• Korean Chemical Engineering Research
• /
• v.55 no.3
• /
• pp.341-352
• /
• 2017

Butyl acetate is produced from acetic acid and butanol via an esterification reaction in a reactive distillation column. Entrainer can be used for efficient removal of produced water from the reaction region, leading to significant improvement of the column performance. Batch reactive distillation has clear advantages over continuous one in terms of flexibility and adaptability in a small plant. We studied batch and semi-batch reactive distillation processes through process simulation and pilot-scale experiments. We investigated process configuration and type of entrainer for improvement of the column performance and suggested a novel cyclic operation strategy using the semi-batch reactive distillation column. The cyclic strategy was shown to give relatively high production rate and stable operation.

• KSBB Journal
• /
• v.24 no.1
• /
• pp.17-24
• /
• 2009

For the biosurfactant production process at first Candida bombicola, Sphingomonas yanoikuyae, Sphingomonas chungbukensis and Myxococcus flavescens were studied. As the most productive microorganisms C. bombicola, S. yanoikuyae and S. chungbukensis were selected. During many petrochemical industrial processes variable volatile organic componds are produced and they can cause an unpleasent and unhealthy atmosphere. Usually the volatile organic compounds are treated with chemical detergents. The chemical detergents cannot be easily degradable and can be accumulated in the nature. In this study we tried to develop a production process for the biosurfactants, which can substitute some chemical detergents in some chemical processes, with microorganisms. At second the treatment of the volatile organic compounds with the biosurfactants were tested and compared with the treatment with chemical detergent. The production productivities of the biosurfactant with microorganisms were compared. The growth patterns and kinetics of the microbial cells and the surface tension values of the biosurfactants were studied. The changes of the surface tension in variable pH conditions and sodium chloride concentrations were also studied. The volatile organic carbons were treated in a small plant scale. As the result of this study, it indicated that the specific growth rate of S. chungbukensis was the fastest by 0.144 ($hr^{-1}$). For surface tension, C. bombicola (38.1 dyne/cm) had the lowest value, and solubility of the volatile organic carbon was similar in C. bombicola and S. chungbukensis. (Toluene: about 0.1 Unit, Chloroform: about 0.6${\sim}$0.7 Unit, Benzene: about 0.5${\sim}$0.8 Unit). The biosurfactant, which were produced by C. bombicola, was selected for the further study for the volatile organic carbon treatment. With the biosurfactans from C. bombicola could remove the volatile organic carbon about 80% and this removal rate can be comparable with chemical detergent.

• Spatial Information Research
• /
• v.6 no.1
• /
• pp.11-23
• /
• 1998

Map generalization functions to visualize the spatial data or to change their scale by changing the level of details of data. Until recently, the studies on map generalization have concentrated more on line features than on point features. However, point features are one of the essential components of digital maps and cannnot be ignored because of the great amount of information they carry. This study, therefore, aimed to find out a detailed procedure of point features' generalization. Particularly, this work chose the distribution pattern of point features as the most important factor in the point generalization in investigating the geometric characteristics of source data. First, it attempted to find out the characteristics of distribution pattern of point features through quadrat analysis with Grieg-Smith method and nearest-neighbour analysis. It then generalized point features through the generalization threshold which did not alter the characteristics of distribution pattern and the removal of redudant point feautres. Therefore, the generalization procedure of point features provided by this work maintained the geometric characteristics as much as possible.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.33 no.4
• /
• pp.375-380
• /
• 2007

The purpose of this study is to understand anxiety in patients undergoing third molar extraction and care patients of third molar extraction. The subjects in the study were Sixty-three patients who visited the department of dentistry at Pusan Paik Hospital from May 2006 to September 2006 and who underwent third molar extraction. Patients' anxiety(state anxiety and trait anxiety) to use Spielberger's state-trait anxiety inventory(STAI) were measured. They were asked to fill out STAI question paper immediately before third molar extraction(pre-extraction) and on the day after the extraction(post-extraction). And visual analog scale(VAS) to measure patient's postoperative pain on the day after extraction(postextraction day) was used. Then Differences in anxiety before and after extraction, between men and women, between the first and second extraction, with impacted versus non impacted third molar extraction, between extraction time and anxiety, and between postoperative pain and anxiety were evaluated. The anxiety status of patients undergoing third molar extraction could be quantitatively evaluated using the STAI-KYZ. There were significant difference before and after third molar extraction. Especially women and patients of more severe postoperative pain was more anxious. We need to alleviate patient's anxiety(especially women) and to control postoperative pain throughout the tooth removal process.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.2 no.1
• /
• pp.69-80
• /
• 1982

This study was performed to increase the treatment efficiency of the existing anaerobic digestion facilities of the nightsoil treatment plants. Bench-scale anaerobic digesters were operated to evaluate the effect of the ratio (7:3 and 9:1) of the mixture of nightsoil and septic tank sludge on treatment efficiency. The laboratory experiments have demonstrated that the ratio of the mixture does have an effect on the organic removal efficiency. The nightsoil to septage ratio of 7 to 3 appears to yield a higher efficiency than the ratio of 9 to 1. The percent removals of 7 to 3 ratio are 87 % BOD, 82 % COD, 66 % TS, and 78 %. VS whereas those of 9 to 1 ratio are 80 % BOD, 80 % COD, 63 % TS, and 76 % VS. This study also showed that the mixed treatment of the nightsoil and septic tank sludge will be possible at the nightsoil treatment plant.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2005.11a
• /
• pp.179-184
• /
• 2005

