WorldWideScience

Sample records for current large marine

  1. Ocean currents generate large footprints in marine palaeoclimate proxies

    NARCIS (Netherlands)

    van Sebille, E.; Scussolini, P.; Durgadoo, J.V.; Peeters, F.J.C.; Biastoch, A.; Weijer, W.; Turney, C.; Paris, C.B.; Zahn, R.

    2015-01-01

    Fossils of marine microorganisms such as planktic foraminifera are among the cornerstones of palaeoclimatological studies. It is often assumed that the proxies derived from their shells represent ocean conditions above the location where they were deposited. Planktic foraminifera, however, are

  2. Regime shifts in demersal assemblages of the Benguela Current Large Marine Ecosystem: a comparative assessment

    DEFF Research Database (Denmark)

    Kirkman, Stephen P.; Yemane, Dawit; Atkinson, Lara J.

    2015-01-01

    Using long‐term survey data, changes in demersal faunal communities in the Benguela Current Large Marine Ecosystem were analysed at community and population levels to provide a comparative overview of the occurrence and timing of regime shifts. For South Africa, the timing of a community‐level sh......Using long‐term survey data, changes in demersal faunal communities in the Benguela Current Large Marine Ecosystem were analysed at community and population levels to provide a comparative overview of the occurrence and timing of regime shifts. For South Africa, the timing of a community...

  3. Atmospheric Wind Relaxations and the Oceanic Response in the California Current Large Marine Ecosystem

    Science.gov (United States)

    Fewings, M. R.; Dorman, C. E.; Washburn, L.; Liu, W.

    2010-12-01

    the Gulf of Alaska influence ocean conditions in central and southern California via these wind relaxations. The ocean response within a few km of the coast involves poleward-flowing currents that transport warm water out of the lees of capes and headlands and counter to the direction of the California Current [Send et al. 1987, Harms and Winant 1998, Winant et al. 2003, Melton et al. 2009]. A similar response occurs in the Benguela and Canary Current coastal upwelling systems. The ocean response involves both barotropic and baroclinic dynamics and is consistent with existing geophysical models of buoyant, coastally-trapped plumes [Washburn et al., in prep]. Our ongoing work includes i) studying the regional ocean response to determine its spatial extent, time evolution, and ocean-atmosphere coupling dynamics; ii) developing an atmospheric index to predict wind relaxations in southern California based on pressure in the Gulf of Alaska; iii) examining the strength and frequency of wind relaxations over the past 30 years for connections to El Niño and the Pacific Decadal Oscillation; and iv) predicting future variations in wind relaxations and the response of the California Current Large Marine Ecosystem.

  4. Physical oceanography - Developing end-to-end models of the California Current Large Marine Ecosystem

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to develop spatially discrete end-to-end models of the California Current LME, linking oceanography, biogeochemistry, food web...

  5. Atlantis model outputs - Developing end-to-end models of the California Current Large Marine Ecosystem

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to develop spatially discrete end-to-end models of the California Current LME, linking oceanography, biogeochemistry, food web...

  6. Geostatistical modelling of the spatial life history of post-larval deepwater hake Merluccius paradoxus in the Benguela Current Large Marine Ecosystem

    DEFF Research Database (Denmark)

    Jansen, T; Kristensen, K; Fairweather, T. P.

    2017-01-01

    paradoxus are not reflected in the current assessment and management practices for the Benguela Current Large Marine Ecosystem. In this study, we compiled data from multiple demersal trawl surveys from the entire distribution area and applied state-of the-art geostatistical population modelling (Geo...

  7. Migration, distribution and population (stock) structure of shallow-water hake (Merluccius capensis) in the Benguela Current Large Marine Ecosystem inferred using a geostatistical population model

    DEFF Research Database (Denmark)

    Jansen, Teunis; Kristensen, Kasper; Kainge, Paulus Inekela

    2016-01-01

    Shallow-water hake (Merluccius capensis) is of considerable ecological and economic importance in the Benguela Current Large Marine Ecosystem in South Africa and Namibia. Optimal management of the resource is currently constrained by the limited understanding of migration patterns and population...

  8. 2002–2012: 10 Years of Research Progress in Horizontal-Axis Marine Current Turbines

    Directory of Open Access Journals (Sweden)

    Kai-Wern Ng

    2013-03-01

    Full Text Available Research in marine current energy, including tidal and ocean currents, has undergone significant growth in the past decade. The horizontal-axis marine current turbine is one of the machines used to harness marine current energy, which appears to be the most technologically and economically viable one at this stage. A number of large-scale marine current turbines rated at more than 1 MW have been deployed around the World. Parallel to the development of industry, academic research on horizontal-axis marine current turbines has also shown positive growth. This paper reviews previous research on horizontal-axis marine current turbines and provides a concise overview for future researchers who might be interested in horizontal-axis marine current turbines. The review covers several main aspects, such as: energy assessment, turbine design, wakes, generators, novel modifications and environmental impact. Future trends for research on horizontal-axis marine current turbines are also discussed.

  9. Large-capacity current leads

    International Nuclear Information System (INIS)

    Ballarino, A.

    2008-01-01

    Feeding superconducting magnets with reliable low-loss devices is a key issue for any cryo-electrical system. Conventional or HTS current leads can be used, and cooling methods, materials, and geometries can be chosen to optimize the thermo-electrical performance of the system. The LHC magnets are powered via more than 3000 current leads transporting altogether about 3 MA of current. With thousands of leads, the LHC lead project represents today the largest project of its kind ever undertaken. Following a review of the LHC lead project, an overview of the choices that can be made for the optimization of large capacity current leads is presented. Examples are given of other leads for large scale magnet systems for which the use of HTS is being envisaged

  10. An Analysis of Current and Proposed Oversight Processes for the Acquisition of Large-Scale Services as Seen Through the Eyes of the Navy Marine Corps Intranet Program

    National Research Council Canada - National Science Library

    Rozier, JoCephas

    2002-01-01

    At approximately 56,9 billion, The Navy-Marine Corps Intranet (NMCI) was the largest service contract that DoD had ever awarded, The U'S, Navy viewed it as a typical multi-year, Performance Based Services Contract (PBSC...

  11. Marine current energy devices: Current status and possible future applications in Ireland

    International Nuclear Information System (INIS)

    Rourke, Fergal O.; Boyle, Fergal; Reynolds, Anthony

    2010-01-01

    There is a growing demand for the use of renewable energy technologies to generate electricity due to concerns over climate change. The oceans provide a huge potential resource of energy. Energy extraction using marine current energy devices (MCEDs) offers a sustainable alternative to conventional sources and a predictable alternative to other renewable energy technologies. A MCED utilises the kinetic energy of the tides as opposed to the potential energy which is utilised by a tidal barrage. Over the past decade MCEDs have become an increasingly popular method of energy extraction. However, marine current energy technology is still not economically viable on a large scale due to its current stage of development. Ireland has an excellent marine current energy resource as it is an island nation and experiences excellent marine current flows. This paper reviews marine current energy devices, including a detailed up-to-date description of the current status of development. Issues such as network integration, economics, and environmental implications are addressed as well as the application and costs of MCEDs in Ireland. (author)

  12. West Coast fish, mammal, and bird species diets - Developing end-to-end models of the California Current Large Marine Ecosystem

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to develop spatially discrete end-to-end models of the California Current LME, linking oceanography, biogeochemistry, food web...

  13. West Coast fish, mammal, bird life history and abunance parameters - Developing end-to-end models of the California Current Large Marine Ecosystem

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to develop spatially discrete end-to-end models of the California Current LME, linking oceanography, biogeochemistry, food web...

  14. Construction and Screening of Marine Metagenomic Large Insert Libraries.

    Science.gov (United States)

    Weiland-Bräuer, Nancy; Langfeldt, Daniela; Schmitz, Ruth A

    2017-01-01

    The marine environment covers more than 70 % of the world's surface. Marine microbial communities are highly diverse and have evolved during extended evolutionary processes of physiological adaptations under the influence of a variety of ecological conditions and selection pressures. They harbor an enormous diversity of microbes with still unknown and probably new physiological characteristics. In the past, marine microbes, mostly bacteria of microbial consortia attached to marine tissues of multicellular organisms, have proven to be a rich source of highly potent bioactive compounds, which represent a considerable number of drug candidates. However, to date, the biodiversity of marine microbes and the versatility of their bioactive compounds and metabolites have not been fully explored. This chapter describes sampling in the marine environment, construction of metagenomic large insert libraries from marine habitats, and exemplarily one function based screen of metagenomic clones for identification of quorum quenching activities.

  15. Stability analysis of offshore wind farm and marine current farm

    Science.gov (United States)

    Shawon, Mohammad Hasanuzzaman

    Renewable energy has been playing an important role to meet power demand and 'Green Energy' market is getting bigger platform all over the world in the last few years. Due to massive increase in the prices of fossil fuels along with global warming issues, energy harvesting from renewable energy sources has received considerable interest, nowadays, where extensive researches are going on to ensure optimum use of renewable sources. In order to meet the increasing demand of electricity and power, integration of renewable energy is getting highest priorities around the world. Wind is one of the most top growing renewable energy resources and wind power market penetration is expected to reach 3.35 percent by 2013 from its present market of about 240 GW. A wind energy system is the most environmental friendly, cost effective and safe among all renewable energy resources available. Another promising form of renewable energy is ocean energy which covers 70 % of the earth. Ocean energy can be tapped from waves, tides and thermal elements. Offshore Wind farm (OWF) has already become very popular for large scale wind power integration with the onshore grid. Recently, marine current farm (MCF) is also showing good potential to become mainstream energy sources and already successfully commissioned in United Kingdom. However, squirrel cage induction generator (SCIG) has the stability problem similar to synchronous generator especially during fault location to restore the electromagnetic torque. Series dynamic braking resistor (SDBR) has been known as a useful mean to stabilize fixed speed wind generator system. On the other hand, doubly fed induction generator (DFIG) has the capability of coupling the control of active and reactive power and to provide necessary reactive power demand during grid fault conditions. Series dynamic braking resistor (SDBR) can also be employed with DFIG to limit the rotor over current. An integration of wind and tidal energy represents a new

  16. Marine renewable energy in China: Current status and perspectives

    OpenAIRE

    Yong-liang Zhang; Zheng Lin; Qiu-lin Liu

    2014-01-01

    Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy, ocean thermal energy, and salinity gradient energy in China's coastal seas, such as the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, is presented. We have found that these kinds of marine renewable energy resources will play an important role in meeti...

  17. Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    1967-03-01

    This report consists of answers submitted by various laboratory directors or individual investigators who responded to an International Atomic Energy Agency questionnaire concerning their present research programme, future scope of that programme, the investigators' ideas and opinions on marine radioecology research. Information on the possibility of co-operation with other laboratories is also included

  18. Marine renewable energy in China: Current status and perspectives

    Directory of Open Access Journals (Sweden)

    Yong-liang Zhang

    2014-07-01

    Full Text Available Based on a general review of marine renewable energy in China, an assessment of the development status and amount of various marine renewable energy resources, including tidal energy, tidal current energy, wave energy, ocean thermal energy, and salinity gradient energy in China's coastal seas, such as the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea, is presented. We have found that these kinds of marine renewable energy resources will play an important role in meeting China's future energy needs. Additionally, considering the uneven distribution of China's marine renewable energy and the influences of its exploitation on the environment, we have suggested several sites with great potential for each kind of marine energy. Furthermore, perspectives on and challenges related with marine renewable energy in China are addressed.

  19. Current Knowledge and Recent Advances in Marine Dinoflagellate Transcriptomic Research

    Directory of Open Access Journals (Sweden)

    Muhamad Afiq Akbar

    2018-02-01

    Full Text Available Dinoflagellates are essential components in marine ecosystems, and they possess two dissimilar flagella to facilitate movement. Dinoflagellates are major components of marine food webs and of extreme importance in balancing the ecosystem energy flux in oceans. They have been reported to be the primary cause of harmful algae bloom (HABs events around the world, causing seafood poisoning and therefore having a direct impact on human health. Interestingly, dinoflagellates in the genus Symbiodinium are major components of coral reef foundations. Knowledge regarding their genes and genome organization is currently limited due to their large genome size and other genetic and cytological characteristics that hinder whole genome sequencing of dinoflagellates. Transcriptomic approaches and genetic analyses have been employed to unravel the physiological and metabolic characteristics of dinoflagellates and their complexity. In this review, we summarize the current knowledge and findings from transcriptomic studies to understand the cell growth, effects on environmental stress, toxin biosynthesis, dynamic of HABs, phylogeny and endosymbiosis of dinoflagellates. With the advancement of high throughput sequencing technologies and lower cost of sequencing, transcriptomic approaches will likely deepen our understanding in other aspects of dinoflagellates’ molecular biology such as gene functional analysis, systems biology and development of model organisms.

  20. Wake Survey of a Marine Current Turbine Under Steady Conditions

    Science.gov (United States)

    Lust, Ethan; Luznik, Luksa; Flack, Karen

    2016-11-01

    A submersible particle image velocimetry (PIV) system was used to study the wake of a horizontal axis marine current turbine. The turbine was tested in a large tow tank facility at the United States Naval Academy. The turbine is a 1/25th scale model of the U.S. National Renewable Energy Laboratory's Reference Model 1 (RM1) tidal turbine. It is a two-bladed turbine measuring 0.8 m in diameter and featuring a NACA 63-618 airfoil cross section. Separate wind tunnel testing has shown the foil section used on the turbine to be Reynolds number independent with respect to lift at the experimental parameters of tow carriage speed (Utow = 1 . 68 m/s) and tip speed ratio (TSR = 7). The wake survey was conducted over an area extending 0.25D forward of the turbine tip path to 2.0D aft, and to a depth of 1.0D beneath the turbine output shaft in the streamwise plane. Each field of view was approximately 30 cm by 30 cm, and each overlapped the adjacent fields of view by 5 cm. The entire flow field was then reconstructed into a single field of investigation. Results include streamwise and vertical ensemble average velocity fields averaged over approximately 1,000 realizations, as well as higher-order statistics. Turbine tip vortex centers were identified and plotted showing increasing aperiodicity with wake age. keywords: horizontal axis marine current turbine, particle image velocimetry, towing tank, wake survey

  1. Current problems of marine pollution. Papers

    International Nuclear Information System (INIS)

    Dethlefsen, V.

    1993-01-01

    During the lecture meeting of the working committee for waste water problems of the German Fishery Association, papers were presented on current problems of waste pollution and on the potential effects of climate changes on the fishing industry. (EF) [de

  2. Influence of marine current on vertical migration of Pb in marine bay

    Science.gov (United States)

    Yu, Chen; Hong, Ai; Danfeng, Yang; Huijuan, Zhao; Dongfang, Yang

    2018-02-01

    This paper analyzed that vertical migration of Pb contents waters in Jiaozhou Bay, and revealed the influence of marine current on vertical migration process. Results showed that Pb contents in bottom waters of Jiaozhou Bay in April and July 1988 were 1.49-18.53 μg L-1 and 12.68/-27.64 μg L-1, respectively. The pollution level of Pb in bottom waters was moderate to heavy, and were showing temporal variations and spatial heterogeneity. The vertical migration process of Pb in April 1988 included a drifting process from the southwest to the north by means of the marine current was rapid in this region. The vertical migration process of Pb in July 1988 in the open waters included no drifting process since the flow rate of marine current was relative low in this region. The vertical migration process of Pb was jointly determined by vertical water’s effect, source input and water exchange, and the influence of marine current on the vertical migration of Pb in marine bay was significant.

  3. Current and future trends in marine image annotation software

    Science.gov (United States)

    Gomes-Pereira, Jose Nuno; Auger, Vincent; Beisiegel, Kolja; Benjamin, Robert; Bergmann, Melanie; Bowden, David; Buhl-Mortensen, Pal; De Leo, Fabio C.; Dionísio, Gisela; Durden, Jennifer M.; Edwards, Luke; Friedman, Ariell; Greinert, Jens; Jacobsen-Stout, Nancy; Lerner, Steve; Leslie, Murray; Nattkemper, Tim W.; Sameoto, Jessica A.; Schoening, Timm; Schouten, Ronald; Seager, James; Singh, Hanumant; Soubigou, Olivier; Tojeira, Inês; van den Beld, Inge; Dias, Frederico; Tempera, Fernando; Santos, Ricardo S.

    2016-12-01

    Given the need to describe, analyze and index large quantities of marine imagery data for exploration and monitoring activities, a range of specialized image annotation tools have been developed worldwide. Image annotation - the process of transposing objects or events represented in a video or still image to the semantic level, may involve human interactions and computer-assisted solutions. Marine image annotation software (MIAS) have enabled over 500 publications to date. We review the functioning, application trends and developments, by comparing general and advanced features of 23 different tools utilized in underwater image analysis. MIAS requiring human input are basically a graphical user interface, with a video player or image browser that recognizes a specific time code or image code, allowing to log events in a time-stamped (and/or geo-referenced) manner. MIAS differ from similar software by the capability of integrating data associated to video collection, the most simple being the position coordinates of the video recording platform. MIAS have three main characteristics: annotating events in real time, posteriorly to annotation and interact with a database. These range from simple annotation interfaces, to full onboard data management systems, with a variety of toolboxes. Advanced packages allow to input and display data from multiple sensors or multiple annotators via intranet or internet. Posterior human-mediated annotation often include tools for data display and image analysis, e.g. length, area, image segmentation, point count; and in a few cases the possibility of browsing and editing previous dive logs or to analyze the annotations. The interaction with a database allows the automatic integration of annotations from different surveys, repeated annotation and collaborative annotation of shared datasets, browsing and querying of data. Progress in the field of automated annotation is mostly in post processing, for stable platforms or still images

  4. Vacuum Large Current Parallel Transfer Numerical Analysis

    Directory of Open Access Journals (Sweden)

    Enyuan Dong

    2014-01-01

    Full Text Available The stable operation and reliable breaking of large generator current are a difficult problem in power system. It can be solved successfully by the parallel interrupters and proper timing sequence with phase-control technology, in which the strategy of breaker’s control is decided by the time of both the first-opening phase and second-opening phase. The precise transfer current’s model can provide the proper timing sequence to break the generator circuit breaker. By analysis of the transfer current’s experiments and data, the real vacuum arc resistance and precise correctional model in the large transfer current’s process are obtained in this paper. The transfer time calculated by the correctional model of transfer current is very close to the actual transfer time. It can provide guidance for planning proper timing sequence and breaking the vacuum generator circuit breaker with the parallel interrupters.

  5. Monaco - IAEA [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Joseph, J.; Chipman, W.A.; Fukai, R.; Duursma, E.K.

    1967-01-01

    Present and future research: Transport of radionuclides by turbulent diffusion processes. The radionuclides which are introduced into the sea will be dispersed by turbulent processes caused by currents, tides, waves and so forth. One of the most urgent needs for estimation of radionuclide behaviour in the sea is to study such diffusion processes and to interpret and describe the results so that they can be used for prediction of similar processes affecting the dispersion of radioactive materials in marine environments

  6. One-Dimensional Modelling of Marine Current Turbine Runaway Behaviour

    Directory of Open Access Journals (Sweden)

    Staffan Lundin

    2016-04-01

    Full Text Available If a turbine loses its electrical load, it will rotate freely and increase speed, eventually achieving that rotational speed which produces zero net torque. This is known as a runaway situation. Unlike many other types of turbine, a marine current turbine will typically overshoot the final runaway speed before slowing down and settling at the runaway speed. Since the hydrodynamic forces acting on the turbine are dependent on rotational speed and acceleration, turbine behaviour during runaway becomes important for load analyses during turbine design. In this article, we consider analytical and numerical models of marine current turbine runaway behaviour in one dimension. The analytical model is found not to capture the overshoot phenomenon, while still providing useful estimates of acceleration at the onset of runaway. The numerical model incorporates turbine wake build-up and predicts a rotational speed overshoot. The predictions of the models are compared against measurements of runaway of a marine current turbine. The models are also used to recreate previously-published results for a tidal turbine and applied to a wind turbine. It is found that both models provide reasonable estimates of maximum accelerations. The numerical model is found to capture the speed overshoot well.

  7. Participatory Sensing Marine Debris: Current Trends and Future Opportunities

    Science.gov (United States)

    Jambeck, J.; Johnsen, K.

    2016-02-01

    The monitoring of litter and debris is challenging at the global scale because of spatial and temporal variability, disconnected local organizations and the use of paper and pen for documentation. The Marine Debris Tracker mobile app and citizen science program allows for the collection of global standardized data at a scale, speed and efficiency that was not previously possible. The app itself also serves as an outreach and education tool, creating an engaged participatory sensing instrument. This instrument is characterized by several aspects including range and frequency, accuracy and precision, accessibility, measurement dimensions, participant performance, and statistical analysis. Also, important to Marine Debris Tracker is open data and transparency. A web portal provides data that users have logged allowing immediate feedback to users and additional education opportunities. The engagement of users through a top tracker competition and social media keeps participants interested in the Marine Debris Tracker community. Over half a million items have been tracked globally, and maps provide both global and local distribution of data. The Marine Debris Tracker community and dataset continues to grow daily. We will present current usage and engagement, participatory sensing data distributions, choropleth maps of areas of active tracking, and discuss future technologies and platforms to expand data collection and conduct statistical analysis.

  8. Marine mimivirus relatives are probably large algal viruses

    Directory of Open Access Journals (Sweden)

    Claverie Jean-Michel

    2008-01-01

    Full Text Available Abstract Background Acanthamoeba polyphaga mimivirus is the largest known ds-DNA virus and its 1.2 Mb-genome sequence has revealed many unique features. Mimivirus occupies an independent lineage among eukaryotic viruses and its known hosts include only species from the Acanthamoeba genus. The existence of mimivirus relatives was first suggested by the analysis of the Sargasso Sea metagenomic data. Results We now further demonstrate the presence of numerous "mimivirus-like" sequences using a larger marine metagenomic data set. We also show that the DNA polymerase sequences from three algal viruses (CeV01, PpV01, PoV01 infecting different marine algal species (Chrysochromulina ericina, Phaeocystis pouchetii, Pyramimonas orientalis are very closely related to their homolog in mimivirus. Conclusion Our results suggest that the numerous mimivirus-related sequences identified in marine environments are likely to originate from diverse large DNA viruses infecting phytoplankton. Micro-algae thus constitute a new category of potential hosts in which to look for new species of Mimiviridae.

  9. Israel [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Gilat, E.; Steiger-Shafrir, N.H.

    1967-01-01

    Present research programme - Radioactive contamination in marine environment and biota in the eastern Mediterranean. Detail of programme: (1) Objectives and most important points: The study of radioactive contamination of marine environment and biota involved qualitative and quantitative determinations for radionuclides of biological interest. The purpose of such an investigation is to determine; (a) Rate of passage of radionuclides through the food chain to the human organism in subtropical conditions prevailing in the eastern Mediterranean. The Levantine Basin of the Mediterranean is characterized by high temperatures and salinities which are typical for a tropical area. These are the cause of survival and development of numerous Indo-Pacific organisms which penetrate from the Red Sea through the Suez Canal into the eastern Mediterranean. It is therefore of interest to determine concentrations of radionuclides taken up by the endemic as well as the Indo-Pacific species at various levels of the food chain, (b) Indicator organisms which can be used in measuring the concentration of radionuclides in marine environment. (c) Effect of organisms on the distribution of elements in the sea. The elements, of which a large proportion passes through the organisms, will thus undergo a modification in their spatial and seasonal distribution in the water and sediments

  10. Heat Transfer in Large Two-Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Jensen, Michael Vincent

    Heat transfer between the cylinder gas and the piston surface during combustion in large two-stroke uniflow scavenged marine diesel engines has been investigated in the present work. The piston surface experiences a severe thermal load during combustion due to the close proximity of the combustion...... zone to the surface. At the same time, cooling of the piston crown is relatively complicated. This can cause large thermal stresses in the piston crown and weakening of the material strength, which may be critical as it can lead to formation of cracks. Information about the piston surface heat transfer...... is thus important for the engine manufactures. The piston surface heat transfer was studied in the event of impingement of hot combustion products on the piston during combustion, and an estimate was obtained of the peak heat flux level experienced on the piston surface. The investigation was carried out...

  11. Assessing trade-offs in large marine protected areas.

    Science.gov (United States)

    Davies, Tammy E; Epstein, Graham; Aguilera, Stacy E; Brooks, Cassandra M; Cox, Michael; Evans, Louisa S; Maxwell, Sara M; Nenadovic, Mateja; Ban, Natalie C

    2018-01-01

    Large marine protected areas (LMPAs) are increasingly being established and have a high profile in marine conservation. LMPAs are expected to achieve multiple objectives, and because of their size are postulated to avoid trade-offs that are common in smaller MPAs. However, evaluations across multiple outcomes are lacking. We used a systematic approach to code several social and ecological outcomes of 12 LMPAs. We found evidence of three types of trade-offs: trade-offs between different ecological resources (supply trade-offs); trade-offs between ecological resource conditions and the well-being of resource users (supply-demand trade-offs); and trade-offs between the well-being outcomes of different resource users (demand trade-offs). We also found several divergent outcomes that were attributed to influences beyond the scope of the LMPA. We suggest that despite their size, trade-offs can develop in LMPAs and should be considered in planning and design. LMPAs may improve their performance across multiple social and ecological objectives if integrated with larger-scale conservation efforts.

  12. Addressing Criticisms of Large-Scale Marine Protected Areas

    Science.gov (United States)

    Ban, Natalie C; Fernandez, Miriam; Friedlander, Alan M; García-Borboroglu, Pablo; Golbuu, Yimnang; Guidetti, Paolo; Harris, Jean M; Hawkins, Julie P; Langlois, Tim; McCauley, Douglas J; Pikitch, Ellen K; Richmond, Robert H; Roberts, Callum M

    2018-01-01

    Abstract Designated large-scale marine protected areas (LSMPAs, 100,000 or more square kilometers) constitute over two-thirds of the approximately 6.6% of the ocean and approximately 14.5% of the exclusive economic zones within marine protected areas. Although LSMPAs have received support among scientists and conservation bodies for wilderness protection, regional ecological connectivity, and improving resilience to climate change, there are also concerns. We identified 10 common criticisms of LSMPAs along three themes: (1) placement, governance, and management; (2) political expediency; and (3) social–ecological value and cost. Through critical evaluation of scientific evidence, we discuss the value, achievements, challenges, and potential of LSMPAs in these arenas. We conclude that although some criticisms are valid and need addressing, none pertain exclusively to LSMPAs, and many involve challenges ubiquitous in management. We argue that LSMPAs are an important component of a diversified management portfolio that tempers potential losses, hedges against uncertainty, and enhances the probability of achieving sustainably managed oceans. PMID:29731514

  13. India [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Ganguly, A.K.; Viswanathan, R.; Patel, B.; Bhatt, Y.M.; Pillai, K.C.

    1967-01-01

    Present research programme (long-term) - Radioactivity studies in the marine environment of the West Coast of India: (a) To understand the radioactivity and trace-element distribution in the continental shelf in Arabian Sea. This has the twin objectives of gaining basic information on marine geochemistry and marine biochemistry and assessing the capacity of the region to receive radioactive wastes from atomic energy installations. (b) To derive maximum permissible radioactive contamination limits in sea-water, marine organisms and marine products. (c) To collaborate with IAEA in research contract (Project Marina) with objectives stated in (a) and (b) above

  14. Marine current turbine design for zero emission renewable energy producing a sailing boat

    OpenAIRE

    EKİNCİ, Serkan; ALVAR, Mustafa

    2016-01-01

    In the recent years, rapid increase in theoretical studies and applications on electrical power generation from renewable sources, such as wind, sun, marine or tidal currents, can be encountered in the literature. Among these, marine current turbines, produce energy by taking the advantage of alternating motion of water, and have the ability to produce energy even at low flow rates, and are operated in oceans and seas as a renewable energy source. In this study, design of marine current turbi...

  15. Italy. Report 1 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Argiero, L.

    1967-01-01

    Present research programme: Studies on radioactive, biological and hydrographic characteristics of Tyrrhenian Sea; Organization of suitable control network of marine water and fauna: systematic measurement of present components of natural and artificial radioactivity of water, sediments and of the marine food chain techniques of sampling; analysis and measurement of particular radioisotopes in marine water. α, β, γ analysis of samples; γ spectrometry, research on 90 Sr and 137 Cs. Determination of concentration factors of radioisotopes which are responsible for contamination of principal components of the flora and fauna in the Tyrrhenian Sea; research of hydrographie factors influencing the distribution of marine radioactivity. Nuclide content of other organisms of the Tyrrhenian flora and fauna

  16. Puerto Rico [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Lowman, Frank G.

    1967-01-01

    Present research programme: Marine biology programme (marine biogeochemistry). The programme is designed to provide measurements of the distribution and movements of selected trace elements in a restricted but complete ecological and biogeochemical system. To obtain information on interactions between the marine biosphere and hydrosphere, measurements are being made of biological productivity, amounts of trace elements in the organisms and the environment, biological half-lives of trace elements, characteristics of food webs, and the influence of physical and chemical oceanographic factors upon the distribution patterns of trace elements in the marine waters, organisms and sediments offshore from the west coast of Puerto Rico

  17. Yugoslavia. Report 1 [Marine Radioecology. Current Research and Future Scope

    Energy Technology Data Exchange (ETDEWEB)

    Kečkeš, S.; Pučar, Z. [Laboratory of Marine Radiobiology and Laboratory for Electromigration, Institute ' ' Ruder Boskovic' ' , Rovinj and Zagreb, Yugoslavia (Croatia)

    1967-03-15

    Present research programme (long-term): Transport of various radiqnuclides in marine environment. Uptake, loss and accumulation of radionuclides in selected marine biota. Study of the physico-chemical forms of various radionuclides in sea water. Tracer experiments on the uptake and loss rate in biota. Electromigration techniques for the characterization of the physico-chemical forms of radionuclides.

  18. Diffuser Design for Marine Outfalls in Areas with Strong Currents, High waves and Sediment Transport

    DEFF Research Database (Denmark)

    Larsen, Torben

    1995-01-01

    The design of marine outfalls is often based on environmental criteria for a minimum initial dilution. Accordingly advanced diffuser arrangement are designed to fulfil these requirements. A large number of examples of malfunction and blocking in sea outfalls have occurred around the world...... as a result of this uncompromising consent to environmental demands. Two examples of unconventional design are given in this paper. Both cases involved risk of blockage of the diffuser section because of wave and current induced sediment transport The paper also discusses how acceptable far field dilution...

