankle fractures were treated with open reduction and internal fixation and its followed up periods were at least 2 years. All cases were classified into three groups according to the method of preoperative radiographic evaluation. Two radiographic views (AP and lateral views) were taken in group A and four radiographic views (AP, lateral and both oblique views) were taken in group B. 12 Cases were evaluated with three dimensional computed tomography (3D CT). Four radiographic views and 3D CT were taken in group C. All cases were classified according to the Danis-Weber and Lauge-Hansen classification. Displacement of fracture fragment of medial, lateral, posterior malleolus and size of fracture fragment of posterior malleous were measured using picture archiving communication system (PACS). Results: Although kappa value between two or four radiographic views were good or excellent in Danis-Weber classification and Lauge-Hansen classification of ankle fractures, the displacements of medial and lateral malleoli were statistically different. Four radiographic views evalulated the degree of displacement of medial and lateral fragments more accurately compared to two radiographic views. Conclusion: Four radiographic views will be more useful than two radiographic views to decide the method of treatment and operation considering the displacement of fracture fragment.

• Journal of Electrochemical Science and Technology
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• v.2 no.2
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• pp.110-115
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• 2011

The effect of $TiO_2$ nanotube (TNT) and nanoparticle (TNP) composite photoelectrode and the role of TNT to enhance the photo conversion efficiency in dye-sensitized solar cell (DSSC) have investigated in this study. Results demonstrated that the increase of the TNT content (1-15 %) into the electron collecting TNP film increases the open-circuit potential ($V_{oc}$) and short circuit current density ($J_{sc}$). Based on the impedance analysis, the increased $V_{oc}$ was attributed to the suppressed recombination between electrode and electrolyte or dye. Photochemical analysis revealed that the increased Jsc with the increased TNT content was due to the scattering effect and the reduced electron diffusion path of TNT. The highest $J_{sc}$ (12.6 mA/$cm^2$), Voc (711 mV) and conversion efficiency (5.9%) were obtained in the composite photoelectrode with 15% TNT. However, $J_{sc}$ and $V_{oc}$ was decreased for the case of 20% TNT, which results from the significant reduction of adsorbed dye amount and the poor attachment of the film on the fluorine-doped tin oxide (FTO). Therefore, application of this composite photoelectrode is expected to be a promising approach to improve the energy conversion efficiency of DSSC.