• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.267-274
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• 2008

This study is about efficiency of pretreatment process and operating factor to membrane process at continuous coagulation/ultrafiltration process in water treatment. The capacity of pilot plant was $0.06{\beta}(C)/d$. The raw water used was from Nakdong stream which was characteristized by high organic matter and high turbidity. The result of the test was that coagulation is good process as to high removal rate to organic matter and turbidity but It caused problem to membrane pore blocking. This paper is to determine the membrane fouling potential under different membrane flux, backwash pressure and linear velocity. Backwash pressure and flux is important parameter on operation of membrane system. Those are directly affected on membrane system. When backwash pressure increased from 150 kPa to 200 kPa, the result showed that fouling (pressure increase rate) changed from 3.69 kPa/h to 0.93 kPa/h and the recovery rate changed from 90.7 % to 82.0 %. Linear velocity had slightly effect on fouling. Linear velocity increased from 0.2 m/s to 0.5 m/s, the corresponding pressure rate changed from 0.93 kPa/d to 0.77 kPa/d.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.3
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• pp.143-150
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• 2000

Ferritic plasma nitrocarburising was performed on pure iron using a modified DC plasma unit. This investigation was carried out with various gas compositions which consisted of nitrogen, hydrogen and carbon monoxide gases, and various gas pressures for 3 hours at $570^{\circ}C$. After treatment, the different cooling rates(slow cooling and fast cooling) were used to investigate its effect on the structure of the compound layer. The ${\varepsilon}$ phase occupied the outer part of the compound layer and ${\gamma}^{\prime}$ phase existed between the ${\varepsilon}$ phase and the diffusion zone. The gas composition of the atmosphere influenced the constitution of the compound layer produced, i.e. high nitrogen contents were essential for the production of ${\varepsilon}$ phase compound layer. It was found that with increasing carbon content in the gas mixture the compound layer thickness increased up to 10%. In the gas pressure around 3 mbar, the compound layer characteristics were slightly effected by gas pressure. However, in the low gas pressure and high gas pressure, the compound layer characteristics were significantly changed. The constitution of the compound layer was altered by varying the cooling rate. A large amount of ${\gamma}^{\prime}$ phase was transformed from the ${\varepsilon}$ phase during slow cooling.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.477-490
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• 2014

Non-thermal atmospheric-pressure plasma, also named cold plasma, is defined as a partly ionized gas. Therefore, it cannot be equated with plasma from blood; it is not biological in nature. Non-thermal atmospheric-pressure plasma is a new innovative approach in medicine not only for the treatment of wounds, but with a wide-range of other applications, as e.g. topical treatment of other skin diseases with microbial involvement or treatment of cancer diseases. This review emphasizes plasma effects on wound healing. Non-thermal atmospheric-pressure plasma can support wound healing by its antiseptic effects, by stimulation of proliferation and migration of wound relating skin cells, by activation or inhibition of integrin receptors on the cell surface or by its pro-angiogenic effect. We summarize the effects of plasma on eukaryotic cells, especially on keratinocytes in terms of viability, proliferation, DNA, adhesion molecules and angiogenesis together with the role of reactive oxygen species and other components of plasma. The outcome of first clinical trials regarding wound healing is pointed out.

• Food Science of Animal Resources
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• v.21 no.1
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• pp.32-37
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• 2001

The study investigated the effects of protein concentration, EGTA and strength of hydrostatic pressure on pH, viscosity and turbidity for ultra filtrated skim milk retentates. The results showed that hydrostatic pressure treatments up to 600 MPa did not affect the viscosity of skim milk, while the turbidity of skim milk increased at higher than 200 MPa. Addition of EGTA caused reduction in turbidity of skim milk, two times (2SR) and three times (3SR) concentrated skim milk retentates. Viscosity for 2SR and 3SR increased proportionally to the amount of EGTA, but viscosity of skim milk was not influenced by EGTA. High pressure treatment also did not cause any difference in viscosity and turbidity of skim milk. However, this treatment decreased viscosity and turbidity for 2SR and 3SR. In particular, 200 MPa treatment showed to induce a higher decrease in turbidity compared with 400 MPa.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.98-103
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• 2010

The effect of plasma treatment on surface characteristics of polycarbonate (PC) films was investigated using low pressure plasma and atmospheric pressure plasma with oxygen and argon. Untreated PC has a contact angle of $82.31^{\circ}$ with de-ionized water which reduced to $9.17^{\circ}$ as the lowest value after being treated with a low pressure plasma treatment with oxygen. Increase of delivered powers such as RF and AC with a high frequency and gas flow rates was not effective to reduce contact angles dramatically but gave the trend of reducing gradually. The surface of PC treated with plasma shows a low contact angle but the contact angle increases rapidly according to the exposure time in air ambient. Oxygen plasma was more effective to generate the polar functional group regardless of the type of plasma. Conclusively, a low plasma treatment with oxygen is more recommendable when the hydrophilic surface of PC is required.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.85-95
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• 2002

