• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.21 no.10
• /
• pp.1371-1379
• /
• 1997

The high pressure drop is frequently required in the by-pass line of the pump or of the heat exchanger in power plants. However, cavitation produced by a high pressure drop could damage the pipe and pump blades. Conical orifices are adopted to reduce cavitation due to high pressure drop. The discharge coefficients of conical orifice plates were measured by weighing method in the standard water flow system. The discharge coefficients were larger when the ratios of thickness of orifice edge to throat diameter were larger. The noise generated from a conical orifice due to cavitation was measured with a sound level meter and a hydrophone. With increasing the bore diameter of the orifice, the sound pressure level or the noise level due to cavitation became higher. The noise level was suddenly increased at the inception of cavitation.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.1
• /
• pp.79-90
• /
• 1998

One of the objectives of this study were to develop a process for manufacturing activated carbons from agricultural by-products(rice shells and saw dust) and another is to measure the iodine number, ash content and removal ratio of COD. The other is to compare those values with those of commercialized activated carbons. Agricultural by-products based activated carbons were manufactured through the steam-reaction method. A rotary kiln type furnace was used for both carbonization and activation. The optimum operating temperatures for carbonization and activation were $650^{\circ}C$ and $900^{\circ}C$, respectively. For the activated carbons produced under these conditions, the iodine number was 1,127mg/g. Especially, removal efficiency of COD was 61.5% for 40mg/L of wastewater and 30% for 150mg/L of SLS(Sodium Lauryl Sulfate).

• Journal of KIBIM
• /
• v.11 no.3
• /
• pp.34-44
• /
• 2021

This study quantitatively analyzes the work performance of the structural safety diagnosis team that diagnoses pipe racks. To this end, a method for evaluating the performance of the structural safety diagnosis team using the queuing model was proposed. For verification, the case of applying the existing method and the method of introducing a 3D laser scanner for one site was used. The period, number of people, and initial investment cost of each project were collected through interviews with case project experts. As a result of analyzing the performance of the structural safety diagnosis team using the queuing model, it was possible to confirm the probability of delay in the work of each project and the amount of delayed work. Through this, the cost (standby cost) when the project was delayed was analyzed. Finally, economic analysis was conducted in consideration of the waiting cost, labor cost, and initial investment cost. The results of this study can be used to decide whether to introduce 3D laser scanners.

• Korean Journal of Veterinary Research
• /
• v.58 no.4
• /
• pp.183-192
• /
• 2018

Although hyaluronic acid (HA) has been developed as a nanoparticle (NP; 320-400 nm) for a drug delivery system, the tissue targeting efficacy and the pharmacokinetics of HA-NPs are not yet fully understood. After a dose of 5 mg/kg of cyanine 5.5-labeled HA-NPs or HA-polymers was intravenously administrated into mice, the fluorescence was measured from 0.5 h to 28 days. The HA-NPs fluorescence was generally stronger than that of HA-polymers, which was maintained at a high level over 7 days in vivo, after which it gradually decreased. Upon ex vivo imaging, liver, spleen, kidney, lung, testis and sublingual gland fluorescences were much higher than that of other organs. The fluorescence of HA-NPs in the liver, spleen and kidney was highest at 30 min, where it was generally maintained until 4 h, while it drastically decreased at 1 day. However, the fluorescence in the liver and spleen increased sharply at 7 days relative to 3 days, then decreased drastically at 14 days. Conversely, the fluorescence of HA-polymers in the lymph node was higher than that of HA-NPs. The results presented herein may have important clinical implications regarding the safety of as self-assembled HA-NPs, which can be widely used in biomedical applications.

• Mycobiology
• /
• v.40 no.2
• /
• pp.124-128
• /
• 2012

Multiple treatment modalities, including topical and systemic corticosteroid and phototherapy, have been used in treatment of patients with atopic dermatitis. However, long-term corticosteroid therapy may have various adverse effects. The purpose of this study was to investigate the therapeutic efficacy and safety of bath therapy using green tea extracts for treatment of patients with atopic dermatitis. A total of four patients with atopic dermatitis were enrolled in this study. A Malassezia multiplex detection kit was used in performance of multiplex PCR on clinical isolates, which confirmed Malassezia sympodialis. Subjects underwent treatment with bath therapy using green tea extracts three times per wk for a period of 4 wk. Assessment using the scoring atopic dermatitis (SCORAD) index, the visual analogue scale for pruritus, and transepidermal water loss was performed weekly. Laboratory tests were performed before and after treatment. All patients showed marked improvement on the mean SCORAD and visual analogue scale, and a significant decrease in the mean values of serum eosinophil counts was observed after treatment. Bath therapy with green tea extract is an effective, safe, and nonsteroidal therapy for treatment of patients with atopic dermatitis associated with Malassezia sympodialis.

