• Journal of Mechanical Science and Technology
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• v.16 no.1
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• pp.46-59
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• 2002

The main purpose of this study is to investigate the variation of tool electrode edge wear and machining performance outputs, namely, the machining rate (workpiece removal rate), tool wear rate and the relative wear, with the varying machining parameters (pulse time, discharge current and dielectric flushing pressure) in EDM die sinking. The edge wear profiles obtained are modeled by using the circular arcs, exponential and poller functions. The variation of radii of the circular arcs with machining parameters is given. It is observed that the exponential function models the edge wear profiles of the electrodes, very accurately. The variation of exponential model parameters with machining parameters is presented.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.69-72
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• 2003

The purpose of this study is the development of hybrid horizontal electrokinetic(EK) remediation system on rifle range soil under unsaturated conditions. In order to remediate soil polluted by multi-species heavy metals, in pi]of scale, a series of EK remediation tests are carried out. PVC and PDB(Plastic Drain Board) electrode systems that connected with the power supply of constant voltage and vacuum pressure of 0.5kgf/$\textrm{cm}^2$ are installed, The test results showed that the pH distribution in the sample is below 8, which is maintained until the test is finished, because of the injection of flushing solution. The final concentration, which is normalized by initial concentration, is ranged about 50 to 90%.

• Journal of Chest Surgery
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• v.26 no.12
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• pp.955-958
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• 1993

Pseudocoarctation is extremely rare and is due to elongation and kinking of aortic arch which mimiks true coarctation but has no pressure gradient across it. This state is essentially benign entity and needs no surgical intervention, but it frequently tends to progress into the aortic aneurysm that results in compressive symptom due to mass effect and unawared rupture and death.We experienced a descending aortic aneurysm secondary to pseudocoarctation. The patient was 53 year-old female presented as easy f`atiguability and facial flushing. The aortogram revealed tortuous and enlarged aorta at the level of ligamentum arteriosum. The aneurysm was resected and was end-to-end anastomosed successfully under partial cardiopulmonary bypass. The postoperative course was uneventful and the patient was discharged on postoperative 10 day.

• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.1
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• pp.54-57
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• 2004

Disulfiram (tetraethylthiuram disulphid) is used in the treatment of chronic alcoholism since it causes an unpleasant aversive reaction to alcohol. It works by inactivating hepatic aldehyde dehydrogenase, leading to pronounced rise in the acetaldehyde concentration when ethanol is metabolized. Acetaldehyde causes alcohol sensitivity, which involve vasodilation associated with feeling of hotness and facial flushing, increased heart rate and respiration rates, lowered blood pressure, nausea, headache. One of its metabolites, diethyldithiocarbamate (DDC) can inhibit the enzyme dopamine $\beta$-hydroxylase (DBH), this may account for the profound refractory hypotension and hypothermia seen with the disulfiram-ethanol reaction (DER), resulting from norepinephrine depletion. This report is presents the case of a patient we met, who presented with hypothermia caused by the disulfiram-ethanol reaction, and along with a brief review of the subject.

• Journal of Chest Surgery
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• v.28 no.12
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• pp.1096-1106
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• 1995