In the present study, conceptual design of the main wing for 20 seats WIG{wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The high stiffness and strength Carbon-Epoxy material was used for the major structure and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, firstly the design load was estimated with maximum flight load, and then flanges of the front and the rear spar from major bending load and the skin structure and the webs of the spars were preliminarily sized using the netting rules and the rule of mixture. In order to investigate the structural safety and stability, stress analysis was performed by Finite Element Codes such as NASTRAN/PA TRAN[6] and NISA II [7]. From the stress analysis results, it was confirmed that the upper skin structure between the front spar and rear spar was very unstable for the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich structure at the upper skin and the web were added. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed. Moreover, in order to fix the wing structure at the fuselage, the insert bolt type structure with six high strength bolts was adopted for easy assembly and removal.

• Journal of Life Science
• /
• v.9 no.6
• /
• pp.692-697
• /
• 1999

For further removal of non-biodegradable CODs and color in biologically treated distillery waster water, we selected a chemical treatment with Fe(III) and cationic polymers and then another chemical treatment with Fenton reagent. We developed Pregenerated Bubble Flotation(PBF) to effectively remove the chemical sludge from each chemical reaction process. The flotation unit was constructed with hydraulic loading rate, 7 ㎥/$m^2$.hr. The CODMn and suspended solids (SS) in biologically treated distillery waste water were reduced by the first PBF from 310-1096 mg/L to 141-303 mg/L and from 160-990 mg/L to 48-385 mg/L, respectively. Again, after the Fenton reaction process, floated SS was skimmed off at the top of the flotation unit and the final effluent was directly discharged without any tap water dilution. The quality of final effluent can be below 40 mg/L-CODMn but IISan Distilery has been maintained effluent quality of 73 mg/L-CODMn and 10-80 mg/L-SS. The chemical cost was saved by more than 30% as compared with that of prior process.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.12
• /
• pp.43-48
• /
• 2011

Among various methods proposed earlier, fuzzy image filtering is usually one of the favored techniques because it has less blurring effect and the decrease of noise removal rate after filtering. However, fuzzy filtering is ineffective on color images since it is firstly developed with gray scale. Thus, in this paper, we propose a fuzzy filtering algorithm for color images. First, we divide RGB color information from image into three channels of R, G, and B and judge the possibility of each pixel with mask by fuzzy logic independently. The output pixel value might be the average or median according to the degree of noise. Our experiment successfully verifies the effectiveness of new algorithm in color image.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.5
• /
• pp.81-96
• /
• 2018

The purpose of this study is to analyze the characteristics of vegetation changes and structures in the buffer green zone of Sihwa Industrial Complex and propose environmental, ecological and multi-functional vegetation management directions. The density of the Pinus thunbergii decreased from $23.1trees/100m^2$ in 2006 to $9.6trees/100m^2$ in 2017 due to the influence of thinning works. Its green volume increased from $0.97m^3/m^2$ to $2.02m^3/m^2$, contributing to the improvement of the atmospheric environment and promotion of biodiversity. The density of deciduous broad-leaved trees at the top maintained at $18{\sim}21trees/100m^2$. In the areas where the understory vegetation was removed, Pueraria lobata spread as an invasive plant and disturbed the forest. In the areas where the understory vegetation was not removed, various native plant species including the Rhus javanica and Celtis sinensis were introduced and contributed to the development of a forest in a multiple structure. There was a concern with the spread of Robinia pseudoacacia which developed into understory vegetation in Pinus thunbergii forest and some canopy forest. The study proposed vegetation management directions for the back, top and front side according to the physical structure of large-scale buffer green zone formed in a long linear form and the usage characteristics of adjacent land.

• Journal of Trauma and Injury
• /
• v.19 no.1
• /
• pp.89-92
• /
• 2006

Penetrating facial wounds are uncommon and are usually life threatening because of the possibility of brain damage. There are three possible pathways for penetrating the cranium through the orbit: via the orbital roof, via the superior orbital fissure, or between the optic canal and lateral wall of the orbit. Brain injuries resulting from the penetrating wounds show extensive parenchymal damage, hemorrhage, and brain edema. Transorbital penetrating wounds can lead to diverse lesions of the optical apparatus, including the eye globe, the optical nerve, and the chiasm. Moreover, intracerebral structures may be hurt, and bleeding and infection may occur. Early diagnosis and prompt debridement are the fundamental factors affecting the outcome of a penetrating facial wound. An 87-year-old man was admitted to the emergency department with a grinder impacted into the medial aspect of the right eye. On presentation, the man was fully conscious with a Glasgow Coma Scale score of 15 and complained of a visual disturbance of the right eye. Computed tomography demonstrated a right orbital medial and inferior wall fracture, a frontal bone fracture, and a contusional hemorrhage in frontal lobe of the brain. A craniotomy with hematoma removal and repair of the orbital floor was done. He showed no neurological deficits except right visual loss. This appears to be the first report of a man with a penetrating facial wound caused by a grinder, who presented with a potentially disastrous craniocerebral injury that did not lead to any serious neurological seguelae.