• Journal of Ecology and Environment
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• v.33 no.1
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• pp.59-65
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• 2010

Because seagrass production significantly contributes to the biodiversity and production of coastal and estuarine ecosystems, accurate estimation of seagrass productivity is a critical step toward understanding the ecological roles of seagrass in these ecosystems. To develop an accurate and effective method of measuring seagrass productivity, we estimated leaf productivity of eelgrass (Zostera marina) on the southern coast of Korea using three methods, the conventional leaf marking method, the elongation-mass method (Short '87 method), and the plastochrone method. In each season, shoots were pierced through the bundle sheath using a hypodermic needle and were collected after 2-4 weeks had elapsed to estimate their productivity. The leaf elongation and the leaf plastochrone intervals varied significantly among seasons. On an annual basis, the conventional leaf marking method showed the lowest leaf productivity estimates compared to the elongation-mass method and the plastochrone method, suggesting that the conventional leaf marking method underestimated leaf productivity as it ignored leaf maturation processes and new leaf growth within the sheath. Since the elongation-mass method considered leaf maturation processes, this method produced higher leaf productivity estimates than the conventional leaf marking method. On an annual basis, the plastochrone method produced the highest leaf productivity estimates. Below-ground productivity, which can be easily estimated using the plastochrone method, ranged between 3.29 and 5.73 (mg dry weight $shoot^{-1}\;day^{-1}$) and accounted for about 17.8% to 30.3% of total productivity. Because of the high contributions of below-ground productivity to total seagrass production, we suggest that the plastochrone method is an effective and simple technique for assessing both above- and below-ground productivities.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.244-250
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• 1976

Candida brumptii was one of the best isolates which could grow on alcohol distillation slops (reported in the previous paper). Attempts were made to investigate the cultural conditions for cell mass production by this strain, and the results obtained were as follow. The supernatant of the alcohol distillation slops without dilution support ed better growth of the strain than diluted ones. The addition of ammonium sulfate (0.2%), ammonium phosphate (0.1-0.2%), potassium phosphate (0.2%) to the supernatant resulted in positive effects for the growth, among the various inorganic nitrogen and other salts supplements. BOD and COD of the supernatant were reduced approximately 30% and 20%, respectively in 3 days culture. Cell production was maximized when grown at $35^{\circ}C$ and pH 5.0. The yield of cell mass was 1.03% by dry weight and its crude protein content was about 52.65%

• Land and Housing Review
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• v.14 no.2
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• pp.97-107
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• 2023

This study examined how to better provide quality temporary housing for people in the event of natural and social disasters. Design for Manufacture and Assembly (DfMA) is suitable for creating an efficient planning model for the mass production and transport of a modular house. The proposed DfMA model has the following three characteristics. First is the division of the modular house into service modules and functional modules and to create diversity by developing standard parts and multi-functional parts. Second is a flexible layout suitable for various site conditions. Such flexible layouts would allow identical homes to be mass produced and deployed to a variety of locations, both nationally and internationally. Third is to simplify and minimize the automation process with dry construction to increase production efficiency. Application of this DfMA design method can lead to reduced construction time and cost and improve housing quality.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2005.11a
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• pp.37-41
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• 2005

When screen size of the Flat Panel Display (FPD) becomes larger, the traditional photo-lithography using photomasks and UV lamps might not be possible to make patterns on Photo Resist (PR) material due to limitation of the mask size. Though the maskless photo-lithography using UV lasers and scanners had been developed to implement large screen display, it was very slow to apply the process for mass-production systems. The laser exposure system using 405 nm semi-conductor lasers and Digital Micromirror Devices (DMD) has been developed to overcome above-mentioned problems and make more than 100 inches FPD devices. It makes very fine patterns for full HD display and exposes them very fast. The optical engines which contain DMD, Micro Lens Array (MLA) and projection lenses are designed for 10 to 50 ${\mu}m$ bitmap pattern resolutions. The test patterns for LCD and PDP displays are exposed on PR and Dry Film Resists (DFR) which are coated or laminated on some specific substrates and developed. The fabricated edges of the sample patterns are well-defined and the results are satisfied with tight manufacturing requirements.

