• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.169-174
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• 1999

The reclamation area of Saemangeum (Kunsan) located between 126$^{\circ}$10' -126$^{\circ}$50'E and and 35$^{\circ}$35'N -36$^{\circ}$05'N at the western coast of Korea. The construction of the 33km sea dike is building in the Saemangeum area. When the construction of the sea dike in the coastal region takes plase, there exists a certain amount of soil which is diffused by the tidal current. Behavior of the soil diffusion usually depends on its intrinsic characteristics, bathymetry, construction method and used mchinery. The amount of soil at the construction acts as a pollutant which is the cause of changing the marine environment. When the soil material is diffused , it may form a layer which obstructs the light passing into the sea and causes the extinction or alteration of the living beings on the sea bottom. The settlement of soil material could change the sea bottom deposit. The purpose of MITIGATION is to harmonize the development and the conservation of environment, to restrict environmental destruction and to reproduce the enviroment damaged by the construction in the coastal region. The purpose of this study is to find the method by which we minimize the anti-function of development in the coastal region. Tide and tidal current are calculated using a two-dimensional numerical model before the construction of sea dike in Saemangeum Bay. The numerical results are compared well with field observations. On the basis of these results, we caculated the tide and tidal current after the construction of the sea dike in order to investigate the change of the tide and tidal current after the construction of the sea dike. Moreover, we calculated the tide and tidal current after the construction of submerged breakwater in order to preserve the enviornmental condition of creature habitat . We compared the tide and tidal current before and after the construction of submerbed breakwater, to investigate the possbility of MITIGATION in the fisheries.

• 반도체디스플레이기술학회지
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• 제4권2호
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• pp.15-19
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• 2005

The organic light-emitting devices(OLEDs) based on fluorescence have low efficiency due to the requirement of spin-symmetry conservation. By using the phosphorescent material, the internal quantum efficiency can reach 100$\%$, compared to 25$\%$ in case of the fluorescent material [1]. Thus recently phosphorescent OLEDs have been extensively studied and showed higher internal quantum efficiency than conventional OLEDs. In this study, we have applied a new Ir complex as a red dopant and fabricated a red phosphorescent OLED on a flexible PC(Polycarbonate) substrate. Also, we have investigated the electrical and optical properties of the devices with a structure of A1/LiF/Alq3/(RD05 doped)BAlq/NPB/2-TNAIA/ITO/PC substrate. Our device showed the lightening efficiency of > 30 cd/A at an initial brightness of 1000 cd/$m^{2}$. The CIE(Commission Internationale de L'Eclairage) coordinates for the device were (0.62,0.37) at a current density of 1 mA/$cm^{2}$. In addition, although the sheet resistance of ITO films on PC substrate is higher than that on glass substrate, the flexible OLED showed much better lightening efficiency without much increase in operating voltage.

• Tribology and Lubricants
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• 제30권6호
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• pp.343-349
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• 2014

Currently, in order to resist the scratching of the fuel rod surface while fabricating the fuel assembly of the light-water nuclear reactor, we use a solution of nitrocellulose, an explosive material, as a dry lubricant along with its solvent. However, the demand for developing safe and harmless aqueous alternative materials for environment-conservation and field-worker safety has increased. In this study, we demonstrate the preparation of a novel aqueous resin composite using a formulation of aqueous polymeric resin, alcoholic solvent, and water. Subsequently, we characterize this composite on the basis of hardness, adhesive property, and water solubility using plates similar to the fuel rod material. The insertion test of a fuel rod coated with the YS-3 composite shows load values of $18.8-20.5kg/cm^2$, which is comparable with $18.8-20.5kg/cm^2$ of the nitrocellulose coating agent. In addition, the depth and width of longitudinal scratches caused by the YS-3 composite test are 50% higher than those of the standard. We can develop a harmless and safe aqueous dry lubricant to replace the existing NC products through field testing of 264 pieces of fuel rods, after producing 350 kg of the YS-3 prototype. The scratch test for the rod surface showed that weight of chip of YS-3 prototype was smaller than that of NC before and after solvent treatment, indicating the properties of YS-3 prototype was comparable to the counterpart.

