• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.47-52
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• 2013

The higher energy efficiency for ship and the lower pollution for global environment are required strictly. However the performance of marine diesel engine is gradually deteriorated with time. And also the operation condition is varied with sea conditions. Hence the optimization for operating condition of marine engines is needed for energy saving and environment kindly. In this paper, it was attempted to investigate the influence of aging for marine diesel engine. The deterioration of engine performance is assessed by the calculation results of the simulation program for two-stroke marine diesel engine developed by author which was reported before. And three parameters for deterioration of engine performance were considered such as lower efficiency of turbocharger by fouling, increase of blow-by gas due to wear of cylinder liner and getting worse of combustion by poor injection. By the results, it was shown that the influence of engine performance by aging was relatively not so small - 10.4 bar low in Pmax and 3.2% decrease in Pmi.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.874-885
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• 2012

In the present study, the possibility of whether the pharmacological effects of Scutellariae Radix Aqueous Extracts(SR) were favorably changed by report that lipopolysaccharide(LPS)-induced rat acute lung injury was treated with Red-Koji(Monascus purpureus 12002) fermentation. Three different dosages of Red-Koji fermented SR extract(fSR), 125, 250 and 500 mg/kg were orally administered once a day for 28 days before LPS(Escherichia coli 0111:B4) treatments, and then 5 hours after LPS treatment(500 ${\mu}g$/head, intra trachea instillation), all rats were sacrificed. Changes in the body weights, lung weights, pulmonary transcapillary albumin transit, arterial gas parameters(pH, $PaO_2$ and $PaCO_2$) bronchoalveolar lavage fluid(BALF) protein, lactate dehydrogenase(LDH) and proinflammatory cytokine tumor necrosis factor-${\alpha}$(TNF-${\alpha}$), interleukin-$1{\beta}$(IL-$1{\beta}$) contents, total cell numbers, neutrophil and alveolar macrophage ratios, lung malondialdehyde(MDA), myeloperoxidase(MPO), proinflammatory cytokine TNF-${\alpha}$ and IL-$1{\beta}$ contents were observed with histopathology of the lung, changes on luminal surface of alveolus(LSA), thickness of alveolar septum, number of polymorphonuclear neutrophils(PMNs). As results of LPS-injection, dramatical increases in lung weights, pulmonary transcapillary albumin transit increases in $PaCO_2$, decreases in pH of arterial blood and $PaO_2$, increases of BALF protein, LDH, TNF-${\alpha}$ and IL-$1{\beta}$ contents, total cells, neutrophil and alveolar macrophage ratios, lung MDA, MPO, TNF-${\alpha}$ and IL-$1{\beta}$ contents increases were detected with decreases in LSA and increases of alveolar septum and PMNs numbers, respectively as compared with intact control. Especially fSR 125 mg/kg showed quite similar favorable effects on the LPS-induced acute lung injuries as compared with 60 mg/kg of ${\alpha}$-lipoic acid and 250 mg/kg of SR. The results suggest that over 125 mg/kg of fSR extracts showed favorable effects on the LPS-induced acute lung injury mediated by their antioxidant and anti-inflammatory effects. Moreover, increases of the pharmacological effects of SR on LPS-induced acute lung injury were observed by Red-Koji fermentation in this study, at least 2-fold higher.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.834-840
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• 2018

In this study, the characteristics of air pollutant emissions from ships' engines have been investigated by conducting E2 and E3 cycle mode tests. A engine 360Ps (Doosan L126TIH engine) and 400kW dynamometer Horiba-Schenck were utilized for engine tests. The FTIR analyzer and SPC were used to measure exhaust gas (NOx, SOx etc.) and PM (particulate matter), respectively. The results showed that the emissions of THC and CO produced from engine were increased with the increase of sulfur content in fuel oils at E2 and E3 cycle modes. The kinetic viscosity of the fuel increased as the sulfur content of the fuel increased, thereby the specific fuel oil consumption (SFC) of the engine improved. This result is considered to be due to improved combustion conditions due to increased average diameters of sprayed particles and due to increased kinetic viscosity under constant fuel injection pressure in this study. In the case of NOx emission, this study showed no significant change in amount of sulfur content.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.1
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• pp.49-69
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• 2011