• Current Optics and Photonics
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• v.1 no.1
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• pp.7-11
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• 2017

In this study, multilayered graphene was easily transferred to the target substrate in one step using thermal release tape. The transmittance of the transferred graphene according to the number of layers was measured using a spectrophotometer. The sheet resistance was measured using a four-point probe system. Graphene formed using this transfer method showed almost the same electrical and optical properties as that formed using the conventional poly (methyl methacrylate) transfer method. This method is suitable for the mass production of graphene because of the short process time and easy large-area transfer. In addition, multilayered graphene can be transferred on various substrates without wetting problem using the one-step dry transfer method. In this work, this easy transfer method was used for dielectric substrates such as glass, paper and polyethylene terephthalate, and a sheet resistance of ~240 ohm/sq was obtained with three-layer graphene. By fabricating organic solar cells, we verified the feasibility of using this method for optoelectronic devices.

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.205-216
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• 2002

This study was conducted to examine the effect of long-day (LD) period before short-day (SD) treatment on the vegetative growth of greenhouse-grown cut chrysanthemum cv. Reagan Improved at Wageningen Agricultural University, The Netherlands. Rooted cuttings of cut chrysanthemum cv, Reagan Improved were transplanted on 6th, 13th, 20th of September and all of them were treated with LD before SD treatment on 27th of September, The periods from transplanting until final harvest were 70, 77, and 84 days for 1, 2, and 3 week-LD treatment, respectively. The final plant height increased in the plot of 3 week-LD period and decreased in the plot of 1 week-LD period before the SD treatment. Total fresh weight and the leaf area were increased more in the plot of 3 week-LD period than that of 1 week-LD period, but the absolute growth rate after SD treatment was the same on plant growth rate and increase of the number of leaves in all treatments. The final dry matter production (g.m$^{-2}$ ) was increased more in the plot of 3 week-LD period than that of 1, 2week-LD period before SD treatment. Plant height and fresh weight were followed by the condition of LD period. In addition, dry mass production was highest in 3 week-LD period.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2002.09b
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• pp.5-56
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• 2002

The problems in the current domestic forage production were evaluated, and the prospective improvement was suggested in this paper. Grassland development in forest, production of high quality forages in upland and paddy land, efficient utilization of rice straw, development of new varieties of forages suitable for our environmental conditions and imported forages were described Among them, preferential production and utilization of forages using paddy field after rice harvest . should be enlarged for domestic supply of forages in Korea. Several studies were carried out to select the promising forage crops and barley cultivars for whole crop silage production, to determine productivity, nutritive value and production cost of forages produced in paddy field, and feeding effect of forages with Hanuwoo and milking cow for whole crop silage with forages produced in paddy field, 1999 to 2001, and also discussed restraint factors and activation plans for enlargement of forage production in paddy land. The promising forage crops in paddy field were rye and barley for Middle region, and rye, barley, early maturing Italian ryegrass and wheat for Southern region. The promising barley cultivars for whole crop silage in paddy field were Albori in Suwon, Keunalbori, Milyang 92, Saessalbori, and Naehanssalbori in Iksan, and Keunalbori, Albori, Naehanssalbori, and Saegangbori in Milyang, respectively. Silage production, quality and animal palatability of silage by trench and round bale were also compared. The production yields of whole crop barley silage(WBS) were 17,135kg as a fresh matter, and 6,011kg as a dry matter per ha, and the quality of WBS was 2∼3 grade, while that of rice straw silage was 4 grade as a farm basis. The production cost of WBS per kg was 83won as a fresh matter, and 238won as a dry matter. Feeding of WBS as forages on Hanwoo was very desirable for the improvement of live-weight gain, beef quality and farm income, particularly in growing stage of Hanwoo. Milk production and income were also increased, and feed cost was decreased by feeding of WBS. The daily voluntary intake of WBS in milking cow was 26.3kg as a fresh matter(DM 7.7kg) per head. Milk production when WBS was fed, was very similar to that of imported hay feeding such as Kentucky bluegrass or domestic corn silage. The issues to be solved in near future f3r stable forage production and supply in paddy land are sustainable livestock-forages policy, development & seed production of new varieties of barley, rye, Italian ryegrass and other promising forages, efficient demand & supply system of forages, solidification for mass production and utilization of forages, efficient application management of animal slurry on paddy field considering environmental agriculture/livestock industry, and break k development of bottleneck technique in production field. Domestic production & supply of high cost agricultural machine (round baler, wrapper, handler and so on), plastic wrapping film, and silage additives are also important.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.624-628
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• 1989

