• Ocean Systems Engineering
• /
• 제5권4호
• /
• pp.319-329
• /
• 2015

Submerged breakwaters are used to prevent shore line erosion and sediment transportation. One of their advantages is low visual impact. In this paper, the effects of discontinuous submerged breakwaters over water surface elevation was numerically studied considering the extended Boussinesq equations as governing equations using MIKE21 software. The result of discontinuous breakwater was compared with a beach without breakwater. The results showed that the gap dramatically effects on surface elevation from shore line to offshore. It is also evident from results that with approaching the center of the gap, fluctuation of surface elevation is generated. It is because of passing longshore currents towards offshore through the gap which leads to an increase in sediment transportation rate. Nevertheless, transferring water mass from breakwater gap results in powerful rip currents leading to high changes on longshore wave profile.

• Ocean Systems Engineering
• /
• 제5권4호
• /
• pp.301-318
• /
• 2015

The present investigations introduce the shell-finite element discretization for the dynamics of slender marine pipelines. A long catenary pipeline, corresponding to a particular Steel Catenary Riser (SCR), is investigated under long-standing cyclic loading. The long structure is divided into smaller tubular parts which are discretized with 8-node planar shell elements. The transient analysis of each part is carried out by the implicit time integration scheme, within a Finite Elements (FE) solver. The time varying external loads and boundary conditions on each part are the results of a prior solution of an integrated line-dynamics model. The celebrated FE approximation can produce a more detailed stress distribution along the structural surface than the simplistic "line-dynamics" approach.

• 한국동물학회지
• /
• 제31권4호
• /
• pp.300-308
• /
• 1988

Human placental alkaline phosphatase (PLAP), one of the oncofetal antigen was purified from placentas through the procedures including butanol extraction, concanavalin A-Sephar-ose, DEAE-cellulose and Sephadex G-200 gel chromatography. Monoclonal antibodies (fibs) against human PMP were produced by hybridizing SP 210-Ag 14 mouse myeloma cells with spleen ceils of Balblc mice immunized with PLAP. Six stable monoclones uvere obtained by cloning tuvice in serial dilutions, and the monoclonal speclfidty of these MAbs was confirmed by biochemical and immunonogical criteria. Tumor marker의 하나인 태반형 alkaline phosphatase(PLAP)에 대한 단일 클론항체의 생산과 분석을 위하여, 태반조직을 재료로 butanol 추출법 및 concanavaline A-Sepharose, DEAE-cellulose, Sephadex G-200 gel 크로마토그라피법에 의하여 PLAP를 순수 분리하였다. 이를 항원으로 하여 하이브리도마 방법에 의해 항-PLAP 단일 클론항체를 생산 분비하는 안정된 6클론세포를 얻었으며 생화학적 및 면역학적 분석방법으로 이들의 단일 클론성을 확인하였다.

• 미생물학회지
• /
• 제4권1호
• /
• pp.14-20
• /
• 1966

1. Uniformly $^{32}P$-labeled Chlorella cells were further grown in a standard "cold" medium and aliquots of the algal cells were taken out at the beginning of, and at intervals during the culture, and subjected to analyze the contents of $^{32}$ P and total P in various fractions of the cell constituents. 2. When the $^{32}P$--labeled algae were grown in a normal "cold" medium, the P-contents in the fractions of DNA and protein increased. In the meantime the $^{32}P$- in acid-insoluble polyphosphate fraction decreased considerably, while that in RNA-polyphosphate complex significantly increased. 3. It was inferred that, under the experimental conditions of the present study, the phosphorus in polyphosphate seems to be transferred to RNA polyposphate complex and the phosphorus used in the synthesis of DNA and protein was, directly or indirectly, taken from those fractions above.ose fractions above.

• Ocean Systems Engineering
• /
• 제6권2호
• /
• pp.203-216
• /
• 2016

Over recent years the offshore wind turbines are becoming more feasible solution to the energy problem, which is crucial for Egypt. In this article a three floating support structure, tension leg platform types (TLP), for 5-MW wind turbine have been considered. The dynamic behavior of a triangular, square, and pentagon TLP configurations under multi-directional regular and random waves have been investigated. The environmental loads have been considered according to the Egyptian Metrological Authority records in northern Red sea zone. The dynamic analysis were carried out using ANSYS-AQWA a finite element analysis software, FAST a wind turbine dynamic software, and MATLAB software. Investigation results give a better understanding of dynamical behavior and stability of the floating wind turbines. Results include time history, Power Spectrum densities (PSD's), and plan stability for all configurations.

