• 한국가스학회지
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• 제10권1호
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• pp.7-12
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• 2006

소형저장탱크를 이용한 벌크공급시스템은 LP가스의 공급이 중단되거나 공급량이 부족하지 않도록 LP가스 사용가구의 최대가스소비량을 초과하는 가스량을 발생시켜 공급할 수 있어야 한다. 이때 벌크공급시스템에서 공급할 수 있는 가스량은 소형저장탱크의 가스발생능력이 되며, 소형저장탱크의 선정기준이 된다. 현재 우리나라는 소형저장탱크의 충전량, 연속사용시간 등에 따른 가스발생능력 산정기준이 없어 LP가스 사용가구수에 대하여 적합한 소형저장탱크의 선정이 어려운 상태로서 소형저장탱크의 원활한 보급에 문제가 되고 있다. 본 연구는 소형저장탱크의 선정기준이 되는 가스발생능력을 충전량, 외기온도, 연속사용시간 및 충전조성 등에 따라 산정하여 제시하고자 한다.

• 한국양식학회지
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• 제12권2호
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• pp.155-161
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• 1999

In order to obtain the basic information for seeding production of Echiuroid worm, Urechis unicinctus, the influence of pH and salinity on egg development was investigated. Mature adult of U. unicinctus were collected at the Diving Cooperation of Yosu in Korea and reared during 5 weeks. We carried out the artificial insemination in the laboratory on Dec. 29, 1998, and reared the embryo under different pH and salinity. Treatments were carried out with different pH(4~10) and salinity($0~45\textperthousand$). Embryos in pH 4, salinity $0\textperthousand$, $10\textperthousand$, $40\textperthousand$ and $45\textperthousand$ tanks did not develope after fertilization and became deformed or dead, before swimming embryo. In these pH and salinity conditions, deformation rate of embryo was high at 8-cell stage and 16-cell stage. But embryos in pH 5~10, salinity $20~35\textperthousand$ tanks developed into swimming embryo stage. These result indicate that an echiuran inhabits in both intertidal and subtidal mudflates. After fertilization, sixteen-cell stage took 5.3~5.6 hours in pH 5~10 tanks, and 5.1~5.8 hours in $20~35\textperthousand$ tanks. And swimming embryo took 13.3~ 14.1 hours in all conditions. The desirable pH and salinity for egg development were 7~8 and $30\textperthousand$, respectively.

• 한국소음진동공학회논문집
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• 제24권3호
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• pp.227-235
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• 2014

The demand of natural gas is gradually increasing as a clean fuel in the world. Therefore, LNG storage tanks and related facilities of the importance of leading a community-based facility have emerged. The seismic design of LNG storage tank including seismic analysis have been developed steadily. But, the seismic analysis and design techniques for LNG storage tanks are lacking, in Korea. Consequently, it is necessary to develop an analysis model that LNG storage tanks in isolation system can describe the behavior. Further, LNG storage tank capable of ensuring safety and economy, it is necessary to develop design techniques. The studies have suggested seismic design procedures of LNG storage tanks with isolation system including triple-FPB and idealized complex hysteresis model of triple-FPB.

• 한국농공학회지
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• 제36권1호
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• pp.141-152
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• 1994

Our experiment investigated the degree of soil contaimination caused by oil leakage. Each soil sample was taken by boring 5, 8m below the test areas, located 5 to 30m from storage tanks at oil stations. According to the results from a series of laboratory tests(both soxhiet extract test and gas chromatograph test), Traces of a light oil were found in all samples except in Dj8, rocky soil and gasoline and petroleum were not detected. We concluded that soil contamination was caused by the corrosion of storage tanks or alternatively by oil overflow caused during the flooding of underground water seeping into the tank during heavy rain fall or the spillage caused by carelessness during lubrication. Old stations without a concrete box enclosing their metal tanks run a greater risk of oil leakage. To research the effect of oil leakage on plant growth and underground water, We examined the results of research conducted overseas. According to these results, when oil leakage occurs, plant growth is repressed and agricultural crops experience low productivity levels. Also, the contamination of underground water can be serious when oil spreads to the aquifer layer. As a result of these problems, to prevent oil leakage and minimize its contaminating effects at oil stations, it is necessary to improve facilities of storage tanks and have the monitoring system of oil leakage.

• Corrosion Science and Technology
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• 제7권4호
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• pp.219-223
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• 2008

In 2006, as a means to minimize early corrosion failure of ships, thus to enhance marine safety, International Maritime Organization (IMO), proposed a mandatory regulation for Performance Standards for the Protective Coatings (PSPC) for ballast tanks of newly built ships to satisfy 15 years of target useful life. In this regulation, several unprecedented strict rules are adopted as minimum, mandatory requirements for protective coatings of ship's water ballast tanks, and all type of ships sailing international sea are subjected to this regulation which is to be effective as early as June of 2008. The PSPC addresses many technical issues in the areas of surface pretreatment (primary and secondary), coating materials, coating application procedure and inspection as well as necessary documentation. The PSPC rules are new and unproven concepts, which calls for rigorous incorporation of reality-based evidences currently available, since there are no practical experiences in terms of the validity of the PSPC rules. There has been much controversy surrounding these regulations and considerable effort has been made by both shipyards and ship owners alike to achieve a performance standard for ballast tank coatings, which is acceptable to all. In this paper, the background and overview of the PSPC rules are given, and several issues in the PSPC are reviewed as a base to achieve robustness of the proposed PSPC, which will serve as a means to minimize early corrosion and to ensure 15 year target useful life of ships.

