• Economic and Environmental Geology
• /
• v.54 no.1
• /
• pp.105-115
• /
• 2021

The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.4
• /
• pp.45-59
• /
• 2023

The global focus on mitigating climate change has traditionally centered on carbon dioxide, but recent attention has shifted towards methane as a crucial factor in climate change adaptation. Natural settings, particularly aquatic environments such as wetlands, reservoirs, and lakes, play a significant role as sources of greenhouse gases. The accumulation of organic contaminants on the lake and reservoir beds can lead to the microbial decomposition of sedimentary material, generating greenhouse gases, notably methane, under anaerobic conditions. The escalation of methane emissions in freshwater is attributed to the growing impact of non-point sources, alterations in water bodies for diverse purposes, and the introduction of structures such as river crossings that disrupt natural flow patterns. Furthermore, the effects of climate change, including rising water temperatures and ensuing hydrological and water quality challenges, contribute to an acceleration in methane emissions into the atmosphere. Methane emissions occur through various pathways, with ebullition fluxes-where methane bubbles are formed and released from bed sediments-recognized as a major mechanism. This study employs Biochemical Methane Potential (BMP) tests to analyze and quantify the factors influencing methane gas emissions. Methane production rates are measured under diverse conditions, including temperature, substrate type (glucose), shear velocity, and sediment properties. Additionally, numerical simulations are conducted to analyze the relationship between fluid shear stress on the sand bed and methane ebullition rates. The findings reveal that biochemical factors significantly influence methane production, whereas shear velocity primarily affects methane ebullition. Sediment properties are identified as influential factors impacting both methane production and ebullition. Overall, this study establishes empirical relationships between bubble dynamics, the Weber number, and methane emissions, presenting a formula to estimate methane ebullition flux. Future research, incorporating specific conditions such as water depth, effective shear stress beneath the sediment's tensile strength, and organic matter, is expected to contribute to the development of biogeochemical and hydro-environmental impact assessment methods suitable for in-situ applications.

• Journal of Food Hygiene and Safety
• /
• v.29 no.2
• /
• pp.79-84
• /
• 2014

This study has been performed for about 270 days at analyzing biologically hazardous factors in order to develop HACCP system for the non heat-frozen carrot juice. A process chart was prepared by manufacturing process of raw agricultural products of non heat-frozen carrot juice, which was contained water and packing material, storage, washing, cutting, extraction of the juice, internal packing, metal detection, external packing, storage and consignment (delivery). As a result of measuring Coliform group, Staphylococcus aureus, Salmonella spp., Bacillus cereus, Listeria Monocytogenes, Enterohemorrhagic E. coli before and after washing raw carrot, Standard plate count was $4.7{\times}10^4CFU/g$ before washing but it was $1.2{\times}10^2CFU/g$ detected after washing. As a result of testing airborne bacteria (Standard plate count, Coliform group, Yeast and Fungal) depending on each workplace, number of microorganism of in packaging room, shower room and juice extraction room was detected to be 10 CFU/Plate, 60 CFU/Plate, 20 CFU/Plate, respectively. As a result of testing palm condition of workers, as number of Standard plate count, Coliform group and Staphylococcus aureus was represented to be high as $6{\times}10^4CFU/cm^2$, $0CFU/cm^2$ and $0CFU/cm^2$, respectively, an education and training for individual sanitation control was considered to be required. As a result of inspecting surface pollution level of manufacturing facility and devices, Coliform group was not detected in all the specimen but Standard plate count was most dominantly detected in scouring kier, scouring kier tray, cooling tank, grinding extractor, storage tank and packaging machine-nozzle as $8.00{\times}10CFU/cm^2$, $3.0{\times}10CFU/cm^2$, $4.3{\times}10^2CFU/cm^2$, $7.5{\times}10^2CFU/cm^2$, $6.0{\times}10CFU/cm^2$, $8.5{\times}10^2CFU/cm^2$ respectively. As a result of analyzing above hazardous factors, processing process of ultraviolet ray sterilizing where pathogenic bacteria may be prevented, reduced or removed is required to be controlled by CCP-B (Biological) and critical level (critical control point) was set at flow speed is 4L/min. Therefore, it is considered that thorough HACCP control plan including control criteria (point) of seasoning fluid processing process, countermeasures in case of its deviation, its verification method, education/training and record control would be required.

