• Title/Summary/Keyword: long term storage

Search Result 795, Processing Time 0.033 seconds

A Study on Development of Long-Term Runoff Model for Water Resources Planning and Management (수자원의 이용계획을 위한 장기유출모형의 개발에 관한 연구)

  • Cho, Hyeon-Kyeong
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.16 no.3
    • /
    • pp.61-68
    • /
    • 2013
  • Long-term runoff model can be used to establish the effective plan of water reources allocation and the determination of the storage capacity of reservoir. So this study aims at the development of monthly runoff model using artificial neural network technique. For this, it was selected multi-layer neural network(MLN) and radial basis function neural network(RFN) model. In this study, it was applied model to analysis monthly runoff process at the Wi stream basin in Nakdong river which is representative experimental river basin of IHP. For this, multi-layer neural network model tried to construct input 3, hidden 7, and output 1 for each number of layer. As the result of analysis of monthly runoff process using models connected with artificial neural network technique, it showed that these models were effective in the simulation of monthly runoff.

Growth of Ice Crystal with Concentration of Surfactant in Water Solution (계면활성제 농도가 빙결정의 입자크기에 미치는 영향)

  • ;稻葉英男
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.26 no.2
    • /
    • pp.240-247
    • /
    • 2002
  • Recently, a thermal energy storage system has been developed actively fur the purpose of saving energy and reducing the peak electrical demand. Especially, ice slurry is a promising working fluid for low temperature energy storage systems. A flow of ice crystals has a large cooling capacity as a result of the involvement of latent heat. However, there are still problems related to the recrystallization of ice crystals for realizing long term storage and long distance transportation. To find improvements fur this, a method for the creation of ice crystals resistant to recrystallization has been proposed and researched by the use of an antifreeze protein (AFP) solution etc. In the present study, it has been investigated the growth of ice crystal in several kinds of water solution added non-ionic surfactant. The results shows that size of ice crystal was smaller with increasing in added surfactant. And ice crystal was not increased with added surfactant.

Quality Variation of Sibjeondaebotang according to Long-term Storage (십전대보탕의 장기보관 중 품질변화)

  • Kim, Ae-kyung;Lee, Chun-yeong;Hwang, Kwang-ho;Lee, Young-jong;Kim, Su-jin;Lee, Young-ju;Lee, Hyun-kyung;Lee, Sae-ram;Kim, Il-young;Lee, Jeong-mi;Yu, In-sil;Jung, Kweon
    • Korean Journal of Pharmacognosy
    • /
    • v.47 no.4
    • /
    • pp.374-380
    • /
    • 2016
  • The purpose of this study was to evaluate of quality variation of Sibujeondaebotang according to storage period and temperature (5 and $25^{\circ}C$) Identificaion test, pH, specific gravity, heavy metal, microbial limit test and glycyrrhizic acid, paeoniflorin content of Sibjeondaebotang were performed during 12 months. The significant change was not shown on identificaion test, specific gravity, microbial limit test under long term storage and the result suited a safe level standards of 'Korean National Standard of Traditional Medicinal (Herbal and Botanical) Materials - "Sibjeondaebotang"'. The test of pH showed meaningful changes between two storage temperature (5 and $25^{\circ}C$) according to increasing storage period. The contents of glycyrrhizic acid and paeoniflorin had no relation with storage temperature($5^{\circ}C$, $25^{\circ}C$) but it showed a tendency to decrease according to the length of storage period. We predicted shelf-life of glycyrrhizic acid and paeoniflorin at storgae temperature(5 and $25^{\circ}C$) as about 6 and 3 months, respecttively. Therefore considering glycyrrhizic acid and paeoniflorin, sibjeondaebotang is determined to be in good condition within 3 months, regardless of the room temperature and refrigerated temperature. We were expected to serve as a basis for the guideline of medication counseling sibjeondaebotang.

Unit Commitment Considering Variable Power of Hydro and Pumped Storage Hydro Units (수력 및 앙수발전기의 가변출력운전을 고려한 기동전지 계획에 관한 연구)

  • 송길영;이범;김용하
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.43 no.3
    • /
    • pp.351-362
    • /
    • 1994
  • This paper presents a new method for solving a long term unit commitment problem including hydro and pumped storage hydro units in a large scale power system. The proposed method makes it possible to get variable power of hydro and pumpde storage hydro units and results in the better unit commitment with good convergency. Moreover this paper proposes an unit commitment algorithm to consider variable power of these units effectively by Lagrangian Relaxation method. By applying the proposed method to the test system and the real system, it is verified the usefulness of this method.

OPTIMUM STORAGE REALLOCATION AND GATE OPERATION IN MULTIPURPOSE RESERVOIRS

  • Hamid Moradkhani
    • Water Engineering Research
    • /
    • v.3 no.1
    • /
    • pp.57-62
    • /
    • 2002
  • This research is intended to integrate long-term operation rules and real time operation policy for conservation & flood control in a reservoir. The familiar Yield model has been modified and used to provide long-term rule curves. The model employs linear programming technique under given physical conditions, i.e., total capacity, dead storage, spillways, outlet capacity and their respective elevations to find required and desired minimum storage fur different demands. To investigate the system behavior resulting from the above-mentioned operating policy, i.e., the rule curves, the simulation model was used. Results of the simulation model show that the results of the optimization model are indeed valid. After confirmation of the above mentioned rule curves by the simulation models, gate operation procedure was merged with the long term operation rules to determine the optimum reservoir operating policy. In the gate operation procedure, operating policy in downstream flood plain, i.e., determination of damaging and non-damaging discharges in flood plain, peak floods, which could be routed by reservoir, are determined. Also outflow hydrograph and variations of water surface levels for two known hydrographs are determined. To examine efficiency of the above-mentioned models and their ability in determining the optimum operation policy, Esteghlal reservoir in Iran was analyzed as a case study. A numerical model fur the solution of two-dimensional dam break problems using fractional step method is developed on unstructured grid. The model is based on second-order Weighted Averaged Flux(WAF) scheme with HLLC approximate Riemann solver. To control the nonphysical oscillations associated with second-order accuracy, TVD scheme with SUPERBEE limiter is used. The developed model is verified by comparing the computational solutions with analytic solutions in idealized test cases. Very good agreements have been achieved in the verifications.

  • PDF

Temperature Evaluation on Long-term Storage of Radioactive Waste Produced in the Process of Isotope Production (동위원소 생산공정에서 발생한 방사성 폐기물 장기저장소 온도평가)

  • Jeong, Namgyun;Jo, Daeseong
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.40 no.7
    • /
    • pp.471-475
    • /
    • 2016
  • In the present study, temperature evaluations on long-term storage of radioactive waste produced in the process of isotope production were performed using two different methods. Three-dimensional analysis was carried out assuming a volumetric heat source, while two-dimensional studies were performed assuming a point source. The maximum temperature difference between the predictions of the volumetric and point source models was approximately $5^{\circ}C$. For the conceptual design level, a point source model may be suitable to obtain the overall temperature characteristics of different loading locations. For more detailed analysis, the model with the volumetric source may be applicable to optimize the loading pattern in order to obtain minimum temperatures.