  19. The stratigraphic distribution of large marine vertebrates and shell beds in the Pliocene of Tuscany

    Science.gov (United States)

    Dominici, Stefano; Benvenuti, Marco; Danise, Silvia

    2015-04-01

    The record of 337 shark fossils, 142 cetaceans and 10 sea cows from the Pliocene of Tuscany, mostly from historical museum collections, is revised. The majority of these fossils are concentrated at a few geographic sites from separated hinterland basins, on the South-Western side of the Northern Apennines. To better understand the meaning of these concentrations, the sequence stratigraphic distribution of more recent findings of large marine vertebrates is reconstructed against a high-resolution framework based on sedimentary facies analysis. These remains are usually covered by, or included in mudstones deposited far from the coast (N=12), skeletons being usually articulated, slightly displaced, and often bioeroded. A minor part of better preserved articulated skeletons is associated with sandstones from deltaic paleonenvironments (N=2). Marine mammal and shark remains may be associated with laterally-continuous shell accumulations, a type of concentration occurring at maximum flooding surfaces, separating relatively coarse-grained facies from open marine mudstones. Shell beds were bulk-sampled at 66 locations from six basins, covering a wide range of sedimentary facies, and spanning a chronologic interval of about 2.5 million years. A dataset of 62,655 mollusc specimens belonging to 496 species formed the basis of a statistical study to reconstruct the structure of the benthic communities, and to estimate paleodepths from intertidal to upper bathyal settings. Mollusc associations closely mirror the distribution of sedimentary facies, allowing for a fine tuning of the sequence stratigraphic architecture. Merging paleogeographic, stratigraphic and paleoecologic data, we conclude that the more abundant and diverse accumulations of large vertebrates took place in settings under the influence of coastal upwelling. A modern analogue occurs today in the Ligurian Sea, on the Tuscan offshore, where abundant nutrients carried by deep-marine currents of Western origin

  20. Dynamics of a Marine Turbine for Deep Ocean Currents

    Directory of Open Access Journals (Sweden)

    Ling-Yuan Chang

    2016-09-01

    Full Text Available For most of the ocean currents, such as the Kuroshio at east Taiwan, the Gulf Stream at east Florida and the Agulhas Current at southeast Africa, the depth of the seabed is generally deeper than one hundred meters, some waters of which can even reach one thousand meters. In such deep waters, the design of the turbine, as well as the anchoring system shall have special features so that existing ocean engineering technologies can be applied and the engineering cost can be lowered. Thus, as regards design, in addition to the analysis of the interaction between turbine and current, priority shall also be given to the design of the anchoring system of the turbine. To address the concerns, the authors propose an ocean turbine featured as follows: (1 it can be anchored in deep waters with a single cable; (2 it can generate high power in a current of moderate flow speed while producing low drag; (3 it can be self-balanced against current disturbance; (4 it is shrouded to enhance power efficiency; (5 the dynamic variations due to the interaction between the turbine and current are small. All of these features are confirmed with the computational results, leading to a detailed design of the turbine structure. If the easy-to-install high-efficiency shrouded turbines, having the capability to self-balance and requiring minimum maintenance effort, are successfully developed, the power supply pressure in Taiwan can be greatly alleviated. The Kuroshio was chosen as the typical current for the present dynamic analysis because, firstly, the flow characteristics of Kuroshio are similar to those of other large-scale currents mentioned above, and secondly, the data of Kuroshio are highly available to us so that a thorough analysis can be done.

  1. Canada. Report 2 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Ophel, I.L.

    1967-01-01

    There are two areas where I have long thought that knowledge is sadly lacking. These have considerable fundamental interest but the knowledge is even more Important for the setting of permissible levels of radioactive waste disposals into the oceans. They are as follows: (1) Effects of chronic irradiation on the developmental and adult stages of marine organisms - particularly edible fish; (2) Biological half-lives of fission products in marine organisms

  2. Canada. Report 2 [Marine Radioecology. Current Research and Future Scope

    Energy Technology Data Exchange (ETDEWEB)

    Ophel, I. L. [Atomic Energy of Canada Limited, Biology and Health Physics Division, Environmental Research Branch, Chalk River, ON (Canada)

    1967-03-15

    There are two areas where I have long thought that knowledge is sadly lacking. These have considerable fundamental interest but the knowledge is even more Important for the setting of permissible levels of radioactive waste disposals into the oceans. They are as follows: (1) Effects of chronic irradiation on the developmental and adult stages of marine organisms - particularly edible fish; (2) Biological half-lives of fission products in marine organisms.

  3. Wind turbine underwater noise and marine mammals : implications of current knowledge and data needs

    OpenAIRE

    Madsen, P T; Wahlberg, M; Tougaard, J; Lucke, K; Tyack, Peter Lloyd

    2006-01-01

    The demand for renewable energy has led to construction of offshore wind farms with high-power turbines, and many more wind farms are being planned for the shallow waters of the world's marine habitats. The growth of offshore wind farms has raised concerns about their impact on the marine environment. Marine mammals use sound for foraging, orientation and communication and are therefore possibly susceptible to negative effects of man-made noise generated from constructing and operating large ...

  4. Japan [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Saiki, M.

    1967-01-01

    Among the present research programmes: Studies on rcidiochemical analysis of sea-water and fishes; Studies on uptake of radionuclides by marine organisms; Studies on internal exposure arising from marine products; The convenient and appropriate method of analysis and determination of radioactivity in sea— water and fishes is investigated; Biological concentration of fission products and induced products in fishes and plankton arc studied from the radioecological point of view; Contribution of radionuclides in fishes and algae to those in the total Japanese diet is studied, in connection with fall-out studies

  5. As multiple fish species in large marine ecosystems are harvested ...

    African Journals Online (AJOL)

    CMPTMAC10

    and of other top predators such as marine mammals. This concern ... whereas single-species fishing theory implies that fishing leads to surplus by removing larger, older, less-productive ...... pools (the “cod is not a tuna” problem, Longhurst.

  6. Potential scour for marine current turbines based on experience of offshore wind turbine

    International Nuclear Information System (INIS)

    Chen, L; Lam, W H; Shamsuddin, A H

    2013-01-01

    The oceans have tremendous untapped natural resources. These sources are capable to make significant contribution to our future energy demands. Marine current energy offers sustainable and renewable alternative to conventional sources. Survival problems of Marine Current Turbines (MCTs) need to be addressed due to the harsh marine environment. The analogous researches in wind turbine have been conducted. Some of the results and knowledge are transferable to marine current energy industry. There still exist some gaps in the state of knowledge. Scour around marine structures have been well recognised as an engineering issue as scour is likely to cause structural instability. This paper aims to review different types of foundation of MCTs and potential scour and scour protection around these foundations based on the experience of offshore wind turbine farm.

  7. Assessment of Current Practice for Tank Testing of Small Marine Energy Devices

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter

    Discussion Report. Equitable Testing and Evaluation of Marine Energy Extraction Devices in terms of Performance, Cost and Environmental Impact. The report is a contribution by Aalborg University (AAU) to the deliverable on Assessment of current practice for tank testing of small marine energy...

  8. Marine biodiversity in South Africa: an evaluation of current states of knowledge.

    Directory of Open Access Journals (Sweden)

    Charles L Griffiths

    Full Text Available Continental South Africa has a coastline of some 3,650 km and an Exclusive Economic Zone (EEZ of just over 1 million km(2. Waters in the EEZ extend to a depth of 5,700 m, with more than 65% deeper than 2,000 m. Despite its status as a developing nation, South Africa has a relatively strong history of marine taxonomic research and maintains comprehensive and well-curated museum collections totaling over 291,000 records. Over 3 million locality records from more than 23,000 species have been lodged in the regional AfrOBIS (African Ocean Biogeographic Information System data center (which stores data from a wider African region. A large number of regional guides to the marine fauna and flora are also available and are listed. The currently recorded marine biota of South Africa numbers at least 12,914 species, although many taxa, particularly those of small body size, remain poorly documented. The coastal zone is relatively well sampled with some 2,500 samples of benthic invertebrate communities have been taken by grab, dredge, or trawl. Almost none of these samples, however, were collected after 1980, and over 99% of existing samples are from depths shallower than 1,000 m--indeed 83% are from less than 100 m. The abyssal zone thus remains almost completely unexplored. South Africa has a fairly large industrial fishing industry, of which the largest fisheries are the pelagic (pilchard and anchovy and demersal (hake sectors, both focused on the west and south coasts. The east coast has fewer, smaller commercial fisheries, but a high coastal population density, resulting in intense exploitation of inshore resources by recreational and subsistence fishers, and this has resulted in the overexploitation of many coastal fish and invertebrate stocks. South Africa has a small aquaculture industry rearing mussels, oysters, prawns, and abalone-the latter two in land-based facilities. Compared with many other developing countries, South Africa has a well

  9. Italy. Report 2 [Marine Radioecology. Current Research and Future Scope

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, B. [Istituto di Zoologia, Universita-Parma (Italy)

    1967-03-15

    Present research programme (long-term): Radionuclides in plankton an marine sediments. Ecology of Anvantheria as Sr ''scanengers''. General distribution of radionuclides in marine environment Systematics and ecology of Avantharia, studied in different seas as a biological problem. Content of {sup 90}Sr in plankton in relation to the presence or absence of Avantharia Radiochemistry of sea sediments (littoral); sedimentological and petrographical researches for stratigraphic purposes. Fall-out and wastes radionuclides absorbed by sediments. Correlation between Acantharia and concentration factor for {sup 90}Sr. Stratigraphy of fall-out radionuclides in sea sediments. Biological researches on Acantharia rearing for turnover studies in vitro. Stratigraphical researches on recent coastal sediments for geochronological problems by means of fall-out radionuclides.

  10. Italy. Report 2 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Schreiber, B.

    1967-01-01

    Present research programme (long-term): Radionuclides in plankton an marine sediments. Ecology of Anvantheria as Sr ''scanengers''. General distribution of radionuclides in marine environment Systematics and ecology of Avantharia, studied in different seas as a biological problem. Content of 90 Sr in plankton in relation to the presence or absence of Avantharia Radiochemistry of sea sediments (littoral); sedimentological and petrographical researches for stratigraphic purposes. Fall-out and wastes radionuclides absorbed by sediments. Correlation between Acantharia and concentration factor for 90 Sr. Stratigraphy of fall-out radionuclides in sea sediments. Biological researches on Acantharia rearing for turnover studies in vitro. Stratigraphical researches on recent coastal sediments for geochronological problems by means of fall-out radionuclides

  11. Resource characterization and variability studies for marine current power

    OpenAIRE

    Carpman, Nicole

    2017-01-01

    Producing electricity from marine renewable resources is a research area that develops continuously. The field of tidal energy is on the edge to progress from the prototype stage to the commercial stage. However, tidal resource characterization, and the effect of tidal turbines on the flow, is still an ongoing research area in which this thesis aims to contribute. In this thesis, measurements of flow velocities have been performed at three kinds of sites. Firstly, a tidal site has been invest...

  12. Submarine canyons represent an essential habitat network for krill hotspots in a Large Marine Ecosystem.

    Science.gov (United States)

    Santora, Jarrod A; Zeno, Ramona; Dorman, Jeffrey G; Sydeman, William J

    2018-05-15

    Submarine canyon systems are ubiquitous features of marine ecosystems, known to support high levels of biodiversity. Canyons may be important to benthic-pelagic ecosystem coupling, but their role in concentrating plankton and structuring pelagic communities is not well known. We hypothesize that at the scale of a large marine ecosystem, canyons provide a critical habitat network, which maintain energy flow and trophic interactions. We evaluate canyon characteristics relative to the distribution and abundance of krill, critically important prey in the California Current Ecosystem. Using a geological database, we conducted a census of canyon locations, evaluated their dimensions, and quantified functional relationships with krill hotspots (i.e., sites of persistently elevated abundance) derived from hydro-acoustic surveys. We found that 76% of krill hotspots occurred within and adjacent to canyons. Most krill hotspots were associated with large shelf-incising canyons. Krill hotspots and canyon dimensions displayed similar coherence as a function of latitude and indicate a potential regional habitat network. The latitudinal migration of many fish, seabirds and mammals may be enhanced by using this canyon-krill network to maintain foraging opportunities. Biogeographic assessments and predictions of krill and krill-predator distributions under climate change may be improved by accounting for canyons in habitat models.

  13. Quantized acoustoelectric current in the presence of large tunneling counterflow

    DEFF Research Database (Denmark)

    Gloos, K.; Utko, P.; Hansen, Jørn Bindslev

    2004-01-01

    A surface acoustic wave drives an electrical current through a short quantum wire. A second tunneling current is injected by biasing one side of the quantum wire. These two contributions to the total current, which flow in opposite directions, are controlled almost independently by the gate...... and the bias voltage, respectively. We have observed the quantization of the acoustoelectric current at up to ten times larger counterflowing tunneling currents. At large tunneling currents the acoustoelectric current can be strongly suppressed. However, this does not seem to be due to an electrostatic...... interaction between the two currents, but is probably caused by the complex potential landscape in the narrow channel of the quantum wire....

  14. Quantized acoustoelectric current in the presence of large tunneling counterflow

    International Nuclear Information System (INIS)

    Gloos, K.; Utko, P.; Lindelof, P.E.; Hansen, J. Bindslev

    2004-01-01

    A surface acoustic wave drives an electrical current through a short quantum wire. A second tunneling current is injected by biasing one side of the quantum wire. These two contributions to the total current, which flow in opposite directions, are controlled almost independently by the gate and the bias voltage, respectively. We have observed the quantization of the acoustoelectric current at up to ten times larger counterflowing tunneling currents. At large tunneling currents the acoustoelectric current can be strongly suppressed. However, this does not seem to be due to an electrostatic interaction between the two currents, but is probably caused by the complex potential landscape in the narrow channel of the quantum wire

  15. Potential effects of climate change on a marine invasion: The importance of current context

    Directory of Open Access Journals (Sweden)

    Isabelle M. CÔTÉ, Stephanie J. GREEN

    2012-02-01

    Full Text Available Species invasions threaten marine biodiversity globally. There is a concern that climate change is exacerbating this problem. Here, we examined some of the potential effects of warming water temperatures on the invasion of Western Atlantic habitats by a marine predator, the Indo-Pacific lionfish (Pterois volitans and P. miles. We focussed on two temperature-dependent aspects of lionfish life-history and behaviour: pelagic larval duration, because of its link to dispersal potential, and prey consumption rate, because it is an important determinant of the impacts of lionfish on native prey. Using models derived from fundamental metabolic theory, we predict that the length of time spent by lionfish in the plankton in early life should decrease with warming temperatures, with a concomitant reduction in potential dispersal distance. Although the uncertainty around change in dispersal distances is large, predicted reductions are, on average, more than an order of magnitude smaller than the current rate of range expansion of lionfish in the Caribbean. Nevertheless, because shorter pelagic larval duration has the potential to increase local retention of larvae, local lionfish management will become increasingly important under projected climate change. Increasing temperature is also expected to worsen the current imbalance between rates of prey consumption by lionfish and biomass production by their prey, leading to a heightened decline in native reef fish biomass. However, the magnitude of climate-induced decline is predicted to be minor compared to the effect of current rates of lionfish population increases (and hence overall prey consumption rates on invaded reefs. Placing the predicted effects of climate change in the current context thus reveals that, at least for the lionfish invasion, the threat is clear and present, rather than future [Current Zoology 58 (1: 1–8, 2012].

  16. Shore-based Path Planning for Marine Vehicles Using a Model of Ocean Currents

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop path planning methods that incorporate an approximate model of ocean currents in path planning for a range of autonomous marine vehicles such as surface...

  17. Australia [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Fry, R.M.

    1967-01-01

    Present research programme: 1.1. Investigation of the fate of radioactive nuclides introduced into a tidal estuary. 1.2. To obtain information on the eventual accumulation of radioactive nuclides in marine organisms which form part of the human food chain. 1.3. Studies are being made of the ecology of the estuarine system and the passage of selected nuclides through various trophic levels. Particular attention is being paid to oysters (Saxostrea commercialis) and stable Zn, Ca, Sr and In levels in the oysters and in estuarine water being measured to determine concentration factors for these elements in this organism

  18. Australia [Marine Radioecology. Current Research and Future Scope

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R. M. [Australian Atomic Energy Commission Research Establishment, AAEC, Research Establishment, Private Mail Bag, Sutherland, N.S.W. (Australia)

    1967-03-15

    Present research programme: 1.1. Investigation of the fate of radioactive nuclides introduced into a tidal estuary. 1.2. To obtain information on the eventual accumulation of radioactive nuclides in marine organisms which form part of the human food chain. 1.3. Studies are being made of the ecology of the estuarine system and the passage of selected nuclides through various trophic levels. Particular attention is being paid to oysters (Saxostrea commercialis) and stable Zn, Ca, Sr and In levels in the oysters and in estuarine water being measured to determine concentration factors for these elements in this organism.

  19. Specimen banking of marine organisms in the United States: Current status and long-term prospective

    Science.gov (United States)

    Becker, P.R.; Wise, S.A.; Thorsteinson, L.; Koster, B.J.; Rowles, T.

    1997-01-01

    A major part of the activities conducted over the last decade by the National Biomonitoring Specimen Bank (NBSB) has involved the archival of marine specimens collected by ongoing environmental monitoring programs. These archived specimens include bivalves, marine sediments, and fish tissues collected by the National Status and Trends and the Exxon Valdez Oil Spill Damage Assessment programs, and marine mammal tissues collected by the Marine Mammal Health and Stranding Response Program and the Alaska Marine Mammal Tissue Archival Project. In addition to supporting these programs, the specimens have been used to investigate circumpolar patterns of chlorinated hydrocarbon concentrations, genetic separation of marine animal stocks, baseline levels of essential and nonessential elements in marine mammals, and the potential risk to human consumers in the Arctic from anthropogenic contaminants found in local subsistence foods. The NBSB specimens represent a resource that has the potential for addressing future issues of marine environmental quality and ecosystem changes through retrospective analysis; however, an ecosystem-based food web approach would maximize this potential. The current status of the NBSB activities related to the banking of marine organisms is presented and discussed, the long-term prospective of these activities is presented, and the importance of an ecosystem-based food web monitoring approach to the value of specimen banking is discussed.

  20. The Large Marine Ecosystem Approach for 21st Century Ocean Health and International Sustainable Development

    Science.gov (United States)

    Honey, K. T.

    2014-12-01

    The global coastal ocean and watersheds are divided into 66 Large Marine Ecosystems (LMEs), which encompass regions from river basins, estuaries, and coasts to the seaward boundaries of continental shelves and margins of major currents. Approximately 80% of global fisheries catch comes from LME waters. Ecosystem goods and services from LMEs contribute an estimated US 18-25 trillion dollars annually to the global economy in market and non-market value. The critical importance of these large-scale systems, however, is threatened by human populations and pressures, including climate change. Fortunately, there is pragmatic reason for optimism. Interdisciplinary frameworks exist, such as the Large Marine Ecosystem (LME) approach for adaptive management that can integrate both nature-centric and human-centric views into ecosystem monitoring, assessment, and adaptive management practices for long-term sustainability. Originally proposed almost 30 years ago, the LME approach rests on five modules are: (i) productivity, (ii) fish and fisheries, (iii) pollution and ecosystem health, (iv) socioeconomics, and (v) governance for iterative adaptive management at a large, international scale of 200,000 km2 or greater. The Global Environment Facility (GEF), World Bank, and United Nations agencies recognize and support the LME approach—as evidenced by over 3.15 billion in financial assistance to date for LME projects. This year of 2014 is an exciting milestone in LME history, after 20 years of the United Nations and GEF organizations adopting LMEs as a unit for ecosystem-based approaches to management. The LME approach, however, is not perfect. Nor is it immutable. Similar to the adaptive management framework it propones, the LME approach itself must adapt to new and emerging 21st Century technologies, science, and realities. The LME approach must further consider socioeconomics and governance. Within the socioeconomics module alone, several trillion-dollar opportunities exist

  1. Matrix Metalloproteinase Inhibitors (MMPIs from Marine Natural Products: the Current Situation and Future Prospects

    Directory of Open Access Journals (Sweden)

    Se-Kwon Kim

    2009-03-01

    Full Text Available Matrix metalloproteinases (MMPs are a family of more than twenty five secreted and membrane-bound zinc-endopeptidases which can degrade extracellular matrix (ECM components. They also play important roles in a variety of biological and pathological processes. Matrix metalloproteinase inhibitors (MMPIs have been identified as potential therapeutic candidates for metastasis, arthritis, chronic inflammation and wrinkle formation. Up to present, more than 20,000 new compounds have been isolated from marine organisms, where considerable numbers of these naturally occurring derivatives are developed as potential candidates for pharmaceutical application. Eventhough the quantity of marine derived MMPIs is less when compare with the MMPIs derived from terrestrial materials, huge potential for bioactivity of these marine derived MMPIs has lead to large number of researches. Saccharoids, flavonoids and polyphones, fatty acids are the most important groups of MMPIs derived from marine natural products. In this review we focus on the progress of MMPIs from marine natural products.

  2. Response to ocean acidification in larvae of a large tropical marine fish, Rachycentron canadum.

    Science.gov (United States)

    Bignami, Sean; Sponaugle, Su; Cowen, Robert K

    2013-04-01

    Currently, ocean acidification is occurring at a faster rate than at any time in the last 300 million years, posing an ecological challenge to marine organisms globally. There is a critical need to understand the effects of acidification on the vulnerable larval stages of marine fishes, as there is potential for large ecological and economic impacts on fish populations and the human economies that rely on them. We expand upon the narrow taxonomic scope found in the literature today, which overlooks many life history characteristics of harvested species, by reporting on the larvae of Rachycentron canadum (cobia), a large, highly mobile, pelagic-spawning, widely distributed species with a life history and fishery value contrasting other species studied to date. We raised larval cobia through the first 3 weeks of ontogeny under conditions of predicted future ocean acidification to determine effects on somatic growth, development, otolith formation, swimming ability, and swimming activity. Cobia exhibited resistance to treatment effects on growth, development, swimming ability, and swimming activity at 800 and 2100 μatm pCO2 . However, these scenarios resulted in a significant increase in otolith size (up to 25% larger area) at the lowest pCO2 levels reported to date, as well as the first report of significantly wider daily otolith growth increments. When raised under more extreme scenarios of 3500 and 5400 μatm pCO2 , cobia exhibited significantly reduced size-at-age (up to 25% smaller) and a 2-3 days developmental delay. The robust nature of cobia may be due to the naturally variable environmental conditions this species currently encounters throughout ontogeny in coastal environments, which may lead to an increased acclimatization ability even during long-term exposure to stressors. © 2012 Blackwell Publishing Ltd.

  3. Marines in the Boxer Rebellion as a Model for Current Marine Corps Operations

    Science.gov (United States)

    2016-06-10

    landed in New Providence, Bahamas in 1778, raising the American flag for the first time on foreign soil .2 Years later, First Lieutenant Presley O’Bannon...Marines conducted landings (and in some cases multiple landings) in support of American interests in the Hawaiian Islands, Egypt, Colombia , Haiti, Samoa...Argentina, Chile, Nicaragua, Colombia , and Trinidad. Most instances centered on insurgent forces unwilling to accept

  4. Marine phospholipids: The current understanding of their oxidation mechanisms and potential uses for food fortification

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2017-01-01

    reactions, namely, Strecker aldehydes, pyrroles, oxypolymers, and other impurities that may positively or negatively affect the oxidative stability and quality of marine PL. This review was undertaken to provide the industry and academia with an overview of the current understanding of the quality changes......There is a growing interest in using marine phospholipids (PL) as ingredient for food fortification due to their numerous health benefits. However, the use of marine PL for food fortification is a challenge due to the complex nature of the degradation products that are formed during the handling...... and storage of marine PL. For example, nonenzymatic browning reactions may occur between lipid oxidation products and primary amine group from phosphatidylethanolamine or amino acid residues that are present inmarine PL. Therefore, marine PL contain products from nonenzymatic browning and lipid oxidation...

  5. Carotenoids in Marine Invertebrates Living along the Kuroshio Current Coast

    Directory of Open Access Journals (Sweden)

    Yoshikazu Sakagami

    2011-08-01

    Full Text Available Carotenoids of the corals Acropora japonica, A. secale, and A. hyacinthus, the tridacnid clam Tridacna squamosa, the crown-of-thorns starfish Acanthaster planci, and the small sea snail Drupella fragum were investigated. The corals and the tridacnid clam are filter feeders and are associated with symbiotic zooxanthellae. Peridinin and pyrrhoxanthin, which originated from symbiotic zooxanthellae, were found to be major carotenoids in corals and the tridacnid clam. The crown-of-thorns starfish and the sea snail D. fragum are carnivorous and mainly feed on corals. Peridinin-3-acyl esters were major carotenoids in the sea snail D. fragum. On the other hand, ketocarotenoids such as 7,8-didehydroastaxanthin and astaxanthin were major carotenoids in the crown-of-thorns starfish. Carotenoids found in these marine animals closely reflected not only their metabolism but also their food chains.

  6. Mapping the ocean current strength and persistence in the Agulhas to inform marine energy development

    CSIR Research Space (South Africa)

    Meyer, I

    2017-04-01

    Full Text Available sensing - Acoustic Doppler Current Profiler - Natal pulses U N C O R R EC TE D PR O O F 1 Mapping the Ocean Current Strength 2 and Persistence in the Agulhas to Inform 3 Marine Energy Development 4 I. Meyer, L. Braby, M. Krug and B. Backeberg 5... International Publishing AG 2017 Z. Yang and A. Copping (eds.), Marine Renewable Energy, DOI 10.1007/978-3-319-53536-4_8 1 A u th o r P ro o f U N C O R R EC TE D PR O O F 16 Current. Western boundary ocean currents have become an area of focus (Duerr and 17...

  7. Weak Compliance Undermines the Success of No-Take Zones in a Large Government-Controlled Marine Protected Area

    KAUST Repository

    Campbell, Stuart J.; Hoey, Andrew; Maynard, Jeffrey; Kartawijaya, Tasrif; Cinner, Joshua; Graham, Nicholas A. J.; Baird, Andrew H.

    2012-01-01

    The effectiveness of marine protected areas depends largely on whether people comply with the rules. We quantified temporal changes in benthic composition, reef fish biomass, and fishing effort among marine park zones (including no-take areas

  8. Zener diode controls switching of large direct currents

    Science.gov (United States)

    1965-01-01

    High-current zener diode is connected in series with the positive input terminal of a dc supply to block the flow of direct current until a high-frequency control signal is applied across the zener diode. This circuit controls the switching of large dc signals.

  9. On the ecological relevance of landscape mapping and its application in the spatial planning of very large marine protected areas.

    Science.gov (United States)

    Hogg, Oliver T; Huvenne, Veerle A I; Griffiths, Huw J; Linse, Katrin

    2018-06-01

    In recent years very large marine protected areas (VLMPAs) have become the dominant form of spatial protection in the marine environment. Whilst seen as a holistic and geopolitically achievable approach to conservation, there is currently a mismatch between the size of VLMPAs, and the data available to underpin their establishment and inform on their management. Habitat mapping has increasingly been adopted as a means of addressing paucity in biological data, through use of environmental proxies to estimate species and community distribution. Small-scale studies have demonstrated environmental-biological links in marine systems. Such links, however, are rarely demonstrated across larger spatial scales in the benthic environment. As such, the utility of habitat mapping as an effective approach to the ecosystem-based management of VLMPAs remains, thus far, largely undetermined. The aim of this study was to assess the ecological relevance of broadscale landscape mapping. Specifically we test the relationship between broad-scale marine landscapes and the structure of their benthic faunal communities. We focussed our work at the sub-Antarctic island of South Georgia, site of one of the largest MPAs in the world. We demonstrate a statistically significant relationship between environmentally derived landscape mapping clusters, and the composition of presence-only species data from the region. To demonstrate this relationship required specific re-sampling of historical species occurrence data to balance biological rarity, biological cosmopolitism, range-restricted sampling and fine-scale heterogeneity between sampling stations. The relationship reveals a distinct biological signature in the faunal composition of individual landscapes, attributing ecological relevance to South Georgia's environmentally derived marine landscape map. We argue therefore, that landscape mapping represents an effective framework for ensuring representative protection of habitats in management

  10. Electric currents couple spatially separated biogeochemical processes in marine sediment

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter; Risgaard-Petersen, Nils; Fossing, Henrik

    2010-01-01

    Some bacteria are capable of extracellular electron transfer, thereby enabling them to use electron acceptors and donors without direct cell contact 1, 2, 3, 4 . Beyond the micrometre scale, however, no firm evidence has previously existed that spatially segregated biogeochemical processes can...... be coupled by electric currents in nature. Here we provide evidence that electric currents running through defaunated sediment couple oxygen consumption at the sediment surface to oxidation of hydrogen sulphide and organic carbon deep within the sediment. Altering the oxygen concentration in the sea water...... in the sediment was driven by electrons conducted from the anoxic zone. A distinct pH peak in the oxic zone could be explained by electrochemical oxygen reduction, but not by any conventional sets of aerobic sediment processes. We suggest that the electric current was conducted by bacterial nanowires combined...

  11. Succession of cable bacteria and electric currents in marine sediment

    DEFF Research Database (Denmark)

    Schauer, Regina; Risgaard-Petersen, Nils; Kjeldsen, Kasper Urup

    2014-01-01

    conductivity, we followed a population for 53 days after exposing sulphidic sediment with initially no detectable filaments to oxygen. After 10 days, cable bacteria and electric currents were established throughout the top 15[thinsp]mm of the sediment, and after 21 days the filament density peaked with a total......][mu]m, with a general increase over time and depth, and yet they shared 16S rRNA sequence identity of >98%. Comparison of the increase in biovolume and electric current density suggested high cellular growth efficiency. While the vertical expansion of filaments continued over time and reached 30[thinsp]mm, the electric...... current density and biomass declined after 13 and 21 days, respectively. This might reflect a breakdown of short filaments as their solid sulphide sources became depleted in the top layers of the anoxic zone. In conclusion, cable bacteria combine rapid and efficient growth with oriented movement...

  12. Current and potential uses of bioactive molecules from marine processing waste.

    Science.gov (United States)

    Suleria, Hafiz Ansar Rasul; Masci, Paul; Gobe, Glenda; Osborne, Simone

    2016-03-15

    Food industries produce huge amounts of processing waste that are often disposed of incurring expenses and impacting upon the environment. For these and other reasons, food processing waste streams, in particular marine processing waste streams, are gaining popularity amongst pharmaceutical, cosmetic and nutraceutical industries as sources of bioactive molecules. In the last 30 years, there has been a gradual increase in processed marine products with a concomitant increase in waste streams that include viscera, heads, skins, fins, bones, trimmings and shellfish waste. In 2010, these waste streams equated to approximately 24 million tonnes of mostly unused resources. Marine processing waste streams not only represent an abundant resource, they are also enriched with structurally diverse molecules that possess a broad panel of bioactivities including anti-oxidant, anti-coagulant, anti-thrombotic, anti-cancer and immune-stimulatory activities. Retrieval and characterisation of bioactive molecules from marine processing waste also contributes valuable information to the vast field of marine natural product discovery. This review summarises the current use of bioactive molecules from marine processing waste in different products and industries. Moreover, this review summarises new research into processing waste streams and the potential for adoption by industries in the creation of new products containing marine processing waste bioactives. © 2015 Society of Chemical Industry.

  13. Piston surface heat transfer during combustion in large marine diesel engines

    DEFF Research Database (Denmark)

    Jensen, Michael Vincent; Walther, Jens Honore

    2010-01-01

    In the design process of large marine diesel engines information on the maximum heat load on the piston surface experienced during the engine cycle is an important parameter. The peak heat load occurs during combustion when hot combustion products impinge on the piston surface. Although the maximum...... heat load is only present for a short time of the total engine cycle, it is a severe thermal load on the piston surface. At the same time, cooling of the piston crown is generally more complicated than cooling of the other components of the combustion chamber. This can occasionally cause problems...... with burning off piston surface material. In this work the peak heat load on the piston surface of large marine diesel engines during combustion was investigated. Measurements of the instantaneous surface temperature and surface heat flux on pistons in large marine engines are difficult due to expensive...