• Tunnel and Underground Space
• /
• v.28 no.5
• /
• pp.400-425
• /
• 2018

This study presents the research results and current status of the DECOVALEX-2019 project Task B. Task B named 'Fault slip modelling' is aiming at developing a numerical method to simulate the coupled hydro-mechanical behavior of fault, including slip or reactivation, induced by water injection. The first research step of Task B is a benchmark simulation which is designed for the modelling teams to familiarize themselves with the problem and to set up their own codes to reproduce the hydro-mechanical coupling between the fault hydraulic transmissivity and the mechanically-induced displacement. We reproduced the coupled hydro-mechanical process of fault slip using TOUGH-FLAC simulator. The fluid flow along a fault was modelled with solid elements and governed by Darcy's law with the cubic law in TOUGH2, whereas the mechanical behavior of a single fault was represented by creating interface elements between two separating rock blocks in FLAC3D. A methodology to formulate the hydro-mechanical coupling relations of two different hydraulic aperture models and link the solid element of TOUGH2 and the interface element of FLAC3D was suggested. In addition, we developed a coupling module to update the changes in geometric features (mesh) and hydrological properties of fault caused by water injection at every calculation step for TOUGH-FLAC simulator. Then, the transient responses of the fault, including elastic deformation, reactivation, progressive evolutions of pathway, pressure distribution and water injection rate, to stepwise pressurization were examined during the simulations. The results of the simulations suggest that the developed model can provide a reasonable prediction of the hydro-mechanical behavior related to fault reactivation. The numerical model will be enhanced by continuing collaboration and interaction with other research teams of DECOLVAEX-2019 Task B and validated using the field data from fault activation experiments in a further study.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.6
• /
• pp.1092-1099
• /
• 2022

Research on exhaust aftertreatment devices to reduce air pollutants and greenhouse gas emissions is being actively conducted. However, in the case of the particulate matters/nitrogen oxides (PM/NOx) simultaneous reduction device for ships, the problem of back pressure on the diesel engine and replacement of the filter carrier is occurring. In this study, for the optimal design of the integrated device that can simultaneously reduce PM/NOx, an appropriate standard was presented by studying the flow inside the device and change in back pressure through the inlet/outlet pressure. Ansys Fluent was used to apply porous media conditions to a diesel particulate filter (DPF) and selective catalytic reduction (SCR) by setting porosity to 30%, 40%, 50%, 60%, and 70%. In addition, the ef ect on back pressure was analyzed by applying the inlet velocity according to the engine load to 7.4 m/s, 10.3 m/s, 13.1 m/s, and 26.2 m/s as boundary conditions. As a result of a computational fluid dynamics analysis, the rate of change for back pressure by changing the inlet velocity was greater than when inlet temperature was changed, and the maximum rate of change was 27.4 mbar. This was evaluated as a suitable device for ships of 1800kW because the back pressure in all boundary conditions did not exceed the classification standard of 68mbar.

