• Journal of Advanced Marine Engineering and Technology
• /
• v.41 no.3
• /
• pp.216-221
• /
• 2017

Diesel engines have the highest brake thermal efficiency among internal combustion engines. Therefore, they are utilized in medium and large transportation vehicles requiring large amounts of power such as heavy trucks, ships, power generation systems, etc. However, diesel engines have a disadvantage of generating large quantities of nitrogen oxides during the combustion process. Therefore, the authors tried to reduce the amount of nitrogen oxides in marine diesel engines using a wet-type exhaust gas cleaning system utilizing the undivided electrolyzed seawater method. In this method, electrolyzed seawater in injected into the harmful gas discharge from the diesel engine using real seawater. The authors investigated the reduction of NO and NOx from the pH value, available chlorine concentration, and the temperature of electrolyzed seawater. The results of this experiment indicated that when the electrolyzed seawater is acidic, the NO oxidation rate in the oxidation tower is higher than that when the electrolyzed seawater has a neutral pH. Likewise, the NO oxidation rate increased with the increase in concentration of chlorine. Further, it was confirmed that the electrolyzed seawater temperature had no effect on the NO oxidation rate. Thus, the NOx exhaust emission value produced by the diesel engine was reduced by means of electrolyzed seawater treatment.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1998.06a
• /
• pp.135-153
• /
• 1998

Nanofiltration (NF) is a recently introduced term in membrane separation. In 1988, Eriksson was one of the first authors using the word 'nanofiltration' explicitly. Some years before, FilmTech started to use this term for their NF50 membrane which was supposed to be a very loose reverse osmosis membrane or a very tight ultrafiltration membrane. Since then, this term has been introduced to indicate a specific boundary of membrane technology in between ultrafiltration and reverse osmosis. The application fields of the NF membranes are very broad as follows: Demeneralizing water, Cleaning up contaminated groundwater, Ultrapure water production, Treatment of effleunts containing heavy metals, Offshore oil platforms, Yeast production, Pulp and paper mills, Textile production, Electroless copper plating, Cheese whey production, Cyclodextrin production, Lactose production. The earliest NF membrane was made by Cadotte et al, using piperazine and trimesoyl chloride as monomers for the formation of polyamide active layer of the composite type membrane. They coated very thin interfacially potymerized polyamide on the surface of the microporous polysulfone supports. The NF membrane exhibited low rejections for monovalent anions (chloride) and high rejections for bivalent anions (sulphate). This membrane was called NS300. Some of the earliest NF membranes, like the NF40 membrane of FilmTech, the NTR7250 of Nitto-Denko and the UTC20 and UTC60 of Toray, are formed by a comparable synthesis route as the NS300 membrane. Commercially available NF membranes nowadays are as follows: ASP35 (Advanced Membrane Technology), MPF21; MPF32 (Kiryat Weizmann), UTC20; UTC60; UTC70; UTC90 (Toray), CTA-LP; TFCS (Fluid Systems), NF45; NF70 (FilmTec), BQ01; MX07; HG01; HG19; SX01; SX10 (Osmonics), 8040-LSY-PVDI (Hydranautics), NF CA30; NF PES 10 (Hoechst), WFN0505 (Stork Friesland). The typical ones among the commercially available NF membranes are polyamide composite membrane consisting of interfacially polymerized polyamide active layer and microporous support. While showing high water fluxes and high rejections of multivalent ions and small organic molecules, these membranes have relatively low chemical stability. These membranes have low chlorine tolerance and are unstable in acid or base solution. This chemical instability is appearing to be a big obstacle for their applications. To improve the chemical stability, we have tried, in this study, to prepare chemically stable NF membranes from PVA. The ionomers and interfacially polymerized polyamide were used for the modification of'the PVA membranes. For the detail study of the active layer, homogeneous NF membranes made only from active layer materials were prepared and for the high performance, composite type NF membranes were prepared by coating the active layer materials on microporous polysulfone supports.

• KSBB Journal
• /
• v.20 no.6
• /
• pp.431-437
• /
• 2005

Molecular methods were employed to investigate microorganisms in a thermophilic continuous stirred tank reactor(CSTR) used for continuous $H_2$ production. The reactor was inoculated with heat-treated anaerobic sludge and fed with a glucose-based medium. Denaturing gradient gel electrophoresis showed dynamic changes of bacterial populations in the reactor during 43 days of operation. Gas composition was constant from approximately 14 days but population shift still occurred. Populations affiliated with Fervidobactrium gondwanens and Thermoanaerobacterium thermosaccharolyticum were dominant on 21 and 41 days, respectively. Keeping pH of the medium at 5.0 could suppress methanogenic activity that was detected during initial operation period. $CH_4$ and mcrA detected in the samples obtained from the reactor or inoculum suggested the heat treatment condition employed in this study is not enough to remove methanogens in the inoculum. PCR using primer sets specific to 4 main orders of methanogens suggested that major $H_2$-consuming methanogens in the CSTR belong to the order Methanobacteriales.