  14. Submerged electricity generation plane with marine current-driven motors

    Science.gov (United States)

    Dehlsen, James G.P.; Dehlsen, James B.; Fleming, Alexander

    2014-07-01

    An underwater apparatus for generating electric power from ocean currents and deep water tides. A submersible platform including two or more power pods, each having a rotor with fixed-pitch blades, with drivetrains housed in pressure vessels that are connected by a transverse structure providing buoyancy, which can be a wing depressor, hydrofoil, truss, or faired tube. The platform is connected to anchors on the seafloor by forward mooring lines and a vertical mooring line that restricts the depth of the device in the water column. The platform operates using passive, rather than active, depth control. The wing depressor, along with rotor drag loads, ensures the platform seeks the desired operational current velocity. The rotors are directly coupled to a hydraulic pump that drives at least one constant-speed hydraulic-motor generator set and enables hydraulic braking. A fluidic bearing decouples non-torque rotor loads to the main shaft driving the hydraulic pumps.

  15. Investigation of electrically exploded large area foil for current switching

    International Nuclear Information System (INIS)

    Chernyshev, V.K.; Boyko, A.M.; Kostyukov, V.N.; Kuzyaev, A.I.; Kulagin, A.A.; Mamyshev, V.I.; Mezhevov, A.B.; Nechaev, A.I.; Petrukhin, A.A.; Protasov, M.S.; Shevtsov, V.I.; Yakubov, V.B.

    1990-01-01

    The possibility of microsecond ∼40 MA current switching from EMG into a quasiconstant inductive load by an electrically exploded foil is investigated. The copper foil of large area, S ∼ 10 4 cm 2 , was placed between thin-walled insulators into a coaxial transmission line (TL). This paper shows a conceptual device scheme. To feed a foil opening switch (FOS), a disc explosive magnetic generator (DEMG) with 20 μs current rise time was employed. An inductive coaxial load was connected to a FOS at a moment, that was close to the foil vaporization start by means of an axisymmetric explosive current commutator (ECC)

  16. Seasonal dependence of large-scale Birkeland currents

    International Nuclear Information System (INIS)

    Fujii, R.; Iijima, T.; Potemra, T.A.; Sugiura, M.

    1981-01-01

    The seasonal dependence of large-scale Birkeland currents has been determined from the analysis of vector magnetic field data acquired by the TRIAD satellite in the northern hemisphere. Statistical characteristics of single sheet (i.e., net currents) and double sheet Birkeland currents were determined from 555 TRIAD passes during the summer, and 408 passes during the winter (more complicated multiple-sheet current systems were not included in this study). The average K/sub p/ value for the summer events is 1.9 and for the winter events is 2.0. The principal results include the following: (1) The single sheet Birkeland currents are statistically observed more often than the double sheet currents in the dayside of the auroral zone during any season. The single sheet currents are also observed more often in the summer than in the winter (as much as 2 to 3 times as often depending upon the MLT sector). (2) The intensities of the single and double sheet Birkeland currents on the dayside, from approximately 1000 MLT to 1800 MLT, are larger during the summer (in comparison to winter) by a factor of about 2. (3) The intensities of the double sheet Birkeland currents in the nightside (the dominant system in this local time) do not show a significant difference from summer to winter. (4) The single and double sheet currents in the dayside (between 0600 and 1800 MLT) appear at higher latitudes (by about 1 0 to 3 0 ) during the summer in comparison to the winter. These characterisctis suggest that the Birkeland current intensities are controlled by the ionosphere conductivity in the polar region. The greater occurrence of single sheet Birkeland currents during the summertime supports the suggestion that these currents close via the polar cap when the conductivity there is sufficiently high to permit it

  17. Unusually large tsunamis frequent a currently creeping part of the Aleutian megathrust

    Science.gov (United States)

    Witter, Robert C.; Carver, G.A.; Briggs, Richard; Gelfenbaum, Guy R.; Koehler, R.D.; La Selle, SeanPaul M.; Bender, Adrian M.; Engelhart, S.E.; Hemphill-Haley, E.; Hill, Troy D.

    2016-01-01

    Current models used to assess earthquake and tsunami hazards are inadequate where creep dominates a subduction megathrust. Here we report geological evidence for large tsunamis, occurring on average every 300–340 years, near the source areas of the 1946 and 1957 Aleutian tsunamis. These areas bookend a postulated seismic gap over 200 km long where modern geodetic measurements indicate that the megathrust is currently creeping. At Sedanka Island, evidence for large tsunamis includes six sand sheets that blanket a lowland facing the Pacific Ocean, rise to 15 m above mean sea level, contain marine diatoms, cap terraces, adjoin evidence for scour, and date from the past 1700 years. The youngest sheet, and modern drift logs found as far as 800 m inland and >18 m elevation, likely record the 1957 tsunami. Modern creep on the megathrust coexists with previously unrecognized tsunami sources along this part of the Aleutian Subduction Zone.

  18. Currents and radiation from the large D black hole membrane

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, Sayantani; Mandal, Anup Kumar [Department of Physics, Indian Institute of Technology Kanpur,Kalyanpur, Kanpur, Uttar Pradesh 208016 (India); Mandlik, Mangesh [Department of Theoretical Physics, Tata Institute of Fundamental Research,1, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005 (India); Mehta, Umang [Department of Physics, Indian Institute of Technology Bombay,JVLR, Mumbai, Maharashtra 400076 (India); Minwalla, Shiraz [Department of Theoretical Physics, Tata Institute of Fundamental Research,1, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005 (India); Sharma, Utkarsh [Department of Electrical Engineering, Indian Institute of Technology Bombay,JVLR, Mumbai, Maharashtra 400076 (India); Thakur, Somyadip [Department of Theoretical Physics, Tata Institute of Fundamental Research,1, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 400005 (India)

    2017-05-18

    It has recently been demonstrated that black hole dynamics in a large number of dimensions D reduces to the dynamics of a codimension one membrane propagating in flat space. In this paper we define a stress tensor and charge current on this membrane and explicitly determine these currents at low orders in the expansion in (1/D). We demonstrate that dynamical membrane equations of motion derived in earlier work are simply conservation equations for our stress tensor and charge current. Through the paper we focus on solutions of the membrane equations which vary on a time scale of order unity. Even though the charge current and stress tensor are not parametrically small in such solutions, we show that the radiation sourced by the corresponding membrane currents is generically of order (1/(D{sup D})). In this regime it follows that the ‘near horizon’ membrane degrees of freedom are decoupled from asymptotic flat space at every perturbative order in the (1/D) expansion. We also define an entropy current on the membrane and use the Hawking area theorem to demonstrate that the divergence of the entropy current is point wise non negative. We view this result as a local form of the second law of thermodynamics for membrane motion.

  19. Stability of large orbit, high-current particle rings

    International Nuclear Information System (INIS)

    Lovelace, R.V.E.

    1994-01-01

    A review is made of theory of the low-frequency stability of large orbit, high-current particle rings which continue to be of interest for compact fusion systems. The precession mode was the first mode predicted by Furth and observed by Christofilos to be unstable under certain conditions. Subsequently, many detailed studies have been made of the stability of particle rings- different modes, different ring geometries, systems with/without a toroidal B field, and sytems with/without a current carrying plasma component. The possibly dangerous modes are still thought to include the precession mode, the tilting mode, and the low order kink modes. copyright American Institute of Physics

  20. A Numerical Modeling for Study Marine Current in the Manado Bay, North Sulawesi

    Directory of Open Access Journals (Sweden)

    Parabelem Tinno Dolf Rompas

    2018-02-01

    Full Text Available This study is investigating about marine currents provided electrical energy through the numerical model. The objective of this study is to know the available power distributions in the Manado Bay, North Sulawesi, Indonesia. The Manado Bay was width 2200 m with 79 m of depth. In computation, we are made grids in x and y horizontal were 7 m respectively, also for z vertical of four layers. The results shown that the available power distributions in the Manado Bay at 0.1 Sv were 0.00-20.00 kW/m2 when low tide currents and when high tide currents were 0.00-105 kW/m2. The values will enable for marine currents power plant in the Manado Bay to future.

  1. Large-Scale Trade in Legally Protected Marine Mollusc Shells from Java and Bali, Indonesia.

    Directory of Open Access Journals (Sweden)

    Vincent Nijman

    Full Text Available Tropical marine molluscs are traded globally. Larger species with slow life histories are under threat from over-exploitation. We report on the trade in protected marine mollusc shells in and from Java and Bali, Indonesia. Since 1987 twelve species of marine molluscs are protected under Indonesian law to shield them from overexploitation. Despite this protection they are traded openly in large volumes.We collected data on species composition, origins, volumes and prices at two large open markets (2013, collected data from wholesale traders (2013, and compiled seizure data by the Indonesian authorities (2008-2013. All twelve protected species were observed in trade. Smaller species were traded for 32,000 shells valued at USD500,000, chambered nautilus (Nautilus pompilius (>3,000 shells, USD60,000 and giant clams (Tridacna spp. (>2,000 shells, USD45,000 were traded in largest volumes. Two-thirds of this trade was destined for international markets, including in the USA and Asia-Pacific region.We demonstrated that the trade in protected marine mollusc shells in Indonesia is not controlled nor monitored, that it involves large volumes, and that networks of shell collectors, traders, middlemen and exporters span the globe. This impedes protection of these species on the ground and calls into question the effectiveness of protected species management in Indonesia; solutions are unlikely to be found only in Indonesia and must involve the cooperation of importing countries.

  2. Potential consequences of climate change for primary production and fish production in large marine ecosystems.

    Science.gov (United States)

    Blanchard, Julia L; Jennings, Simon; Holmes, Robert; Harle, James; Merino, Gorka; Allen, J Icarus; Holt, Jason; Dulvy, Nicholas K; Barange, Manuel

    2012-11-05

    Existing methods to predict the effects of climate change on the biomass and production of marine communities are predicated on modelling the interactions and dynamics of individual species, a very challenging approach when interactions and distributions are changing and little is known about the ecological mechanisms driving the responses of many species. An informative parallel approach is to develop size-based methods. These capture the properties of food webs that describe energy flux and production at a particular size, independent of species' ecology. We couple a physical-biogeochemical model with a dynamic, size-based food web model to predict the future effects of climate change on fish biomass and production in 11 large regional shelf seas, with and without fishing effects. Changes in potential fish production are shown to most strongly mirror changes in phytoplankton production. We project declines of 30-60% in potential fish production across some important areas of tropical shelf and upwelling seas, most notably in the eastern Indo-Pacific, the northern Humboldt and the North Canary Current. Conversely, in some areas of the high latitude shelf seas, the production of pelagic predators was projected to increase by 28-89%.

  3. An Improved Current-Doubler Rectifier for the Marine Controlled Source Electromagnetic Transmitter

    Directory of Open Access Journals (Sweden)

    Hongxi Song

    2018-01-01

    Full Text Available High power marine controlled source electromagnetic transmitters have gained interest with applications in marine geological survey and mineral resources exploration. The direct current to direct current (DC-DC converter that is typically used in marine transmitters has some issues, as the insulated-gate bipolar transistor (IGBT tube cannot achieve zero-voltage switching (ZVS. In particular, lagging-leg switching cannot easily achieve ZVS. The conversion efficiency of the heat converter requires improvement. This paper proposes an improved current-doubler rectifier for the marine controlled source electromagnetic transmitter (ICDR-MCSET. Resonant inductance is increased and a blocking capacitor is added to the converter (DC-DC circuit, where the converter can achieve ZVS in a wide load range. This results in the effective decrease of the heating temperature and the improvement of transformation efficiency. Saber software simulation and a 20 KW electromagnetic transmitter are used to verify the results, which show that the method is feasible and effective.

  4. Current developments in marine microbiology: high-pressure biotechnology and the genetic engineering of piezophiles.

    Science.gov (United States)

    Zhang, Yu; Li, Xuegong; Bartlett, Douglas H; Xiao, Xiang

    2015-06-01

    A key aspect of marine environments is elevated pressure; for example, ∼70% of the ocean is at a pressure of at least 38MPa. Many types of Bacteria and Archaea reside under these high pressures, which drive oceanic biogeochemical cycles and catalyze reactions among rocks, sediments and fluids. Most marine prokaryotes are classified as piezotolerant or as (obligate)-piezophiles with few cultivated relatives. The biochemistry and physiology of these organisms are largely unknown. Recently, high-pressure cultivation technology has been combined with omics and DNA recombination methodologies to examine the physiology of piezophilic marine microorganisms. We are now beginning to understand the adaptive mechanisms of these organisms, along with their ecological functions and evolutionary processes. This knowledge is leading to the further development of high-pressure-based biotechnology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Polybrominated diphenyl ethers in marine ecosystems of the American continents: foresight from current knowledge.

    Science.gov (United States)

    Shaw, Susan D; Kannan, Kurunthachalam

    2009-01-01

    Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta- and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.

  6. Large-scale climatic anomalies affect marine predator foraging behaviour and demography

    Science.gov (United States)

    Bost, Charles A.; Cotté, Cedric; Terray, Pascal; Barbraud, Christophe; Bon, Cécile; Delord, Karine; Gimenez, Olivier; Handrich, Yves; Naito, Yasuhiko; Guinet, Christophe; Weimerskirch, Henri

    2015-10-01

    Determining the links between the behavioural and population responses of wild species to environmental variations is critical for understanding the impact of climate variability on ecosystems. Using long-term data sets, we show how large-scale climatic anomalies in the Southern Hemisphere affect the foraging behaviour and population dynamics of a key marine predator, the king penguin. When large-scale subtropical dipole events occur simultaneously in both subtropical Southern Indian and Atlantic Oceans, they generate tropical anomalies that shift the foraging zone southward. Consequently the distances that penguins foraged from the colony and their feeding depths increased and the population size decreased. This represents an example of a robust and fast impact of large-scale climatic anomalies affecting a marine predator through changes in its at-sea behaviour and demography, despite lack of information on prey availability. Our results highlight a possible behavioural mechanism through which climate variability may affect population processes.

  7. Energy Yield Potential Estimation Using Marine Current Turbine Simulations for the Bosphorus

    DEFF Research Database (Denmark)

    Yazicioglu, Hasan; Tunc, K. M. Murat; Ozbek, Muammer

    2017-01-01

    . The differences in elevation and salinity ratios between these two seas cause strong underwater currents. Depending on the morphology of the canal the speed of the flow varies and at some specific locations the energy intensity reaches to sufficient levels where electricity generation by marine current turbines...... becomes economically feasible. In this study, several simulations are performed for a 10 MW marine turbine farm/ cluster whose location is selected by taking into account several factors such as the canal morphology, current speed and passage of vessels. 360 different simulations are performed for 15...... within the selected region, the analyses are performed for three different flow speeds corresponding to 10 % increase and decrease in the average value. For each simulation the annual energy yield and cluster efficiency are calculated....

  8. Large-Scale Trade in Legally Protected Marine Mollusc Shells from Java and Bali, Indonesia

    Science.gov (United States)

    Nijman, Vincent; Spaan, Denise; Nekaris, K. Anne-Isola

    2015-01-01

    Background Tropical marine molluscs are traded globally. Larger species with slow life histories are under threat from over-exploitation. We report on the trade in protected marine mollusc shells in and from Java and Bali, Indonesia. Since 1987 twelve species of marine molluscs are protected under Indonesian law to shield them from overexploitation. Despite this protection they are traded openly in large volumes. Methodology/Principal Findings We collected data on species composition, origins, volumes and prices at two large open markets (2013), collected data from wholesale traders (2013), and compiled seizure data by the Indonesian authorities (2008–2013). All twelve protected species were observed in trade. Smaller species were traded for trade involves networks stretching hundreds of kilometres throughout Indonesia. Wholesale traders offer protected marine mollusc shells for the export market by the container or by the metric ton. Data from 20 confiscated shipments show an on-going trade in these molluscs. Over 42,000 shells were seized over a 5-year period, with a retail value of USD700,000 within Indonesia; horned helmet (Cassis cornuta) (>32,000 shells valued at USD500,000), chambered nautilus (Nautilus pompilius) (>3,000 shells, USD60,000) and giant clams (Tridacna spp.) (>2,000 shells, USD45,000) were traded in largest volumes. Two-thirds of this trade was destined for international markets, including in the USA and Asia-Pacific region. Conclusions/Significance We demonstrated that the trade in protected marine mollusc shells in Indonesia is not controlled nor monitored, that it involves large volumes, and that networks of shell collectors, traders, middlemen and exporters span the globe. This impedes protection of these species on the ground and calls into question the effectiveness of protected species management in Indonesia; solutions are unlikely to be found only in Indonesia and must involve the cooperation of importing countries. PMID:26717021

  9. Large-Scale Trade in Legally Protected Marine Mollusc Shells from Java and Bali, Indonesia.

    Science.gov (United States)

    Nijman, Vincent; Spaan, Denise; Nekaris, K Anne-Isola

    2015-01-01

    Tropical marine molluscs are traded globally. Larger species with slow life histories are under threat from over-exploitation. We report on the trade in protected marine mollusc shells in and from Java and Bali, Indonesia. Since 1987 twelve species of marine molluscs are protected under Indonesian law to shield them from overexploitation. Despite this protection they are traded openly in large volumes. We collected data on species composition, origins, volumes and prices at two large open markets (2013), collected data from wholesale traders (2013), and compiled seizure data by the Indonesian authorities (2008-2013). All twelve protected species were observed in trade. Smaller species were traded for Java and Bali, but the trade involves networks stretching hundreds of kilometres throughout Indonesia. Wholesale traders offer protected marine mollusc shells for the export market by the container or by the metric ton. Data from 20 confiscated shipments show an on-going trade in these molluscs. Over 42,000 shells were seized over a 5-year period, with a retail value of USD700,000 within Indonesia; horned helmet (Cassis cornuta) (>32,000 shells valued at USD500,000), chambered nautilus (Nautilus pompilius) (>3,000 shells, USD60,000) and giant clams (Tridacna spp.) (>2,000 shells, USD45,000) were traded in largest volumes. Two-thirds of this trade was destined for international markets, including in the USA and Asia-Pacific region. We demonstrated that the trade in protected marine mollusc shells in Indonesia is not controlled nor monitored, that it involves large volumes, and that networks of shell collectors, traders, middlemen and exporters span the globe. This impedes protection of these species on the ground and calls into question the effectiveness of protected species management in Indonesia; solutions are unlikely to be found only in Indonesia and must involve the cooperation of importing countries.

  10. Large Marine Ecosystems and coastal water archetypes implemented in LCIA methods for marine eutrophication and metals ecotoxicity

    DEFF Research Database (Denmark)

    Cosme, Nuno Miguel Dias; Dong, Yan; Hauschild, Michael Zwicky

    LMEs expressing the system’s flushing through local hydrodynamics is required for the parameterisation of the FF term to estimate the loss of N or metals from the LME through advection. The RT was found in literature for 36% of the LMEs, whereas 4 archetypes were built for the remaining, for which...... no data was found (47%) or to settle high variability of found sources (17%). The 4 archetypes were defined by the exposure to currents and regional marine circulation, depth and profile of the continental shelf, and stratification. Archetype 1 (high dynamics and exposure) with estimated RT=3 months......, Archetype 2 (medium dynamics and exposure) with RT=2 yr, Archetype 3 (low dynamics) with RT=25 yr, and Archetype 4 (very low dynamics, embayed, often stratified) with RT=90 yr. It is assumed that the system dynamics is determining the RT of both N and metals in the photic zone in each LME. The LME...

  11. Current status of large-scale cryogenic gravitational wave telescope

    International Nuclear Information System (INIS)

    Kuroda, K; Ohashi, M; Miyoki, S; Uchiyama, T; Ishitsuka, H; Yamamoto, K; Kasahara, K; Fujimoto, M-K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Nagano, S; Tsunesada, Y; Zhu, Zong-Hong; Shintomi, T; Yamamoto, A; Suzuki, T; Saito, Y; Haruyama, T; Sato, N; Higashi, Y; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Aso, Y; Ueda, K-I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Tagoshi, H; Nakamura, T; Sasaki, M; Tanaka, T; Oohara, K; Takahashi, H; Miyakawa, O; Tobar, M E

    2003-01-01

    The large-scale cryogenic gravitational wave telescope (LCGT) project is the proposed advancement of TAMA, which will be able to detect the coalescences of binary neutron stars occurring in our galaxy. LCGT intends to detect the coalescence events within about 240 Mpc, the rate of which is expected to be from 0.1 to several events in a year. LCGT has Fabry-Perot cavities of 3 km baseline and the mirrors are cooled down to a cryogenic temperature of 20 K. It is planned to be built in the underground of Kamioka mine. This paper overviews the revision of the design and the current status of the R and D

  12. A high-speed transmission method for large-scale marine seismic prospecting systems

    International Nuclear Information System (INIS)

    KeZhu, Song; Ping, Cao; JunFeng, Yang; FuMing, Ruan

    2012-01-01

    A marine seismic prospecting system is a kind of data acquisition and transmission system with large-scale coverage and synchronous multi-node acquisition. In this kind of system, data transmission is a fundamental and difficult technique. In this paper, a high-speed data-transmission method is proposed, its implications and limitations are discussed, and conclusions are drawn. The method we propose has obvious advantages over traditional techniques with respect to long-distance operation, high speed, and real-time transmission. A marine seismic system with four streamers, each 6000 m long and capable of supporting up to 1920 channels, was designed and built based on this method. The effective transmission baud rate of this system was found to reach up to 240 Mbps, while the minimum sampling interval time was as short as 0.25 ms. This system was found to achieve a good synchronization: 83 ns. Laboratory and in situ experiments showed that this marine-prospecting system could work correctly and robustly, which verifies the feasibility and validity of the method proposed in this paper. In addition to the marine seismic applications, this method can also be used in land seismic applications and certain other transmission applications such as environmental or engineering monitoring systems. (paper)

  13. A high-speed transmission method for large-scale marine seismic prospecting systems

    Science.gov (United States)

    KeZhu, Song; Ping, Cao; JunFeng, Yang; FuMing, Ruan

    2012-12-01

    A marine seismic prospecting system is a kind of data acquisition and transmission system with large-scale coverage and synchronous multi-node acquisition. In this kind of system, data transmission is a fundamental and difficult technique. In this paper, a high-speed data-transmission method is proposed, its implications and limitations are discussed, and conclusions are drawn. The method we propose has obvious advantages over traditional techniques with respect to long-distance operation, high speed, and real-time transmission. A marine seismic system with four streamers, each 6000 m long and capable of supporting up to 1920 channels, was designed and built based on this method. The effective transmission baud rate of this system was found to reach up to 240 Mbps, while the minimum sampling interval time was as short as 0.25 ms. This system was found to achieve a good synchronization: 83 ns. Laboratory and in situ experiments showed that this marine-prospecting system could work correctly and robustly, which verifies the feasibility and validity of the method proposed in this paper. In addition to the marine seismic applications, this method can also be used in land seismic applications and certain other transmission applications such as environmental or engineering monitoring systems.

  14. HORIZONTAL AXIS MARINE CURRENT TURBINE DESIGN FOR WIND-ELECTRIC HYBRID SAILING BOAT

    OpenAIRE

    Ekinci, Serkan; Alvar, Mustafa

    2017-01-01

    In recent decades, the number of theoretical studies and applications on electric power production from renewable sources such as wind, solar, sea and tidal flows, has been increasing rapidly. Marine Current Turbines (MCTs), among the power turbines, produce power from alternating flows and are a means of power production even at lower flow rates in oceans and seas. In this study, while maintaining functional requirements, an initial and detailed design (mechanic and hydrodynamic), of an M...

  15. Current Status and Future Prospects of Marine Natural Products (MNPs) as Antimicrobials.

    Science.gov (United States)

    Choudhary, Alka; Naughton, Lynn M; Montánchez, Itxaso; Dobson, Alan D W; Rai, Dilip K

    2017-08-28

    The marine environment is a rich source of chemically diverse, biologically active natural products, and serves as an invaluable resource in the ongoing search for novel antimicrobial compounds. Recent advances in extraction and isolation techniques, and in state-of-the-art technologies involved in organic synthesis and chemical structure elucidation, have accelerated the numbers of antimicrobial molecules originating from the ocean moving into clinical trials. The chemical diversity associated with these marine-derived molecules is immense, varying from simple linear peptides and fatty acids to complex alkaloids, terpenes and polyketides, etc. Such an array of structurally distinct molecules performs functionally diverse biological activities against many pathogenic bacteria and fungi, making marine-derived natural products valuable commodities, particularly in the current age of antimicrobial resistance. In this review, we have highlighted several marine-derived natural products (and their synthetic derivatives), which have gained recognition as effective antimicrobial agents over the past five years (2012-2017). These natural products have been categorized based on their chemical structures and the structure-activity mediated relationships of some of these bioactive molecules have been discussed. Finally, we have provided an insight into how genome mining efforts are likely to expedite the discovery of novel antimicrobial compounds.

  16. Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure

    Science.gov (United States)

    Adams, Josh; Kelsey, Emily C.; Felis, Jonathan J.; Pereksta, David M.

    2016-10-27

    With growing climate change concerns and energy constraints, there is an increasing need for renewable energy sources within the United States and globally. Looking forward, offshore wind-energy infrastructure (OWEI) has the potential to produce a significant proportion of the power needed to reach our Nation’s renewable energy goal. Offshore wind-energy sites can capitalize open areas within Federal waters that have persistent, high winds with large energy production potential. Although there are few locations in the California Current System (CCS) where it would be acceptable to build pile-mounted wind turbines in waters less than 50 m deep, the development of technology able to support deep-water OWEI (>200 m depth) could enable wind-energy production in the CCS. As with all human-use of the marine environment, understanding the potential impacts of wind-energy infrastructure on the marine ecosystem is an integral part of offshore wind-energy research and planning. Herein, we present a comprehensive database to quantify marine bird vulnerability to potential OWEI in the CCS (see https://doi.org/10.5066/F79C6VJ0). These data were used to quantify marine bird vulnerabilities at the population level. For 81 marine bird species present in the CCS, we created three vulnerability indices: Population Vulnerability, Collision Vulnerability, and Displacement Vulnerability. Population Vulnerability was used as a scaling factor to generate two comprehensive indicies: Population Collision Vulnerability (PCV) and Population Displacement Vulnerability (PDV). Within the CCS, pelicans, terns (Forster’s [Sterna forsteri], Caspian [Hydroprogne caspia], Elegant [Thalasseus elegans], and Least Tern [Sternula antillarum]), gulls (Western [Larus occidentalis] and Bonaparte’s Gull [Chroicocephalus philadelphia]), South Polar Skua (Stercorarius maccormicki), and Brandt’s Cormorant (Phalacrocorax penicillatus) had the greatest PCV scores. Brown Pelican (Pelicanus occidentalis

  17. MATHEMATICAL MODELING OF THE ELECTRIC CURRENT GENERATION IN A MICROBIAL FUEL CELL INOCULATED WITH MARINE SEDIMENT

    Directory of Open Access Journals (Sweden)

    J. T. Teleken

    Full Text Available Abstract Microbial fuel cells (MFC are electrochemical devices that utilize the ability of some microorganisms to oxidize organic matter and transfer electrons resulting from their metabolism to an insoluble acceptor. The goal of the present study was to model the kinetics of electrical current generation from an MFC inoculated with marine sediment. For this purpose, a differential equation system was used, including the Nernst-Monod relationship and Ohm's Law, to describe the microbial metabolism and the mechanism of extracellular electron transfer (EET, respectively. The experimental data obtained by cyclic voltammetry analysis were properly described by the model. It was concluded that marine microorganisms preferably use a direct mechanism of EET by means of nanowires to establish the electrochemical contact with the anode. The mathematical modeling could help understand MFC operation and, consequently, contribute to improving power generation from this source.

  18. Use of Biosensors as Alternatives to Current Regulatory Methods for Marine Biotoxins

    Directory of Open Access Journals (Sweden)

    Luis M. Botana

    2009-11-01

    Full Text Available Marine toxins are currently monitored by means of a bioassay that requires the use of many mice, which poses a technical and ethical problem in many countries. With the exception of domoic acid, there is a legal requirement for the presence of other toxins (yessotoxin, saxitoxin and analogs, okadaic acid and analogs, pectenotoxins and azaspiracids in seafood to be controlled by bioassay, but other toxins, such as palytoxin, cyclic imines, ciguatera and tetrodotoxin are potentially present in European food and there are no legal requirements or technical approaches available to identify their presence. The need for alternative methods to the bioassay is clearly important, and biosensors have become in recent years a feasible alternative to animal sacrifice. This review will discuss the advantages and disadvantages of using biosensors as alternatives to animal assays for marine toxins, with particular focus on surface plasmon resonance (SPR technology.

  19. An Algorithm for Surface Current Retrieval from X-band Marine Radar Images

    Directory of Open Access Journals (Sweden)

    Chengxi Shen

    2015-06-01

    Full Text Available In this paper, a novel current inversion algorithm from X-band marine radar images is proposed. The routine, for which deep water is assumed, begins with 3-D FFT of the radar image sequence, followed by the extraction of the dispersion shell from the 3-D image spectrum. Next, the dispersion shell is converted to a polar current shell (PCS using a polar coordinate transformation. After removing outliers along each radial direction of the PCS, a robust sinusoidal curve fitting is applied to the data points along each circumferential direction of the PCS. The angle corresponding to the maximum of the estimated sinusoid function is determined to be the current direction, and the amplitude of this sinusoidal function is the current speed. For validation, the algorithm is tested against both simulated radar images and field data collected by a vertically-polarized X-band system and ground-truthed with measurements from an acoustic Doppler current profiler (ADCP. From the field data, it is observed that when the current speed is less than 0.5 m/s, the root mean square differences between the radar-derived and the ADCP-measured current speed and direction are 7.3 cm/s and 32.7°, respectively. The results indicate that the proposed procedure, unlike most existing current inversion schemes, is not susceptible to high current speeds and circumvents the need to consider aliasing. Meanwhile, the relatively low computational cost makes it an excellent choice in practical marine applications.

  20. Properties Variation of Carbon Fiber Reinforced Composite for Marine Current Turbine in Seawater

    Directory of Open Access Journals (Sweden)

    Li Jing

    2016-01-01

    Full Text Available Turbine blade which are generally made of composite is a core device among components of tidal current power generator that converts the flow of tidal current into a turning force. Recent years, damages of composite turbine blades have been reported due to reasons like seawater degradation, lake of strength, manufacture etc. In this paper, water absorption, tensile, bending, longitudinal transverse shearing properties of carbon fiber reinforced plastic (CRP composite which would be applied to fabricate the marine current turbine blade has been investigated. Furthermore, the variations of properties with seawater immersion period were studied. The results indicated that the water absorption increased almost linearly at the beginning of immersion and then became stable. Tensile strength of specimen tended to decrease firstly and then recovered slightly. However, the longitudinal transverse shearing strength showed reverse variation trend comparing to tensile strength. And the bending property of specimens was depressed significantly. The properties variations in seawater shall be referenced to design and fabrication of composite marine current turbine blade.