• Fire Science and Engineering
• /
• v.26 no.6
• /
• pp.57-63
• /
• 2012

The modern trend for high-rise buildings makes the application of fire protection systems difficult and the current systems have a limitation to provide appropriate functions. Indoor hydrant systems are fire suppression systems installed in most buildings that require valves, hoses, and nozzles to be manually operated in the event of a fire. Therefore, high discharge pressure can cause difficulty in the operation of indoor fire hydrant systems and damage to hoses due to a high reaction force. To prevent these problems, the pressure is reduced and decompression valves are commonly installed at angle valves which are the discharge points of indoor hydrants. In the case of high-rise buildings, however, there are cases where stable operation is difficult even with the installation of decompression valves. To verify this, we have measured the decompression performance by the orifice diameter and calculated the reaction force. Results of the study showed that decompression valves need to be produced in different sizes to provide stable decompression where high pressure is required as in high-rise buildings.

• Journal of Acupuncture Research
• /
• v.26 no.2
• /
• pp.71-77
• /
• 2009

Objectives : This study was designed to evaluate the influence of the period of disease on Bell's palsy patients Methods : We investigated 40 cases of patients with peripheral facial palsy who visited Yumin Oriental Hospital from 1st January to 31st August, 2008 with both oriental and western medical therapy and classified them as period of disease. The period of disease of Group A was within 3 days. The period of disease of Group B was from 4 to 10days. We evaluated the treatment effect of each group by House-Brackmann grade before treatment and 1, 2 week treatment. Results: 1. There was a statistical significant difference in period of disease between Group A and Group B. 2. After 1 week treatment, Group A showed more recovery compared with Group B. 3. After 2 week treatment, there was no statistical significant difference in House-Brackmann grade between Group A and Group B Conclusions : These results suggest that early treatment could be more effective in recovery of Bell's palsy.

• Toxicological Research
• /
• v.28 no.2
• /
• pp.113-116
• /
• 2012

Various kinds of positive effects of green tea extracts had been studied for long time which included anti-inflammation, anti-aging, and cardiometabolic effects. Although topical steroid and non-steroidal calcineurin inhibitors may control clinical symptoms of allergic contact dermatitis, some of patients also present allergic reaction to these topical agents. Therefore, we have tried green tea extracts for managing this skin disorder with expectation of anti-inflammatory effect without potential side effects including skin irritation and toxic responses. The toxicity test of green tea extract also did not show any sign of irritation in the skin throughout the test period. Moderate severity of allergic contact dermatitis presented satisfactory clinical outcome at second week follow-up which was final visit of outpatient. This result mean that green tea extract has a positive effect for managing allergic contact dermatitis but its potency and efficacy seem to be so not strong enough to control moderate severity allergy skin lesion. In this pilot study, we were able to conclude that green tea cell extracts might be applied for potential anti-inflammatory soaking without skin toxicity.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.4
• /
• pp.995-1000
• /
• 2004

This study was purposed to investigate the effect of Gamgung-tang(GGT) on immune responses induced by glucocorticoid in mice. GGT solution was treated by intraperitoneal injection for 7 days after glucocorticoid treatment(80㎎/㎏). And then B and T cell proliferation and cytolytic activity of natural killer(NK) cells were measured. There was 25% inhibition in B cell proliferation with treatment of glucocorticoid. However, B cell proliferation was not influenced by GGT treatment. T cell proliferation was also inhibited by 18.4% with treatment of glucocorticoid. On the other hand, T cell proliferation was increased dose-dependent manner in GGT treated group. Furthermore in purified T cell, the proliferation was furtherly increased than non-purified T cell. At concentration of 18㎎/mouse GGT, purified T cell proliferation was increase to above level of normal group. The cytotoxic activity of NK cell was decreased by 35.3% with treatment of glucocorticoid. In GGT treated group, the cytotoxic activity of NK cell was increased to the normal level. In purified NK cell, the cytolytic activity of NK cell was further increased than non-purifed NK cell. These results suggest that GGT may proliferate T cell that is suppressed by glucocorticoid, and activate NK cell activity.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.19 no.1
• /
• pp.98-101
• /
• 2005

Gamgung-tang(GGT) that is included in Gamdu-tang(consists of Glycyrrhizae Radix, black beans) and Gunggui-tang(consists of Angelicae Radix and Cnidii Rhizoma), showed therapeutic effects of autoimmume thyroiditis in the previous reports. GGT was tested for the safety using Rec assay and enzymatic methods. In the Rec assay, Bacillus subtilis H-17$(Rec^+)$ and M-45$(Rec^-)$ strains were used to test DNA damage activity. From the results, there was no DNA damage of GGT. Hepatotoxicity of GGT to female ICR mice was also monitored by the measurements of serum(s)-GOT, s-GPT and LDH activities after oral feeding for 15 days. GGT was not shown any significant changes of s-GOT, s-GPT and LDH activities in mice sera.