• Ocean Systems Engineering
• /
• 제6권2호
• /
• pp.191-201
• /
• 2016

Stern bearing is a key component of marine propulsion plant. Its environment is diverse, working condition changeable, and condition severe, so that stern bearing load is of strong time variability, which directly affects the safety and reliability of the system and the normal navigation of ships. In this paper, three affecting factors of the stern bearing load such as hull deformation, propeller hydrodynamic vertical force and bearing wear are calculated and characterized by random theory. The uncertainty mathematical model of stern bearing load is established to research the relationships between factors and uncertainty load of stern bearing. The validity of calculation mathematical model and results is verified by examples and experiment yet. Therefore, the research on the uncertainty load of stern bearing has important theoretical significance and engineering practical value.

• Ocean Systems Engineering
• /
• 제6권2호
• /
• pp.129-141
• /
• 2016

Due to the structural complexity, the response of a flexible riser under axisymmetric loads is quite difficult to determine. Based on equilibrium conditions, geometrical relations and constitutive equations, an analytical model that can accurately predict the axisymmetric behavior of flexible risers is deduced in this paper. Since the mutual exclusion between the contact pressure and interlayer gap is considered in this model, the influence of the load direction on the structural behavior can be analyzed. Meanwhile, a detailed finite element analysis for unbonded flexible risers is conducted. Based on the analytical and numerical models, the structural response of a typical flexible riser under tension, torsion, internal and outer pressure has been studied in detail. The results are compared with experimental data obtained from the literature, and good agreement is found. Studies have shown that the proposed analytical and numerical models can provide an insightful reference for analysis and design of flexible risers.

• Ocean Systems Engineering
• /
• 제4권3호
• /
• pp.243-261
• /
• 2014

Aqua is an underwater biomimetic vehicle designed and built at McGill University that uses six paddles to produce control and propulsion forces. It has the particularity of having time-periodic thrust due to its oscillating paddles. Using an existing model of the vehicle, two types of controller were developed: a PD controller and a Floquet controller. The Floquet controller has the advantage of explicitly addressing the time-periodicity of the system. The performance of the controllers was assessed through simulation and experimentally in the Caribbean Sea. We find that the vehicle was able to follow the prescribed trajectories with relative accuracy using both controllers, though, the Floquet controller slightly outperforms the PD controller. Furthermore, a key advantage of the Floquet controller is that it requires no tuning while the PD controller had to be tuned by trial and error.

• Ocean Systems Engineering
• /
• 제3권4호
• /
• pp.309-325
• /
• 2013

Ocean Thermal Energy Conversion (OTEC) systems utilize the temperature difference between the surface water and deep ocean water to generate electrical energy. In addition to ocean surface waves, wind and current, in certain locations like the Andaman Sea, Sulu Sea and the South China Sea the presence of strong internal waves may become a concern in floating OTEC system design. The current paper focuses on studying the dependence of the CWP hydrodynamic drag on relative velocity of the flow around the pipe, the effect of drag amplification due to vortex induced vibrations and the influence of internal waves on the floating semi and the cold water pipe integrated OTEC system. Two CWP sizes are modeled; the 4m diameter pipe represents a small scale prototype and the 10m diameter pipe represents a full commercial size CWP. are considered in the study.

• Ocean Systems Engineering
• /
• 제6권3호
• /
• pp.289-303
• /
• 2016

With more than 100 years exploration and development of offshore oil, more and more offshore oil fields will gradually lose the economic profit to operate. In this article, to take the target oil field for example, the procedure of decommissioning for FPSO, TCMS, subsea system and well abandonment have been analyzed. Meanwhile, the environment impact and mitigation measure have been proposed. The successful project experience will provide a guide line for the offshore facilities decommissioning and abandonment.