• Journal of Korean Medical classics
• /
• v.24 no.4
• /
• pp.157-174
• /
• 2011

We derived following result by organizing research about processing of medicinal of before Han(漢) dynesty. The human being intake of natural substance for the purpose of treatment was what happened later than the use of natural substance as food. According to the record of by the early years of Shang(商) dynasty, we can assume that we cooked food with water and fire. The reason why there is no appearance of common production that can be included under the name of 'Tang Ye(湯液)' in the medical record discovered from Ma Wang Dui(馬王堆) is because 'Tang Ye' was yet developed. However, as the presentation of format of medicine process, there was gradual formation of medicinal fluid concept. There are quite of records on major details of cloth manufacture like washing and selection, grinding, processing of medicine from the recordings of "Wu Shi Er Bing Fang(五十二病方)", "Yang Sheng Fang(養生方)", "Za Liao Fang(雜療方)" discovered at Ma Wang Dui. It used words like 'Ze(擇)', 'Qu(去)' for the selection and 'Jiu(酒)', 'Zhuo(濯)' for the wash as a process method before cloth manufacture. When filter the processed medicine, it used words like 'Zhuo(捉)', 'Suo(索)', 'Jun(浚)' and used 'Yin Gan(陰乾)', 'Bao(暴)', 'Yang(暘)' for dry. The 'cutting(切削)' that crushes the medicine used different names based on the properties of medicines. The most frequent crush is 'Ye(冶)' and it means the powered medicine after dry. There was thermal process of mild fire(微火) and heating of 'Wen(溫)'. There are many states of medicine seen from the medical record discovered at Ma Wang Dui so they can be said as original medicine. 藥末劑 is relatively commercialized type then. Here, it includes later 湯劑 but there was no name such as 'decoction(湯)' or 'decoction of medical ingredients(湯液)'. Also, 'Fu Ju(㕮咀)' is the transformation of what was 'Fu Qie(父且)' at "Ja Liao Fang" of medical books of Ma Wang Dui with time flow. The original meaning of 'Fu Qie(父且)' is 'Fu Zu(斧俎)' and it means the crushing medicine with axe. The most important thing among the medical books of Han dynasty is "Shen Nong Ben Cao Jing(神農本草經)" and "Shang Han Za Bing Lun(傷寒雜病論)" of Zhang Zhong Jing(張仲景). "Shen Nong Ben Cao Jing" mentioned the dry method of medicine, collection and process production time, cooked and uncooked use of medicine and there are several types of medicine. Other than those, it mentioned 'Seven methods of combining herbs(七情合和)' to address cautions for combining medicines. Therefore, the 'processing of medicinal' in east Han dynasty period entered the theoretical step. However, there is only little recording on cloth manufacture of detailed medicine. From the "Shang Han Za Bing Lun" of Zhang Zhong Jing, the development in the way of 'processing of medicinal' reveled the cloth manufacture for each medicine. This tradition is continued until today and so it presents the development of purpose of 'processing of medicinal' is to greatly present the effect of medicine and to reduce the side-effect.

• Journal of Korean Society of Environmental Engineers
• /
• v.31 no.11
• /
• pp.1007-1018
• /
• 2009

Hydrocyclone is widely used in industry, because of its simplicity in design, high capacity, low maintenance and operational cost. The separation action of a hydrocyclone treating particulate slurry is a consequence of the swirling flow that produces a centrifugal force on the fluid and suspended particles. In spite of hydrocyclone have many advantage, the application for treatment of urban stormwater case study were rare. We conducted a laboratory scale study on treatable potential of micro particles using hydrocyclone filter (HCF) that was a combined modified hydrocyclone with perlite filter cartridge. Since it was not easy to use actual storm water in the scaled-down hydraulic model investigations, it was necessary to reproduce ranges of particles sizes with synthetic materials. The synthesized storm runoff was made with water and addition of particles; ion exchange resin, road sediment, commercial area manhole sediment, and silica gel particles. Experimental studies have been carried out about the particle separation performance of HCF-open system and HCF-closed system. The principal structural differences of these HCFs are underflow zone structure and vortex finder. HCF was made of acryl resin with 120 mm of diameter hydrocyclone and 250 mm of diameter filter chamber and overall height of 800 mm. To determine the removal efficiency for various influent concentrations of suspended solids (SS) and chemical oxygen demand (COD), tests were performed with different operational conditions. The operated maximum of surface loading rate was about 700 $m^3/m^2$/day for HCF-open system, and 1,200 $m^3/m^2$/day for HCF-closed system. It was found that particle removal efficiency for the HCF-closed system is better than the HCF-open system under same surface loading rate. Results showed that SS removal efficiency with the HCF-closed system improved by about 8~20% compared with HCF-open system. The average removal efficiency difference for HCF-closed system between measurement and CFD particle tracking simulation was about 4%.