  1. Ethogram of Immature Green Turtles: Behavioral Strategies for Somatic Growth in Large Marine Herbivores

    Science.gov (United States)

    Okuyama, Junichi; Nakajima, Kana; Noda, Takuji; Kimura, Satoko; Kamihata, Hiroko; Kobayashi, Masato; Arai, Nobuaki; Kagawa, Shiro; Kawabata, Yuuki; Yamada, Hideaki

    2013-01-01

    Animals are assumed to obtain/conserve energy effectively to maximise their fitness, which manifests itself in a variety of behavioral strategies. For marine animals, however, these behavioral strategies are generally unknown due to the lack of high-resolution monitoring techniques in marine habitats. As large marine herbivores, immature green turtles do not need to allocate energy to reproduction but are at risk of shark predation, although it is a rare occurrence. They are therefore assumed to select/use feeding and resting sites that maximise their fitness in terms of somatic growth, while avoiding predation. We investigated fine-scale behavioral patterns (feeding, resting and other behaviors), microhabitat use and time spent on each behavior for eight immature green turtles using data loggers including: depth, global positioning system, head acceleration, speed and video sensors. Immature green turtles at Iriomote Island, Japan, spent an average of 4.8 h feeding on seagrass each day, with two peaks, between 5∶00 and 9∶00, and between 17∶00 and 20∶00. This feeding pattern appeared to be restricted by gut capacity, and thus maximised energy acquisition. Meanwhile, most of the remaining time was spent resting at locations close to feeding grounds, which allowed turtles to conserve energy spent travelling and reduced the duration of periods exposed to predation. These behavioral patterns and time allocations allow immature green turtles to effectively obtain/conserve energy for growth, thus maximising their fitness. PMID:23840367

  2. Ethogram of Immature Green Turtles: Behavioral Strategies for Somatic Growth in Large Marine Herbivores.

    Directory of Open Access Journals (Sweden)

    Junichi Okuyama

    Full Text Available Animals are assumed to obtain/conserve energy effectively to maximise their fitness, which manifests itself in a variety of behavioral strategies. For marine animals, however, these behavioral strategies are generally unknown due to the lack of high-resolution monitoring techniques in marine habitats. As large marine herbivores, immature green turtles do not need to allocate energy to reproduction but are at risk of shark predation, although it is a rare occurrence. They are therefore assumed to select/use feeding and resting sites that maximise their fitness in terms of somatic growth, while avoiding predation. We investigated fine-scale behavioral patterns (feeding, resting and other behaviors, microhabitat use and time spent on each behavior for eight immature green turtles using data loggers including: depth, global positioning system, head acceleration, speed and video sensors. Immature green turtles at Iriomote Island, Japan, spent an average of 4.8 h feeding on seagrass each day, with two peaks, between 5∶00 and 9∶00, and between 17∶00 and 20∶00. This feeding pattern appeared to be restricted by gut capacity, and thus maximised energy acquisition. Meanwhile, most of the remaining time was spent resting at locations close to feeding grounds, which allowed turtles to conserve energy spent travelling and reduced the duration of periods exposed to predation. These behavioral patterns and time allocations allow immature green turtles to effectively obtain/conserve energy for growth, thus maximising their fitness.

  3. HORIZONTAL AXIS MARINE CURRENT TURBINE DESIGN FOR WIND-ELECTRIC HYBRID SAILING BOAT

    Directory of Open Access Journals (Sweden)

    Serkan Ekinci

    2017-01-01

    Full Text Available In recent decades, the number of theoretical studies and applications on electric power production from renewable sources such as wind, solar, sea and tidal flows, has been increasing rapidly. Marine Current Turbines (MCTs, among the power turbines, produce power from alternating flows and are a means of power production even at lower flow rates in oceans and seas. In this study, while maintaining functional requirements, an initial and detailed design (mechanic and hydrodynamic, of an MCT fixed on a sailing boat and at sail which extracts power from the flow around the boat, is undertaken. In the design stages, for analysis and optimization of the marine turbine blade design, the Momentum Blade Element Method is utilized. The Horizontal Axis Marine Turbine (HAMT, determined by the initial and mechanical design, is illustrated with its components included. Computational fluid dynamics (CFD analyses, covering turbine pod geometry at required flow rates and turbine speeds are performed. These analyses are performed very close to real conditions, considering sailing with and without the turbine running (on and off states. The alternator is determined from the results, and the final design which meets the design requirements, is obtained. As a result, a user friendly and innovative turbine design for sail boats, offering more power and efficiency, which is longer lasting compared to solar and wind technologies, that also makes use of renewable sources, such as wind and/or solar, and in addition stores and uses accumulated energy when needed, is proposed.

  4. Effect of Flow Velocity on Corrosion Rate and Corrosion Protection Current of Marine Material

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong Jong [Kunsan National University, Kunsan (Korea, Republic of); Han, Min Su; Jang, Seok Ki; Kim, Seong Jong [Mokpo National Maritime University, Mokpo (Korea, Republic of)

    2015-10-15

    In spite of highly advanced paint coating techniques, corrosion damage of marine metal and alloys increase more and more due to inherent micro-cracks and porosities in coatings formed during the coating process. Furthermore, flowing seawater conditions promote the breakdown of the protective oxide of the materials introducing more oxygen into marine environments, leading to the acceleration of corrosion. Various corrosion protection methods are available to prevent steel from marine corrosion. Cathodic protection is one of the useful corrosion protection methods by which the potential of the corroded metal is intentionally lowered to an immune state having the advantage of providing additional protection barriers to steel exposed to aqueous corrosion or soil corrosion, in addition to the coating. In the present investigation, the effect of flow velocity was examined for the determination of the optimum corrosion protection current density in cathodic protection as well as the corrosion rate of the steel. It is demonstrated from the result that the material corrosion under dynamic flowing conditions seems more prone to corrosion than under static conditions.

  5. Patterns and drivers of fish community assembly in a large marine ecosystem

    DEFF Research Database (Denmark)

    Pécuchet, Lauréne; Törnroos, Anna; Lindegren, Martin

    2016-01-01

    . To determine assembly rules, ecological similarities of co-occurring species are often investigated. This can be evaluated using trait-based indices summarizing the species’ niches in a given community. In order to investigate the underlying processes shaping community assembly in marine ecosystems, we...... investigated the patterns and drivers of fish community composition in the Baltic Sea, a semi-enclosed sea characterized by a pronounced environmental gradient. Our results showed a marked decline in species- and functional richness, largely explained by decreasing salinities. In addition, habitat complexity...

  6. Testing of Bearing Materials for Large Two-stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Klit, Peder; Persson, Sebastian; Vølund, Anders

    2013-01-01

    In large two-stroke marine diesel engines bearings are designed with the intention that these need not be replaced during the life of the engine. The design has shown very good service experiences. The design parameters of the main bearings are, among others, based on the average maximum specific...... load which the bearing should operate under. In general, the frictional loss is less than 1% of the nominal power of the engine but is still a target for optimization. Fatigue mechanisms of bearing lining material are not fully understood and the design limits with regards to minimum oil film thickness...

  7. Testing of bearing materials for large two-stroke marine diesel engines

    DEFF Research Database (Denmark)

    Vølund, Anders; Klit, Peder; Persson, Sebastian

    2017-01-01

    In large two-stroke marine diesel engines, bearings are designed to last the lifetime of the engine. The design has shown very good service experiences. The design parameters of the main bearings are, among others, based on the average maximum specific load which the bearing should operate under....... In general, the frictional loss is less than 1% of the nominal power of the engine but is still a target for optimization. Fatigue mechanisms of bearing lining material are not fully understood and the design limits with regards to minimum oil film thickness, max oil film pressure and oil film pressure...

  8. United States of America. Report 6 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Rice, T.R.

    1967-01-01

    The cycling of radionuclides and effects of radiation in the marine environment are studied at the Radiobiological Laboratory. To gain a more complete understanding of the events following the introduction of radionuclides into the marine environment, we are investigating basic problems in ecology, radiobiology, biochemistry and geochemistry. Emphasis is placed on the cycling of radioactive trace metals through the water, sediment, and biota of the environment and the transmission of these metals through the food web of the sea. Because ionizing radiations from the introduced radionuclides interact with other environmental factors to affect the growth and survival of the biota, we are determining the responses of marine organisms to radiation in various environmental situations. Laboratory facilities consist of a two-storey laboratory, a highlevel radiation building, and a storage building containing a crematory for ashing radioactive organisms. The main building has office and' laboratory space for approximately 16 investigators and supporting staff plus space for visiting investigators. There are now 23 permanent staff members. The main building houses two large salt-water laboratories, three constant temperature rooms and several counting and instrument rooms. Salt water is supplied to the salt-water laboratories, three research laboratories and to the radiation buildings Specialized equipment available to investigators includes an atomic absorption spectrophotometer; differential respirometer; continuous flow, refrigerated centrifuge; 512-channel analyser and low-level detecting equipment; a small animal detector, single-channel analyser equipped with detectors of various sizes, an X-ray machine; and two cobalt-60 irradiators: a 7-curie single-point source used for continuous irradiation and a 1500-curie self-contained source in which marine organisms can be irradiated in flowing sea water. Field equipment is also available. Research activities of the

  9. United States of America. Report 6 [Marine Radioecology. Current Research and Future Scope

    Energy Technology Data Exchange (ETDEWEB)

    Rice, T. R. [Radiobiological Laboratory, Beaufort, NC (United States); others, and

    1967-03-15

    The cycling of radionuclides and effects of radiation in the marine environment are studied at the Radiobiological Laboratory. To gain a more complete understanding of the events following the introduction of radionuclides into the marine environment, we are investigating basic problems in ecology, radiobiology, biochemistry and geochemistry. Emphasis is placed on the cycling of radioactive trace metals through the water, sediment, and biota of the environment and the transmission of these metals through the food web of the sea. Because ionizing radiations from the introduced radionuclides interact with other environmental factors to affect the growth and survival of the biota, we are determining the responses of marine organisms to radiation in various environmental situations. Laboratory facilities consist of a two-storey laboratory, a highlevel radiation building, and a storage building containing a crematory for ashing radioactive organisms. The main building has office and' laboratory space for approximately 16 investigators and supporting staff plus space for visiting investigators. There are now 23 permanent staff members. The main building houses two large salt-water laboratories, three constant temperature rooms and several counting and instrument rooms. Salt water is supplied to the salt-water laboratories, three research laboratories and to the radiation buildings Specialized equipment available to investigators includes an atomic absorption spectrophotometer; differential respirometer; continuous flow, refrigerated centrifuge; 512-channel analyser and low-level detecting equipment; a small animal detector, single-channel analyser equipped with detectors of various sizes, an X-ray machine; and two cobalt-60 irradiators: a 7-curie single-point source used for continuous irradiation and a 1500-curie self-contained source in which marine organisms can be irradiated in flowing sea water. Field equipment is also available. Research activities of the

  10. The ISMAR high frequency coastal radar network: Monitoring surface currents for management of marine resources

    DEFF Research Database (Denmark)

    Carlson, Daniel Frazier

    2015-01-01

    The Institute of Marine Sciences (ISMAR) of the National Research Council of Italy (CNR) established a High Frequency (HF) Coastal Radar Network for the measurement of the velocity of surface currents in coastal seas. The network consists of four HF radar systems located on the coast of the Gargano...... Promontory (Southern Adriatic, Italy). The network has been operational since May 2013 and covers an area of approximately 1700 square kilometers in the Gulf of Manfredonia. Quality Assessment (QA) procedures are applied for the systems deployment and maintenance and Quality Control (QC) procedures...

  11. Marine chemistry, fish / shell-fish surveys, benthic organisms, and marine toxic substances and pollutants data from current meter and other instruments in the Gulf of Mexico from 1993-01-26 to 1994-06-13 (NODC Accession 9500088)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine chemistry, fish / shell-fish surveys, benthic organisms, and marine toxic substances and pollutants data were collected using current meter and other...

  12. Locomotion and the Cost of Hunting in Large, Stealthy Marine Carnivores.

    Science.gov (United States)

    Williams, Terrie M; Fuiman, Lee A; Davis, Randall W

    2015-10-01

    Foraging by large (>25 kg), mammalian carnivores often entails cryptic tactics to surreptitiously locate and overcome highly mobile prey. Many forms of intermittent locomotion from stroke-and-glide maneuvers by marine mammals to sneak-and-pounce behaviors by terrestrial canids, ursids, and felids are involved. While affording proximity to vigilant prey, these tactics are also associated with unique energetic costs and benefits to the predator. We examined the energetic consequences of intermittent locomotion in mammalian carnivores and assessed the role of these behaviors in overall foraging efficiency. Behaviorally-linked, three-axis accelerometers were calibrated to provide instantaneous locomotor behaviors and associated energetic costs for wild adult Weddell seals (Leptonychotes weddellii) diving beneath the Antarctic ice. The results were compared with previously published values for other marine and terrestrial carnivores. We found that intermittent locomotion in the form of extended glides, burst-and-glide swimming, and rollercoaster maneuvers while hunting silverfish (Pleuragramma antarcticum) resulted in a marked energetic savings for the diving seals relative to continuously stroking. The cost of a foraging dive by the seals decreased by 9.2-59.6%, depending on the proportion of time gliding. These energetic savings translated into exceptionally low transport costs during hunting (COTHUNT) for diving mammals. COTHUNT for Weddell seals was nearly six times lower than predicted for large terrestrial carnivores, and demonstrates the importance of turning off the propulsive machinery to facilitate cost-efficient foraging in highly active, air-breathing marine predators. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  13. The Influence of Fuel Sulfur on the Operation of Large Two-Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Faurskov

    The present work focusses on SO3/H2SO4 formation and sulfuric acid (H2SO4) condensation in a large low speed 2-stroke marine diesel engine. SO3 formation is treated theoretically from a formulated multizone engine model described in this work that includes a detailed and validated sulfur reaction...... mechanism. Model results show that for a large marine engine generally about 3 % - 6 % of the fuel sulfur converts to SO3 while the remainder leaves the engine as SO2 from which the SO3 is formed during the expansion stroke. SO3 formation scales with the cylinder pressure and inversely with the engine speed...... as also demonstrated by a number of SO3 experiments described in this work. The experiments are carried out with a heavy duty medium speed 4 stroke diesel engine operating on heavy fuel oil including ≈ 2 wt. % sulfur. SO3 was measured successfully in the exhaust gas with the PENTOL SO3 analyzer...

  14. Development and experiment of a 60 kW horizontal-axis marine current power system

    International Nuclear Information System (INIS)

    Xu, Quan-kun; Liu, Hong-wei; Lin, Yong-gang; Yin, Xiu-xing; Li, Wei; Gu, Ya-jing

    2015-01-01

    A 60 kW horizontal-axis marine current power system is designed, built and tested to provide potentially cost-competitive electrical power for residents in remote islands. This power system mainly consists of a three-bladed marine current turbine, a drive-train system, power electronics and a control console. The turbine blade parameters are reasonably calculated and optimized based on the blade element momentum theory. The hydrodynamic performances of this turbine are predicted over a wide range of operating conditions. An adequate drive-train system is carefully designed to make the marine power system work smoothly and quietly even under harsh marine current conditions. The control console is also developed to facilitate the condition monitoring and generator power and speed regulations for this power system by adequately controlling the onshore power electronics. This power system has been tested under real marine current conditions to thoroughly evaluate its dynamic characteristics and effectiveness. - Highlights: • A 60°kW horizontal-axis marine current power system is designed, built and tested. • Detailed design procedure and experimental data are provided. • Experimental results demonstrate high power convention efficiency of the system

  15. Recent developments at CNR-INSEAN on testing and modelling marine renewable energy systems for waves and currents

    International Nuclear Information System (INIS)

    Salvatore, Francesco; Di Felice, Fabio; Fabbri Luigi

    2015-01-01

    Hydrodynamic testing centers are nowadays challenged by a continuously increasing demand for studies aimed at the development, verification and assessment of marine renewable energy capturing systems. This paper describes the experience matured over the last years at CNR-INSEAN, the marine technology research Institute of the Italian National Research Council. Originally designed for hydrodynamics testing of marine vehicles, the Institute’s experimental facilities like wave and calm water tanks, circulating water channel, now host testing programs on wave energy converters, marine current turbines and hybrid systems, combining devices to extract energy from different marine sources like waves and winds. Selected case studies are described and main findings are discussed in the paper.

  16. Shellfish Fishery Severely Reduces Condition and Survival of Oystercatchers Despite Creation of Large Marine Protected Areas

    Directory of Open Access Journals (Sweden)

    Simon Verhulst

    2004-06-01

    Full Text Available Fisheries and other human activities pose a global threat to the marine environment. Marine protected areas (MPAs are an emerging tool to cope with such threats. In the Dutch Wadden Sea, large MPAs (covering 31% of all intertidal flats have been created to protect shellfish-eating birds and allow recovery of important habitats. Even though shellfish fishing is prohibited in these areas, populations of shellfish-eating birds in the Wadden Sea have declined sharply. The role of shellfish fisheries in these declines is hotly debated, therefore, we investigated the effectiveness of MPAs for protecting oystercatcher (Haematopus ostralegus populations. Shellfish stocks (cockles, Cerastoderma edule were substantially higher in the MPAs, but surprisingly this has not resulted in a redistribution of wintering oystercatchers. Oystercatchers in unprotected areas had less shellfish in their diet and lower condition (a combined measure of mass and haematological parameters, and their estimated mortality was 43% higher. It is likely, therefore, that shellfish fishing explains at least part of the 40% decline in oystercatcher numbers in recent years. Condition and mortality effects were strongest in males, and the population sex ratio was female biased, in agreement with the fact that males rely more on shellfish. The unprotected areas apparently function as an "ecological trap," because oystercatchers did not respond as anticipated to the artificial spatial heterogeneity in food supply. Consequently, the MPAs are effective on a local scale, but not on a global scale. Similar problems are likely to exist in terrestrial ecosystems, and distribution strategies of target species need to be considered when designing terrestrial and marine protected areas if they are to be effective.

  17. Large area dispenser cathode applied to high current linac

    International Nuclear Information System (INIS)

    Yang Anmin; China Academy of Engineering Physics, Mianyang; Wu Dengxue; Liu Chenjun; Xia Liansheng; Wang Wendou; Zhang Kaizhi

    2005-01-01

    The paper introduced a dispenser cathode (411 M) which was 55 mm in diameter. A 200 kV long pulsed power generator with 2 μs flattop based on Marx-PEN and system with heat and voltage insulation were built. A 52 A space charge limited current was gained, when the temperature was 1165 degree C and the filament current was 18 A on the cathode and the voltage of the pulse was 75 kV at the cathode test stand. Experimental results show that the current values are consistent with the numerical simulation. The experiment reveals that the deflated gas will influence the cathode emission ability. (authors)

  18. Scanning tunneling spectroscopy under large current flow through the sample.

    Science.gov (United States)

    Maldonado, A; Guillamón, I; Suderow, H; Vieira, S

    2011-07-01

    We describe a method to make scanning tunneling microscopy/spectroscopy imaging at very low temperatures while driving a constant electric current up to some tens of mA through the sample. It gives a new local probe, which we term current driven scanning tunneling microscopy/spectroscopy. We show spectroscopic and topographic measurements under the application of a current in superconducting Al and NbSe(2) at 100 mK. Perspective of applications of this local imaging method includes local vortex motion experiments, and Doppler shift local density of states studies.

  19. Characteristics of vertical velocity in marine stratocumulus: comparison of large eddy simulations with observations

    International Nuclear Information System (INIS)

    Guo Huan; Liu Yangang; Daum, Peter H; Senum, Gunnar I; Tao, W-K

    2008-01-01

    We simulated a marine stratus deck sampled during the Marine Stratus/Stratocumulus Experiment (MASE) with a three-dimensional large eddy simulation (LES) model at different model resolutions. Various characteristics of the vertical velocity from the model simulations were evaluated against those derived from the corresponding aircraft in situ observations, focusing on standard deviation, skewness, kurtosis, probability density function (PDF), power spectrum, and structure function. Our results show that although the LES model captures reasonably well the lower-order moments (e.g., horizontal averages and standard deviations), it fails to simulate many aspects of the higher-order moments, such as kurtosis, especially near cloud base and cloud top. Further investigations of the PDFs, power spectra, and structure functions reveal that compared to the observations, the model generally underestimates relatively strong variations on small scales. The results also suggest that increasing the model resolutions improves the agreements between the model results and the observations in virtually all of the properties that we examined. Furthermore, the results indicate that a vertical grid size <10 m is necessary for accurately simulating even the standard-deviation profile, posing new challenges to computer resources.

  20. Inexpensive Aerial Photogrammetry for Studies of Whales and Large Marine Animals

    Directory of Open Access Journals (Sweden)

    Stephen M. Dawson

    2017-11-01

    Full Text Available We describe a simple system enabling accurate measurement of swimming marine mammals and other large vertebrates from low-altitude single-frame photogrammetry via inexpensive modifications to a “prosumer” unmanned aerial vehicle (UAV equipped with gimballed micro4/3 camera and 25 mm lens. Image scale is established via an independently powered LIDAR/GPS data-logging system recording altitude and GPS location at 1 Hz. Photogrammetric calibration of the camera and lens allowed distortion parameters to be rigorously accounted for during image analysis, via a custom-programmed Graphical User Interface (GUI running in MATLAB. The datalogger, camera calibration methods and measurement software are adaptable to a wide range of UAV platforms. Mean LIDAR accuracy, measured from 10 bridges 9–39 m above water, was 99.9%. We conducted 136 flights in New Zealand's subantarctic Auckland Islands to measure southern right whales. Mean lengths of 10 individual whales, each photographed between 7 and 15 times, had CVs (SD/mean ranging from 0.5 to 1.8% (mean = 1.2%. Repeated measurements of a floating reference target showed a mean error of c.1%. Our system is relatively inexpensive, easily put together, produces accurate, repeatable measurements from single vertical images, and hence is applicable to a wide range of ecological questions in marine and terrestrial habitats.

  1. Modelling marine sediment biogeochemistry: Current knowledge gaps, challenges, and some methodological advice for advancement

    DEFF Research Database (Denmark)

    Lessin, Gennadi; Artioli, Yuri; Almroth-Rosell, Elin

    2018-01-01

    The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological improveme......The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological...... improvements in quality and quantity of benthic data, it is necessary to ensure that benthic systems are appropriately represented in coupled benthic-pelagic biogeochemical and ecological modelling studies. In this paper we focus on five topical challenges related to various aspects of modelling benthic...... environments: organic matter reactivity, dynamics of benthic-pelagic boundary layer, microphytobenthos, biological transport and small-scale heterogeneity, and impacts of episodic events. We discuss current gaps in their understanding and indicate plausible ways ahead. Further, we propose a three...

  2. Modelling Marine Sediment Biogeochemistry: Current Knowledge Gaps, Challenges, and Some Methodological Advice for Advancement

    Directory of Open Access Journals (Sweden)

    Gennadi Lessin

    2018-02-01

    Full Text Available The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological improvements in quality and quantity of benthic data, it is necessary to ensure that benthic systems are appropriately represented in coupled benthic-pelagic biogeochemical and ecological modelling studies. In this paper we focus on five topical challenges related to various aspects of modelling benthic environments: organic matter reactivity, dynamics of benthic-pelagic boundary layer, microphytobenthos, biological transport and small-scale heterogeneity, and impacts of episodic events. We discuss current gaps in their understanding and indicate plausible ways ahead. Further, we propose a three-pronged approach for the advancement of benthic and benthic-pelagic modelling, essential for improved understanding, management and prediction of the marine environment. This includes: (A development of a traceable and hierarchical framework for benthic-pelagic models, which will facilitate integration among models, reduce risk of bias, and clarify model limitations; (B extended cross-disciplinary approach to promote effective collaboration between modelling and empirical scientists of various backgrounds and better involvement of stakeholders and end-users; (C a common vocabulary for terminology used in benthic modelling, to promote model development and integration, and also to enhance mutual understanding.

  3. A Back-to-Back 2L-3L Grid Integration of a Marine Current Energy Converter

    Directory of Open Access Journals (Sweden)

    Senad Apelfröjd

    2015-01-01

    Full Text Available The paper proposes a back-to-back 2L-3L grid connection topology for a marine current energy converter. A prototype marine current energy converter has been deployed by a research group at Uppsala University. The concept behind the prototype revolves around a fixed pitch vertical axis turbine directly connected to a permanent magnet synchronous generator (PMSG. The proposed grid connection system utilizes a well known and proven two level voltage source converter generator-side combined with a three-level cascaded H-bridge (CHB multilevel converter grid-side. The multilevel converter brings benefits in terms of efficiency, power quality and DC-link utilization. The system is here presented for a single marine current energy converter but can easily be scaled up for clusters of marine current energy converters. Control schemes for both grid-side and generator-side voltage source converters are presented. The start-up, steady state and dynamic performance of the marine current energy converter are investigated and simulation results are presented in this paper.

  4. Megacities and large urban agglomerations in the coastal zone: interactions between atmosphere, land, and marine ecosystems.

    Science.gov (United States)

    von Glasow, Roland; Jickells, Tim D; Baklanov, Alexander; Carmichael, Gregory R; Church, Tom M; Gallardo, Laura; Hughes, Claire; Kanakidou, Maria; Liss, Peter S; Mee, Laurence; Raine, Robin; Ramachandran, Purvaja; Ramesh, R; Sundseth, Kyrre; Tsunogai, Urumu; Uematsu, Mitsuo; Zhu, Tong

    2013-02-01

    Megacities are not only important drivers for socio-economic development but also sources of environmental challenges. Many megacities and large urban agglomerations are located in the coastal zone where land, atmosphere, and ocean meet, posing multiple environmental challenges which we consider here. The atmospheric flow around megacities is complicated by urban heat island effects and topographic flows and sea breezes and influences air pollution and human health. The outflow of polluted air over the ocean perturbs biogeochemical processes. Contaminant inputs can damage downstream coastal zone ecosystem function and resources including fisheries, induce harmful algal blooms and feedback to the atmosphere via marine emissions. The scale of influence of megacities in the coastal zone is hundreds to thousands of kilometers in the atmosphere and tens to hundreds of kilometers in the ocean. We list research needs to further our understanding of coastal megacities with the ultimate aim to improve their environmental management.

  5. Large-Signal Code TESLA: Current Status and Recent Development

    National Research Council Canada - National Science Library

    Chernyavskiy, Igor A; Vlasov, Alexander N; Cooke, Simon J; Abe, David K; Levush, Baruch; Antonsen, Jr., Thomas M; Nguyen, Khanh T

    2008-01-01

    .... One such tool is the large-signal code TESLA, which was successfully applied for the modeling of single-beam and multiple-beam klystron devices at the Naval Research Laboratory and which is now used by number of U.S. companies...

  6. The Occurrence of Paraffin and Other Petroleum Waxes in the Marine Environment: A Review of the Current Legislative Framework and Shipping Operational Practices

    Directory of Open Access Journals (Sweden)

    Giuseppe Suaria

    2018-03-01

    Full Text Available Among the various materials that make up marine debris, lumps of petroleum waxes such as paraffin and microcrystalline wax, are regularly found on beaches worldwide, although not included in the current definition of marine litter. Ingestion by marine organisms is occasionally documented in the scientific literature and mass beaching events are frequently reported along the European coasts, with obvious detrimental consequences to the local communities that have to manage the clean-up and disposal of this substance. According to Annex II of the MARPOL regulation, petroleum waxes are classified as “high viscosity, solidifying, and persistent floating products,” whose discharge at sea of tank-washing residues is strictly regulated, but currently permitted within certain limits. Starting from the description of a large stranding event occurred along the Italian coasts in 2017, we review the existing knowledge and regulatory framework and urge the relevant authorities to address this issue, showing that wax pollution is creating evident damages to the European coastal municipalities. Pending further investigations on the potential hazard that this kind of pollution is posing to marine ecosystems, we suggest a careful and more stringent revision of the policies regulating discharges of these products at sea.

  7. Chemical pollution in the Arctic and Sub-Arctic marine ecosystems: an overview of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Savinova, T N; Gabrielsen, G W; Falk-Petersen, S

    1995-02-01

    This report is part of a research project in the framework of the Norwegian-Russian Environmental Cooperation, which was initiated in 1991 to elucidate the present status of environmental contaminants in the highly sensitive Arctic aquatic ecosystem, with special focus on sea birds. Although these ecosystems are the least polluted areas in the world, they are contaminated. The main pathways of contamination into Arctic and sub-Arctic marine ecosystems are atmospheric transport, ocean currents and rivers and in some areas, dumping and ship accidents. A literature survey reveals: (1) there is a lack of data from several trophic levels, (2) previous data are difficult to compare with recent data because of increased quality requirement, (3) not much has been done to investigate the effects of contaminants on the cellular level, at individual or population levels. 389 refs., 7 figs., 32 tabs.

  8. A methodology for laser diagnostics in large-bore marine two-stroke diesel engines

    International Nuclear Information System (INIS)

    Hult, J; Mayer, S

    2013-01-01

    Large two-stroke diesel engines for marine propulsion offer several challenges to successful implementation of the laser diagnostic techniques applied extensively in smaller automotive engines. For this purpose a fully operational large-bore engine has been modified to allow flexible optical access, through 24 optical ports with clear diameters of 40 mm. By mounting the entire optical set-up directly to the engine, effects of the vigorous vibrations and thermal drifts on alignment can be minimized. Wide-angle observation and illumination, as well as relatively large aperture detection, is made possible through mounting of optical modules and relays inside optical ports. This allows positioning of the last optical element within 10 mm from the cylinder wall. Finally, the implementation on a multi-cylinder engine allows for flexible and independent operation of the optically accessible cylinder for testing purposes. The performance of the integrated optical engine and imaging system developed is demonstrated through laser Mie scattering imaging of fuel jet structures, from which information on liquid penetration and spray angles can be deduced. Double pulse laser-sheet imaging of native in-cylinder structures is also demonstrated, for the purpose of velocimetry. (paper)

  9. Enabling the Integrated Assessment of Large Marine Ecosystems: Informatics to the Forefront of Science-Based Decision Support

    Science.gov (United States)

    Di Stefano, M.; Fox, P. A.; Beaulieu, S. E.; Maffei, A. R.; West, P.; Hare, J. A.

    2012-12-01

    Integrated assessments of large marine ecosystems require the understanding of interactions between environmental, ecological, and socio-economic factors that affect production and utilization of marine natural resources. Assessing the functioning of complex coupled natural-human systems calls for collaboration between natural and social scientists across disciplinary and national boundaries. We are developing a platform to implement and sustain informatics solutions for these applications, providing interoperability among very diverse and heterogeneous data and information sources, as well as multi-disciplinary organizations and people. We have partnered with NOAA NMFS scientists to facilitate the deployment of an integrated ecosystem approach to management in the Northeast U.S. (NES) and California Current Large Marine Ecosystems (LMEs). Our platform will facilitate the collaboration and knowledge sharing among NMFS natural and social scientists, promoting community participation in integrating data, models, and knowledge. Here, we present collaborative software tools developed to aid the production of the Ecosystem Status Report (ESR) for the NES LME. The ESR addresses the D-P-S portion of the DPSIR (Driver-Pressure-State-Impact-Response) management framework: reporting data, indicators, and information products for climate drivers, physical and human (fisheries) pressures, and ecosystem state (primary and secondary production and higher trophic levels). We are developing our tools in open-source software, with the main tool based on a web application capable of providing the ability to work on multiple data types from a variety of sources, providing an effective way to share the source code used to generate data products and associated metadata as well as track workflow provenance to allow in the reproducibility of a data product. Our platform retrieves data, conducts standard analyses, reports data quality and other standardized metadata, provides iterative

  10. Processes that initiate turbidity currents and their influence on turbidites: A marine geology perspective

    Science.gov (United States)

    Piper, David J.W.; Normark, William R.

