The U.S. National Science Foundation (NSF) supports basic scientific research in the ocean sciences and research fundamental to the ocean engineering process in order to understand better all aspects of the global oceans and their interactions with the earth and the atmosphere. Because the oceans are so vast and our knowledge of them comparatively small, NSF often works collaboratively with researchers from other nations to further our understanding about the ocean. Japan is a key partner to NSF in this pursuit. Current NSF-Japan joint research projects in ocean research number more than 40. Joint research topics comprise many facets of biological, chemical, and physical oceanography as well as ocean engineering including, but not limited to: geophysical observations of the deep seafloor; behavioral ecology of the midwater community; biochemical control of larval settlement and recruitment; subduction processes; hydrothermal systems; ocean circulation; ocean-atmosphere interaction; underwater robotics; deep-ocean drilling; and regional global change research, especially in Asia and the Pacific. Support for NSF-sponsored scientists and engineers who work collaboratively with Japanese counterparts is provided in several ways: to individual scientists, to small groups of cooperating scientists, and to large multilateral projects. What follows are detailed descriptions and examples of each type of funding modality.
- Virginia Pasour of North Carolina State University worked with Professor Hidekatsu Yamazaki of the Tokyo University of Fisheries in the mathematical/statistical modeling of marine processes.
- Jared Ackers of the University of Maryland helped to develop an analytical technique for quantification of vitellogenin and its m-RNA induced by endocrine disrupting chemicals in fishes. Mr. Ackers' host scientist was Dr. Hiroaki Shiraishi of the National Institute for Environmental Studies.
- Karen Crow of the University of California at Santa Cruz collaborated with Professor Ziyusei Kanamoto of the Marine Biological Station at Ehime University on a study of the reproductive biology of hexagrammid fishes.
- David Shull of the University of Massachusetts at Boston measured radionuclides of bottom sediments with Dr. Masashi Kusakabe of the Japan Marine Science and Technology Center (JAMSTEC).
- Maria Efthimiadis of Nova Southeastern University was hosted by Dr. Makoto Terazaki of the Ocean Research Institute of the University of Tokyo. Their work focused on major marine issues in Japan especially on how marine environmental problems impact human health.
For those interested in learning more about research sponsored by the Summer Programs in Japan, or how to apply, please visit http://www.twics.com/~nsftokyo/spmenu.html
In May of 1997, Dr. Umesh Korde began a 24-month STA fellowship at JAMSTEC entitled, "Optimal Control of Floating Wave Energy Converters". Dr. Korde's host is Dr. Yukihisa Washio of the Marine Technology Department at JAMSTEC; they are conducting research on optimal control of floating wave energy converters. For their work, they are utilizing an offshore floating device called the "Mighty Whale."
The following description was prepared by Dr. Korde:
The "Mighty Whale" was developed by JAMSTEC, through funding provided by STA. Envisioned applications include fish farming and coastal-water aeration. Work on this device has been in progress since 1987, and the final prototype design is based on results from a number of laboratory tests at progressively increasing scales. The prototype tends to resemble a whale in appearance, and is 50 m X 30 m X 12 m in overall dimensions. It is designed to float at a draft of 8 m at even keel, and is moored in a water depth of 40 m. The device has three oscillating water column chambers distributed breadth-wise.
Prototype construction is in steel and structural design is in accordance with NK (Japan Classification Society) Part P regulations for special-purpose floating platforms. The device has been in construction at the Ishikawajima Harima Heavy Industries (IHI) Aioi Shipyard in Hyogo Prefecture. A 1.7 m diameter, Aluminum-alloy, biplane (i.e. with tandem rotors), self-reciprocating Wells turbine is provided for each chamber. Each rotor has 8 camberless blades with the NACA 0021 profile. Four induction generators are used on board. Two of the four generators are rated at 30 kW, one at 50 kW, and one at 10 kW. A 7.5 kW air compressor is also provided. The total rated capacity is 110 kW, and an automatically controlled switching circuitry selects the appropriate combination of generators at any given time.