• Journal of Chest Surgery
• /
• v.30 no.6
• /
• pp.591-597
• /
• 1997

Cardiopulmonary bypass in children is associated with capillary leak which results in an increase in total body water after open heart surgery The purpose of these studies was to assess the cardiopulmonary effects of modified ultrafiltration after pediatric open heart surgery Study h: Twenty-six consecutive children aged 0.1 ~ 10 years(median 7 months) underwent cardiac operation inc rporating modified ultrafiltration. After completion of cardiopulmonary bypass, modified ultrafiltration was commenced at the flow rate of 100~ 15011min for 3 ~ 14 min. After modified ultrafiltration, elevation of hematocrit(28.3% $\pm$ 3.6% vs. 33.8olo $\pm$ 4.Ooloi p < 0.001), increased systolic 1)loots Pressure(66.7 $\pm$ 11.2mmHg vs. 76.2$\pm$ 11.BmmHg, p < 0.02), and decreased central venous pressure(7.8 $\pm$ 3.7mmHg vs. 6.9$\pm$ 2.gmmHg, p<0.001) were observed. Study B: Twenty-six children who underwent cardiac operation with the diagnosis of VSD under 2 years were assigned to control(n= 14) or modified ultrafiltration(n= 12). Peak inspiratory pressure checked immediately after operation was significantly lower in modified ultrafiltration group than in control group(20.0$\pm$ 2.4 cmH20 vs.22.4$\pm$ 2.3cmH20, p < 0.03). Modified ultrafiltration after cardiopillmonary bypass in children improves early homodynamics and pulmonary mechanics, and represents an excellent option for perioperative managemen of accumulation of fluid in the tissues. We will continually employ the modified ultrafiltration technique in pediatric cardiac operations.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.15 no.1
• /
• pp.198-218
• /
• 2002