    2009-01-01

    How the processes that initiate turbidity currents influence turbidite deposition is poorly understood, and many discussions in the literature rely on concepts that are overly simplistic. Marine geological studies provide information on the initiation and flow path of turbidity currents, including their response to gradient. In case studies of late Quaternary turbidites on the eastern Canadian and western U.S. margins, initiation processes are inferred either from real-time data for historical flows or indirectly from the age and contemporary paleogeography, erosional features, and depositional record. Three major types of initiation process are recognized: transformation of failed sediment, hyperpycnal flow from rivers or ice margins, and resuspension of sediment near the shelf edge by oceanographic processes. Many high-concentration flows result from hyperpycnal supply of hyperconcentrated bedload, or liquefaction failure of coarse-grained sediment, and most tend to deposit in slope conduits and on gradients turbidity flows. In most basins, there is a complex feedback between different types of turbidity-current initiation, the transformation of the flows, and the associated slope morphology. As a result, there is no simple relationship between initiating process and type of deposit.

  11. Fast Kicker for High Current Beam Manipulation in Large Aperture

    CERN Document Server

    Gambaryan, V

    2017-01-01

    The pulsed deflecting magnet (kicker) project was worked out in Budker Institute of Nuclear Physics. The kicker design parameters are: impulsive force, 1 mT*m; pulse edge, 5 ns; impulse duration, 200 ns. The unconventional approach is that the plates must be replaced by a set of cylinders. The obtained magnet construction enables the field homogeneity to be controlled by changing current magnitudes in cylinders. Furthermore, we demonstrated the method of field optimization. In addition, measurement technique for the harmonic components was considered and the possibility of control harmonic components value was demonstrated.

  12. Detection of large numbers of novel sequences in the metatranscriptomes of complex marine microbial communities.

    Science.gov (United States)

    Gilbert, Jack A; Field, Dawn; Huang, Ying; Edwards, Rob; Li, Weizhong; Gilna, Paul; Joint, Ian

    2008-08-22

    Sequencing the expressed genetic information of an ecosystem (metatranscriptome) can provide information about the response of organisms to varying environmental conditions. Until recently, metatranscriptomics has been limited to microarray technology and random cloning methodologies. The application of high-throughput sequencing technology is now enabling access to both known and previously unknown transcripts in natural communities. We present a study of a complex marine metatranscriptome obtained from random whole-community mRNA using the GS-FLX Pyrosequencing technology. Eight samples, four DNA and four mRNA, were processed from two time points in a controlled coastal ocean mesocosm study (Bergen, Norway) involving an induced phytoplankton bloom producing a total of 323,161,989 base pairs. Our study confirms the finding of the first published metatranscriptomic studies of marine and soil environments that metatranscriptomics targets highly expressed sequences which are frequently novel. Our alternative methodology increases the range of experimental options available for conducting such studies and is characterized by an exceptional enrichment of mRNA (99.92%) versus ribosomal RNA. Analysis of corresponding metagenomes confirms much higher levels of assembly in the metatranscriptomic samples and a far higher yield of large gene families with >100 members, approximately 91% of which were novel. This study provides further evidence that metatranscriptomic studies of natural microbial communities are not only feasible, but when paired with metagenomic data sets, offer an unprecedented opportunity to explore both structure and function of microbial communities--if we can overcome the challenges of elucidating the functions of so many never-seen-before gene families.

  13. Enriching Metal-Oxidizing Microbes from Marine Sediment on Cathodic Currents

    Science.gov (United States)

    Rowe, A. R.; Nealson, K. H.

    2013-12-01

    The ability of organisms to transfer electrons to and from substrates outside the cell is reshaping the way we look at microbial respiration. While this process, termed extracellular electron transport (EET), has been described in a number of metal reducing organisms, current evidence suggests that this process is widespread in nature and across physiologies. Additionally, it has been speculated that these previously overlooked electrochemical interactions may play an important role in global biogeochemical cycles. Requirements for EET could play a role in why the ';uncultured majority' have so far been resistant to culturing. As such, we are currently developing culturing techniques to target microbes capable of utilizing insoluble electron acceptors utilizing electrochemical techniques. Microbe-electrode interactions are analogous to the reactions that occur between microbes and minerals and may provide an apt way to mimic the environmental conditions (i.e., insoluble electron donor/acceptor at specific redox potentials) required for culturing specialized or EET dependent metabolisms. It has been previously demonstrated that aquatic sediments are capable of utilizing anodes as electron acceptors, thereby generating a current. While, it is known that microbes utilize electrons from a cathode for the reduction of different metals and oxygen in microbial fuel cells, currently there are no reports of environmental enrichments of microbes using cathodes. Replicate microcosms from marine sediments (sampled from Catalina Harbor, California) were incubated with ITO plated glass electrodes. Negative current production at -400mV (vs. Ag/AgCl reference electrodes) potentials was sustained for four weeks. Secondary enrichments were then constructed using the cathode as the primary electron source and a variety of anaerobic terminal electron acceptors--Nitrate, Fe3+, and SO42-. Positive current was maintained in enrichment cultures (compared to abiotic control containing

  14. Three-Dimensional Dynamics of a Flexible Marine Riser Undergoing Large Elastic Deformations

    International Nuclear Information System (INIS)

    Raman-Nair, W.; Baddour, R.E.

    2003-01-01

    The equations of the three dimensional motion of a marine riser undergoing large elastic deformations are formulated using Kane's formalism. The riser is modeled using lumped masses connected by extensional and rotational springs including structural damping. Surface waves are described by Stokes? second-order wave theory. Fluid-structure coupling is achieved by application of the hydrodynamic loads via Morison's equation and added-mass coefficients using the instantaneous relative velocities and accelerations between the fluid field and the riser segments. In the same way, a model for incorporating the effects of vortex-induced lift forces is included. The effect of internal flow is included in the model. The detailed algorithm is presented and the equations are solved using a robust implementation of the Runge-Kutta method provided in MATLAB. The mathematical model and associated algorithm are validated by comparing the steady-state equilibrium configuration of the riser with special cases of an elastic catenary mooring line and large deflection statics of a cantilever beam. The results of sample simulations are presented

  15. Description of the East Brazil Large Marine Ecosystem using a trophic model

    Directory of Open Access Journals (Sweden)

    Kátia M.F. Freire

    2008-09-01

    Full Text Available The objective of this study was to describe the marine ecosystem off northeastern Brazil. A trophic model was constructed for the 1970s using Ecopath with Ecosim. The impact of most of the forty-one functional groups was modest, probably due to the highly reticulated diet matrix. However, seagrass and macroalgae exerted a strong positive impact on manatee and herbivorous reef fishes, respectively. A high negative impact of omnivorous reef fishes on spiny lobsters and of sharks on swordfish was observed. Spiny lobsters and swordfish had the largest biomass changes for the simulation period (1978-2000; tunas, other large pelagics and sharks showed intermediate rates of biomass decline; and a slight increase in biomass was observed for toothed cetaceans, large carnivorous reef fishes, and dolphinfish. Recycling was an important feature of this ecosystem with low phytoplankton-originated primary production. The mean transfer efficiency between trophic levels was 11.4%. The gross efficiency of the fisheries was very low (0.00002, probably due to the low exploitation rate of most of the resources in the 1970s. Basic local information was missing for many groups. When information gaps are filled, this model may serve more credibly for the exploration of fishing policies for this area within an ecosystem approach.

  16. Measuring current emission and work functions of large thermionic cathodes

    International Nuclear Information System (INIS)

    Fortgang, C.M.

    2001-01-01

    As one component of the nations Stockpile Stewardship program, Los Alamos National Laboratory is constructing a 20 MeV, 2 kA (with a 4 kA upgrade capability), 3ps induction linac for doing x-ray radiography of explosive devices. The linac is one leg of a facility called the Dual-Axis Radiography Hydrodynamic Test Facility (DARHT). The electron gun is designed to operate at 3.2 MV. The gun is a Pierce type design and uses a 6.5' cathode for 2 kA operation and an 8' cathode for 4 kA operation. We have constructed a small facility called the Cathode Test Stand (CTS) to investigate engineering and physics issues regarding large thermionic dispenser-cathodes. In particular, we have looked at the issues of temperature uniformity on the cathode surface and cathode quality as measured by its work function. We have done thermal imaging of both 8' and 6.5' cathodes. Here we report on measurements of the cathode work function, both the average value and how it vanes across the face of the cathode.

  17. Cathodic current enhancement via manganese and oxygen related reactions in marine biofilms

    Science.gov (United States)

    Strom, Matthew James

    out the enzymatic catalysis of ORR and supported the catalysis by MnO2. Sustainable redox reactions at the cathode were evaluated by monitoring the cathodic current of biofilm coated stainless steel for a year under different polarization intensities. The results showed that sustainable cathodic reactions were present in marine biofilms but their influence on the cathodic current was negligible until a potential was reached where the ORR could take place. Additionally seasonal variability was observed in the enhanced cathodic current in Delaware Bay biofilms. This was attributed to the seasonal variability of manganese in the water column.

  18. An imbalance fault detection method based on data normalization and EMD for marine current turbines.

    Science.gov (United States)

    Zhang, Milu; Wang, Tianzhen; Tang, Tianhao; Benbouzid, Mohamed; Diallo, Demba

    2017-05-01

    This paper proposes an imbalance fault detection method based on data normalization and Empirical Mode Decomposition (EMD) for variable speed direct-drive Marine Current Turbine (MCT) system. The method is based on the MCT stator current under the condition of wave and turbulence. The goal of this method is to extract blade imbalance fault feature, which is concealed by the supply frequency and the environment noise. First, a Generalized Likelihood Ratio Test (GLRT) detector is developed and the monitoring variable is selected by analyzing the relationship between the variables. Then, the selected monitoring variable is converted into a time series through data normalization, which makes the imbalance fault characteristic frequency into a constant. At the end, the monitoring variable is filtered out by EMD method to eliminate the effect of turbulence. The experiments show that the proposed method is robust against turbulence through comparing the different fault severities and the different turbulence intensities. Comparison with other methods, the experimental results indicate the feasibility and efficacy of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Coastal marine pollution and toxicology : overview of current research and future needs

    International Nuclear Information System (INIS)

    Zubir Din

    1996-01-01

    The contents are marine pollution and toxicology studies at Universiti Sains Malaysia, their facilities, and research projects have been done on this subject. In coastal pollution monitoring and baseline studies, the emphasis have been on determination of levels of trace-metals in the coastal marine environment, in relation to other physico-chemical parameters. The future needs and goals of marine pollution and toxicology studies in Malaysia also discussed

  20. Rescue, rehabilitation, and release of marine mammals: An analysis of current views and practices.

    OpenAIRE

    St. Aubin, David J.; Geraci, Joseph R.; Lounsbury, Valerie J.

    1996-01-01

    Stranded marine mammals have long attracted public attention. Those that wash up dead are, for all their value to science, seldom seen by the public as more than curiosities. Animals that are sick, injured, orphaned or abandoned ignite a different response. Generally, public sentiment supports any effort to rescue, treat and return them to sea. Institutions displaying marine mammals showed an early interest in live-stranded animals as a source of specimens -- in 1948, Marine Studios in...

  1. Coastal marine pollution and toxicology : overview of current research and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Din, Zubir [Science Univ. of Malaysia, Minden, Pulau Pinang (Malaysia). Centre for Marine and Coastal Studies

    1997-12-31

    The contents are marine pollution and toxicology studies at Universiti Sains Malaysia, their facilities, and research projects have been done on this subject. In coastal pollution monitoring and baseline studies, the emphasis have been on determination of levels of trace-metals in the coastal marine environment, in relation to other physico-chemical parameters. The future needs and goals of marine pollution and toxicology studies in Malaysia also discussed.

  2. United States of America. Report 1 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Nakatani, R.E.

    1967-01-01

    Biology Department's aquatic research activities are primarily in freshwater radioecology and not in marine radioecology. The major reason for this lack of marine work is geographical location of our laboratory on the banks of the Columbia River, roughly 300 miles from the ocean. Recently, however, we have completed some preliminary work with 65 Zn metabolism in Anonyx sp., a marine benthic amphipod. Lake some inland laboratories, we have found that limited marine work can be done by hauling in sea water. We have been able to maintain the amphipods in a reasonably healthy state in our laboratory for about four weeks

  3. Numerical Simulation of Condensation of Sulfuric Acid and Water in a Large Two-stroke Marine Diesel Engine

    DEFF Research Database (Denmark)

    Walther, Jens Honore; Karvounis, Nikolas; Pang, Kar Mun

    2016-01-01

    We present results from computational fluid dynamics simulations of the condensation of sulfuric acid (H2SO4) and water (H2O) in a large two-stroke marine diesel engine. The model uses a reduced n-heptane skeletal chemical mechanism coupled with a sulfur subsetto simulate the combustion process...

  4. Investigation of Different Piston Ring Curvatures on Lubricant Transport along Cylinder Liner in Large Two-Stroke Marine Diesel Engines

    DEFF Research Database (Denmark)

    Overgaard, Hannibal Christian; Klit, Peder; Vølund, Anders

    2016-01-01

    A theoretical investigation of the hydrodynamic lubrication of the top compression piston ring in a large two-stroke marine diesel engine is presented. The groove mounted piston ring is driven by the reciprocal motion of the piston. The ring shape follows a circular geometry and the effect...

  5. Investigation of different piston ring curvatures on lubricant transport along cylinder liner in large two-stroke marine diesel engines

    DEFF Research Database (Denmark)

    Overgaard, H; Klit, P; Vølund, A

    2017-01-01

    A theoretical investigation of the hydrodynamic lubrication of the top compression piston ring in a large two-stroke marine diesel engine is presented. The groove mounted piston ring is driven by the reciprocal motion of the piston. The ring shape follows a circular geometry and the effect...

  6. The multi-objective optimization of the horizontal-axis marine current turbine based on NSGA-II algorithm

    International Nuclear Information System (INIS)

    Zhu, G J; Guo, P C; Luo, X Q; Feng, J J

    2012-01-01

    The present paper describes a hydrodynamic optimization technique for horizontal-axial marine current turbine. The pitch angle distribution is important to marine current turbine. In this paper, the pitch angle distribution curve is parameterized as four control points by Bezier curve method. The coordinates of the four control points are chosen as optimization variables, and the sample space are structured according to the Box-Behnken experimental design method (BBD). Then the power capture coefficient and axial thrust coefficient in design tip-speed ratio is obtained for all the elements in the sample space by CFD numerical simulation. The power capture coefficient and axial thrust are chosen as objective function, and quadratic polynomial regression equations are constructed to fit the relationship between the optimization variables and each objective function according to response surface model. With the obtained quadratic polynomial regression equations as performance prediction model, the marine current turbine is optimized using the NSGA-II multi-objective genetic algorithm, which finally offers an improved marine current turbine.

  7. Computation of the current density in nonlinear materials subjected to large current pulses

    International Nuclear Information System (INIS)

    Hodgdon, M.L.; Hixson, R.S.; Parsons, W.M.

    1991-01-01

    This paper reports that the finite element method and the finite difference method are used to calculate the current distribution in two nonlinear conductors. The first conductor is a small ferromagnetic wire subjected to a current pulse that rises to 10,000 Amperes in 10 microseconds. Results from the transient thermal and transient magnetic solvers of the finite element code FLUX2D are used to compute the current density in the wire. The second conductor is a metal oxide varistor. Maxwell's equations, Ohm's law and the varistor relation for the resistivity and the current density of p = αj -β are used to derive a nonlinear differential equation. The solutions of the differential equation are obtained by a finite difference approximation and a shooting method. The behavior predicted by these calculations is in agreement with experiments

  8. Contamination of port zone sediments by metals from Large Marine Ecosystems of Brazil.

    Science.gov (United States)

    Buruaem, Lucas M; Hortellani, Marcos A; Sarkis, Jorge E; Costa-Lotufo, Leticia V; Abessa, Denis M S

    2012-03-01

    Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecém) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Experimental assessment of blade tip immersion depth from free surface on average power and thrust coefficients of marine current turbine

    Science.gov (United States)

    Lust, Ethan; Flack, Karen; Luznik, Luksa

    2014-11-01

    Results from an experimental study on the effects of marine current turbine immersion depth from the free surface are presented. Measurements are performed with a 1/25 scale (diameter D = 0.8m) two bladed horizontal axis turbine towed in the large towing tank at the U.S. Naval Academy. Thrust and torque are measured using a dynamometer, mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using a shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Two optical wave height sensors are used to measure the free surface elevation. The turbine is towed at 1.68 m/s, resulting in a 70% chord based Rec = 4 × 105. An Acoustic Doppler Velocimeter (ADV) is installed one turbine diameter upstream of the turbine rotation plane to characterize the inflow turbulence. Measurements are obtained at four relative blade tip immersion depths of z/D = 0.5, 0.4, 0.3, and 0.2 at a TSR value of 7 to identify the depth where free surface effects impact overall turbine performance. The overall average power and thrust coefficient are presented and compared to previously conducted baseline tests. The influence of wake expansion blockage on the turbine performance due to presence of the free surface at these immersion depths will also be discussed.

  10. Pharmacological developments obtained from marine natural products and current pipeline perspective.

    Science.gov (United States)

    Galeano, Elkin; Rojas, Jhon J; Martínez, Alejandro

    2011-02-01

    Marine organisms represent a new extensive source for bioactive molecules. They have the potential to provide new therapeutic alternatives to treat human diseases. In this paper, we describe and discuss a variety of isolated and semisynthetic molecules obtained from marine sources. These compounds are in phase II, phase III and at the commercialization stage of new drug development. A description of the mechanism of action, dosage used and side effects are also reported. The positive results obtained from these studies have triggered the development of new studies to evaluate the prospects for utilization of marine organisms.

  11. Solid Waste Transportation through Ocean Currents: Marine Debris Sightings and their Waste Quantification at Port Dickson Beaches, Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Chong Jing Yi

    2016-07-01

    Full Text Available Four beaches at Port Dickson, Peninsular Malaysia, namely Saujana Beach, Nelayan Beach, Bagan Pinang Beach and Cermin beach have been sampled for marine debris from 7th June 2014 until 26th July 2014, on every Saturday. These beaches face the Strait of Malacca with a coastline stretching 18 km each. Our observations revealed a total debris items of 13193 in those beaches. The top three items of highest frequency were cigarette butts, foamed fragments and food wrappers. Plastic debris scaled high upto 41% of the total debris. Compared to the ocean conservancy�s 2013 report of marine debris in Malaysian beaches, which was 27,005 items with in 6.44 km, the current count is slightly low. However, Malaysia was ranked 14th place among the top 20 countries in International Marine Debris Watch program. Nelayan Beach is the dirtiest beach in Port Dickson. Around 50% of the total plastic items collected are found on those beaches. The marine debris items indicated that they arrived there by land-based and ocean-based activities. High energy conditions such as wind and waves in the beaches correlated well with less debris deposition on the beaches. With debris equivalent of 4193 items/km, Malaysia harvests less solid wastes compared to Croatia, USA, Singapore and Turkey. However, a nation wide survey is needed to assess the seriousness of marine debris problem in Malaysia.

  12. 78 FR 42653 - Taking of Marine Mammals Incidental to Commercial Fishing Operations; Atlantic Large Whale Take...

    Science.gov (United States)

    2013-07-16

    ... defines a strategic stock of marine mammals as a stock: (1) For which the level of direct human-caused... Whales, Eubalaena australis. Behaviour 88(1/2):42-60. BILLING CODE 3510-22-P [GRAPHIC] [TIFF OMITTED...

  13. Relating large-scale subsidence to convection development in Arctic mixed-phase marine stratocumulus

    Science.gov (United States)

    Young, Gillian; Connolly, Paul J.; Dearden, Christopher; Choularton, Thomas W.

    2018-02-01

    Large-scale subsidence, associated with high-pressure systems, is often imposed in large-eddy simulation (LES) models to maintain the height of boundary layer (BL) clouds. Previous studies have considered the influence of subsidence on warm liquid clouds in subtropical regions; however, the relationship between subsidence and mixed-phase cloud microphysics has not specifically been studied. For the first time, we investigate how widespread subsidence associated with synoptic-scale meteorological features can affect the microphysics of Arctic mixed-phase marine stratocumulus (Sc) clouds. Modelled with LES, four idealised scenarios - a stable Sc, varied droplet (Ndrop) or ice (Nice) number concentrations, and a warming surface (representing motion southwards) - were subjected to different levels of subsidence to investigate the cloud microphysical response. We find strong sensitivities to large-scale subsidence, indicating that high-pressure systems in the ocean-exposed Arctic regions have the potential to generate turbulence and changes in cloud microphysics in any resident BL mixed-phase clouds.Increased cloud convection is modelled with increased subsidence, driven by longwave radiative cooling at cloud top and rain evaporative cooling and latent heating from snow growth below cloud. Subsidence strengthens the BL temperature inversion, thus reducing entrainment and allowing the liquid- and ice-water paths (LWPs, IWPs) to increase. Through increased cloud-top radiative cooling and subsequent convective overturning, precipitation production is enhanced: rain particle number concentrations (Nrain), in-cloud rain mass production rates, and below-cloud evaporation rates increase with increased subsidence.Ice number concentrations (Nice) play an important role, as greater concentrations suppress the liquid phase; therefore, Nice acts to mediate the strength of turbulent overturning promoted by increased subsidence. With a warming surface, a lack of - or low - subsidence

  14. Steady-state configuration and tension calculations of marine cables under complex currents via separated particle swarm optimization

    Science.gov (United States)

    Xu, Xue-song

    2014-12-01

    Under complex currents, the motion governing equations of marine cables are complex and nonlinear, and the calculations of cable configuration and tension become difficult compared with those under the uniform or simple currents. To obtain the numerical results, the usual Newton-Raphson iteration is often adopted, but its stability depends on the initial guessed solution to the governing equations. To improve the stability of numerical calculation, this paper proposed separated the particle swarm optimization, in which the variables are separated into several groups, and the dimension of search space is reduced to facilitate the particle swarm optimization. Via the separated particle swarm optimization, these governing nonlinear equations can be solved successfully with any initial solution, and the process of numerical calculation is very stable. For the calculations of cable configuration and tension of marine cables under complex currents, the proposed separated swarm particle optimization is more effective than the other particle swarm optimizations.

  15. The world's marine fisheries currently generate a catch of about 150 ...

    African Journals Online (AJOL)

    spamer

    marine fisheries are ecosystem processes, occurring ... functional definition, i.e. the type of definition that, in ... An important element of a functional definition of ... to the fishing industry to one serving a broader set of clients is emphasized.

  16. Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters

    International Nuclear Information System (INIS)

    Zhang, Wei; Wang, Wen-Xiong

    2012-01-01

    Highlights: ► A large-scale study on trace element levels in marine wild fish from Chinese waters. ► Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. ► The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. ► No biomagnification occurred for any of the trace elements studied in marine fish. ► No obvious health risk from the intake of trace elements through fish consumption. - Abstract: We conducted a large scale investigation of twelve trace element levels and stable isotopes (δ 13 C and δ 15 N) in twenty-nine marine wild fish species collected from Chinese coastal waters. Trace element levels varied significantly with species. Clear spatial variations were found for Al, As, Cd, Cr, Fe, Ni, and Pb, whereas Ag, Cu, Mo, Se and Zn did not show much spatial variation. The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb, whereas the most southern waters (Haikou) contained the lowest concentrations of Al, Fe, and Pb. There was no correlation between log-transformed trace elements concentrations and δ 15 N values or δ 13 C values, indicating no biomagnification among these trace elements. The calculated hazard quotients (HQ) of 10 elements were less than 1, thus there was no obvious health risk from the intake of trace elements through marine wild fish consumption.

  17. United Kingdom. Report 1 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Templeton, W.L.

    1967-01-01

    Present research programme (long-term): There are five separate research projects in this Group, viz: A. Low-level irradiation studies on marine and fresh-water fish eggs. B. Accumulation and. metabolism of radionuclides by marine organisms. C. Physico-chemical states of radionuclides in sea water, D. Dispersion and transport of radionuclides in the coastal waters of Windscale. E. Mechanisms of the toxicity of zinc to fish. Details of each project are outlined

  18. Knowledge discovery in large model datasets in the marine environment: the THREDDS Data Server example

    Directory of Open Access Journals (Sweden)

    A. Bergamasco

    2012-06-01

    Full Text Available In order to monitor, describe and understand the marine environment, many research institutions are involved in the acquisition and distribution of ocean data, both from observations and models. Scientists from these institutions are spending too much time looking for, accessing, and reformatting data: they need better tools and procedures to make the science they do more efficient. The U.S. Integrated Ocean Observing System (US-IOOS is working on making large amounts of distributed data usable in an easy and efficient way. It is essentially a network of scientists, technicians and technologies designed to acquire, collect and disseminate observational and modelled data resulting from coastal and oceanic marine regions investigations to researchers, stakeholders and policy makers. In order to be successful, this effort requires standard data protocols, web services and standards-based tools. Starting from the US-IOOS approach, which is being adopted throughout much of the oceanographic and meteorological sectors, we describe here the CNR-ISMAR Venice experience in the direction of setting up a national Italian IOOS framework using the THREDDS (THematic Real-time Environmental Distributed Data Services Data Server (TDS, a middleware designed to fill the gap between data providers and data users. The TDS provides services that allow data users to find the data sets pertaining to their scientific needs, to access, to visualize and to use them in an easy way, without downloading files to the local workspace. In order to achieve this, it is necessary that the data providers make their data available in a standard form that the TDS understands, and with sufficient metadata to allow the data to be read and searched in a standard way. The core idea is then to utilize a Common Data Model (CDM, a unified conceptual model that describes different datatypes within each dataset. More specifically, Unidata (www.unidata.ucar.edu has developed CDM

  19. Offshore renewable energies, offshore wind power marine currents and waves; Energies renouvelables en mer eolien en mer courants marins et vagues

    Energy Technology Data Exchange (ETDEWEB)

    Paillard, M [Institut Francais de Recherche pour l' Exploitation de la Mer, 92 - Issy les Moulineaux (France); Peirano, E [Agence de Environnement et de la Maitrise de l' Energie (ADEME), 06 - Valbonne (France)

    2004-07-01

    This colloquium aims to take stock on the development of ocean energies, mainly exploitation of offshore wind energy, but also exploitation of marine currents and waves for energy conversion by discussing their perspectives, their constraints, and their environmental and socio-economic impacts. It proposes also a review the recent methodological and technological advances. The different subjects introduced are: state of the art and prospects; resource assessments, forecasting and short-term prediction, site conditions; technical assessments, installation,decommissioning, certification; environmental impacts, social aspects and acceptability; policies, market perspectives and constraints; project developments and feedback. (A.L.B.)

  20. Large recovery of fish biomass in a no-take marine reserve.

    Directory of Open Access Journals (Sweden)

    Octavio Aburto-Oropeza

    Full Text Available No-take marine reserves are effective management tools used to restore fish biomass and community structure in areas depleted by overfishing. Cabo Pulmo National Park (CPNP was created in 1995 and is the only well enforced no-take area in the Gulf of California, Mexico, mostly because of widespread support from the local community. In 1999, four years after the establishment of the reserve, there were no significant differences in fish biomass between CPNP (0.75 t ha(-1 on average and other marine protected areas or open access areas in the Gulf of California. By 2009, total fish biomass at CPNP had increased to 4.24 t ha(-1 (absolute biomass increase of 3.49 t ha(-1, or 463%, and the biomass of top predators and carnivores increased by 11 and 4 times, respectively. However, fish biomass did not change significantly in other marine protected areas or open access areas over the same time period. The absolute increase in fish biomass at CPNP within a decade is the largest measured in a marine reserve worldwide, and it is likely due to a combination of social (strong community leadership, social cohesion, effective enforcement and ecological factors. The recovery of fish biomass inside CPNP has resulted in significant economic benefits, indicating that community-managed marine reserves are a viable solution to unsustainable coastal development and fisheries collapse in the Gulf of California and elsewhere.

  1. Current direction, chemical, and marine toxic substances data from moored current meter casts and other instruments in the Gulf of Mexico during the Brine Disposal project, 1978-09-09 to 1979-11-19 (NODC Accession 8000043)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, marine toxic substances, and chemical data were collected using moored current meter casts and other instruments in the Gulf of Mexico from...

  2. The Effects of Inter-annual Climate Variability on the Departures of Leatherback Marine Turtles from the California Current Ecosystem

    OpenAIRE

    Van Zerr, Vanessa E

    2013-01-01

    The Pacific Ocean is a highly variable environment, and changes in oceanographic conditions impact the distributions of many organisms. Inter-annual climate variability, especially the El Niño/Southern Oscillation, is known to have wide-ranging impacts on organisms in the California Current. Understanding the factors that drive changes in the spatial ecology of organisms, such as inter-annual climate variability, is essential in many cases for effective conservation. Leatherback marine turtle...

  3. The development of control and monitoring system on marine current renewable energy Case study: strait of Toyapakeh - Nusa Penida, Bali

    Science.gov (United States)

    Arief, I. S.; Suherman, I. H.; Wardani, A. Y.; Baidowi, A.

    2017-05-01

    Control and monitoring system is a continuous process of securing the asset in the Marine Current Renewable Energy. A control and monitoring system is existed each critical components which is embedded in Failure Mode Effect Analysis (FMEA) method. As the result, the process in this paper developed through a matrix sensor. The matrix correlated to critical components and monitoring system which supported by sensors to conduct decision-making.

  4. Annotated bibliography: Marine geologic hazards of the Hawaiian Islands with special focus on submarine slides and turbidity currents

    Energy Technology Data Exchange (ETDEWEB)

    Normark, W.R.; Herring, H.H.

    1993-10-01

    This annotated bibliography was compiled to highlight the submarine geology of the Hawaiian Islands and identify known and potential marine geologic hazards with special emphasis on turbidity currents, submarine slides and tsunamis. Some references are included that are not specific to Hawaii but are needed to understand the geologic processes that can affect the integrity of submarine cables and other man-made structures. Entries specific to the Hawaiian Island area are shown in bold type.

  5. The Occurrence of Paraffin and Other Petroleum Waxes in the Marine Environment: A Review of the Current Legislative Framework and Shipping Operational Practices

    OpenAIRE

    Giuseppe Suaria; Giuseppe Suaria; Stefano Aliani; Silvia Merlino; Marinella Abbate

    2018-01-01

    Among the various materials that make up marine debris, lumps of petroleum waxes such as paraffin and microcrystalline wax, are regularly found on beaches worldwide, although not included in the current definition of marine litter. Ingestion by marine organisms is occasionally documented in the scientific literature and mass beaching events are frequently reported along the European coasts, with obvious detrimental consequences to the local communities that have to manage the clean-up and dis...

  6. Development, installation and testing of a large-scale tidal current turbine

    Energy Technology Data Exchange (ETDEWEB)

    Thake, J.

    2005-10-15

    This report summarises the findings of the Seaflow project to investigate the feasibility of building and operating a commercial scale marine current horizontal axis tidal turbine and to evaluate the long-term economics of producing electricity using tidal turbines. Details are given of competitive tidal stream technologies and their commercial status, the selection of the site on the North Devon coast of the UK, and the evaluation of the turbine design, manufacture, testing, installation, commissioning, and maintenance of the turbine. The organisations working on the Seaflow project and cost estimations are discussed.

  7. The stratigraphic record and processes of turbidity current transformation across deep-marine lobes

    NARCIS (Netherlands)

    Kane, Ian A.; Ponten, Anna; Vangdal, Brita; Eggenhuisen, Joris|info:eu-repo/dai/nl/322850274; Hodgson, David M.; Spychala, Yvonne T.|info:eu-repo/dai/nl/411435019

    Sedimentary facies in the distal parts of deep-marine lobes can diverge significantly from those predicted by classical turbidite models, and sedimentological processes in these environments are poorly understood. This gap may be bridged using outcrop studies and theoretical models. In the

  8. Investigating the Marine Protected Areas most at risk of current-driven pollution in the Gulf of Finland, the Baltic Sea, using a Lagrangian transport model.