Mooring is by means of 6 lines (each with intermediate weights) terminating in box-type anchors. The test site is just outside the mouth of Gokasho Bay off Mie Prefecture. Experiments began in July 1998 and continue through July 2000. More than 48 parameters are to be monitored and analyzed on board. Many of the results are expected to be transmitted to shore. In addition to generating technologically important data, the device is also expected to serve as an offshore platform for measurements of interest to oceanographic and environmental sciences.
Offshore floating devices such as the Mighty Whale have at least three advantages over shore/seafloor fixed devices: First, significant economy results from the fact that floating hulls experience considerably lower impact loads in extreme wave conditions. Second, available wave energy generally increases with increasing water depth (exceptions are shallow-water regions where refractions due to favorable bottom topography can lead to localized focusing of energy). Third, rigid-body motion of the hull can increase energy absorption in certain wave conditions, due to increased relative motion between the oscillating water column (OWC) and the hull.
Part of this project concerns the third effect. For axisymmetric, primarily heaving buoys supporting OWCs, the buoy heave motion is generally found to increase energy absorption. However, theory and laboratory experiments on a Kaimei-type floating OWC device have shown the rigid-body motion of the hull to reduce energy absorption at most wave frequencies of interest. Similar observations have also been made with Mighty Whale laboratory models.
For this reason, a system is being developed as a part of this work, whereby the rigid- body motion of the Mighty Whale hull can be utilized to supplement the energy already being generated by the OWCs. The design constraints are: to achieve this without the use of actuated moorings or tethers, to retain the original advantages of a floating hull, and to minimize any energy required to operate such a system.
The system exploits favorable interaction of two or more coupled oscillators (spring-mass systems) whereby one of the masses is locked into zero displacement at a certain frequency. This phenomenon is often used in "dynamic vibration absorbers," and can be utilized in heave compensation systems for drill ships. Real-time control of at least one of the oscillators is necessary in the case of a floating wave-energy device. This is because ocean waves are irregular (when not very large, an irregular wave can be considered to be a linear superposition of a large number of sinusoidal waves of different frequencies), and the phenomenon above occurs at a single frequency. Control using correctly applied reactive forces allows the phenomenon to be extended to a range of frequencies. Thus, when waves and hull motions are not very large, such control produces good hull-motion compensation in irregular waves.
Passive versions of the system were tested on a 1/62.5 scale model of the Mighty Whale device; as well as on a "point-absorber" type axisymmetric buoy consisting of an OWC in a long tube inside a flotation collar. In both cases the system was arranged to provide compensation against hull-heave for a platform placed near the roof of the model, across the vertical airflow passage. With the hull heaving and the platform stationary the piston action of the platform was expected to increase the magnitudes of overall airflow and gage pressure in the chamber. Improvement in energy absorption was noticed for both devices near the frequencies at which effective motion compensation was achieved. The tests also highlighted some essential design aspects to be considered prior to building an active system.
1/62.5 scale experiments on the active system are expected to begin once the control hardware is fully tested. These experiments are to be carried out with the compensator arranged in the surge mode, because this is the dominant mode for the Mighty Whale at low frequencies, and because considerably more energy is carried by incident waves at low frequencies. For precise quantification of the additional energy-absorption enabled by the system, the model is constrained (from above) to pure surge motion. A specially constructed Scott-Russell mechanism is being used for this purpose. Motion feedback is derived using single-axis accelerometers. Actuator signals are currently being generated using an analog circuit.
A linear mathematical model with numerically computed hydrodynamic parameters is being used to validate/interpret the experimental results. This model also shows that, for perfect motion compensation, energy consumed by the control system is as low as heat losses in the actuators. However, actuator forces can be high over some frequencies, and full-scale design may require significant thought.
If you are interested in more information about this project, please direct your inquires to either Dr. Korde (uak@jamstec.go.jp ) or Dr. Washio (washioy@jamstec.go.jp).
For those interested in obtaining an STA Fellowship to work at JAMSTEC or another national laboratory in Japan, please visit http://www.twics.com/~nsftokyo/fel-new.html.