A study on the citric acid production using Saccharomycopsis lipolytica (NRRL Y7576) was carried out in shake-flasks, air-lift and membrane recycle bioreactors. The cells entrapped in Ca-alginate beads were used in shake-flasks and air-lift reactor. Repeated batch fermentation in shake-flasks was successfully performed for 34 days and resulted in a yield of 54%. Increased yield (63%) was obtained in the air-lift reactor operation using nitrogen deficient medium (NDM). In the membrane recycle bioreactor operation, the maximal dry cell mass concentration was 39 g/1 at a dilution rate of 0.02 h$^{-1}$ and the yield with NDM was higher than that with growth medium. In addition, the yield and volumetric productivity with pure oxygen supply were greatly improved compared with those with air supply.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.617-621
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• 2002

In order to optimize the carrot hairy root culture for SOD production, a fed-batch culture of hairy roots was performed in a bioreactor. Maximum SOD activity was obtained when the hairy roots were transferred to the MS medium containing 110 g/1 concentration of sucrose. By controlling the sucrose concentration (70 g/1 sucrose for growth and 110 g/1 sucrose far production, respectively) In a two-stage fed-batch culture, 29 g/1 of the hairy roots was obtained based on the final dry mass. The volumetrically determined SOD activity and productivity in the fed-batch culture were about 6 times higher than those from the flask culture containing sucrose at 30 g/1 concentration.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.21-30
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• 2015

Ceramic foams are prepared as positive images corresponding to a plastic foam structure which exhibits high porosities (85-90%). This structure makes the ceramic foams attractive as a catalyst in a dry reforming process, because it could reduce a high pressure drop problem. This problem causes low mass and heat transfers in the process. Furthermore, the reactants would shortly contact to catalyst surface, thus low conversion could occur. Therefore, this research addressed the preparation of dry reforming catalysts using a sol-gel catalyst preparation via a polymeric sponge method. The specific objectives of this work are to investigate the effects of polymer foam structure (such as porosity, pore sizes, and cell characteristics) on a catalyst performance and to observe the influences of catalyst preparation parameters to yield a replica of the original structure of polymeric foam. To accomplish these objectives industrial waste foams, polyurethane (PU) and polyvinyl alcohol (PVA) foams, were used as a polymeric template. Results indicated that the porosity of the polyurethane and polyvinyl alcohol foams were about 99% and 97%. Their average cell sizes were approximate 200 and 50 micrometres, respectively. The cell characteristics of polymer foams exhibited the character of a high permeability material that can be able to dip with ceramic slurry, which was synthesized with various viscosities, during a catalyst preparation step. Next, morphology of ceramic foams was explored using scanning electron microscopy (SEM), and catalyst properties, such as; temperature profile of catalyst reduction, metal dispersion, and surface area, were also characterized by $H_2-TPR$ and $H_2-TPD$ techniques, and BET, respectively. From the results, it was found that metal-particle dispersion was relatively high about 5.89%, whereas the surface area of ceramic foam catalysts was $64.52m^2/g$. Finally, the catalytic behaviour toward hydrogen production through the dry reforming of methane using a fixed-bed reactor was evaluated under certain operating conditions. The approaches from this research provide a direction for further improvement of marketable environmental friendly catalyst production.