On the basis of Imjeungjinamuian(臨證指南醫案), authors investigated the pathogenesis and treatment of ophthalmotolaryngobgic diseases from the viewpoint of Onbyeong(溫病). 1. The symptoms and diseases investigated according to department were as follows;. 1) Ophthalmology : blepharitis, blepharedema, lacrimal hypersecretion, hyperemia, ophthalmalgla, photopsia, visual disturbance, mydriasis 2) Otology : full-feeling, otorrhea, otalgla, mastoiditis, tinnitus, hearing disturbance, vertigo 3) Rhinology : rhinorrhea, nasal obstruction, sinusitis, epistaxis 4) Laryngology : sore throat, hoarseness 5) The Others : headache, cough, asthma 2. The pathogenesis and treatment of ophthalmotolaryngologic diseases were as follows. 1) When the pathogenesis of hyperemia, otorrhea, otalgia, mastoiditis, hearing disturhance. epistaxis, sore throat, headache and cough are wind-stagnanc(風鬱), wind-warm(風溫), wind-fire(風火), wind-dryness(風燥), dryness-heat(燥熱), the treatment of pungent-cool-evaporating(辛凉解表) with Dajosan(茶調散), Mori Folium(桑葉), Lonicerae Flos(金銀花), Forsythiae Fructus(連翹), Viticis Fructus(蔓荊子), Prunellae Spica(夏枯草), Arctii Fructus(牛蒡子), etc can be applied. 2) When the pathogenesis of hoarseness, cough and asthma are cold(寒), cold with endogenous heat(寒包熱, 外冷內熱), water retention(水邪), fluid retention(伏飮), impairment of YangKi by overexertion(勞傷陽氣), the treatment of pungent-warm-evaporating(辛溫解表) with Mahaenggamseoktang(麻杏甘石湯), Socheongryongtang(小靑龍湯), Jeongryeokdaejosapyetang(정력대조사폐탕), Gyejitang(桂枝湯), Armeniacae Amarum Semen(杏仁), etc can be applied. 3) When the pathogenesis of photopsia, otorrhea, otalgia, rhinorrhea, sinusitis, epistaxis, sore throat, hoarseness, headache and cough are stagnancy-induced heat(鬱熱), wind-dryness(風燥), wind-heat(風熱), summer heat(暑熱), summer wind(暑風), insidious summer heat(伏暑), autumn heat(秋暑), autumn wind(秋風), autumn dryness(秋燥), dryness-heat(燥熱), heat in Ki system(氣分熱), insidious warm(溫伏), brain discharge by fire in Ki system(氣火 腦熱), heat in stomach(胃熱), endogenous fire by deficiency of Yin(陰虛內火), deficiency of Yin in stomach(胃陰虛), the treatment of Ki-cooling(淸氣) with Bangpungtongseongsan(防風通聖散), Ikweonsan(益元散), Gyejibaekhotang(桂枝白虎湯), Geumgwemaekmundongtang(금궤맥문동탕), Gyeongokgo(瓊玉膏), Sojae Semen Praeparatum(두시), Scutellariae Radix(黃芩), Phyllostachys Folium(竹葉), Adenophorae Radix(沙參), Mori Cortex(桑白皮), Fritillariae Cirrhosae Bulbus(貝母), etc can be applied. 4) When the pathogenesis of blepharitis, hyperemia, ophthalmalgia, full-feeling, otorrhea, otalgia, tinnitus, hearing disturbance, sinusitis, hoarseness, headache and cough are fire in liver(肝火), fire in gallbladder(膽火), ministerial fire in Soyang system(少陽相火), wind-stagnancy(風鬱), stagnancy-induced fire(鬱火), brain discharge by phlegm-fire(痰火 腦熱), the treatment of mediation(和解) with Gardeniae Fructus(梔子), Moutan Cortex(牧丹皮), Saigae Tataricae Cornu(羚羊角), Artemisiae Annuae Herba(靑蒿), Cyperi Rhizoma(香附子), Poria(적복령), etc can be applied. 5) When the pathogenesis of blepharedema and cough are dampness in both spleen and lung(脾肺濕) damp-heat(濕熱), damp-phlegm(濕痰), the treatment of dampness-resolving(化濕) with Poria(백복령), Coicis Semen(薏苡仁), Tetrapanacis Medulla(通草), Armeniacae Amarum Semen(杏仁), Talcum(滑石), etc can be applied. 6) When the pathogenesis of vertigo and cough are deficiency of Yong(營虛), heat in Yong, system(營熱), the treatment of Yong-cooling(淸營) with Rehmanniae Radix(生地黃), Liriopis Tuber(麥門冬), Biotae Semen(柏子仁), Lilii Bulbus(百合), Phyllostachys Folium(竹葉), etc can be applied. 