Objective : The object of this study was to observe the effects of Lonicerae Flos (LF) aqueous extracts on lipopolysaccharide (LPS)-induced rat acute lung injury. Method : Five different dosages of LF extracts were orally administered once a day for 28 days before LPS treatments, and then all rats were sacrificed after 5 hour-treatment of LPS. Eight groups of 16 rats each were used in the present study. The following parameters caused by LPS treatment were observed ; body weights, lung weights, pulmonary transcapillary albumin transit, arterial gas parameters (pH, $PaO_2$ and $PaCO_2$) bronchoalveolar lavage fluid (BALF) protein lactate dehydrogenase (LDH), and proinflammatory cytokines tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$) contents, total cell numbers, neutrophil and alveolar macrophage ratios, lung malondialdehyde (MDA), myeloperoxidase (MPO), proinflammatory cytokines TNF-${\alpha}$ and IL-$1{\beta}$ contents. In addition, the histopathologic changes were observed in the lung in terms of luminal surface of alveolus, thickness of alveolar septum, number of polymorphonuclear neutrophils. Result : As results of LPS-injection, dramatical increases in lung weights, pulmonary transcapillary albumin transit increases, increases in $PaCO_2$, decreases in pH of arterial blood and $PaO_2$, increases of BALF protein, LDH, TNF-${\alpha}$ and IL-$1{\beta}$ contents, total cells, neutrophil and alveolar macrophage ratios, TNF-${\alpha}$ and IL-$1{\beta}$ contents increases were detected with decreases in LSA and increases of alveolar septum and PMNs numbers, respectively as compared with intact control. These are means that acute lung injuries (resembling acute respiratory distress syndrome) are induced by treatment of LPS mediated by inflammatory responses, oxidative stress and related lipid peroxidation in the present study. However, these LPS-induced acute lung injuries were inhibited by 28 days continuous pretreatment of 250 and 500mg/kg of LF extracts. Because of lower three dosages of LF treated groups, 31.25 and 62.5 and 125mg/kg did not showed any favorable effects as compared with LPS control, the effective dosages of LF in LPS-induced acute lung injuries in the present study, is considered as about 125mg/kg. The effects of 250mg/kg of LF extracts showed almost similar effects with ${\alpha}$-lipoic acid 60mg/kg in preventing LPS-induced acute lung injuries. Conclusion : It seems that LF play a role in protecting the acute respiratory distress syndrome caused by LPS.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.511-519
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• 2022

In order to develop an air-stripping based remediation process to remove the TOC (Total Organic Carbon) in groundwater around the underground LPG storage cavern, the laboratory scale experiments at various conditions (change of air injection volume and temperature, the application of ultrasonic treatment, etc.) for two types of groundwater (initial TOC concentration of 608 mg/L and 153 mg/L, respectively). From results of experiment, as the air injection rate for stripping into groundwater increased from 2 L/min to 11 L/min and as the air-stripping time increased from 1 hour to 24 hour, the TOC removal efficiency of air-stripping increased. However, the TOC concentration of treated groundwater was higher than the discharge tolerance limit (100 mg/L) even after 24 hour stripping at the maximum air injection rate of 11 L/min. The main compounds of the TOC in groundwater were identified as methanol and propane and the long stripping time (more than 24 hour) was needed to separate the methanol from groundwater because of the affinity between water and methanol. At 20℃ and 4 L/min of air injection, the TOC removal efficiency increased to 59.1% after 24 hour air-stripping. When the temperature of groundwater increased to 30℃ and 40℃, the TOC removal efficiency increased up to 80.0% and 82.8%, suggesting that more than 24 hour air-stripping at 40℃ is needed to lower the TOC concentration to below 100 mg/L and the additional TOC removal process as well as the air-stripping is necessary. When the temperature increased to 60℃ and the ultrasonic treatment was conjugated with the air-stripping, the TOC removal efficiency increased to 87.8% within 5 hour stripping and the final TOC concentration (72.4 mg/L) was satisfied with the TOC discharge tolerance limit. The TOC removal efficiency for groundwater having low TOC concentration (153 mg/L) also showed similar removal efficiency of 89.7% (the final TOC concentration: 18.9 mg/L). Results in this study supported that the air-stripping conjugated with the ultrasonic treatment could remove successfully the TOC in groundwater around the underground LPG strorage cavern.