In 1997, a three year collaborative research entitled, "Virtual Collaborative World Simulator for Underwater Robots using a Multi-Dimensional, Synthetic Environment" began. This project involves teams of researchers from the University of Hawaii and the University of Tokyo. The team from the University of Hawaii is led by Dr. Junku Yuh; the team from the University of Tokyo is led by Professor Tamaki Ura. Professors Yuh and Ura are internationally well-known and leading authors in the area of Underwater Robotics. This project undertakes a study of a virtual collaborative world simulator for underwater robots using a multi-dimensional, synthetic environment. The major objective is to develop a virtual 3-dimensional, hybrid environment platform with a high-level control and information architecture. The major goals of the project are to: l) enable remote sharing of underwater robotic resources; 2) enhance the remote monitoring and control of the robots from globally remote locations; and 3) enhance and stimulate the development of other areas such as underwater communication, sonar and acoustic sensors and underwater visualization. Successful planning of the robot operation requires integrated simulation of the actual robot with environmental data and operating conditions. The project brings together the efforts of two laboratories working on different aspects of autonomous underwater vehicles: the team from the University of Hawaii has experience in developing a virtual reality platform and an underwater vehicle whereas the University of Tokyo team has developed the graphic platform, underwater vehicles, and shallow water testing. Research and development of underwater robotic systems will be a low-cost way to better understanding marine and other environmental issues; to protect the earth's resources from pollution; and to efficiently utilize the vehicles for human welfare. The data gathered from the research project is providing information on the performance, effectiveness, interactivity, and safety of an underwater vehicle and its environment.
If you are interested in more information about this project, please visit either http://www.eng.hawaii.edu/~asl or http://manta.iis.u-tokyo.ac.jp/Welcome-e.html. You may also direct your inquires to either Dr. Yuh (yuh@wiliki.eng.hawaii.edu) or Professor Ura (ura@iis.u-tokyo.ac.jp).
For those interested in learning more about research sponsored by the US-Japan Cooperative Science Program, or how to apply, please visit http://www.twics.com/~nsftokyo/csp-res.html
This U.S.-Japan seminar on Bioorganic Marine Chemistry will be held in Santa Cruz, California from December 14-18, 1998. The co-organizers are Professors Phillip Crews of the University of California at Santa Cruz and Takenori Kusumi of Tokushima University in Japan. The seminar will address a broad range of topics including: (a) chemodiversity of marine macroorganisms; (b) marine-derived microorganisms as a resource for unusual metabolites (c) new materials as a focus for marine biotechnology; (d) interactions between species mediated by secondary metabolites; (e) pharmacological tools from marine sources; and (f) mechanisms of marine biosynthesis. Marine bioorganic chemistry continues to be regarded as an exciting area of research, watched closely by scientists from many disciplines in both chemistry and biology. Interest in marine bioorganic technology is also escalating in both the academic and industrial domain worldwide. A majority of the major labs, as well as the new investigators in this field, are concentrated in the U.S. and Japan. Frequently, the ideas and techniques developed by academic and industrial research groups in these two countries are extremely influential. In addition, younger scientists will participate in the seminar. The exchange of ideas and data with Japanese experts in this field enables U.S. participants to advance their own work, and set the stage for future collaborative projects.
If you are interested in more information about this seminar, please direct your inquires to either Dr. Crews (phil@chemistry.ucsc.edu) or Professor Kusumi (tkusumi@ph.tokushima-u.ac.jp).