7) When the pathogenesis of epistaxis are heat in blood system of heart(心血熱), reversed flow of fire(火上逆), overexertion(努力), the treatment of blood-cooling(凉血) with Rhinoceri Cornu(犀角), Rehmanniae Radix(生地黃), Moutan Cortex(牧丹皮), Salviae Miltiorrhizae Radix(丹參), Scrophulariae Radix(玄蔘), etc can be applied. 8) When the pathogenesis of nasal obstruction is pathogen-stagnancy(邪鬱), the treatment of resuscitation(開竅) with Sosang(少商, LU11) acupuncture can be applied. When the pathogenesis of hoarseness is evil Ki(穢濁), the treatment of resuscitation(開竅) with Arctii Fructus(牛蒡子), Lasiosphaera Seu Calvatia(馬勃), Curcumae Radix(鬱金), etc can be applied. When the pathogenesis of headache is stasis of both Ki and blood(氣血瘀痺), the treatment of resuscitation(開竅) with Cnidii Rhizoma(川芎), Asari Herba Cum Radice(細辛), Scorpio(全蝎), moxibustion(灸), etc can be applied. 9) When the pathogenesis of lacrimal hypersecretion, visual disturbance, mydriasis, tinnitus, hearing disturbance, sinusitis, epistaxis, hoarseness and cough are deficiency of Yin(陰虛), deficiency of kidney(腎虛), deficiency of both liver and kidney(肝腎虛), deficiency of both heart and kidney(心腎虛), brain discharge by deficiency of Yin(陰虛 腦熱), exuberance of Yang in liver(肝陽上亢), overexertion(勞損), the treatment of Yin-replenishing(滋陰) with Yukmijihwanghwan(六味地黃丸), Hojamhwan(虎潛丸), Jeobutang(猪膚湯), Lycii Fructus(枸杞子), Polygoni Multiflori Radix(何首烏), Rehmanniae Radix(生地黃), Schizandrae Fructus(五味子), Liriopis Tuber(麥門冬), Asini Gelatinum(阿膠), etc can be applied. 10) When the pathogenesis of ophthalmalgia, mydriasis, vertigo and headache are deficiency of Yin in liver(肝陰虛), exuberance of Yang in liver(肝陽上亢), endogenous wind(內風), excess in upper and deficiency in lower part(上實下虛), the treatment of Yin-replenishing(滋陰) and endogenous wind-calming(熄風) with Rehmanniae Radix Preparat(熟地黃), Lycii Fructus(枸杞子), Polygoni Multiflori Radix(何首烏), Paeoniae Radix Alba(白芍藥), Ostreae Concha(牡蠣), Saigae Tataricae Cornu(羚羊角), Chrysanthemi Flos(菊花), etc be applied. 11) When the pathogenesis of mydriasis, sinusitis, hoarseness, headache, cough and asthma are exhaustion of vital essence(精氣無收藏), brain discharge(腦髓不固), floating Yang(陽虛浮), exsanguination(失血), deficiency of both Yin and Yang(陰陽不足), overexertion(勞損), deficiency of Yang in kidney(腎陽虛), the treatment of Yang-restoring and exhaustion-arresting(回陽固脫) with Yangyeongtang(養營湯), Cheonjinhwan(天眞丸), Bokmaektang(복맥탕), Geonjungtang(建中湯), Dogihwan(都氣丸), Singihwan(腎氣丸), Jinmutang(眞武湯), Ostreae Concha(牡蠣), Nelumbinis Semen(蓮子肉), etc can be applied. 12) When the pathogenesis of lacrimal hypersecretion, vertigo and headache are deficiency of stomach and endogenous wind(胃虛內風), endogenous wind with phlegm(內風挾痰), liver check of stomach(肝木橫擾), the treatment of concomitant-treating of both liver and stomach(肝胃同治) with Paeoniae Radix Alba(白芍藥), Uncariae Ramulus Et Uncus(釣鉤藤), Gastrodiae Rhizoma(天麻), Astragali Radix(황기), Pinelliae Rhizoma(半夏), etc can be applied. When the pathogenesis of asthma is failure of kidney to promote inspiration(腎不納氣), the treatment of kidney-tonifing and inspiration-promoting(補腎納氣) with Singihwan(腎氣丸), Psoraleae Fructus(補骨脂), Juglandis Semen(胡桃), Aquilariae Resinatum Lignum(沈香), etc can be applied. When the pathogenesis of asthma is deficiency of Ki(氣虛), the treatment of Ki-reinforcing(補氣) with Sagunjatang(四君子湯), Insamgeonjungtang(人參建中湯), etc can be applied.

• Journal of Biomedical Engineering Research
• /
• v.6 no.2
• /
• pp.1-8
• /
• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.