Objectives : Daechu (Dazhui:GV14 (Governor Vessel 14))-point is located between the spinous process of the 7th cervical vertebra and that of the 1st thoracic vertebra. GV14 has been used to treat hypertension, high fever, neck pain, common cold, headache and so on. Hypertension often negatively affects the improvement of stroke patients. We investigated whether wet-cupping at GV14 had any effect of decreasing blood pressure (BP). Methods : In this study, 81 stroke patients were studied, from Oct. 2000 to Sept. 2001. They were composed of a Sample group (n=36) and Control group (n=45). The Sample group (n=36) was divided into Sample-Normal (n=9), Sample-Mild (n=7), Sample-Moderate (n=l1), and Sample-Severe group (n=9). The Control group (n=45) was divided into Control-Moderate (n=34) and Control-Severe group (n=ll). We checked blood pressure 5 times (just before treatment, then after 30,60, 90, and 120min. (2hrs.)) in each sample group and 3 times (baseline, after 30, and after 120min. (2hrs)) in the control group. Results : In a comparison of before-treatment BP and after-treatment BP in the sample group, SBP significantly decreased as time passed, while DBP slightly decreased but not significantly. In comparison of BP differences in each sample subgroup, BP slightly increased in the Sample-Normal group, but significantly decreased in the Sample-Mild, Sample-Moderate, and Sample-Severe groups. In comparison of BP differences between the sample and control groups, SBP and DBP of the sample group definitely decreased more than those of the control group, but not significantly. Conclusions : This study suggests that wet-cupping at GV14 has significant decreasing effectson blood pressure in stroke patients. Accordingly, we hope that this measure will be used more widely as an emergent treatment for increased blood pressure.

• The korean journal of orthodontics
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• v.22 no.2 s.37
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• pp.297-308
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• 1992

The effect of orthodontic force on the collagenase and phosphatase activities of the adjacent alveolar bone was evaluated. Maxillary canines of male cats were treated orthodontically with closed coil spring so as to exert about 80g force. Sixteen cats were equally divided into one control group and seven experimental groups (12 hrs, 24 hrs, 36 hrs, 2 days, 3 days, 5 days and 7 days after orthodontic treatment). After sacrificing all animals on experimental intervals, collagenase, acid phosphatase (ACP) and alkaline phosphatase (ALP) activities were determined in the pressure and tension sides of alveolar bones. ACP activities increased in both the pressure and tension sides, but significantly increased in the pressure side continuously. ALP activities increased in the tension side at early stage (1-2 days after treatment), but changed small amount in the pressure side. Collagenase activities increased in the pressure side, especially at late stage (5-7 days after treatment). These results suggest that (1) orthodontic fore force increases the ACP, ALP and collagenase activities generally and (2) activities of ACP and collagenase increase in the pressure side, but that of ALP in the tension side and (3) activities of ACP and ALP increase at early stage, but that of collagenase at late stage after orthodontic treatment. Therefore it is shown that there are time differences in the formation and destruction of organic and inorganic components in the bone metabolism of alveolus with application of the orthodontic forces.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.106-118
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• 2001

A rigorous study of single droplet vaporization under quiescent high pressure atmosphere is attempted adopting method of flash evaporation calculation for vapor-liquid equilibrium. Results due to flash method shows excellent agreement with measurement. Also shown is the present model fairly capable of depicting transients of droplet vaporization under high pressure environment, such as ambient gas solubility, property variation, and multicomponent transports. Systematic treatment of these effects with emphasis on vapor-liquid phase equilibrium revealed; conventional treatment for subcritical droplet vaporization, such as $d^2$-law, leads to erroneous prediction of droplet history, augmented gas solubility is significant under supercritical pressure, and vaporization rate proportionally increase with pressure.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.2
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• pp.69-74
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• 2010

AlN thin films were deposited by using a two-facing-targets type sputtering system (TFTS), and their deposition characteristics, microstructure and texture were investigated. Total gas pressure was kept constant at 0.4 Pa and the partial pressures of nitrogen, $PN_2$ (($N_2$ pressure)/($Ar+N_2$ pressure)) varied from 0 to 0.4 Pa. The texture of the film cross-sections and surface morphology were observed by field emission scanning electron microscope (FE-SEM). The crystallographic orientation of the films were analyzed by X-ray diffraction (XRD). Deposition of AlN film depends on $N_2$ partial pressure. The best preferred oriented AlN thin films can be deposited at a nitrogen partial pressure of $PN_2$ = 0.52. As-deposited AlN films show preferred orientation and columnar structure, and the grAlN size of AlN films increases with increasing sputtering current.

• Journal of Korean Physical Therapy Science
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• v.9 no.1
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• pp.159-166
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• 2002

The purpose of this study was to review the knowledge related to historic background, causes, symptoms, etiology and rehabilitation methods related to this disease and suggest some ways to reduce complications from it. The importance of underwater pressure disease was not emphasized, therefore, there is a need for continuous research on treatment methods and prevention for it. As one goes into the deeper water, they will be affected by the hydraulic pressure rather then the atmospheric pressure, and it will be increased 1mmHg by 10meters. Underwater pressure disease can be occurred when one comes out of deeper water too quicked. This results the imbalance of the composition rate of nitrogen in blood. However, there is not enough facilities to treat this disease and these facilities are located in limited areas. Therefore, there is an urgent need to set up a medial center that is specialized in prevention and treatment of underwater pressure disease.