• KSBB Journal
• /
• v.20 no.6
• /
• pp.425-430
• /
• 2005

Thermophilic $H_2$ was produced for 1 year using a bench-scale continuous stirred tank reactor(CSTR). The CSTR was inoculated with anaerobically digested sludge after heat treatment and fed with a glucose-based medium. The reactor showed relatively short start-up period(30 days) and high maximal $H_2$ yield(2.4 mol $H_2/mol$ glucose). Keeping pH 5.0 or less suppressed methanogenic activity. Bacteria affiliated with Thermoanaerobacterium thermosaccharolyticum kept being dominant from approximately 40 days as determined by DGGE. Environmental perturbation(pH or temperature) caused the decrease of biomass concentration in the reactor and the instability of reactor performance, $H_2$ production rate and $H_2$ yield. The unstable performance was accompanied with high concentration of lactate in the effluent. Taken together, the poor recovery of CSTR after perturbations could be partly explained by low biomass concentration and/or metabolic shift of the major population in the CSTR.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.9
• /
• pp.1459-1463
• /
• 2005

Not enough data on nutritional change of foods by gamma irradiation are accumulated. It is known that amounts and digestibility of macronutrients such as carbohydrates, proteins and lipids are not significantly altered by irradiation treatment. However, among micronutrients, vitamins are known to be susceptible to irradiation. This study was conducted to investigate the change of contents of riboflavin in egg powder and niacin in chicken breast. By irradiation of 5 and 10 kGy, riboflavin contents of egg powder were respectively reduced to $80.18\%\;and\;84.80\%$ of non-irradiated sample, and niacin contents in chicken breast were reduced to $85.30\%\;and\;92.60\%$, respectively. These results suggest that the reduction rate by gamma irradiation seems to be lower in niacin content than in riboflavin, and the losses of riboflavin and niacin occur within the range of $20\%$ by irradiation of up to 10 kGy.

• Journal of Distribution Research
• /
• v.15 no.5
• /
• pp.61-79
• /
• 2010

As the interest and the importance of environmental protection increases rapidly, the environment considers to be not only the item that requires a control and a duty fundamental element but the fundamental element to enhance the internection icompetitiveness n so. Along with the collapse of the foreign trade barrier and the quality improvement of a customer's life qu life of a an object is shortened liforder to sectsfy the customer's lemands and as the result of it quaother critical issues rmparding the waste treatment and recasles are now thought to be momentou onlyaddition to the issue of the greenhou e gases reduction that is considered as one of me q issues among many internection ienvironmental issues. To keep up the pace with the environmental flow qube notd countries have nlreal iput their attempts to solve this environmental problems through a number of rmpulactios and acctios and they have showed a great concern for it as it is an internection iproblem that they should aasroaeronlythe aspect of not just a compan isr a country but of the wte e globn ivillage. Sueroenvironmental flow alemaned the logistic stratmpy of a compan iand it brought up the demand for the reverse logistics in a supply chain. For the reason above, the concept of reverse logistics and classification, the comparison with any similar concepts and its necessity are studied in this research through the theoretical consideration and the current state of the reverse logistics is organized in this research by acknowledging the domestic development process and the properties regarding the recycles of resources. In addition, the way to apply to the nation was investigated by comparing with the environmentalism development process, the reverse logistics policies and examples of advanced countries in logistics. The research proposed building of intimate cooperative system between a shipper and logistic service provider for the reverse logistics throughout the whole supply chain, the financial support, amendment of regulations, support Eco-friendly logistic technology development and the propagation, effective logistic system development and others and it is expected to bring a significant meaning to the reverse logistic policy and operation later on.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.15 no.1
• /
• pp.38-46
• /
• 2012

This study carried out current status, characteristics, and problems of coastal environment management on semi-enclosed Masan Bay in Korea and suggests cost-effective and eco-friendly water quality management policy. The pollutants from terrestrial sources into the Bay have apparently environmental pollution problems, such as eutrophication, red tide, and hypoxia. The carrying capacity of the Bay is estimated by hydrodynamic model and ecosystem model, material circulation including bivalve in ecosystem is analyzed by the growth model of bivalve. The resulting reduction in the input load was found to be 50~90%, which is unrealistic. When the efficiency of water quality improvement through bivalve farming was assessed based on the autochthonous COD, 30.7% of the total COD was allochthonous COD and 69.3% was autochthonous COD. The overall autochthonous COD reduction rate by bivalve aquaculture farm was found to be about 6.7%. This study indicate that bivalve farming is about 31% less expensive than advanced treatment facilities that remove both nitrogen and phosphorous.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.357-360
• /
• 1997