We experienced 7 cases of left single lung transplantation in 14 mongrel dogs and analyzed graft lung function by hemodynamics, blood gas analysis, chest X-ray, biopsy and perfusion lung scan. We performed right pulmonary artery cuff[PA cuff for analysis of graft lung function in 3 cases. The donor lungs were flushed with modified Euro-Collins solution[n=3 or low potassium dextran glucose solution[n=4 and preserved for 4 to 5 hours[n=4 or 24 hours[n=3 at 10o C and implanted to the dogs with similar weight . Assessment of left graft lung was done by occluding the right pulmonary artery for 10 minutes using PA cuff. Assessment for graft lung function was done immediately after an operation and after 3 days, 7days and 3 weeks postoperatively. Four dogs survived for 3days, 7days[2 cases and 3 weeks respectively. Other three dogs expired within 3 hours of reperfusion. Immediate perfusion scans of left lung in four survived dogs after reperfusion were 42.1%, 36% , 11% and 5.9% respectively, and another dog with 4.8% perfusion to left lung was dead due to left atrial thrombi after 3 hours reperfusion. In one case among three acute rejections follow-up perfusion scan was done on 3rd and 11th postoperative day and the result decreased from 36% perfusion immediate postoperatively to 21% and 15% respectively. Three expired dogs postoperatively couldn`t tolerate occlusion of right pulmonary artery with above 40 mmHg of mean pulmonary artery pressure. On the other hand, three survival dogs postoperatively tolerated occlusion of right pulmonay artery with less than 30 mmHg of mean pulmonary artery pressure. and one dog couldn`t tolerate same procedure immediate postopertively but in 2 hours reperfusion later tolerated with 29 mmHg of mean pulmonary artery pressure.In conclusion we couldn`t compare the effect of two flushing solutions but low potassium dextran glucose solution showed relatively safe preservation effect in cases with preservation of more than 20 hours. Also canine left single lung transplantation model with PA cuff indicated useful method for the assessment of graft lung function with effect of lung preservation.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.689-699
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• 2003

This study was to examine characteristics of treating toluene vapor, which gets to be problematic due to its harmful carcinogenicity and mass generation from various sources, through a biological treatment facility which is environment-friendly and adopts a high-efficient and low-cost clean technology. In order to identify whether Alnus Firma Fruit (AFF) can be used as a media for a bioreactor, its utility and basic operating factors, a study was conducted on pressure drop, supply of nutrient substances and retention time which are operating factors of a biofilter, and eliminating characteristics were compared between AFF and the conventional biological activatedcarbon (BAC) widely used as filter media. In the case of AFF, the initial microbial deposits was 2.3${\times}$10$^{7}$ CFU/g dry AFF, which represents the initial microbial density higher than the case of BAC showing 5.5${\times}$10$^{6}$ CFU/g dry BAC And it took about 2 weeks to acclimate until its eliminating rate got to be increased over 90%. As a result of comparing pressure loss taking place with the lapse of time between BAC and AFF, after 130 days passed at SV 25h$^{-1}$ , BAC showed that its eliminating efficiency had a tendency to drop greatly due to a great pressure loss (0.53\longrightarrow54.7 mm$H_2O$/m) caused by an excess of biomass as accumulated. On the other hand. AFF showed that the pressure drop was 0.53 mm$H_2O$/m, about 2 times as much as the initial pressure loss of 0.4 mm$H_2O$/m, which represents no great change in the pressure loss, and its eliminating efficiency was also shown to be continuously high. Therefore, when AFF was used as a filler for a biological treatment facility, a biological filter enabling improvement of the purifying efficiency to be promoted could be provided, and moreover, the pressure loss was so small that the filler replacement cycle or the back flushing cycle could be extended. So, even in terms of the operating cost, it was identified to be an economical filler When an inorganic material was used as a filler, the biofilters performance acted sensitively on whether nutrient substances were supplied or not. In the case of AFF with low adsorptivity, addition of ethyl-alcohol increased the solubility of toluene, and consequently, biodegradation got to be actively made by microbes, and thus, its eliminating rate could be increased. As the flow velocity and the inflow concentration got to be more increased, its eliminating rate got to be lower, and particularly, an increase in the flow velocity made its eliminating rate drop more greatly than an increase in the concentration.

• Journal of the Korean GEO-environmental Society
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• v.8 no.5
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• pp.5-14
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• 2007