• Clean Technology
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• v.23 no.1
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• pp.42-53
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• 2017

Numerical analysis was done to evaluate the fluid distribution inside of the mixing quencher to increase the reaction efficiency of the aqueous hydrogen peroxide solution in the scrubbing column which is used for simultaneous desulfurization and denitrification. Effective injection of the aqueous hydrogen peroxide ($H_2O_2$) solution in the mixing quencher has major effects for improving the reaction efficiency in the scrubbing column by enhancing the mixing of the aqueous $H_2O_2$ solution with the exhaust gas. The current study is to optimize the array of nozzles and the spray angles of the aqueous $H_2O_2$ solution in the mixing quencher by using the computational method. Main concerns of the analysis are how to enhance the uniformity of the $H_2O_2$ concentration distribution in the internal flow. Numerical analysis was done to check the distribution of the internal flow in the mixing quencher in terms of RMS values of the $H_2O_2$ concentration at the end of quencher. The concentration distribution of $H_2O_2$ at the end of is evaluated with respect to the different array of the nozzle pipes and the nozzle tip angles, and we also analyzed the turbulence formation and fluid mixing in the zone. The effect of the spray angle was evaluated with respect to the mixing efficiency in different flow directions. The optimized mixing quencher had the nozzle array at location of 0.3 m from the inlet duct surface and the spray angle is $15^{\circ}$ with the co-current flow. The RMS value of the $H_2O_2$ concentration at the end of the mixing quencher was 12.4%.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.135-146
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• 1993

Background: In acute pulmonary embolism it has been postulated that the constriction of bronchi and pulmonary artery secondary to neurohumoral response plays an important role in cardiopulmonary dysfunction in addition to the mechanical obstruction of pulmonary artery. Serotonin is considered as the most important mediator. Positive end expiratory pressure (PEEP) stimulates $PGI_2$ secretion from the vascular endothelium, but its role in acute pulmonary embolism is still in controversy. Methods: To study the cardiopulmonary effect and therapeutic role of Ketanserin, selective antagonist of 5-HT2 receptor, and PEEP in acute pulmonary embolism experimental acute pulmonary embolism was induced in dogs with autologous blood clot. The experimental animals were divided into 3 groups, that is control group, Ketanserin injection group and PEEP application group. Results: Thirty minutes after embolization, mean pulmonary arterial pressure and pulmonary vascular resistance increased and cardiac output decreased. $PaO_2,\;P\bar{v}O_2$ and oxygen transport decreased and physiological shunt and $PaCO_2$ increased. After injection of Ketanserin, comparing with control group, mean pulmonary arterial pressure, pulmonary vascular resistance and physiological shunt decreased, while cardiac output, $PaO_2$ and oxygen transport increased. All these changes sustained till 4 hours after embolization. After PEEP application pulmonary vascular resistance, $PaO_2$ and $PaCO_2$ increased, while physiological shunt, cardiac output and oxygen transport decreased. After discontinuation of PEEP, mean pulmonary arterial pressure and pulmonary vascular resistance decreased and were lower than control group, while $PaO_2$ and cardiac output increased and higher than control group. $PaCO_2$ decreased but showed no significant difference comparing with control group. Conclusion: It can be concluded that Ketanserin is effective for the treatment of acute pulmonary embolism. With PEEP hemodynamic status deteriorated, but improved better than control group after discontinuation of PEEP. Thus PEEP may be applied carefully for short period in acute pulmonary embolism if the hemodynamic status is tolerable.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.18-23
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• 2006