• Earthquakes and Structures
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• 제13권1호
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• pp.67-77
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• 2017

Oil storage tanks are vital life-line structures, suffered significant damages during past earthquakes. In this study, a numerical model for an unanchored vertical vaulted-type tank was established by ANSYS software, including the tank-liquid coupling, nonlinear uplift and slip effect between the tank bottom and foundation. Four actual earthquakes recorded at different soil sites were selected as input to study the dynamic characteristics of the tank by nonlinear time-history dynamic analysis, including the elephant-foot buckling, the liquid sloshing, the uplift and slip at the bottom. The results demonstrate that, obvious elephant-foot deformation and buckling failure occurred near the bottom of the tank wall under the seismic input of Class-I and Class-IV sites. The local buckling failure appeared at the location close to the elephant-foot because the axial compressive stress exceeded the allowable critical stress. Under the seismic input of Class-IV site, significant nonlinear uplift and slip occurred at the tank bottom. Large amplitude vertical sloshing with a long period occurred on the free surface of the liquid under the seismic wave record at Class-III site. The seismic properties of the storage tank were affected by site class and should be considered in the seismic design of large tanks. Effective measures should be taken to reduce the seismic response of storage tanks, and ensure the safety of tanks.

• Wind and Structures
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• 제31권6호
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• pp.495-508
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• 2020

To investigate the structural behaviour of grouped tanks under wind loads, 2 problems need to be figured out, wind pressures on tank shells and critical loads of the shell under these pressure distribution patterns. Following the wind tunnel tests described in the companion paper, this paper firstly seeks to obtain wind loads on the external wall in a squarely-arranged cylindrical tank group by numerical simulation, considering various layouts. The outcomes demonstrate that the numerical method can provide similar results on wind pressures and better insights on grouping effects through extracted streamlines. Then, geometrically nonlinear analyses are performed using several selected potentially unfavourable wind pressure distributions. It is found that the critical load is controlled by limit point buckling when the tank is empty while excessive deformations when the tank is full. In particular, significant reductions of wind resistance are found on grouped full tanks compared to the isolated tank, considering both serviceability and ultimate limit state, which should receive special attention if the tank is expected to resist severe wind loads with the increase of liquid level.

• Fisheries and Aquatic Sciences
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• 제25권8호
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• pp.429-440
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• 2022

This study assessed the effects of oxygen and ozone nanobubbles on gill morphology, weight gain, and mortality of Pacific white shrimp (Penaeus vannamei), as well as the level of Vibrio parahaemolyticus and water quality of shrimp culture tanks under lab conditions. Two experiments were carried out with oxygen macrobubble, ozone macrobubble, oxygen nanobubble, ozone nanobubble, and control treatments (air-stone macrobubble). Experiments were done in triplicate in 100 L tanks with 15‰ saline water, and 20 shrimp per tank. Tanks in Experiment 1 were not inoculated with bacteria; tanks in Experiment 2 were inoculated with V. parahaemolyticus at a concentration of 10⁶ CFU/mL. The results revealed that short treatments with ozone nanobubbles had minimal impact on shrimp gills, mortality, and growth rates, reduced V. parahaemolyticus concentration in water compared to the other groups, and improve water quality. These laboratory results indicate that ozone nanobubble treatment may be useful for controlling V. parahaemolyticus. More work is needed to find the best protocol to apply the technology on a commercial scale.

• International Journal of Internet, Broadcasting and Communication
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• 제14권4호
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• pp.58-63
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• 2022

Recently, the improvement of computational processing ability due to the rapid development of computing technology has greatly advanced the field of artificial intelligence, and research to apply it in various domains is active. In particular, in the national defense field, attention is paid to intelligent recognition among machine learning techniques, and efforts are being made to develop object identification and monitoring systems using artificial intelligence. To this end, various image processing technologies and object identification algorithms are applied to create a model that can identify friendly and enemy weapon systems and personnel in real-time. In this paper, we conducted image processing and object identification focused on tanks among various weapon systems. We initially conducted processing the tanks' image using a convolutional neural network, a deep learning technique. The feature map was examined and the important characteristics of the tanks crucial for learning were derived. Then, using YOLOv5 Network, a CNN-based object detection network, a model trained by labeling the entire tank and a model trained by labeling only the turret of the tank were created and the results were compared. The model and labeling technique we proposed in this paper can more accurately identify the type of tank and contribute to the intelligent recognition system to be developed in the future.

• Coupled systems mechanics
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• 제11권4호
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• pp.335-355
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• 2022

It's important to note that the number of studies on the lateral vibration of steel liquid storage tanks has been quite modest in the past. The aim of this research has to look at the variables that affect vibration of storage tanks and to highlight the characteristics of a construction that hasn't received much attention in the literature. The storage tank has pre-sized in the study, and aluminum and steel have chosen as components. The specified material qualities and the factors utilized in the investigation has used to calculate vibration frequency values. The resulting calculations are backed up by tables and graphs, and it's an important to look into the parameters that affect the vibration frequencies that will occur on the designed storage tank vary. In the literature, water tanks are usually modelled as lumped masses. The horizontal stiffness of the column on which it is placed is assumed to be constant throughout. This is an approximation method of solving this problem. The column is handled in this study with a more realistic approach that fits the continuum mechanics in the analysis. The reservoir part is incorporated directly into the problem as the boundary condition.