For those interested in learning more about seminars sponsored by the US-Japan Cooperative Science Program, or how to apply, please visit http://www.twics.com/~nsftokyo/csp-sem.html
The Ocean Drilling Program (ODP) is a highly successful, cost-effective, international program of basic research in the marine geosciences. It is supported by the National Science Foundation, Japan, Germany, the United Kingdom, a consortium of Canada, Australia, Korea, and Chinese Taipei, the European Science Foundation (representing Belgium, Denmark, Finland, Portugal, Iceland, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and Turkey), France, and the newest associate member, the People's Republic of China. Scientific drilling operations began in 1985, following conversion of a large commercial drilling vessel, the SEDCO/BP 471, for scientific drilling. Renamed the JOIDES Resolution, the vessel carries over fifty scientists, students, and technicians from the member countries on each of its two-month cruise legs. The Resolution is a unique international resource, representing the only scientific facility capable of deeply coring sedimentary and crustal material in the world's oceans. Additionally, the ODP has developed an extensive geochemical and geophysical logging capability that is unsurpassed in academia. The ODP is managed through a contract between NSF and the Joint Oceanographic Institutions, Inc. (JOI). JOI has subcontracts with Texas A&M University for management of scientific support and drillship operations, and with Lamont-Doherty Earth Observatory of Columbia University for management of the logging program. The first 79 legs of the program have addressed by drilling critical earth science problems that would otherwise be unaccessible. Specifically, the JOIDES Resolution has studied global climate change in most parts of the world's oceans, the early stages of continental rifting and seafloor spreading, fluid flow and tectonic processes in sediments of active margins, the composition and alteration of the oceanic crust, and the formation of ore deposits. ODP developments in drilling and instrument technology provide continuous sediment coring with virtually 100% recovery, essential for constructing detailed climactic records of the earth's past. Other new technological developments allow for the coring of unsedimented oceanic crust, most recently shown by a spectacular 1200-meter core into the deep Indian Ocean crust, detailing for the first time how oceanic crust is built by successive formation and solidification of multiple magma chambers at spreading centers. Development and deployment of down-hole instrument packages for long-term measurement of crustal conditions and processes are another success of the program. Close collaboration with Global Seismic Network planning has lead to initial testing of long-period, digital seismometers in ODP boreholes, with additional deployments by Japanese scientists scheduled for the Japan trench in 1999. Temperature and pressure sensors and fluid samplers have been deployed in holes drilled into an active hydrothermal system on the Juan de Fuca Ridge and a modern accretionary wedge on the Cascadia Margin in the Northeast Pacific. Data and samples from these instruments are being recovered using submersibles and remote vehicles. Although drilling operations are supported by all members of the ODP, each member country independently provides support for the research efforts of its scientists participating in the program. After 18 years of continuously successful operations, the Ocean Drilling Program is scheduled to end in 2003.
Plans are currently underway for implementing an exciting new era in scientific ocean drilling that would utilize a new, Japanese-built, state-of-the-art drillship complemented by a smaller, enhanced Resolution-class drillship. This new, more capable program - named IODP for Integrated Ocean Drilling- is needed to attack fundamental problems in earthquake hazard mitigation, continental margin sedimentation, and deep crustal formation that are currently unaddressable due to safety or drillhole stability problems. International conferences scheduled for the upcoming year will refine the specific scientific objectives to be addressed, which should include studying climate changes on the scale of 10,000 years, the structure and formation of the oceanic crust, tectonic deformation and associated earthquake hazards at the margins of plates, and frontier exploration of the earth's deep biosphere, with possible implications regarding the origin of life on earth. IODP would be highlighted by an equal partnership between Japan and the National Science Foundation in leadership, management, and funding responsibilities. The larger Japanese drillship will feature a technologically advanced riser system, initially built for operation in 2500m of water with projected development for operations in 4000m of water. This riser system combines a sealed borehole with a large pipe enclosing the drillstring that provides return circulation of drilling mud to the drillship, allowing for coring in unstable formations and seafloor well-control in areas where hydrocarbons may be present. This ship is required for holes of several kilometers penetration in regions that are geologically tough to core. For other scientific problems where shallower and more numerous holes are required, the enhanced Resolution-class drillship is needed. This drillship cores with seawater instead of mud, a cost-effective means of drilling moderate depth (<2 km) holes in deep water. For drilling in very shallow water, these two platforms may occasionally supplemented by more specialized, commercial drilling rigs. IODP will provide the operational and scientific foundation for addressing key earth science problems of the 21st century, and will provide detailed knowledge necessary for responsible stewardship of our planet.
For more information about ODP, please visit:
http://www.geo.nsf.gov/oce/drilling.htm
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