For medical students and doctors, knowledge of the 3-dimensional (3D) structure of the heart is very important in diagnosis and treatment of the heart diseases. 2-dimensional (2D) tools (e.g. anatomy book) or classical 3D tools (e.g. plastic model) are not sufficient or understanding the complex structures of the heart. Moreover, it is not always guaranteed to dissect the heart of cadaver when it is necessary. To overcome this problem, virtual dissection systems of the heart have been developed. But these systems are not satisfactory since they are made of radiographs; they are not true 3D images; they can not be used to dissect freely; or they can only be operated on the workstation. It is also necessary to make the dissection systems incorporating the various races and tribes because of the organ's difference according to race and tribe. This study was intended to make the 3D image of the heart from a Korean cadaver, and to establish a virtual dissection system of the heart with a personal computer. The procedures or manufacturing this system were as follows. 1. The heart from a Korean adult cadaver was embedded with gelatin solution, and serially cross-sectioned at 1mm-thickness on a meat slicer. Pictures or 153 cross-sectioned specimens were inputted into the computer using a digital camera ($756{\times}504$ resolution, true color). 2. The alignment system was established by means of the language of IDL, and applied to align 2D images of the heart. In each of 2D images, closed curves lining clean and dirty blood pathways were drawn manually on the CorelDRAW program. 3. Using the language of IDL, the 3D image and the virtual dissection system of the heart were constructed. The virtual dissection system of the heart allowed or ree rotation, any-directional sectioning, and selected visualization of the heart's structure. This system is expected to become more advanced, and to be used widely through Internet or CD-title as an educational tool for medical students and doctors.

• Proceedings of the KOSOMBE Conference
• /
• v.1998 no.11
• /
• pp.57-59
• /
• 1998

For medical students and doctors, knowledge of the three-dimensional (3D) structure of brain is very important in diagnosis and treatment of brain diseases. Two-dimensional (2D) tools (ex: anatomy book) or traditional 3D tools (ex: plastic model) are not sufficient to understand the complex structures of the brain. However, it is not always guaranteed to dissect the brain of cadaver when it is necessary. To overcome this problem, the virtual dissection programs of the brain have been developed. However, most programs include only 2D images that do not permit free dissection and free rotation. Many programs are made of radiographs that are not as realistic as sectioned cadaver because radiographs do not reveal true color and have limited resolution. It is also necessary to make the virtual dissection programs of each race and ethnic group. We attempted to make a virtual dissection program using a 3D image of the brain from a Korean cadaver. The purpose of this study is to present an educational tool for those interested in the anatomy of the brain. The procedures to make this program were as follows. A brain extracted from a 58-years old male Korean cadaver was embedded with gelatin solution, and serially sectioned into 1.4 mm-thickness using a meat slicer. 130 sectioned specimens were inputted to the computer using a scanner ($420\times456$ resolution, true color), and the 2D images were aligned on the alignment program composed using IDL language. Outlines of the brain components (cerebrum, cerebellum, brain stem, lentiform nucleus, caudate nucleus, thalamus, optic nerve, fornix, cerebral artery, and ventricle) were manually drawn from the 2D images on the CorelDRAW program. Multimedia data, including text and voice comments, were inputted to help the user to learn about the brain components. 3D images of the brain were reconstructed through the volume-based rendering of the 2D images. Using the 3D image of the brain as the main feature, virtual dissection program was composed using IDL language. Various dissection functions, such as dissecting 3D image of the brain at free angle to show its plane, presenting multimedia data of brain components, and rotating 3D image of the whole brain or selected brain components at free angle were established. This virtual dissection program is expected to become more advanced, and to be used widely through Internet or CD-title as an educational tool for medical students and doctors.

• The Journal of Korean Physical Therapy
• /
• v.12 no.3
• /
• pp.319-329
• /
• 2000

The purpose of this study w8s to evaluate the effects of pulsed electromagnetic energy(Diapulse) and microcurrent on the wound healing in rabbits. 15 domestic rabbits were randomly assigned to the PRME(n=5). MC(n=5) and CON(n=91 group. Each rabbits were anesthetized with lidocaine HCL $2\%$. Skin wounds were created laterally on the back of IS domestic rabbits(33cm). From 24 hours after being injured, the rabbits of the PEME group were irradiated with an intensity of 3 at a 300 pulses per second, which were applied for 15 minutes every day during the 12 days. The MC group were stimulated with an intensity of $50{\mu}A$ at frequency of40 pulses per second, which were applied for 15 minutes every day during the 12 days. The CON group were not stimulated. The rabbits were sacrificed and the incised wound pans were processed appropriately for the light microscopic examination on the 3rd day, 6th day and 12th day before the beginning of wound treatment. The areas of wound were measured with metric graph paper. The results were as tallows. 1 The PRME and MC group compared with control group showed that wound closure rate increased on 6th, 12th day. 2. It was found that the CON group did not show a complete maturation and had a chronic inflammatory response. Judging from the irregularity of intercellular space and the loose alignment of connective tissue. these findings showed that wound healing was delayed. 3. It showed that inflammatory cells. fibroblasts and epithelial cells activity rapidly processed in the PEME group compared with the CON group. It was found that the PEMI; group showed a advanced remodeling of epithelial layer and a positive repair of connective tissue. 4. It showed that fibroblasts, epithelial cells and inflammatory cells activity rapidly processed in the MC group compared with the CON group. It was found that the MC group showed a improved remodeling of epithelial layer and a dense connective tissue.