    Science.gov (United States)

    Delpeche-Ellmann, Nicole C; Soomere, Tarmo

    2013-02-15

    The possibility of current-driven propagation of contaminants released along a major fairway polluting the Marine Protected Areas (MPAs) in the Gulf of Finland, the Baltic Sea, is examined using a 3D circulation model, a Lagrangian transport model and statistics. Not surprisingly, the number of hits to the MPA decreases almost linearly with its distance from the fairway. In addition, the potential pollution released during a ship accident with the pollutants carried by currents may affect MPAs at very large distances. Typically, a fairway section approximately 125 km long (covering about 1/3 of the approximate 400-km-long gulf) may serve as a source of pollution for each MPA. The largest MPA (in the Eastern Gulf of Finland) may receive pollution from an approximately 210-km-long section (covering about 1/2 of the entire length of the gulf). This information may be useful in assisting maritime management. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Large-scale spatial and interspecies differences in trace elements and stable isotopes in marine wild fish from Chinese waters

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [Key Laboratory of Marine Bio-resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Wang, Wen-Xiong, E-mail: wwang@ust.hk [Division of Life Science, HKUST, Clear Water Bay, Kowloon (Hong Kong)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer A large-scale study on trace element levels in marine wild fish from Chinese waters. Black-Right-Pointing-Pointer Spatial variation found for Al, As, Cd, Cr, Fe, Ni, Pb, but not for Ag, Cu, Mo, Se and Zn. Black-Right-Pointing-Pointer The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb. Black-Right-Pointing-Pointer No biomagnification occurred for any of the trace elements studied in marine fish. Black-Right-Pointing-Pointer No obvious health risk from the intake of trace elements through fish consumption. - Abstract: We conducted a large scale investigation of twelve trace element levels and stable isotopes ({delta}{sup 13}C and {delta}{sup 15}N) in twenty-nine marine wild fish species collected from Chinese coastal waters. Trace element levels varied significantly with species. Clear spatial variations were found for Al, As, Cd, Cr, Fe, Ni, and Pb, whereas Ag, Cu, Mo, Se and Zn did not show much spatial variation. The Pearl River Estuary contained the highest concentrations of Al, Cr, Ni, and Pb, whereas the most southern waters (Haikou) contained the lowest concentrations of Al, Fe, and Pb. There was no correlation between log-transformed trace elements concentrations and {delta}{sup 15}N values or {delta}{sup 13}C values, indicating no biomagnification among these trace elements. The calculated hazard quotients (HQ) of 10 elements were less than 1, thus there was no obvious health risk from the intake of trace elements through marine wild fish consumption.

  10. Large-scale assessment of benthic communities across multiple marine protected areas using an autonomous underwater vehicle.

    Science.gov (United States)

    Ferrari, Renata; Marzinelli, Ezequiel M; Ayroza, Camila Rezende; Jordan, Alan; Figueira, Will F; Byrne, Maria; Malcolm, Hamish A; Williams, Stefan B; Steinberg, Peter D

    2018-01-01

    Marine protected areas (MPAs) are designed to reduce threats to biodiversity and ecosystem functioning from anthropogenic activities. Assessment of MPAs effectiveness requires synchronous sampling of protected and non-protected areas at multiple spatial and temporal scales. We used an autonomous underwater vehicle to map benthic communities in replicate 'no-take' and 'general-use' (fishing allowed) zones within three MPAs along 7o of latitude. We recorded 92 taxa and 38 morpho-groups across three large MPAs. We found that important habitat-forming biota (e.g. massive sponges) were more prevalent and abundant in no-take zones, while short ephemeral algae were more abundant in general-use zones, suggesting potential short-term effects of zoning (5-10 years). Yet, short-term effects of zoning were not detected at the community level (community structure or composition), while community structure varied significantly among MPAs. We conclude that by allowing rapid, simultaneous assessments at multiple spatial scales, autonomous underwater vehicles are useful to document changes in marine communities and identify adequate scales to manage them. This study advanced knowledge of marine benthic communities and their conservation in three ways. First, we quantified benthic biodiversity and abundance, generating the first baseline of these benthic communities against which the effectiveness of three large MPAs can be assessed. Second, we identified the taxonomic resolution necessary to assess both short and long-term effects of MPAs, concluding that coarse taxonomic resolution is sufficient given that analyses of community structure at different taxonomic levels were generally consistent. Yet, observed differences were taxa-specific and may have not been evident using our broader taxonomic classifications, a classification of mid to high taxonomic resolution may be necessary to determine zoning effects on key taxa. Third, we provide an example of statistical analyses and

  11. Dynamic habitat corridors for marine predators; intensive use of a coastal channel by harbour seals is modulated by tidal currents.

    Science.gov (United States)

    Hastie, Gordon D; Russell, Deborah J F; Benjamins, Steven; Moss, Simon; Wilson, Ben; Thompson, Dave

    2016-01-01

    narrow coastal channel subject to strong tidal currents; results showed that seals spent the majority of their time at the narrowest point of the channel foraging during peak tidal currents. This highlights the importance of narrow channels for marine predators and suggests that this usually wide-ranging predator may restrict its geographic range to forage in the channel as a result of increased prey availability and/or foraging efficiency driven by water movements through the narrow corridor.

  12. United Kingdom. Report 5 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Mauchline, J.

    1967-01-01

    Four research programmes are suggested: Physical/chemical states of radionuclides in sea water related to their absorption rates by marine organisms; Studies of sea-water/ fresh-water interphases; To discover effects of raising the levels of background radiation by small amounts over long periods; Special studies of neutron-induced radioisotopes of elements such as chromium, manganese, iron, cobalt,, zinc, antimony, beryllium and iodine

  13. Review of the effects of protection in marine protected areas: current knowledge and gaps

    Directory of Open Access Journals (Sweden)

    Ojeda–Martínez, C.

    2011-06-01

    Full Text Available The effectiveness of marine protected areas (MPAs and the conservation of marine environments must be based on reliable information on the quality of the marine environment that can be obtained in a reasonable timeframe. We reviewed studies that evaluated all aspects related to the effectiveness of MPAs in order to describe how the studies were conducted and to detect fields in which research is lacking. Existing parameters used to evaluate the effectiveness of MPAs are summarised. Two-hundred and twenty-two publications were reviewed. We identified the most commonly used study subjects and methodological approaches. Most of the studies concentrated on biological parameters. Peer reviewed studies were based on control vs. impact design. BACI and mBACI designs were used in very few studies. Through this review, we have identified gaps in the objectives assigned to MPAs and the way in which they have been evaluated. We suggest some guidelines aimedat improving the assessment of the effects of protection in MPAs.

  14. Application-oriented research on plasma channeling of a large pulsed current

    International Nuclear Information System (INIS)

    Liu Jingye

    2000-01-01

    Utilizing the avalanche effect of plasma produced by the collision of energetic primary electrons with hydrogen molecules in a plasma, channeling of a large pulsed current is achieved, with the plasma acting as the carrier

  15. Numerical Analysis of Soil Settlement Prediction and Its Application In Large-Scale Marine Reclamation Artificial Island Project

    Directory of Open Access Journals (Sweden)

    Zhao Jie

    2017-11-01

    Full Text Available In an artificial island construction project based on the large-scale marine reclamation land, the soil settlement is a key to affect the late safe operation of the whole field. To analyze the factors of the soil settlement in a marine reclamation project, the SEM method in the soil micro-structural analysis method is used to test and study six soil samples such as the representative silt, mucky silty clay, silty clay and clay in the area. The structural characteristics that affect the soil settlement are obtained by observing the SEM charts at different depths. By combining numerical calculation method of Terzaghi’s one-dimensional and Biot’s two-dimensional consolidation theory, the one-dimensional and two-dimensional creep models are established and the numerical calculation results of two consolidation theories are compared in order to predict the maximum settlement of the soils 100 years after completion. The analysis results indicate that the micro-structural characteristics are the essential factor to affect the settlement in this area. Based on numerical analysis of one-dimensional and two-dimensional settlement, the settlement law and trend obtained by two numerical analysis method is similar. The analysis of this paper can provide reference and guidance to the project related to the marine reclamation land.

  16. Quench protection and design of large high-current-density superconducting magnets

    International Nuclear Information System (INIS)

    Green, M.A.

    1981-03-01

    Although most large superconducting magnets have been designed using the concept of cryostability, there is increased need for large magnets which operate at current densities above the cryostable limit (greater than 10 8 Am -2 ). Large high current density superconducting magnets are chosen for the following reasons: reduced mass, reduced coil thickness or size, and reduced cost. The design of large high current density, adiabatically stable, superconducting magnets requires a very different set of design rules than either large cryostable superconducting magnets or small self-protected high current density magnets. The problems associated with large high current density superconducting magnets fall into three categories; (a) quench protection, (b) stress and training, and (c) cryogenic design. The three categories must be considered simultaneously. The paper discusses quench protection and its implication for magnets of large stored energies (this includes strings of smaller magnets). Training and its relationship to quench protection and magnetic strain are discussed. Examples of magnets, built at the Lawrence Berkeley Laboratory and elsewhere using the design guidelines given in this report, are presented

  17. Large fluctuations of the macroscopic current in diffusive systems: a numerical test of the additivity principle.

    Science.gov (United States)

    Hurtado, Pablo I; Garrido, Pedro L

    2010-04-01

    Most systems, when pushed out of equilibrium, respond by building up currents of locally conserved observables. Understanding how microscopic dynamics determines the averages and fluctuations of these currents is one of the main open problems in nonequilibrium statistical physics. The additivity principle is a theoretical proposal that allows to compute the current distribution in many one-dimensional nonequilibrium systems. Using simulations, we validate this conjecture in a simple and general model of energy transport, both in the presence of a temperature gradient and in canonical equilibrium. In particular, we show that the current distribution displays a Gaussian regime for small current fluctuations, as prescribed by the central limit theorem, and non-Gaussian (exponential) tails for large current deviations, obeying in all cases the Gallavotti-Cohen fluctuation theorem. In order to facilitate a given current fluctuation, the system adopts a well-defined temperature profile different from that of the steady state and in accordance with the additivity hypothesis predictions. System statistics during a large current fluctuation is independent of the sign of the current, which implies that the optimal profile (as well as higher-order profiles and spatial correlations) are invariant upon current inversion. We also demonstrate that finite-time joint fluctuations of the current and the profile are well described by the additivity functional. These results suggest the additivity hypothesis as a general and powerful tool to compute current distributions in many nonequilibrium systems.

  18. Weak Compliance Undermines the Success of No-Take Zones in a Large Government-Controlled Marine Protected Area

    KAUST Repository

    Campbell, Stuart J.

    2012-11-30

    The effectiveness of marine protected areas depends largely on whether people comply with the rules. We quantified temporal changes in benthic composition, reef fish biomass, and fishing effort among marine park zones (including no-take areas) to assess levels of compliance following the 2005 rezoning of the government-controlled Karimunjawa National Park (KNP), Indonesia. Four years after the rezoning awareness of fishing regulations was high amongst local fishers, ranging from 79.5±7.9 (SE) % for spatial restrictions to 97.7±1.2% for bans on the use of poisons. Despite this high awareness and strong compliance with gear restrictions, compliance with spatial restrictions was weak. In the four years following the rezoning reef fish biomass declined across all zones within KNP, with >50% reduction within the no-take Core and Protection Zones. These declines were primarily driven by decreases in the biomass of groups targeted by local fishers; planktivores, herbivores, piscivores, and invertivores. These declines in fish biomass were not driven by changes in habitat quality; coral cover increased in all zones, possibly as a result of a shift in fishing gears from those which can damage reefs (i.e., nets) to those which cause little direct damage (i.e., handlines and spears). Direct observations of fishing activities in 2009 revealed there was limited variation in fishing effort between zones in which fishing was allowed or prohibited. The apparent willingness of the KNP communities to comply with gear restrictions, but not spatial restrictions is difficult to explain and highlights the complexities of the social and economic dynamics that influence the ecological success of marine protected areas. Clearly the increased and high awareness of fishery restrictions following the rezoning is a positive step. The challenge now is to understand and foster the conditions that may facilitate compliance with spatial restrictions within KNP and marine parks worldwide. © 2012

  19. Arrays of Synthetic Atoms: Nanocapacitor Batteries with Large Energy Density and Small Leak Currents

    Science.gov (United States)

    2017-11-28

    AFRL-RV-PS- AFRL-RV-PS- TR-2017-0169 TR-2017-0169 ARRAYS OF SYNTHETIC ATOMS: NANOCAPACITOR BATTERIES WITH LARGE ENERGY DENSITY AND SMALL LEAK...1-0247 Arrays of Synthetic Atoms: Nanocapacitor Batteries with Large Energy Density and Small Leak Currents 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...large dielectric strength to a nanoscale rechargeable battery . We fabricated arrays of one-, two- and three-dimensional synthetic atoms and comparison

  20. System analysis and optimisation of a Kalina split-cycle for waste heat recovery on large marine diesel engines

    DEFF Research Database (Denmark)

    Larsen, Ulrik; Nguyen, Tuong-Van; Knudsen, Thomas

    2014-01-01

    Waste heat recovery systems can produce power from heat without using fuel or emitting CO2, therefore their implementation is becoming increasingly relevant. The Kalina cycle is proposed as an efficient process for this purpose. The main reason for its high efficiency is the non-isothermal phase...... change characteristics of the ammonia-water working fluid. The present study investigates a unique type of Kalina process called the Split-cycle, applied to the exhaust heat recovery from large marine engines. In the Split-cycle, the working fluid concentration can be changed during the evaporation...

  1. Exact current to a spherical electrode in a collisionless, large-Debye-length magnetoplasma

    International Nuclear Information System (INIS)

    Sonmor, L.J.; Laframboise, J.G.

    1991-01-01

    Exact calculations of the steady-state current drawn from a collisionless, Maxwellian plasma in a uniform magnetic field by a spherical, perfectly absorbing electrode are presented for a range of dimensionless electrode potentials and magnetic-field strengths. These calculations are valid in the limit of large Debye length. The results are compared with the theory of Rubinstein and Laframboise, which gives upper and lower bounds for both the attracted-species and the repelled-species current. It is found that as the electrode potential increases from space potential with magnetic-field strength fixed, the electron (i.e., attracted-species) current decreases, but not as quickly as the adiabatic-limit (effectively lower-bound) current. The ion current also diverges immediately from the adiabatic-limit current. As the electrode potential increases further, the electron current rises and moves monotonically toward the canonical upper bound, which is the warm-plasma generalization of the well-known Parker and Murphy upper bound. It is unclear whether the current approaches the upper bound asymptotically as the electrode potential becomes large, or instead a constant proportion of the upper bound which varies with magnetic-field strength. The dependence on magnetic-field strength is more complicated. As expected for small fixed electrode potentials, the attracted-species current approaches the adiabatic-limit current monotonically as the magnetic-field strength increases. However, for large electrode potentials this pattern reverses: the current approaches the canonical upper bound monotonically as the magnetic-field strength increases. These patterns are expected to persist when the Debye length is finite. Interpretation of these results leads to an inference that for large electrode potentials, the effect of decreasing the Debye length may be to reduce the current, as in the nonmagnetic case

  2. Origin of large dark current increase in InGaAs/InP avalanche photodiode

    Science.gov (United States)

    Wen, J.; Wang, W. J.; Chen, X. R.; Li, N.; Chen, X. S.; Lu, W.

    2018-04-01

    The large dark current increase near the breakdown voltage of an InGaAs/InP avalanche photodiode is observed and analyzed from the aspect of bulk defects in the device materials. The trap level information is extracted from the temperature-dependent electrical characteristics of the device and the low temperature photoluminescence spectrum of the materials. Simulation results with the extracted trap level taken into consideration show that the trap is in the InP multiplication layer and the trap assisted tunneling current induced by the trap is the main cause of the large dark current increase with the bias from the punch-through voltage to 95% breakdown voltage.

  3. Formation and fate of marine snow: small-scale processes with large- scale implications

    Directory of Open Access Journals (Sweden)

    Thomas Kiørboe

    2001-12-01

    Full Text Available Marine snow aggregates are believed to be the main vehicles for vertical material transport in the ocean. However, aggregates are also sites of elevated heterotrophic activity, which may rather cause enhanced retention of aggregated material in the upper ocean. Small-scale biological-physical interactions govern the formation and fate of marine snow. Aggregates may form by physical coagulation: fluid motion causes collisions between small primary particles (e.g. phytoplankton that may then stick together to form aggregates with enhanced sinking velocities. Bacteria may subsequently solubilise and remineralise aggregated particles. Because the solubilization rate exceeds the remineralization rate, organic solutes leak out of sinking aggregates. The leaking solutes spread by diffusion and advection and form a chemical trail in the wake of the sinking aggregate that may guide small zooplankters to the aggregate. Also, suspended bacteria may enjoy the elevated concentration of organic solutes in the plume. I explore these small-scale formation and degradation processes by means of models, experiments and field observations. The larger scale implications for the structure and functioning of pelagic food chains of export vs. retention of material will be discussed.

  4. Large-current-controllable carbon nanotube field-effect transistor in electrolyte solution

    Science.gov (United States)

    Myodo, Miho; Inaba, Masafumi; Ohara, Kazuyoshi; Kato, Ryogo; Kobayashi, Mikinori; Hirano, Yu; Suzuki, Kazuma; Kawarada, Hiroshi

    2015-05-01

    Large-current-controllable carbon nanotube field-effect transistors (CNT-FETs) were fabricated with mm-long CNT sheets. The sheets, synthesized by remote-plasma-enhanced CVD, contained both single- and double-walled CNTs. Titanium was deposited on the sheet as source and drain electrodes, and an electrolyte solution was used as a gate electrode (solution gate) to apply a gate voltage to the CNTs through electric double layers formed around the CNTs. The drain current came to be well modulated as electrolyte solution penetrated into the sheets, and one of the solution gate CNT-FETs was able to control a large current of over 2.5 A. In addition, we determined the transconductance parameter per tube and compared it with values for other CNT-FETs. The potential of CNT sheets for applications requiring the control of large current is exhibited in this study.

  5. Marine parasites as biological tags in South American Atlantic waters, current status and perspectives.

    Science.gov (United States)

    Cantatore, D M P; Timi, J T

    2015-01-01

    Many marine fisheries in South American Atlantic coasts (SAAC) are threatened by overfishing and under serious risk of collapsing. The SAAC comprises a diversity of environments, possesses a complex oceanography and harbours a vast biodiversity that provide an enormous potential for using parasites as biological tags for fish stock delineation, a prerequisite for the implementation of control and management plans. Here, their use in the SAAC is reviewed. Main evidence is derived from northern Argentine waters, where fish parasite assemblages are dominated by larval helminth species that share a low specificity, long persistence and trophic transmission, parasitizing almost indiscriminately all available fish species. The advantages and constraints of such a combination of characteristics are analysed and recommendations are given for future research. Shifting the focus from fish/parasite populations to communities allows expanding the concept of biological tags from local to regional scales, providing essential information to delineate ecosystem boundaries for host communities. This new concept arose as a powerful tool to help the implementation of ecosystem-based approaches to fisheries management, the new paradigm for fisheries science. Holistic approaches, including parasites as biological tags for stock delineation will render valuable information to help insure fisheries and marine ecosystems against further depletion and collapse.

  6. Vector form Intrinsic Finite Element Method for the Two-Dimensional Analysis of Marine Risers with Large Deformations

    Science.gov (United States)

    Li, Xiaomin; Guo, Xueli; Guo, Haiyan

    2018-06-01

    Robust numerical models that describe the complex behaviors of risers are needed because these constitute dynamically sensitive systems. This paper presents a simple and efficient algorithm for the nonlinear static and dynamic analyses of marine risers. The proposed approach uses the vector form intrinsic finite element (VFIFE) method, which is based on vector mechanics theory and numerical calculation. In this method, the risers are described by a set of particles directly governed by Newton's second law and are connected by weightless elements that can only resist internal forces. The method does not require the integration of the stiffness matrix, nor does it need iterations to solve the governing equations. Due to these advantages, the method can easily increase or decrease the element and change the boundary conditions, thus representing an innovative concept of solving nonlinear behaviors, such as large deformation and large displacement. To prove the feasibility of the VFIFE method in the analysis of the risers, rigid and flexible risers belonging to two different categories of marine risers, which usually have differences in modeling and solving methods, are employed in the present study. In the analysis, the plane beam element is adopted in the simulation of interaction forces between the particles and the axial force, shear force, and bending moment are also considered. The results are compared with the conventional finite element method (FEM) and those reported in the related literature. The findings revealed that both the rigid and flexible risers could be modeled in a similar unified analysis model and that the VFIFE method is feasible for solving problems related to the complex behaviors of marine risers.

  7. Stationary high confinement plasmas with large bootstrap current fraction in JT-60U

    International Nuclear Information System (INIS)

    Sakamoto, Y.; Fujita, T.; Ide, S.; Isayama, A.; Takechi, M.; Suzuki, T.; Takenaga, H.; Oyama, N.; Kamada, Y.

    2005-01-01

    This paper reports the results of the progress in stationary discharges with a large bootstrap current fraction in JT-60U towards steady-state tokamak operation. In the weak shear plasma regime, high-β p ELMy H-mode discharges have been optimized under nearly full non-inductive current drive conditions by the large bootstrap current fraction (f BS ∼ 45%) and the beam driven current fraction (f BD ∼ 50%), which was sustained for 5.8 s in the stationary condition. This duration corresponds to ∼26τ E and ∼2.8τ R , which was limited by the pulse length of negative-ion-based neutral beams. The high confinement enhancement factor H 89 ∼ 2.2 (HH 98y2 ∼ 1.0) was obtained and the profiles of current and pressure reached the stationary condition. In the reversed shear plasma regime, a large bootstrap current fraction (f BS ∼ 75%) has been sustained for 7.4 s under nearly full non-inductive current drive conditions. This duration corresponds to ∼16τ E and ∼2.7τ R . The high confinement enhancement factor H 89 ∼ 3.0 (HH 98y2 ∼ 1.7) was also sustained, and the profiles of current and pressure reached the stationary condition. The large bootstrap current and the off-axis beam driven current sustained this reversed q profile. This duration was limited only by the duration of the neutral beam injection

  8. Acoustic Studies of the Effects of Environmental Stresses on Marine Mammals in Large Ocean Basins

    Science.gov (United States)

    Sidorovskaia, N.; Ma, B.; Ackleh, A. S.; Tiemann, C.; Ioup, G. E.; Ioup, J. W.

    2014-12-01

    Effects of environmental stresses on deep-diving marine mammal populations have not been studied systematically. Long-term regional passive acoustic monitoring of phonating marine mammals opens opportunities for such studies. This paper presents a unique multi-year study conducted by the Littoral Acoustic Demonstration Center (LADC) in the Northern Gulf of Mexico to understand short-term and long-term effects of anthropogenic stresses on resident populations of endangered sperm and elusive beaked whales. Both species spend many hours each day in deep dives which last about one hour each, so any visual observations for population estimates and behavioral responses are very limited. However, much more cost-efficient acoustic recordings of the phonations during dives on bottom-mounted hydrophones are not skewed by weather conditions or daylight requirements. Broadband passive acoustic data were collected by LADC in 2007 and 2010 at three ranges, 15, 40, and 80 km away from the 2010 Deep Water Horizon oil spill site. Pre-spill and post-spill data processing and comparison allow observing responses of both species to local short-term environmental condition changes and long-term responses to the spill. The short-term effects are studied by correlating daily activity cycles with anthropogenic noise curve daily and weekly cycles at different sites. The strong correlation between the decrease in overall daily activity and the increase in anthropogenic noise level associated with seismic exploration signals can be seen. After streaming raw acoustic data through detection algorithms and detailed assessment of false detection rates, the temporal densities of acoustic phonations are passed into statistical algorithms for resident population estimations. The statistically significant results have shown different regional abundance trends, associated with long-term responses to environmental stresses, for these two species.

  9. Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from Marine Boundary Layer over the California Current

    Energy Technology Data Exchange (ETDEWEB)

    William R. Wiley Environmental Sciences Laboratory, Pacific Northwest National Laboratory; Gilles, Mary K; Hopkins, Rebecca J.; Desyaterik, Yury; Tivanski, Alexei V.; Zaveri, Rahul A.; Berkowitz, Carl M.; Tyliszczak, Tolek; Gilles, Mary K.; Laskin, Alexander

    2008-03-12

    Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a combination of complementary microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOF-SIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from air masses that originated over the open ocean and then passed through the area of the California current located along the northern California coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH3SO3-) and non-sea salt sulfate (nss-SO42-) in sea-salt particles with characteristic ratios of nss-S/Na>0.10 and CH3SO3-/nss-SO42->0.6.

  10. Parasites as biological tags for the discrimination of marine fish stocks in Brazil: current status and perspectives

    Directory of Open Access Journals (Sweden)

    Iris Aparecida Soares

    2016-11-01

    Full Text Available ABSTRACT. Soares I.A. & Luque J.L. [Parasites as biological tags for the discrimination of marine fish stocks in Brazil: current status and perspectives.] Parasitos como marcadores biológicos para discriminação de estoques de peixes marinhos no Brasil: estado atual e perspectivas. Revista Brasileira de Medicina Veterinária, 38(supl. 3:99-113, 2016. Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal Rural do Rio de Janeiro, BR 465 Km 7, Seropédica, RJ 23890-000, Brasil. E-mail: luqueufrrj@gmail.com The global state of marine fisheries and its effects endanger the future of fishery resources, which may result in extinction of several species as well as threatening the overall integrity of the ecosystems. As the fish consumption growths, marine fishing and related market activities are stimulated increasing the incidence of threatened or exploited species. Aiming the future sustainability, fishery inventories need to be properly identified as a tool for implementation of more efficient policies on the management and conservation of the natural resources. Thus, by the high heterogeneity observed in the Atlantic coast of Brazil as well as the lack of related studies using this tool, the country represents great potential for the use of this technique, to improve our knowledge of local fishing resources. Therefore, the present study highlights the use of parasites as biological markers on identifying fish populations through robust statistical analysis, which represents an efficient and low cost approach and the lack of similar studies in Brazil showing the need of more research efforts on this subject in Brazil.

  11. Research on resistance characteristics of YBCO tape under short-time DC large current impact

    Science.gov (United States)

    Zhang, Zhifeng; Yang, Jiabin; Qiu, Qingquan; Zhang, Guomin; Lin, Liangzhen

    2017-06-01

    Research of the resistance characteristics of YBCO tape under short-time DC large current impact is the foundation of the developing DC superconducting fault current limiter (SFCL) for voltage source converter-based high voltage direct current system (VSC-HVDC), which is one of the valid approaches to solve the problems of renewable energy integration. SFCL can limit DC short-circuit and enhance the interrupting capabilities of DC circuit breakers. In this paper, under short-time DC large current impacts, the resistance features of naked tape of YBCO tape are studied to find the resistance - temperature change rule and the maximum impact current. The influence of insulation for the resistance - temperature characteristics of YBCO tape is studied by comparison tests with naked tape and insulating tape in 77 K. The influence of operating temperature on the tape is also studied under subcooled liquid nitrogen condition. For the current impact security of YBCO tape, the critical current degradation and top temperature are analyzed and worked as judgment standards. The testing results is helpful for in developing SFCL in VSC-HVDC.

  12. Current fluctuations and statistics during a large deviation event in an exactly solvable transport model

    International Nuclear Information System (INIS)

    Hurtado, Pablo I; Garrido, Pedro L

    2009-01-01

    We study the distribution of the time-integrated current in an exactly solvable toy model of heat conduction, both analytically and numerically. The simplicity of the model allows us to derive the full current large deviation function and the system statistics during a large deviation event. In this way we unveil a relation between system statistics at the end of a large deviation event and for intermediate times. The mid-time statistics is independent of the sign of the current, a reflection of the time-reversal symmetry of microscopic dynamics, while the end-time statistics does depend on the current sign, and also on its microscopic definition. We compare our exact results with simulations based on the direct evaluation of large deviation functions, analyzing the finite-size corrections of this simulation method and deriving detailed bounds for its applicability. We also show how the Gallavotti–Cohen fluctuation theorem can be used to determine the range of validity of simulation results

  13. Compensation methods applied in current control schemes for large AC drive systems

    DEFF Research Database (Denmark)

    Rus, D. C.; Preda, N. S.; Teodorescu, Remus

    2012-01-01

    The paper deals with modified PI current control structures for large AC drive systems which use surface mounted permanent magnet synchronous machines or squirrel-cage induction motors supplied with voltage source inverters. In order to reduce the power losses caused by high frequency switching...

  14. Using environmental DNA to census marine fishes in a large mesocosm.

    Directory of Open Access Journals (Sweden)

    Ryan P Kelly

    Full Text Available The ocean is a soup of its resident species' genetic material, cast off in the forms of metabolic waste, shed skin cells, or damaged tissue. Sampling this environmental DNA (eDNA is a potentially powerful means of assessing whole biological communities, a significant advance over the manual methods of environmental sampling that have historically dominated marine ecology and related fields. Here, we estimate the vertebrate fauna in a 4.5-million-liter mesocosm aquarium tank at the Monterey Bay Aquarium of known species composition by sequencing the eDNA from its constituent seawater. We find that it is generally possible to detect mitochondrial DNA of bony fishes sufficient to identify organisms to taxonomic family- or genus-level using a 106 bp fragment of the 12S ribosomal gene. Within bony fishes, we observe a low false-negative detection rate, although we did not detect the cartilaginous fishes or sea turtles present with this fragment. We find that the rank abundance of recovered eDNA sequences correlates with the abundance of corresponding species' biomass in the mesocosm, but the data in hand do not allow us to develop a quantitative relationship between biomass and eDNA abundance. Finally, we find a low false-positive rate for detection of exogenous eDNA, and we were able to diagnose non-native species' tissue in the food used to maintain the mesocosm, underscoring the sensitivity of eDNA as a technique for community-level ecological surveys. We conclude that eDNA has substantial potential to become a core tool for environmental monitoring, but that a variety of challenges remain before reliable quantitative assessments of ecological communities in the field become possible.

  15. Large-scale assessment of Mediterranean marine protected areas effects on fish assemblages.

    Directory of Open Access Journals (Sweden)

    Paolo Guidetti

    Full Text Available Marine protected areas (MPAs were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS and thermophilic species (ThS is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1 MPAs are numerous, 2 fishing has affected species and ecosystems, and 3 the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP, partially-protected MPAs (IP and fished areas (F at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators, but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide.