Foaming of slag is a thermodynamically unstable phenomenon and has significant effects in iron and steelmaking processes. For better recycling method of pulp sludge, the application as an defoaming agent during steelmaking process was adopted and tested. The forming machine has been modified in order to produce the briquettes, which are made of pulp sludge and slag with different weight ratio. Influencing factors on the foaming phenomena have been studied and tested for better understanding of foaming phenomena. Experiments were carried out with $CaO-FeO-SiO_2$ based slags with Ar gas injection and addition of coke particles. The slag basicity and (%FeO) contents adapted as major factors to treasure foaming tendency of the slag system. It was found that foam index (${\Sigma}$) gradually decreased as both the basicity and the (FeO) content increase. Four kinds of antifoaming agent such as aluminium dross, cokes, rice bran and pulp sludge with steelmaking slag have been tested in actual process. Aluminium dross was the most effective, and pulp sludge with steelmaking slag also showed the desired results.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.88-94
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• 2012

One of the effective ways to reduce both $NO_x$ and PM at the same time in a diesel CI engine is to operate the engine in low temperature combustion (LTC) regimes. In general, two strategies are used to realize the LTC operation-dilution controlled LTC and late injection LTC - and in this study, the former approach was used. In the dilution controlled regime, LTC is achieved by supplying a large amount of EGR to the cylinder. The significant EGR gas increases the heat capacity of in-cylinder charge mixture while decreasing oxygen concentration of the charge, activating low temperature oxidation reaction and lowering PM and $NO_x$ emissions. However, use of high EGR levels also deteriorates combustion efficiency and engine power output. Therefore, it is widely considered to use increased intake pressure as a way to resolve this issue. In this study, the effects of intake pressure variations on performance and emission characteristics of a single cylinder diesel engine operated in LTC regimes were examined. LTC operation was achieved in less than 8% $O_2$ concentration and thus a simultaneous reduction of both PM and $NO_x$ emission was confirmed. As intake pressure increased, combustion efficiency was improved so that THC and CO emissions were decreased. A shift of the peak Soot location was also observed to lower $O_2$ concentration while $NO_x$ levels were kept nearly zero. In addition, an elevation of intake pressure enhanced engine power output as well as indicated thermal efficiency in LTC regimes. All these results suggested that LTC operation range can be extended and emissions can be further reduced by adjusting intake pressure.

• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.103-115
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• 2007

The aim of this study was to compare the reaction of the cardiovascular system, and the anesthetic effect among 3 experimental groups, epidural administration of medetomidine as a single agent, the combination of buprenorphine and medetomidine, and the combination of fentanyl and medetomidine. Twenty one dogs were anesthetized with isoflurane and allowed to breathe spontaneously. Epidural, arterial, and venous catheters were inserted. The tip of epidural catheter was positioned at the level of the space between the sixth and seventh lumbar vertebra. After a stable plane of anesthesia was achieved, these dogs were each administered one of the following treatments epidurally : medetomidine $10{\mu}g/kg$ (Group M), a combination of medetomidine $5{\mu}g/kg$ and buprenorphine $10{\mu}g/kg$ (Group M/B), and a combination of medetomidine $5{\mu}g/kg$ and fentanyl $10{\mu}g/kg$ (Group M/F). Heart rate (HR), Respiratory rate (RR), End-tidal carbon dioxide (EtCO2), and arterial blood pressure were measured before drug administration (base line) and 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 min postinjection. Blood gas analysis was performed before injection and 5, 15, 25, 35, 45, 60 min postinjection. Isoflurane was discontinued 80 min postinjection and pain/motor function were evaluated up to 260 min postinjection every 15 min. At the early stage of drug introduction (until 5 min), the HR was decreased significantly in all 3 groups compared with base line. In Group M, HR was significantly decreased compared with the other 2 groups. With time (starting 20 min after drug introduction), the HR was decreased significantly in Group M/B in respect to base line. However, no significant difference was seen number-wise in all 3 groups. During 60 min after drug introduction, the systolic, diastolic and mean arterial pressures were highest in Group M and lowest in Group M/F. Among 3 groups, drug action and motor loss duration were longest in Group M/F. Analgesic effect observed in the M/F group was the most prominent and long-lasting, compared to those seen in the other 2 groups. Given the fact that the recovery of motor function takes place in a short period of time after analgesic effects disappeared, additional use of M/F depending on the patient's condition would be a good way to achieve effective pain management. However, proper care should be taken to ensure the function of cardiovascular system in the patient because the administration of M/F under isoflurane anesthesia results in a significant decline in arterial blood pressure ($65{\pm}10mmHg$).