• 인간식물환경학회지
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• 제24권6호
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• pp.619-628
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• 2021

Background and objective: Native to the limestone zones of the Korean Peninsula, Zabelia tyaihyonii is a popular plant for landscaping. As it is now classified as a rare species, the conservation of its genetic resources is necessary. Methods: In this study, which aimed to understand the morphological variation of Z. tyaihyonii, 18 characteristics of Z. tyaihyonii from five habitats were examined. Results: Of these 18 characteristics, 16 characteristics showed significant differences among sites, and the coefficient of variation ranged from 5.4% (for corolla lobe number) to 31.3% (for flower number). Notable variations were observed in the size of flower and calyx lobe. When the corolla length and calyx lobe length were used as the classification key of Z. tyaihyonii, the sites were divided into those with small, intermediate, and large values. Hair was observed on the filament of all samples, a finding which conflicts with an earlier report. Rather than classifying Z. tyaihyonii into different species on the basis of corolla length (COL) and calyx lobe length (CALL) values, we recommend modifying the species description to incorporate the variation in these characteristics of interest. Principal component analysis results showed that the first main component was highly correlated with the traits related to the size of the calyx lobe (length: 0.819, width: 0.758), and the second main component was highly correlated with the traits related with the size of the inflorescence (length: 0.790, width: 0.626). Conclusion: Several notable variations were identified among the characteristics related to inflorescence and calyx lobe. There is little genetic exchange among groups, or each group is influenced by micro environmental factors, because sites that are located nearby. In addition, the difference between COL and CALL, which is used as the classification key for Z. tyaihyonii, was divided into small group, large group, and intermediate group, regardless of the sites' geographical distance.

• Journal of Theoretical and Applied Mechanics
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• 제3권1호
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• pp.45-65
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• 2002

A constitutive model on oorthotropic thermo-elasto-viscoplasticity for fiber-reinforced composite materials Is illustrated, and their thermomechanical responses are predicted with the fully-coupled finite element formulation. The unmixing-mixing scheme can be adopted with the multipartite matrix method as the constitutive model. Basic assumptions based upon the composite micromechanics are postulated, and the strain components of thermal expansion due to temperature change are included In the formulation. Also. more than two sets of mechanical variables, which represent the deformation states of multipartite matrix can be introduced arbitrarily. In particular, the unmixing-mixing scheme can be used with any well-known isotropic viscoplastic theory of the matrix material. The scheme unnecessitates the complex processes for developing an orthotropic viscoplastic theory. The governing equations based on fully-coupled thermomechanics are derived with constitutive arrangement by the unmixing-mixing concept. By considering some auxiliary conditions, the Initial-boundary value problem Is completely set up. As a tool of numerical analyses, the finite element method Is used with isoparametric Interpolation fer the displacement and the temperature fields. The equation of mutton and the energy conservation equation are spatially discretized, and then the time marching techniques such as the Newmark method and the Crank-Nicolson technique are applied. To solve the ultimate nonlinear simultaneous equations, a successive iteration algorithm is constructed with subincrementing technique. As a numerical study, a series of analyses are performed with the main focus on the thermomechanical coupling effect in composite materials. The progress of viscoplastic deformation, the stress-strain relation, and the temperature History are careful1y examined when composite laminates are subjected to repeated cyclic loading.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2006년도 추계학술발표대회 논문집
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• pp.275-280
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• 2006

The protection of the environment is one of today's key demanding international activities and interests. All of aspects including industry, economy and society should be changed into environmental friendly industries. The building is not exception in this trend. What is not generally realized is that building, in the lifecycle of construction, use and demolition, account for large construction, not considered with environment impact and conservation in the lifecycle. Expecially, the construction materials and components used in the construction stage has much embodied energy. And much $CO_2$ emit on the production of the construction material and component. The energy use and $CO_2$ emission would continuously diminish the limited natural resources and impact the environment such as ozon layer destruction. In this paper, it studied the estimation of the amount of energy use and $CO_2$ emission in the building construction stage, it would provide the estimation process and applied with the multifamily housing.