  16. Large-Scale Assessment of Mediterranean Marine Protected Areas Effects on Fish Assemblages

    Science.gov (United States)

    Guidetti, Paolo; Baiata, Pasquale; Ballesteros, Enric; Di Franco, Antonio; Hereu, Bernat; Macpherson, Enrique; Micheli, Fiorenza; Pais, Antonio; Panzalis, Pieraugusto; Rosenberg, Andrew A.; Zabala, Mikel; Sala, Enric

    2014-01-01

    Marine protected areas (MPAs) were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS) and thermophilic species (ThS) is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1) MPAs are numerous, 2) fishing has affected species and ecosystems, and 3) the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP), partially-protected MPAs (IP) and fished areas (F) at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators), but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide. PMID:24740479

  17. Power Projection: The Current and Future Relevance of the M1A1Tank to Marine Corps Capabilities

    Science.gov (United States)

    2002-01-01

    Kenneth W. Estes, Marines under Armor : The Marine Corps and the Armored Fighting Vehicle, 1916-2000 (Annapolis, MD: Naval institute Press, 2000), 183...is the M2 heavy barrel machine gun that has been in the U.S. inventory for decades. It can be fired from under armor and has a range of 1800 meters...Accessed 9 January 2002. Estes, Kenneth W. Marines under Armor : The Marine Corps and the Armored Fighting Vehicle, 1916-2000. Annapolis, MD

  18. Effect of bidirectional internal flow on fluid–structure interaction dynamics of conveying marine riser model subject to shear current

    Directory of Open Access Journals (Sweden)

    Zheng-Shou Chen

    2012-03-01

    Full Text Available This article presents a numerical investigation concerning the effect of two kinds of axially progressing internal flows (namely, upward and downward on fluid–structure interaction (FSI dynamics about a marine riser model which is subject to external shear current. The CAE technology behind the current research is a proposed FSI solution, which combines structural analysis software with CFD technology together. Efficiency validation for the CFD software was carried out first. It has been proved that the result from numerical simulations agrees well with the observation from relating model test cases in which the fluidity of internal flow is ignorable. After verifying the numerical code accuracy, simulations are conducted to study the vibration response that attributes to the internal progressive flow. It is found that the existence of internal flow does play an important role in determining the vibration mode (/dominant frequency and the magnitude of instantaneous vibration amplitude. Since asymmetric curvature along the riser span emerges in the case of external shear current, the centrifugal and Coriolis accelerations owing to up- and downward internal progressive flows play different roles in determining the fluid–structure interaction response. The discrepancy between them becomes distinct, when the velocity ratio of internal flow against external shear current is relatively high.

  19. Marine Hydrokinetic (MHK) Systems: A Systems Engineering Approach to Select Locations for the Practical Harvest of Electricity from Shallow Water Tidal Currents

    Science.gov (United States)

    Domenech, John

    Due to increasing atmospheric CO2 concentration and its effect on global climates, the United States Environmental Protection Agency (EPA) proposes a Clean Power Plan (CPP) mandating CO2 reductions which will likely force the early retirement of inefficient, aging power plants. Consequentially, removing these plants equates to a shortfall of approximately 66 GW of electricity. These factors add to the looming resource problems of choosing whether to build large replacement power plants or consider alternative energy sources as a means to help close the gap between electricity supply and demand in a given region. One energy source, shallow water tidal currents, represents opportunities to convert kinetic energy to mechanical forms and provide electricity to homes and businesses. Nearly 2,000 National Oceanic Atmospheric Administration (NOAA) tidal current data points from Maine to Texas are considered. This paper, based on systems engineering thinking, provides key attributes (e.g. turbine efficiency, array size, transmission losses) for consideration as decision makers seek to identify where to site Marine Hydrokinetic (MHK) systems and the number of homes powered by the practical harvest of electricity from tidal currents at those locations with given attributes. A systems engineering process model is proposed for consideration as is a regression based equation to estimate MHK machine parameters needed for power a given number of homes.

  20. Sustainable development - billions of watts under the seas - Marine current turbines play simple - Technological waves

    International Nuclear Information System (INIS)

    Lucas, Th.

    2011-01-01

    The author evokes the opportunities of power generation by the development of sea current or tidal stream turbines. Some developments are already tested by Norwegian, French, Danish, British and American companies. Some specific turbines are briefly presented. In order to reduce the cost of the electricity production from sea currents, manufacturers are using simple and robust technologies, and exploit the experience gained on wind turbines. Some designs and prototypes are evoked for the production of electricity by sea waves (Pelamis and Oyster projects). Principles, strengths and production projects are briefly indicated. The challenge of maintenance in sea environment is outlined for these projects

  1. Novel material and structural design for large-scale marine protective devices

    International Nuclear Information System (INIS)

    Qiu, Ang; Lin, Wei; Ma, Yong; Zhao, Chengbi; Tang, Youhong

    2015-01-01

    Highlights: • Large-scale protective devices with different structural designs have been optimized. • Large-scale protective devices with novel material designs have been optimized. • Protective devices constructed of sandwich panels have the best anti-collision performance. • Protective devices with novel material design can reduce weight and construction cost. - Abstract: Large-scale protective devices must endure the impact of severe forces, large structural deformation, the increased stress and strain rate effects, and multiple coupling effects. In evaluation of the safety of conceptual design through simulation, several key parameters considered in this research are maximum impact force, energy dissipated by the impactor (e.g. a ship) and energy absorbed by the device and the impactor stroke. During impact, the main function of the ring beam structure is to resist and buffer the impact force between ship and bridge pile caps, which could guarantee that the magnitude of impact force meets the corresponding requirements. The means of improving anti-collision performance can be to increase the strength of the beam section or to exchange the steel material with novel fiber reinforced polymer laminates. The main function of the buoyancy tank is to absorb and transfer the ship’s kinetic energy through large plastic deformation, damage, or friction occurring within itself. The energy absorption effect can be improved by structure optimization or by the use of new sandwich panels. Structural and material optimization schemes are proposed on the basis of conceptual design in this research, and protective devices constructed of sandwich panels prove to have the best anti-collision performance

  2. Development of large high current density superconducting solenoid magnets for use in high energy physics experiments

    International Nuclear Information System (INIS)

    Green, M.A.

    1977-05-01

    The development of a unique type of large superconducting solenoid magnet, characterized by very high current density windings and a two-phase helium tubular cooling system is described. The development of the magnet's conceptual design and the construction of two test solenoids are described. The successful test of the superconducting coil and its tubular cooling refrigeration system is presented. The safety, environmental and economic impacts of the test program on future developments in high energy physics are shown. Large solid angle particle detectors for colliding beam physics will analyze both charged and neutral particles. In many cases, these detectors will require neutral particles, such as gamma rays, to pass through the magnet coil with minimum interaction. The magnet coils must be as thin as possible. The use of superconducting windings allows one to minimize radiation thickness, while at the same time maximizing charged particle momentum resolution and saving substantial quantities of electrical energy. The results of the experimental measurements show that large high current density solenoid magnets can be made to operate at high stored energies. The superconducting magnet development described has a positive safety and environmental impact. The use of large high current density thin superconducting solenoids has been proposed in two high energy physics experiments to be conducted at the Stanford Linear Accelerator Center and Cornell University as a result of the successful experiments described

  3. The current situation of inorganic elements in marine turtles: A general review and meta-analysis.

    Science.gov (United States)

    Cortés-Gómez, Adriana A; Romero, Diego; Girondot, Marc

    2017-10-01

    Inorganic elements (Pb, Cd, Hg, Al, As, Cr, Cu, Fe, Mn, Ni, Se and Zn) are present globally in aquatic systems and their potential transfer to marine turtles can be a serious threat to their health status. The environmental fate of these contaminants may be traced by the analysis of turtle tissues. Loggerhead turtles (Caretta caretta) are the most frequently investigated of all the sea turtle species with regards to inorganic elements, followed by Green turtles (Chelonia mydas); all the other species have considerably fewer studies. Literature shows that blood, liver, kidney and muscle are the tissues most frequently used for the quantification of inorganic elements, with Pb, Cd, Cu and Zn being the most studied elements. Chelonia mydas showed the highest concentrations of Cr in muscle (4.8 ± 0.12), Cu in liver (37 ± 7) and Mg in kidney (17 μg g -1 ww), Cr and Cu from the Gulf of Mexico and Mg from Japanese coasts; Lepidochelys olivacea presented the highest concentrations of Pb in blood (4.46 5) and Cd in kidney (150 ± 110 μg g -1 ww), both from the Mexican Pacific; Caretta caretta from the Mediterranean Egyptian coast had the highest report of Hg in blood (0.66 ± 0.13 μg g -1 ww); and Eretmochelys imbricata from Japan had the highest concentration of As in muscle (30 ± 13 13 μg g -1 ww). The meta-analysis allows us to examine some features that were not visible when data was analyzed alone. For instance, Leatherbacks show a unique pattern of concentration compared to other species. Additionally, contamination of different tissues shows some tendencies independent of the species with liver and kidney on one side and bone on the other being different from other tissues. This review provides a general perspective on the accumulation and distribution of these inorganic elements alongside existing information for the 7 sea turtle species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. United Kingdom. Report 3 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Preston, A.

    1967-01-01

    Present research programmes: There are two current programmes, one in the Irish Sea (fission product distribution in coastal water environments) and one in the Blackwater Estuary - North Sea (effects of discharge of neutron activation radionuclides, e.g, 65 Zn, 51 Cr, 60 Co, 54 Mn, on an estuarine environment)

  5. Maaqwi cascadensis: A large, marine diving bird (Avialae: Ornithurae from the Upper Cretaceous of British Columbia, Canada.

    Directory of Open Access Journals (Sweden)

    Sandy M S McLachlan

    Full Text Available Mesozoic bird fossils from the Pacific Coast of North America are rare, but small numbers are known from the Late Cretaceous aged sediments of Hornby Island, British Columbia. Most are unassociated fragments that offer little information, but additional preparation of a large coracoid has revealed more details of its structure, as well as three associated wing bones. Phylogenetic analysis suggests that Maaqwi cascadensis, gen. et sp. nov. represents a derived crown or near-crown member of Ornithurae, and specifically suggests affinities with Vegaviidae. M. cascadensis is characterized by large size, and regressions based on dimensions of the coracoid suggest a large bird, with an estimated body mass of approximately 1.5 kilograms. The bones are robust, with thick walls, suggesting that M. cascadensis was a bird adapted for diving, similar to modern loons and grebes. The wings are short, while the coracoid is unusually short and broad, similar to modern loons. Along with the Ichthyornithes and Hesperornithes, M. cascadensis and Vegaviidae appear to represent a third clade of bird that evolved to exploit marine habitats in the Late Cretaceous, one specialized for foot-propelled diving and rapid cruising flight over water.

  6. Large Eddy Simulations of sediment entrainment induced by a lock-exchange gravity current

    Science.gov (United States)

    Kyrousi, Foteini; Leonardi, A.; Roman, F.; Armenio, V.; Zanello, F.; Zordan, J.; Juez, C.; Falcomer, L.

    2018-04-01

    Large Eddy simulations of lock-exchange gravity currents propagating over a mobile reach are presented. The numerical setting allows to investigate the sediment pick up induced by the currents and to study the underlying mechanisms leading to sediment entrainment for different Grashof numbers and grain sizes. First, the velocity field and the bed shear-stress distribution are investigated, along with turbulent structures formed in the flow, before the current reaches the mobile bed. Then, during the propagation of the current above the erodible section of the bed the contour plots of the entrained material are presented as well as the time evolution of the areas covered by the current and by the sediment at this section. The numerical outcomes are compared with experimental data showing a very good agreement. Overall, the study confirms that sediment pick up is prevalent at the head of the current where the strongest turbulence occurs. Further, above the mobile reach of the bed, settling process seems to be of minor importance, with the entrained material being advected downstream by the current. Additionally, the study shows that, although shear stress is the main mechanism that sets particles in motion, turbulent bursts as well as vertical velocity fluctuations are also necessary to counteract the falling velocity of the particles and maintain them into suspension. Finally, the analysis of the stability conditions of the current shows that, from one side, sediment concentration gives a negligible contribution to the stability of the front of the current and from the other side, the stability conditions provided by the current do not allow sediments to move into the ambient fluid.

  7. Propagation of large amplitude Alfven waves in the solar wind current sheet

    International Nuclear Information System (INIS)

    Malara, Francesco; Primavera, Leonardo; Veltri, Pierluigi

    1996-01-01

    The time evolution of Alfvenic perturbations in the Solar Wind current sheet is studied by using numerical simulations of the compressible magnetohydrodynamic (MHD) equations. The simulations show that the interaction between the large amplitude Alfvenic pertubation and the solar wind current sheet decreases the correlation between velocity and magnetic field fluctuations and produces compressive fluctuations. The characteristics of these compressive fluctuations compare rather well with spatial observations. The behavior of the correlation between density and magnetic field intensity fluctuations and of the their spectra are well reproduced so that the physical mechanisms giving rise to these behaviors can be identified

  8. Current correlators in QCD: Operator product expansion versus large distance dynamics

    International Nuclear Information System (INIS)

    Shevchenko, V.I.; Simonov, Yu.A.

    2004-01-01

    We analyze the structure of current-current correlators in coordinate space in the large N c limit when the corresponding spectral density takes the form of an infinite sum over hadron poles. The latter are computed in the QCD string model with quarks at the ends, including the lowest states, for all channels. The corresponding correlators demonstrate reasonable qualitative agreement with the lattice data without any additional fits. Different issues concerning the structure of the short-distance operator product expansion are discussed

  9. Transient characteristics of current lead losses for the large scale high-temperature superconducting rotating machine

    International Nuclear Information System (INIS)

    Le, T. D.; Kim, J. H.; Park, S. I.; Kim, D. J.; Kim, H. M.; Lee, H. G.; Yoon, Y. S.; Jo, Y. S.; Yoon, K. Y.

    2014-01-01

    To minimize most heat loss of current lead for high-temperature superconducting (HTS) rotating machine, the choice of conductor properties and lead geometry - such as length, cross section, and cooling surface area - are one of the various significant factors must be selected. Therefore, an optimal lead for large scale of HTS rotating machine has presented before. Not let up with these trends, this paper continues to improve of diminishing heat loss for HTS part according to different model. It also determines the simplification conditions for an evaluation of the main flux flow loss and eddy current loss transient characteristics during charging and discharging period.

  10. Small-scale open ocean currents have large effects on wind wave heights

    Science.gov (United States)

    Ardhuin, Fabrice; Gille, Sarah T.; Menemenlis, Dimitris; Rocha, Cesar B.; Rascle, Nicolas; Chapron, Bertrand; Gula, Jonathan; Molemaker, Jeroen

    2017-06-01

    Tidal currents and large-scale oceanic currents are known to modify ocean wave properties, causing extreme sea states that are a hazard to navigation. Recent advances in the understanding and modeling capability of open ocean currents have revealed the ubiquitous presence of eddies, fronts, and filaments at scales 10-100 km. Based on realistic numerical models, we show that these structures can be the main source of variability in significant wave heights at scales less than 200 km, including important variations down to 10 km. Model results are consistent with wave height variations along satellite altimeter tracks, resolved at scales larger than 50 km. The spectrum of significant wave heights is found to be of the order of 70>>2/>(g2>>2>) times the current spectrum, where >> is the spatially averaged significant wave height, >> is the energy-averaged period, and g is the gravity acceleration. This variability induced by currents has been largely overlooked in spite of its relevance for extreme wave heights and remote sensing.Plain Language SummaryWe show that the variations in currents at scales 10 to 100 km are the main source of variations in wave heights at the same scales. Our work uses a combination of realistic numerical models for currents and waves and data from the Jason-3 and SARAL/AltiKa satellites. This finding will be of interest for the investigation of extreme wave heights, remote sensing, and air-sea interactions. As an immediate application, the present results will help constrain the error budget of the up-coming satellite missions, in particular the Surface Water and Ocean Topography (SWOT) mission, and decide how the data will have to be processed to arrive at accurate sea level and wave measurements. It will also help in the analysis of wave measurements by the CFOSAT satellite.

  11. Development of large area silicon semiconductor detectors for use in the current mode

    CERN Document Server

    Ouyang Xia Opin; Li Zhen Fu; Zhang Guo Guang; Zhang Qi; Zhang Xia; Song Xian Cai; Jia Huan Yi; Lei Jian Hua; Sun Yuan Cheng

    2002-01-01

    Large area silicon semiconductor detectors for use in the current mode, with their dimensions of phi 40, phi 50 and phi 60 mm, their depletion thickness of 200-300 mu m, have been developed. Their performance measurements have been made, which indicate that the developed detectors can satisfactorily meet the needs in expectation. Compared with the detectors commercially available on the market, authors' large PIN detectors can serve both as reliable and efficient high-resolution devices for nuclear counting experiments, as well as monitors of high-intensity radiation fields in the current mode under a bias of 100-1000 V, while the detectors commercially available are only for the counting use

  12. Characteristics of Sulfuric Acid Condensation on Cylinder Liners of Large Two-Stroke Marine Engines

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Lage; Mayer, Stefan; Schramm, Jesper

    . Formation of corrosive sulfuric acid in the cylinder gas is modeled with a cali-brated engine model that incorporates a detailed sulfur reaction mechanism. Condensation of sulfuric acid follows the analogy between heat and mass transfer. Average bulk gas acid dew points are calculated by applying two......-phase thermochemistry of the binary H2O-H2SO4 system. Max dew points of typically more than 200 °C are modeled close to max pressure and variations in terms of operating conditions are not large. However small increments of the dew point provided by e.g. the residual gas fraction, operating pressure, sulfur content...

  13. Marine Biomedicine

    Science.gov (United States)

    Bang, Frederik B.

    1977-01-01

    Describes early scientific research involving marine invertebrate pathologic processes that may have led to new insights into human disease. Discussed are inquiries of Metchnikoff, Loeb, and Cantacuzene (immunolgic responses in sea stars, horseshoe crabs, and marine worms, respectively). Describes current research stemming from these early…

  14. United Kingdom. Report 2 [Marine Radioecology. Current Research and Future Scope

    International Nuclear Information System (INIS)

    Martin, J.H.

    1967-01-01

    Present research programme: 1.1. The biology of the Solway Firth in relation to the movement and accumulation of radioactive materials. 1.2. To determine the maximum capacity of the Solway Firth for the receipt of radioactive effluent. 1.3. The work has included study of the estuarine currents, using drifters; study of the relationship between deposition of radioactivity and soil by means of transects; studies of the nature and variation, with season and position in the estuary, of fish feeding; and studies of the flora and fauna of the estuary (including some minor studies of how they are affected by climatic changes)

  15. Paradigms and nursing management, analysis of the current organizational structure in a large hospital.

    Science.gov (United States)

    Wilson, D

    1992-01-01

    Hospitals developed over the period of time when positivism become a predominant world view. Positivism was founded by four Western trends: preponderance of hierarchy and autocracy, popularization of bureaucracy, extensive application of a machine orientation to work and predominance of "scientific" inquiry. Organizational theory developed largely from quantitative research findings arising from a positivistic world view. A case study, analyzing a current nursing organizational structure at one large hospital, is presented. Nursing management was found to be based upon the positivistic paradigm. The predominance of a machine orientation, and an autocratic and bureaucratic structure are evidence of this. A change to shared governance had been attempted, indicating a shift to a more modern organizational structure based on a different paradigm. The article concludes by emphasizing that managers are largely responsible for facilitating change; change that will meet internal human resource needs and the cost-effectiveness crises of hospitals today through more effective use of human resources.

  16. Marine Benthic Habitats and Seabed Suitability Mapping for Potential Ocean Current Energy Siting Offshore Southeast Florida

    Directory of Open Access Journals (Sweden)

    Amanda Mulcan

    2015-05-01

    Full Text Available This study examines the legal framework for ocean current energy policy and regulation to develop a metric for assessing the biological and geological characteristics of a seabed area with respect to the siting of OCE devices, a framework of criteria by which to assess seabed suitability (seabed suitability framework that can facilitate the siting, and implementation of ocean current energy (OCE projects. Seafloor geology and benthic biological data were analyzed in conjunction with seafloor core sample geostatistical interpolation to locate suitable substrates for OCE anchoring. Existing submarine cable pathways were considered to determine pathways for power transmission cables that circumvent biologically sensitive areas. Suitability analysis indicates that areas east of the Miami Terrace and north of recently identified deep-sea coral mounds are the most appropriate for OCE siting due to abundance of sand/sediment substrate, existing underwater cable route access, and minimal biological presence (i.e., little to no benthic communities. Further reconnaissance requires higher resolution maps of geological substrate and benthic community locations to identify specific OCE development locations, classify benthic conditions, and minimize potentially negative OCE environmental impacts.

  17. Generation of pyroclastic density currents from pyroclastic fountaining or transient explosions: insights from large scale experiments

    Energy Technology Data Exchange (ETDEWEB)

    Sulpizio, Roberto; Dellino, Pierfrancesco; Mele, Daniela; La Volpe, Luigi [CIRISIVU, c/o Dipartimento Geomineralogico, via Orabona 4, 70125, Bari (Italy)], E-mail: r.sulpizio@geomin.uniba.it

    2008-10-01

    Pyroclastic density currents (PDCs) are among the most amazing, complex and dangerous volcanic phenomena. They are moving mixtures of particles and gas that flow across the ground, and originate in different ways and from various sources, during explosive eruptions or gravity-driven collapse of domes. We present results from experimental work to investigate the generation of large-scale, multiphase, gravity-driven currents. The experiments described here are particularly devoted to understanding the inception and development of PDCs under impulsive injection conditions by means of the fast application of a finite stress to a finite mass of pyroclastic particles via expansion of compressed gas. We find that, in summary, PDC generation from collapse of pressure-adjusted or overpressurised pyroclastic jets critically depends on behaviour of injection into the atmosphere, which controls the collapsing mechanisms and then the physical parameters of the initiating current.

  18. Economic benefits of large-scale remediation of contaminated marine sediments. A literature review and an application to the Grenland fjords in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Barton, David Nicholas [Norwegian Inst. for Water Research (NIVA) / Norwegian Inst. Nature Research, Oslo (Norway); Navrud, Staale; Bjoerkeslett, Heid; Lilleby, Ingrid [Dept. of Economics and Resource Management, Norwegian Univ. of Life Sciences (UMB), As (Norway)

    2010-03-15

    Purpose: As input to a cost-benefit analysis of large-scale remediation measures of contaminated sediments in the Grenland fjords in Norway, we conducted a contingent valuation (CV) survey of a representative sample of households from municipalities adjacent to these fjords. Materials and methods: The CV method aimed at valuing the benefits perceived by households of removing dietary health advisories on seafood consumption currently in place through the fjords. Results: Mean household willingness-to-pay (WTP) per year over a 10-year period was found to decrease with increased distance from the Grenland fjords and was somewhat higher than in a similar study conducted 10 years earlier than our study. Aggregating mean WTP over all households in neighbouring municipalities to the fjords resulted in total economic benefits of the same magnitude as the total remediation costs. The WTP results make the case in such a way that the high costs of remediation of contaminated marine sediments can be defended by the large economic benefits generated for households around the fjord. The research was financed by the local environmental authorities and the local industry that had caused the contaminated sediments. The WTP results were strongly contested by the industry upon completion of the study. Conclusion: The paper addresses the industry's critiques of this particular CV study and discusses how to better inform local stakeholders about the potential and limitations of the CV method and how to improve communication of economic valuation results. (orig.)

  19. Multi-Annual Climate Predictions for Fisheries: An Assessment of Skill of Sea Surface Temperature Forecasts for Large Marine Ecosystems

    Directory of Open Access Journals (Sweden)

    Desiree Tommasi

    2017-06-01

    Full Text Available Decisions made by fishers and fisheries managers are informed by climate and fisheries observations that now often span more than 50 years. Multi-annual climate forecasts could further inform such decisions if they were skillful in predicting future conditions relative to the 50-year scope of past variability. We demonstrate that an existing multi-annual prediction system skillfully forecasts the probability of next year, the next 1–3 years, and the next 1–10 years being warmer or cooler than the 50-year average at the surface in coastal ecosystems. Probabilistic forecasts of upper and lower seas surface temperature (SST terciles over the next 3 or 10 years from the GFDL CM 2.1 10-member ensemble global prediction system showed significant improvements in skill over the use of a 50-year climatology for most Large Marine Ecosystems (LMEs in the North Atlantic, the western Pacific, and Indian oceans. Through a comparison of the forecast skill of initialized and uninitialized hindcasts, we demonstrate that this skill is largely due to the predictable signature of radiative forcing changes over the 50-year timescale rather than prediction of evolving modes of climate variability. North Atlantic LMEs stood out as the only coastal regions where initialization significantly contributed to SST prediction skill at the 1 to 10 year scale.

  20. Dwarf males, large hermaphrodites and females in marine species: a dynamic optimization model of sex allocation and growth.

    Science.gov (United States)

    Yamaguchi, Sachi; Sawada, Kota; Yusa, Yoichi; Iwasa, Yoh

    2013-05-01

    In this study, we investigate the evolutionarily stable schedule of growth and sex allocation for marine benthic species that contain dwarf males. We consider a population in an ephemeral microhabitat that receives a constant supply of larvae. Small individuals can immediately reproduce as a dwarf male or remain immature and grow. Large individuals allocate reproductive resources between male and female functions. The fraction c of newly settled individuals who remain immature and the sex allocation of large individuals m are quantities to evolve. In the stationary ESS, if the relative reproductive success of dwarf males is greater than the survivorship of immature individuals until they reach a mature size, then the population is a mixture of females and dwarf males. If the opposite inequality holds, the population is dominated by hermaphrodites and lacks dwarf males. There is no case in which a mixture of hermaphrodites and dwarf males to be the ESS in the stationary solution. The ESS can be solved by dynamic programming when the strategies depend on the age of the microhabitat (c(t) and m(t)). Typically, the ESS schedule begins with a population composed only of hermaphrodites, which is replaced by a mixture of dwarf males and hermaphrodites and then by a mixture of dwarf males and pure females. The relative importance of these three phases depends on multiple parameters. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Experimental Results of a DC Bus Voltage Level Control for a Load-Controlled Marine Current Energy Converter

    Directory of Open Access Journals (Sweden)

    Johan Forslund

    2015-05-01

    Full Text Available This paper investigates three load control methods for a  marine current energy converter using a vertical axis current  turbine (VACT mounted on a permanent magnet synchronous generator  (PMSG. The three cases are; a fixed AC load, a fixed pulse width  modulated (PWM DC load and DC bus voltage control of a DC  load. Experimental results show that the DC bus voltage control  reduces the variations of rotational speed by a factor of 3.5 at the cost  of slightly increased losses in the generator and transmission lines.  For all three cases, the tip speed ratio \\(\\lambda\\ can be kept close to  the expected \\(\\lambda_{opt}\\. The power coefficient is estimated to be  0.36 at \\(\\lambda_{opt}\\; however, for all three cases, the average  extracted power was about \\(\\sim 19\\\\%. A maximum power point  tracking (MPPT system, with or without water velocity measurement,  could increase the average extracted power.

  2. Design and flight performance evaluation of the Mariners 6, 7, and 9 short-circuit current, open-circuit voltage transducers

    Science.gov (United States)

    Patterson, R. E.

    1973-01-01

    The purpose of the short-circuit voltage transducer is to provide engineering data to aid the evaluation of array performance during flight. The design, fabrication, calibration, and in-flight performance of the transducers onboard the Mariner 6, 7 and 9 spacecrafts are described. No significant differences were observed in the in-flight electrical performance of the three transducers. The transducers did experience significant losses due to coverslides or adhesive darkening, increased surface reflection, or spectral shifts within coverslide assembly. Mariner 6, 7 and 9 transducers showed non-cell current degradations of 3-1/2%, 3%, and 4%, respectively at Mars encounter and 6%, 3%, and 4-12%, respectively at end of mission. Mariner 9 solar Array Test 2 showed 3-12% current degradation while the transducer showed 4-12% degradation.

  3. Inductive current startup in large tokamaks with expanding minor radius and rf assist

    International Nuclear Information System (INIS)

    Borowski, S.K.

    1984-02-01

    Auxiliary rf heating of electrons before and during the current-rise phase of a large tokamak, such as the Fusion Engineering Device (R = 4.8 m, a = 1.3 m, sigma = 1.6, B/sub T/ = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at approx. 90 GHz is used to create a small volume of high conductivity plasma (T/sub e/ approx. = 100 eV, n/sub e/ approx. = 10 19 m -3 ) near the upper hybrid resonance (UHR) region. This plasma conditioning permits a small radius (a 0 approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to approx. 100 V without rf assist). During the subsequent plasma expansion and current ramp phase, a combination of rf heating (up to 5 MW) and current profile control leads to a substantial savings in volt-seconds by: (1) minimizing the resistive flux consumption; and (2) maintaining the internal flux at or near the flat profile limit

  4. Image subsampling and point scoring approaches for large-scale marine benthic monitoring programs

    Science.gov (United States)

    Perkins, Nicholas R.; Foster, Scott D.; Hill, Nicole A.; Barrett, Neville S.

    2016-07-01

    Benthic imagery is an effective tool for quantitative description of ecologically and economically important benthic habitats and biota. The recent development of autonomous underwater vehicles (AUVs) allows surveying of spatial scales that were previously unfeasible. However, an AUV collects a large number of images, the scoring of which is time and labour intensive. There is a need to optimise the way that subsamples of imagery are chosen and scored to gain meaningful inferences for ecological monitoring studies. We examine the trade-off between the number of images selected within transects and the number of random points scored within images on the percent cover of target biota, the typical output of such monitoring programs. We also investigate the efficacy of various image selection approaches, such as systematic or random, on the bias and precision of cover estimates. We use simulated biotas that have varying size, abundance and distributional patterns. We find that a relatively small sampling effort is required to minimise bias. An increased precision for groups that are likely to be the focus of monitoring programs is best gained through increasing the number of images sampled rather than the number of points scored within images. For rare species, sampling using point count approaches is unlikely to provide sufficient precision, and alternative sampling approaches may need to be employed. The approach by which images are selected (simple random sampling, regularly spaced etc.) had no discernible effect on mean and variance estimates, regardless of the distributional pattern of biota. Field validation of our findings is provided through Monte Carlo resampling analysis of a previously scored benthic survey from temperate waters. We show that point count sampling approaches are capable of providing relatively precise cover estimates for candidate groups that are not overly rare. The amount of sampling required, in terms of both the number of images and

  5. Lubricant transport across the piston ring with flat and triangular lubrication injection profiles on the liner in large two-stroke marine diesel engines

    DEFF Research Database (Denmark)

    Overgaard, H.; Klit, P.; Vølund, A.

    2018-01-01

    A theoretical investigation of the lubricant transport across the top compression piston ring in a large two-stroke marine diesel engine is presented. A numerical model for solving Reynolds equation between the piston ring and cylinder liner based on the finite difference method in one dimension...

  6. Influence of outlet geometry on the swirling flow in a simplfied model of a large two-stroke marine diesel engine

    DEFF Research Database (Denmark)

    Haider, Sajjad; Schnipper, Teis; Meyer, Knud Erik

    We present Stereoscopic particle image velocimetry measurements of the effect of a dummy-valve on the in-cylinder swirling flow in a simplified scale model of a large two-stroke marine diesel engine cylinder using air at room temperature and pressure as the working fluid and Reynolds number 19500...

  7. PIV study of the effect of piston position on the in-cylinder swirling flow during the scavenging process in large two-stroke marine diesel engines

    DEFF Research Database (Denmark)

    Haider, Sajjad; Schnipper, Teis; Obeidat, Anas

    2013-01-01

    A simplified model of a low speed large twostroke marine diesel engine cylinder is developed. The effect of piston position on the in-cylinder swirling flow during the scavenging process is studied using the stereoscopic particle image velocimetry technique. The measurements are conducted...