The quantity of noxious wastes generated by the growth in industrialization and population in all over the world and its potential hazards in subsurface environments are becoming increasingly significant. The extraction of the contaminant from the soil and movement of the water are restricted due to the low permeability and adsorption characteristics of the reclaimed soils. Incorporated technique with PVDs have been used for dewatering from fine-grained soils for the purpose of ground improvement by means of soil flushing and soil vapor extraction systems. This paper is to evaluate several key parameters that affected to the performance of the PVDs specifically with regard to: well resistance of PVD, zone of influence, and smear effects. In the feasibility of contaminant remediation was evaluated in pilot-scale laboratory experiments. Well resistance is affected on the vertical discharge capacity of the PVDs under the various vacuum pressures. The discharge capacity increases consistently in areal extents with higher applied vacuum up to a limiting vacuum pressure. The head values for each piezometer at different vacuum pressures show that the largest head loss occurs within 14 cm of the PVD. Air flow rates and head losses were measured for the PVD placed in the model test box and the gas permeability of the silty soils was calculated. Increasing the equivalent diameter results in a decrease in the calculated gas permeability. It is concluded that the gas permeability determined over the 1,500 to 2,000 $cm^3/s$ flow rates are the most accurate values which yields gas permeability of about 3.152 Darcy.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.6
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• pp.605-613
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• 1999

The purpose of the present study was to evaluate cardiovascular regulation during passive standing (PS) after ethanol ingestion by spectral analysis of heart rate variability (HRV) in flushed and nonflushed subjects. Of 24 young male subjects, 8 belonged to flushed group (F) and 16 to nonflushed group (NF). Two sessions of 10-min PS were performed before and after ethanol (0.5 g/kg) ingestion. Powers of R-R interval variability in very low frequency $(VLF,\;0{\sim}0.05\;Hz),$ low frequency $(LF,\;0.05{\sim}0.15\;Hz)$ and high frequency $(HF,\;0.15{\sim}0.50\;Hz)$ bands, normalized powers (LFn and HFn) and LF/HF ratio were obtained. After ethanol ingestion, F showed higher heart rate than NF. PS increased LFn $(+22.9{\pm}3.6\;in\;NF,\;+12.8{\pm}4.7$ in F, in normalized units) and LF/HF $(+3.10{\pm}0.57\;in\;NF,\;+3.00{\pm}1.08\;in\;F)$ and decreased HFn powers. Ethanol ingestion increased LFn and LF/HF and decreased HFn. PS after ethanol resulted in higher LFn and LF/HF and lower HFn than the prior PS. F showed a greater and more sustained HRV change than NF after ethanol. In conclusion, PS or ethanol ingestion increased LFn and LF/HF and decreased HFn. Flushed subjects showed an accentuated HRV response to ethanol.

• The Korean Journal of Pain
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• v.1 no.2
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• pp.164-170
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• 1988

Neurolysis of the celiac plexus is performed to relieve intractable pain caused by carcinoma of the stomach, liver and pancreas, and upper abdominal metastasis of tumors having more distant origins. It is also occasionally effective in controlling the pain of chronic pancreatitis. Alcohol celiac plexus blocks were done in 22 patients of whom 18 had intractable upper abdominal pain from cancer and 4 had pain from chronic pancreatitis. In most cases, an initial diagnostic block with 0.2 percent bupivacaine was followed by the therapeuntic block performed by injecting 50ml of 60 percent ethyl alcohol. Good to excellent pain relief occurred in 86 percent of patients. Duration of pain relief was from 4 months to 7 months in 55 percent of patients. Complications and side effects were infrequently seen but did include a 16 percent decrease of mean systolic arterial pressure and 16 cases of facial flushing. This block is remarkably safe as well as effective for the relief of upper abdominal pain from cancer origin.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.45-50
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• 1999

Four cast iron pipe sections containing 3 styrene butadiene rubber (SBR) gaskets (1 joint and 2 end caps) were filled with water and maintained at approximately 40 psi internal pressure. The pipe sections were placed inside 16 gallon drums filled with initially clean sand. Three of the tanks were subsequently contaminated with gasoline, gasoline spiked with pyrene and naphthalene, and toluene. The forth tank served as a control. The water inside each pipe was monitored over time for organic chemical contamination. Permeation of organic chemicals into the water inside the pipe systems was found to occur in all 3 contaminated pipe systems after approximately 100 days as measured organic chemicals concentrations were significantly above those in the uncontaminated cell. Flushing experiments in which the water inside the contaminated pipes was replaced with initially clean water showed that organic chemical concentrations inside the pipe rapidly (12 days) reached their preflushing levels.