• 펄프종이기술
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• 제47권4호
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• pp.127-135
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• 2015

Artists have been used animal glues for a long time as binding and sizing materials of paintings in many countries including Korea. Since animal glues as a binding material lose their own adhesive strength by aging, pigment particles or pigment layers are easily detached from painting surface. Restaurators prefer to use animal glues for consolidation of pigment particles or pigment layers because artists use animal glues as a binder for their painting works. It is widely known that animal glues have different characteristics such as viscosity, stability on water etc. But there are still a few requirements to consider their stabilities for the restoration of paintings. Therefore, this study was aimed to evaluate of stability and efficiency of animal glue applications. The efficiency of animal glue application was decreased with increasing the concentration of animal glue solution. This result means the simple tendency, but does not representative data for other animal glues made from same raw materials. In most cases, the surface and mechanical characteristics of animal glues are dependent on some factors, like viscosity and concentration of animal glue solution.

• Journal of Forest and Environmental Science
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• 제29권1호
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• pp.38-48
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• 2013

Decomposition of plant material is an important component in the study of forest ecosystem because of its critical role in nutrient cycling. Different tree species has different nutrient release patterns, which are related to leaf litter quantitative traits and seasonal environmental factors. The quantitative traits of leaf litter are important predictors of decomposition and decomposition rates increase with greater nutrient availability in the forest ecosystems. At the ecosystem level, litter quantitative traits are most often related to the physical and chemical characteristics of the litter, for example, leaf toughness and leaf mass per unit area, and lignin content tannin and total phenolics. Thus, the analysis of litter quantitative traits and decomposition are highly important for the understanding of nutrient cycling in forest ecosystems. By studying the role of litter quantitative traits on decomposition and nutrient cycling in forest ecosystems will provide a valuable insight to how quantitative traits influence ecosystem nutrient dynamics. Such knowledge will contribute to future forest management and conservation practices.

• 분석과학
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• 제32권6호
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• pp.225-232
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• 2019

Traceability establishment in chemical measurements is a like a linkage established through an unbroken chain from the measured results to the international system (SI) of units. The primary process for traceability establishment is the purity assignment of a target material to be measured. In this study, we studied the purity assignment of 17α-hydroxyprogesterone (17-OHP). The presence of 17-OHP is indicative of congenital adrenal hyperplasia (CAH) and it builds up due to the deficiency of 21-hydroxylase and 11β-hydroxylase enzyme in the human blood. The purity assignment of 17-OHP was performed by the mass balance method, in which the impurities are categorized into four classes: total related structural impurities, water, residual organic solvents, and nonvolatiles/inorganics. The total related structural impurities were characterized by HPLC-UV; water content was determined by Karl-Fisher coulometer; and the total residual solvents and nonvolatiles/inorganics were determined by TGA. The purity of 17-OHP from a commercial manufacturer was calculated as 993.30 mg/g, and the expanded uncertainty was 0.58 mg/g. The proposed method was validated by uncertainty evaluation and comparing with the actual value of purity.

• 한국환경과학회지
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• 제13권2호
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• pp.117-127
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• 2004

The purpose of this study is to present the conditions and methods for keeping the sustainability of the landscape resources of the East Coast of Gangwon province, the Republic of Korea by investigating the landscape resources management in the area and pointing out its problems. The unit of analysis in this study is four cities and two counties located along the national road route seven in Gangwon province. The classification and characteristics of the landscape resources in this area was analyzed by a literature review, and we surveyed the tourists visiting the area and statistically analyzed the data in order to examine their satisfaction with the landscape resources management and make recommendations. The problems of the landscape resources management are: 1) the disturbance of the persistence of life by reclamation, the population reduction in the ecosystem due to the overload in environmental capacity, and the severance of space between land and water. 2) the reduction of the benefits from indirect experience by interfering with the conservation of fluxes --- the manipulation of horizontal arrangement of the landscape resource, the visual disturbance by the construction of high-storied buildings, and the disharmony between the color/image and the environment. The means for keeping sustainability of the landscape resources include the regulations of development and use, the change in the recognition of the value of landscape resources and the moral system, and the improvement of resource management skills.