  8. Projecting changes in the distribution and productivity of living marine resources: A critical review of the suite of modelling approaches used in the large European project VECTORS

    NARCIS (Netherlands)

    Peck, Myron A.; Arvanitidis, Christos; Butenschön, Momme; Canu, Donata Melaku; Chatzinikolaou, Eva; Cucco, Andrea; Domenici, Paolo; Fernandes, Jose A.; Gasche, Loic; Huebert, Klaus B.; Hufnagl, Marc; Jones, Miranda C.; Kempf, Alexander; Keyl, Friedemann; Maar, Marie; Mahévas, Stéphanie; Marchal, Paul; Nicolas, Delphine; Pinnegar, John K.; Rivot, Etienne; Rochette, Sébastien; Sell, Anne F.; Sinerchia, Matteo; Solidoro, Cosimo; Somerfield, Paul J.; Teal, Lorna R.; Travers-trolet, Morgan; De Wolfshaar, Van Karen E.

    2018-01-01

    We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of

  9. Climate change and marine life

    DEFF Research Database (Denmark)

    Richardson, Anthony J.; Brown, Christopher J.; Brander, Keith

    2012-01-01

    A Marine Climate Impacts Workshop was held from 29 April to 3 May 2012 at the US National Center of Ecological Analysis and Synthesis in Santa Barbara. This workshop was the culmination of a series of six meetings over the past three years, which had brought together 25 experts in climate change...... ecology, analysis of large datasets, palaeontology, marine ecology and physical oceanography. Aims of these workshops were to produce a global synthesis of climate impacts on marine biota, to identify sensitive habitats and taxa, to inform the current Intergovernmental Panel on Climate Change (IPCC......) process, and to strengthen research into ecological impacts of climate change...

  10. Standard and biological treatment in large vessel vasculitis: guidelines and current approaches.

    Science.gov (United States)

    Muratore, Francesco; Pipitone, Nicolò; Salvarani, Carlo

    2017-04-01

    Giant cell arteritis and Takayasu arteritis are the two major forms of idiopathic large vessel vasculitis. High doses of glucocorticoids are effective in inducing remission in both conditions, but relapses and recurrences are common, requiring prolonged glucocorticoid treatment with the risk of the related adverse events. Areas covered: In this article, we will review the standard and biological treatment strategies in large vessel vasculitis, and we will focus on the current approaches to these diseases. Expert commentary: The results of treatment trials with conventional immunosuppressive agents such as methotrexate, azathioprine, mycophenolate mofetil, and cyclophosphamide have overall been disappointing. TNF-α blockers are ineffective in giant cell arteritis, while observational evidence and a phase 2 randomized trial support the use of tocilizumab in relapsing giant cell arteritis. Observational evidence strongly supports the use of anti-TNF-α agents and tocilizumab in Takayasu patients with relapsing disease. However biological agents are not curative, and relapses remain common.

  11. Experimental study on the effects of surface gravity waves of different wavelengths on the phase averaged performance characteristics of marine current turbine

    Science.gov (United States)

    Luznik, L.; Lust, E.; Flack, K. A.

    2014-12-01

    There are few studies describing the interaction between marine current turbines and an overlying surface gravity wave field. In this work we present an experimental study on the effects of surface gravity waves of different wavelengths on the wave phase averaged performance characteristics of a marine current turbine model. Measurements are performed with a 1/25 scale (diameter D=0.8m) two bladed horizontal axis turbine towed in the large (116m long) towing tank at the U.S. Naval Academy equipped with a dual-flap, servo-controlled wave maker. Three regular waves with wavelengths of 15.8, 8.8 and 3.9m with wave heights adjusted such that all waveforms have the same energy input per unit width are produced by the wave maker and model turbine is towed into the waves at constant carriage speed of 1.68 m/s. This representing the case of waves travelling in the same direction as the mean current. Thrust and torque developed by the model turbine are measured using a dynamometer mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using in in-house designed shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Free surface elevation and wave parameters are measured with two optical wave height sensors, one located in the turbine rotor plane and other one diameter upstream of the rotor. All instruments are synchronized in time and data is sampled at a rate of 700 Hz. All measured quantities are conditionally sampled as a function of the measured surface elevation and transformed to wave phase space using the Hilbert Transform. Phenomena observed in earlier experiments with the same turbine such as phase lag in the torque signal and an increase in thrust due to Stokes drift are examined and presented with the present data as well as spectral analysis of the torque and thrust data.

  12. Luminescence property and large-scale production of ZnO nanowires by current heating deposition

    International Nuclear Information System (INIS)

    Singjai, P.; Jintakosol, T.; Singkarat, S.; Choopun, S.

    2007-01-01

    Large-scale production for ZnO nanowires has been demonstrated by current heating deposition. Based on the use of a solid-vapor phase carbothermal sublimation technique, a ZnO-graphite mixed rod was placed between two copper bars and gradually heated by passing current through it under constant flowing of argon gas at atmospheric pressure. The product seen as white films deposited on the rod surface was separated for further characterizations. The results have shown mainly comb-like structures of ZnO nanowires in diameter ranging from 50 to 200 nm and length up to several tens micrometers. From optical testing, ionoluminescence spectra of as-grown and annealed samples have shown high green emission intensities centered at 510 nm. In contrast, the small UV peak centered at 390 nm was observed clearly in the as-grown sample which almost disappeared after the annealing treatment

  13. Impact of climate change on large scale coastal currents of South Africa

    CSIR Research Space (South Africa)

    Meyer, A

    2010-09-01

    Full Text Available of temperature trends in the southern indian ocean. Geophysical Research Letters, 34, L14611, doi:10.1029/2007gL030380. • De Ruijter, W.P.M., van Aken, H.M., Beier, E.J., Lutjeharms, J.R.E., Matano, R.P. Schouten, M.W. 2004. eddies and dipoles around South... Madagascar: formation, pathways and large- scale impact. Deep-Sea Research I, 51, 383-400. • Lutjeharms, J. R. E. and van Ballegooyen, R. C. 1988. Anomalous upstream retroflection in the agulhas current. Science, 240, 1770-1772. • Rouault, M., Penven...

  14. Breakthrough In Current In Plane Metrology For Monitoring Large Scale MRAM Production

    DEFF Research Database (Denmark)

    Cagliani, Alberto; Østerberg, Frederik Westergaard; Hansen, Ole

    2017-01-01

    The current-in-plane tunneling technique (CIPT) has been a crucial tool in the development of magnetic tunnel junction stacks suitable for Magnetic Random Access Memories (MRAM) for more than a decade. The MRAM development has now reached the maturity to make the transition from R&D to large...... of the Resistance Area product (RA) and the Tunnel Magnetoresistance (TMR) measurements, compared to state of the art CIPT metrology tools dedicated to R&D. On two test wafers, the repeatability of RA and MR was improved up to 350% and the measurement reproducibility up to 1700%. We believe that CIPT metrology now...

  15. Current Barriers to Large-scale Interoperability of Traceability Technology in the Seafood Sector.

    Science.gov (United States)

    Hardt, Marah J; Flett, Keith; Howell, Colleen J

    2017-08-01

    Interoperability is a critical component of full-chain digital traceability, but is almost nonexistent in the seafood industry. Using both quantitative and qualitative methodology, this study explores the barriers impeding progress toward large-scale interoperability among digital traceability systems in the seafood sector from the perspectives of seafood companies, technology vendors, and supply chains as a whole. We highlight lessons from recent research and field work focused on implementing traceability across full supply chains and make some recommendations for next steps in terms of overcoming challenges and scaling current efforts. © 2017 Institute of Food Technologists®.

  16. Inductive current startup in large tokamaks with expanding minor radius and RF assist

    International Nuclear Information System (INIS)

    Borowski, S.K.

    1983-01-01

    Auxiliary RF heating of electrons before and during the current rise phase of a large tokamak, such as the Fusion Engineering Device, is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at approx.90 GHz is used to create a small volume of high conductivity plasma (T/sub e/ approx. = 100 eV, n/sub e/ approx. = 10 19 m -3 ) near the upper hybrid resonance (UHR) region. This plasma conditioning permits a small radius (a 0 approx.< 0.4 m) current channel to be established with a relatively low initial loop voltage (approx.< 25 V as opposed to approx.100 V without RF assist). During the subsequent plasma expansion and current ramp phase, additional RF power is introduced to reduce volt-second consumption due to plasma resistance. To study the preheating phase, a near classical particle and energy transport model is developed to estimate the electron heating efficiency in a currentless toroidal plasma. The model assumes that preferential electron heating at the UHR leads to the formation of an ambipolar sheath potential between the neutral plasma and the conducting vacuum vessel and limiter

  17. Study of the nonequilibrium state of superconductors by large quasiparticle injection from an external current source

    International Nuclear Information System (INIS)

    Iguchi, I.

    1977-01-01

    We have studied the nonequilibrium state of superconductors by injecting large numbers of quasiparticles from an external current source into a superconducting film of a tunnel junction with low tunnel resistance (typically 0.1--1 Ω for junction area approx. = 10 -4 cm 2 ). It was observed that there was a critical tunnel current density at which a voltage appeared locally in the part of a superconducting film confined to the junction area. Its values ranged from 10 2 to 10 3 A/cm 2 for bath temperatures well below T/sub c/. Followed by this voltage onset, a transition region corresponding to the nonequilibrium intermediate resistive state was also observed. For further increase of the tunnel current, the local film resistance developed beyond the value of its normal resistance, suggesting that the nonequilibrium state extends far beyond the voltage onset point. A theory based on the modified Rothwarf-Taylor equations and Parker's T* model is presented to compare with the experimental results. The calculated critical current density yielded almost the same order of magnitude as those found experimentally. The detailed behavior, however, deviates from the theoretical predictions although the film makes a second-order transition in the broad range of temperatures. It is also shown using four-terminal analysis that our observations and those by Wong, Yeh, and Langenberg are essentially the same

  18. Large Eddy Simulations of Compositional Density Currents Flowing Over a Mobile Bed

    Science.gov (United States)

    Kyrousi, Foteini; Zordan, Jessica; Leonardi, Alessandro; Juez, Carmelo; Zanello, Francesca; Armenio, Vincenzo; Franca, Mário J.

    2017-04-01

    Density currents are a ubiquitous phenomenon caused by natural events or anthropogenic activities, and play an important role in the global sediment cycle; they are agents of long distance sediment transport in lakes, seas and oceans. Density gradients induced by salinity, temperature differences, or by the presence of suspended material are all possible triggers of a current. Such flows can travel long distances while eroding or depositing bed materials. This can provoke rapid topological changes, which makes the estimation of their transport capacity of prime interest for environmental engineering. Despite their relevance, field data regarding their dynamics is limited due to density currents scattered and unpredictable occurrence in nature. For this reason, laboratory experiments and numerical simulations have been a preferred way to investigate sediment transport processes associated to density currents. The study of entrainment and deposition processes requires detailed data of velocities spatial and temporal distributions in the boundary layer and bed shear stress, which are troublesome to obtain in laboratory. Motivated by this, we present 3D wall-resolved Large Eddy Simulations (LES) of density currents generated by lock-exchange. The currents travel over a smooth flat bed, which includes a section composed by erodible fine sediment susceptible of eroding. Several sediment sizes and initial density gradients are considered. The grid is set to resolve the velocity field within the boundary layer of the current (a tiny fraction of the total height), which in turn allows to obtain predictions of the bed shear stress. The numerical outcomes are compared with experimental data obtained with an analogous laboratory setting. In laboratory experiments salinity was chosen for generating the initial density gradient in order to facilitate the identification of entrained particles, since salt does not hinder the possibility to track suspended particles. Under these

  19. Marine biology

    International Nuclear Information System (INIS)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  20. Are CH2O measurements in the marine boundary layer suitable for testing the current understanding of CH4 photooxidation?: A model study

    Science.gov (United States)

    Wagner, V.; von Glasow, R.; Fischer, H.; Crutzen, P. J.

    2002-02-01

    On the basis of a data set collected during the Indian Ocean Experiment (INDOEX) campaign 1999, we investigated the formaldehyde (CH2O) budget in the southern Indian Ocean (SIO). With a photochemical box model we simulated the contribution of methane and nonmethane volatile organic compounds to the CH2O budget. To identify the reactions and model constraints that introduce the largest uncertainties in the modeled CH2O concentration, we carried out a local sensitivity analysis. Furthermore, a Monte Carlo method was used to assess the global error of the model predictions. According to this analysis the 2σ uncertainty in the modeled CH2O concentration is 49%. The deviation between observed (200 +/- 70 parts per trillion by volume (pptv) (2σ)) and modeled (224 +/- 110 pptv (2σ)) daily mean CH2O concentration is 12%. However, the combined errors of model and measurement are such that deviations as large as 65% are not significant at the 2σ level. Beyond the ``standard'' photochemistry we analyzed the impact of halogen and aerosol chemistry on the CH2O concentration and investigated the vertical distribution of CH2O in the marine boundary layer (MBL). Calculations with the Model of Chemistry Considering Aerosols indicate that, based on the current understanding, halogen chemistry and aerosol chemistry have no significant impact on the CH2O concentration under conditions encountered in the SIO. However, a detailed investigation including meteorological effects such as precipitation scavenging and convection reveals an uncertainty in state-of-the-art model predictions for CH2O in the MBL that is too large for a meaningful test of the current understanding of CH4 photooxidation.

  1. Development of a towing tank PIV system and a wake survey of a marine current turbine under steady conditions

    Science.gov (United States)

    Lust, Ethan; Luznik, Luksa; Flack, Karen

    2015-11-01

    A submersible particle image velocimetry (PIV) system was designed and built at the U.S. Naval Academy. The system was used to study the wake of a scale-independent horizontal axis marine current turbine. The turbine is a 1/25th scale model of the U.S. National Renewable Energy Laboratory's Reference Model 1 (RM1) tidal turbine. It is a two-bladed turbine measuring 0.8 m in diameter and featuring a NACA 63-618 airfoil cross-section. The wake survey was conducted over an area extending 0.25D forward of the turbine tip path to 2.0D aft to a depth of 1.0D beneath the turbine output shaft in the streamwise plane. Each field of view was approximately 30 cm by 30 cm, and each overlapped the adjacent fields of view by 5 cm. The entire flow field was then reconstructed by registering the resultant vector fields together into a single field of investigation. Results include the field of investigation from a representative case, for the mean velocity field averaged over approximately 1,000 realizations, and turbulent statistics including turbulence intensities, Reynolds shear stresses, and turbulent kinetic energy. This research was funded by the Office of Naval Research.

  2. Large spin current injection in nano-pillar-based lateral spin valve

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Tatsuya [Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395 (Japan); Ohnishi, Kohei; Kimura, Takashi, E-mail: t-kimu@phys.kyushu-u.ac.jp [Department of Physics, Kyushu University, 744 Motooka, Fukuoka, 819-0395 (Japan); Research Center for Quantum Nano-Spin Sciences, Kyushu University, 744 Motooka, Fukuoka, 819-0395 (Japan)

    2016-08-26

    We have investigated the influence of the injection of a large pure spin current on a magnetization process of a non-locally located ferromagnetic dot in nano-pillar-based lateral spin valves. Here, we prepared two kinds of the nano-pillar-type lateral spin valve based on Py nanodots and CoFeAl nanodots fabricated on a Cu film. In the Py/Cu lateral spin valve, although any significant change of the magnetization process of the Py nanodot has not been observed at room temperature. The magnetization reversal process is found to be modified by injecting a large pure spin current at 77 K. Switching the magnetization by the nonlocal spin injection has also been demonstrated at 77 K. In the CoFeAl/Cu lateral spin valve, a room temperature spin valve signal was strongly enhanced from the Py/Cu lateral spin valve because of the highly spin-polarized CoFeAl electrodes. The room temperature nonlocal switching has been demonstrated in the CoFeAl/Cu lateral spin valve.

  3. The Framework for an Information Technology Strategic Roadmap for the United States Marine Corps: How Current Acquisitions Align to the Current Strategic Direction of the Department of Defense, Department of the Navy, and United States Marine Corps

    National Research Council Canada - National Science Library

    Garcia, Richard D; Sloan, Joshua K

    2008-01-01

    ... (IT) roadmap may comprise a "tipping point" for future warfighting effectiveness. This thesis begins the basis for a framework for an information technology strategic roadmap for the United States Marine Corps...

  4. Large high current density superconducting solenoids for use in high energy physics experiments

    International Nuclear Information System (INIS)

    Green, M.A.; Eberhard, P.H.; Taylor, J.D.

    1976-05-01

    Very often the study of high energy physics in colliding beam storage-rings requires a large magnetic field volume in order to detect and analyze charged particles which are created from the collision of two particle beams. Large superconducting solenoids which are greater than 1 meter in diameter are required for this kind of physics. In many cases, interesting physics can be done outside the magnet coil, and this often requires that the amount of material in the magnet coil be minimized. As a result, these solenoids should have high current density (up to 10 9 A m -2 ) superconducting windings. The methods commonly used to stabilize large superconducting magnets cannot be employed because of this need to minimize the amount of material in the coils. A description is given of the Lawrence Berkeley Laboratory program for building and testing prototype solenoid magnets which are designed to operate at coil current densities in excess of 10 9 A m -2 with magnetic stored energies which are as high as 1.5 Megajoules per meter of solenoid length. The coils use intrinsically stable multifilament Nb--Ti superconductors. Control of the magnetic field quench is achieved by using a low resistance aluminum bore tube which is inductively coupled to the coil. The inner cryostat is replaced by a tubular cooling system which carries two phase liquid helium. The magnet coil, the cooling tubes, and aluminum bore tube are cast in epoxy to form a single unified magnet and cryogenic system which is about 2 centimeters thick. The results of the magnet coil tests are discussed

  5. Feasibility study of a large-scale tuned mass damper with eddy current damping mechanism

    Science.gov (United States)

    Wang, Zhihao; Chen, Zhengqing; Wang, Jianhui

    2012-09-01

    Tuned mass dampers (TMDs) have been widely used in recent years to mitigate structural vibration. However, the damping mechanisms employed in the TMDs are mostly based on viscous dampers, which have several well-known disadvantages, such as oil leakage and difficult adjustment of damping ratio for an operating TMD. Alternatively, eddy current damping (ECD) that does not require any contact with the main structure is a potential solution. This paper discusses the design, analysis, manufacture and testing of a large-scale horizontal TMD based on ECD. First, the theoretical model of ECD is formulated, then one large-scale horizontal TMD using ECD is constructed, and finally performance tests of the TMD are conducted. The test results show that the proposed TMD has a very low intrinsic damping ratio, while the damping ratio due to ECD is the dominant damping source, which can be as large as 15% in a proper configuration. In addition, the damping ratios estimated with the theoretical model are roughly consistent with those identified from the test results, and the source of this error is investigated. Moreover, it is demonstrated that the damping ratio in the proposed TMD can be easily adjusted by varying the air gap between permanent magnets and conductive plates. In view of practical applications, possible improvements and feasibility considerations for the proposed TMD are then discussed. It is confirmed that the proposed TMD with ECD is reliable and feasible for use in structural vibration control.

  6. Analysis of a novel autonomous marine hybrid power generation/energy storage system with a high-voltage direct current link

    DEFF Research Database (Denmark)

    Wang, L.; Lee, D. J.; Lee, W. J.

    2008-01-01

    wind turbines andWells turbines to respectively capture wind energy and wave energy from marine wind and oceanwave. In addition to wind-turbine generators(WTGs) andwave-energy turbine generators (WETGs) employed in the studied system, diesel-engine generators (DEGs) and an aqua electrolyzer (AE......This paper presents both time-domain and frequency-domain simulated results of a novel marine hybrid renewable-energy power generation/energy storage system (PG/ESS) feeding isolated loads through an high-voltage direct current (HVDC) link. The studied marine PG subsystems comprise both offshore......) absorbing a part of generated energy from WTGs and WETGs to generate available hydrogen for fuel cells (FCs) are also included in the PG subsystems. The ES subsystems consist of a flywheel energy storage system(FESS) and a compressed air energy storage (CAES) system to balance the required energy...

  7. A uniform laminar air plasma plume with large volume excited by an alternating current voltage

    Science.gov (United States)

    Li, Xuechen; Bao, Wenting; Chu, Jingdi; Zhang, Panpan; Jia, Pengying

    2015-12-01

    Using a plasma jet composed of two needle electrodes, a laminar plasma plume with large volume is generated in air through an alternating current voltage excitation. Based on high-speed photography, a train of filaments is observed to propagate periodically away from their birth place along the gas flow. The laminar plume is in fact a temporal superposition of the arched filament train. The filament consists of a negative glow near the real time cathode, a positive column near the real time anode, and a Faraday dark space between them. It has been found that the propagation velocity of the filament increases with increasing the gas flow rate. Furthermore, the filament lifetime tends to follow a normal distribution (Gaussian distribution). The most probable lifetime decreases with increasing the gas flow rate or decreasing the averaged peak voltage. Results also indicate that the real time peak current decreases and the real time peak voltage increases with the propagation of the filament along the gas flow. The voltage-current curve indicates that, in every discharge cycle, the filament evolves from a Townsend discharge to a glow one and then the discharge quenches. Characteristic regions including a negative glow, a Faraday dark space, and a positive column can be discerned from the discharge filament. Furthermore, the plasma parameters such as the electron density, the vibrational temperature and the gas temperature are investigated based on the optical spectrum emitted from the laminar plume.

  8. Large-eddy simulation study of oil/gas plumes in stratified fluid with cross current

    Science.gov (United States)

    Yang, Di; Xiao, Shuolin; Chen, Bicheng; Chamecki, Marcelo; Meneveau, Charles

    2017-11-01

    Dynamics of the oil/gas plume from a subsea blowout are strongly affected by the seawater stratification and cross current. The buoyant plume entrains ambient seawater and lifts it up to higher elevations. During the rising process, the continuously increasing density difference between the entrained and ambient seawater caused by the stable stratification eventually results in a detrainment of the entrained seawater and small oil droplets at a height of maximum rise (peel height), forming a downward plume outside the rising inner plume. The presence of a cross current breaks the plume's axisymmetry and causes the outer plume to fall along the downstream side of the inner plume. The detrained seawater and oil eventually fall to a neutral buoyancy level (trap height), and disperse horizontally to form an intrusion layer. In this study, the complex plume dynamics is investigated using large-eddy simulation (LES). Various laboratory and field scale cases are simulated to explore the effect of cross current and stratification on the plume dynamics. Based on the LES data, various turbulence statistics of the plume are systematically quantified, leading to some useful insights for modeling the mean plume dynamics using integral plume models. This research is made possible by a RFP-V Grant from The Gulf of Mexico Research Initiative.

  9. The Index to Marine and Lacustrine Geological Samples: Improving Sample Accessibility and Enabling Current and Future Research

    Science.gov (United States)

    Moore, C.

    2011-12-01

    The Index to Marine and Lacustrine Geological Samples is a community designed and maintained resource enabling researchers to locate and request sea floor and lakebed geologic samples archived by partner institutions. Conceived in the dawn of the digital age by representatives from U.S. academic and government marine core repositories and the NOAA National Geophysical Data Center (NGDC) at a 1977 meeting convened by the National Science Foundation (NSF), the Index is based on core concepts of community oversight, common vocabularies, consistent metadata and a shared interface. Form and content of underlying vocabularies and metadata continue to evolve according to the needs of the community, as do supporting technologies and access methodologies. The Curators Consortium, now international in scope, meets at partner institutions biennially to share ideas and discuss best practices. NGDC serves the group by providing database access and maintenance, a list server, digitizing support and long-term archival of sample metadata, data and imagery. Over three decades, participating curators have performed the herculean task of creating and contributing metadata for over 195,000 sea floor and lakebed cores, grabs, and dredges archived in their collections. Some partners use the Index for primary web access to their collections while others use it to increase exposure of more in-depth institutional systems. The Index is currently a geospatially-enabled relational database, publicly accessible via Web Feature and Web Map Services, and text- and ArcGIS map-based web interfaces. To provide as much knowledge as possible about each sample, the Index includes curatorial contact information and links to related data, information and images; 1) at participating institutions, 2) in the NGDC archive, and 3) at sites such as the Rolling Deck to Repository (R2R) and the System for Earth Sample Registration (SESAR). Over 34,000 International GeoSample Numbers (IGSNs) linking to SESAR are

  10. Efficient Preparation of Streptochlorin from Marine Streptomyces sp. SYYLWHS-1-4 by Combination of Response Surface Methodology and High-Speed Counter-Current Chromatography.

    Science.gov (United States)

    Li, Lin; He, Shan; Ding, Lijian; Yuan, Ye; Zhu, Peng; Epstein, Slava; Fan, Jianzhong; Wu, Xiaokai; Yan, Xiaojun

    2016-05-27

    Since first isolated from the lipophilic extract of Streptomyces sp. SF2583, streptochlorin, has attracted a lot of attention because of its various pharmacological properties, such as antibiotic, antiallergic, antitumor, and anti-inflammatory activities. For the efficient preparation of streptochlorin from a producing strain Streptomyces sp. SYYLWHS-1-4, we developed a combinative method by using response surface methodology (RSM) and high-speed counter-current chromatography (HSCCC). In the fermentation process, we used RSM to optimize the condition for the efficient accumulation of streptochlorin, and the optimal parameters were: yeast extract 1.889 g/L, soluble starch 8.636 g/L, K₂HPO₄ 0.359 g/L, CaCl₂ 2.5 g/L, MgSO₄ 0.625 g/L, marine salt 25 g/L, medium volume 50%, initial pH value 7.0, temperature 27.5 °C, which enhanced streptochlorin yield by 17.7-fold. During the purification process, the preparative HSCCC separation was performed using a petroleum ether-ethyl acetate-methanol-water (9:0.8:5:5, v/v/v/v) biphasic solvent system, where 300 mg of crude sample yielded 16.5 mg streptochlorin with over 95% purity as determined by UPLC. Consequently, the combination method provided a feasible strategy for highly effective preparation of streptochlorin, which ensured the supply of large amounts of streptochlorin for in vivo pharmacological assessments or other requirements.

  11. Bioprospecting Marine Plankton

    Directory of Open Access Journals (Sweden)

    Chris Bowler

    2013-11-01

    Full Text Available The ocean dominates the surface of our planet and plays a major role in regulating the biosphere. For example, the microscopic photosynthetic organisms living within provide 50% of the oxygen we breathe, and much of our food and mineral resources are extracted from the ocean. In a time of ecological crisis and major changes in our society, it is essential to turn our attention towards the sea to find additional solutions for a sustainable future. Remarkably, while we are overexploiting many marine resources, particularly the fisheries, the planktonic compartment composed of zooplankton, phytoplankton, bacteria and viruses, represents 95% of marine biomass and yet the extent of its diversity remains largely unknown and underexploited. Consequently, the potential of plankton as a bioresource for humanity is largely untapped. Due to their diverse evolutionary backgrounds, planktonic organisms offer immense opportunities: new resources for medicine, cosmetics and food, renewable energy, and long-term solutions to mitigate climate change. Research programs aiming to exploit culture collections of marine micro-organisms as well as to prospect the huge resources of marine planktonic biodiversity in the oceans are now underway, and several bioactive extracts and purified compounds have already been identified. This review will survey and assess the current state-of-the-art and will propose methodologies to better exploit the potential of marine plankton for drug discovery and for dermocosmetics.

  12. Thermodynamic and economic performances optimization of an organic Rankine cycle system utilizing exhaust gas of a large marine diesel engine

    International Nuclear Information System (INIS)

    Yang, Min-Hsiung; Yeh, Rong-Hua

    2015-01-01

    Highlights: • A new parameter is proposed for optimizing economic performance of the ORC system. • Maximal thermodynamic and economic performances of an ORC system are presented. • The corresponding operating pressures in turbine of optimum thermodynamic and economic performances are investigated. • An optimal effectiveness of pre-heater is obtained for the ORC system. - Abstract: The aim of this study is to investigate the thermodynamic and economic performances optimization for an ORC system recovering the waste heat of exhaust gas from a large marine diesel engine of the merchant ship. Parameters of net power output index and thermal efficiency are used to represent the economic and thermodynamic performances, respectively. The maximum net power output index and thermal efficiency are obtained and the corresponding turbine inlet pressure, turbine outlet pressure, and effectiveness of pre-heater of the ORC system are also evaluated using R1234ze, R245fa, R600, and R600a. Furthermore, the analyses of the effects of turbine inlet temperature and cooling water temperature on the optimal economic and thermodynamic performances of the ORC system are carried out. The results show that R245fa performs the most satisfactorily followed by R600, R600a, and R1234ze under optimal economic performance. However, in the optimal thermodynamic performance evaluations, R1234ze has the largest thermal efficiency followed by R600a, R245fa, and R600. The payback periods will decrease from 0.5 year for R245fa to 0.65 year for R1234ze respectively as the system is equipped with a pre-heater. In addition, compared with conventional diesel oil feeding, the proposed ORC system can reduce 76% CO 2 emission per kilowatt-hour

  13. The Utilisation of Pisang Island as a Platform to Support the Current Safety and Security Needs of Marine Navigation in the Straits of Malacca

    Directory of Open Access Journals (Sweden)

    Ahmad Faizal Ahmad Fuad

    2017-06-01

    Full Text Available Current marine navigational practice relies less on long-range visual marine signals such as lighthouses for reference purposes. This is due to the availability of Global Navigation Satellite Systems (GNSS, which are integrated with other navigational aids on ships. Therefore, the objective of this study is to review the function of Pisang Island lighthouse and to propose the most relevant use of Pisang Island for current navigational needs. The function of the lighthouse was reviewed according to the IALA Navigational Guide and the AIS data image. The result showed that the most suitable navigational use of the lighthouse is to act as a reference for Line of Position (LOP. The AIS data image indicated that mariners are not using Pisang Island lighthouse for LOP. The trend in the Straits of Malacca (SoM was compared with the trend in the Straits of Dover, UK. The selected experts verified that LOP was not practised there. As a specific example, a tanker ship route in the South China Sea was used to further support that LOP was not practised. This evidence supported the view that Pisang Island lighthouse is less relevant for current navigational practice and does not directly support the coastal state VTS operation and the establishment of the marine electronic highway. Furthermore, the existing shore-based VTS radar has limitations on range and the detection of targets near Pisang Island. Therefore, this study proposes the establishment of a new radar station on Pisang Island at the existing site of the lighthouse. The proposed new radar station on Pisang Island will add to the existing coverage of the VTS radar, bridging the coverage gaps to overcome the weakness of the existing shore-based radar and improve the safety and security of marine navigation in the SoM.

  14. Development of net-current free heliotron plasmas in the Large Helical Device

    International Nuclear Information System (INIS)

    Komori, A.; Yamada, H.; Kaneko, O.; Kawahata, K.; Mutoh, T.; Ohyabu, N.; Imagawa, S.; Ida, K.; Nagayama, Y.; Shimozuma, T.; Watanabe, K.Y.; Mito, T.; Kobayashi, M.; Nagaoka, K.; Sakamoto, R.; Ohdachi, S.; Sakakibara, S.; Ashikawa, N.; Igami, H.; Kasahara, H.; Kubo, S.; Kumazawa, R.; Nishiura, M.; Masuzaki, S.; Tanaka, K.; Toi, K.; Yoshinuma, M.; Narushima, Y.; Tamura, N.; Saito, K.; Seki, T.; Sudo, S.; Tanaka, H.; Tokuzawa, T.; Yanagi, N.; Yokoyama, M.; Yoshimura, Y.; Akiyama, T.; Chikaraishi, H.; Emoto, M.; Funaba, H.; Goncharov, P.; Goto, M.; Ichiguchi, K.; Ido, T.; Ikeda, K.; Yoshida, N.; Inagaki, S.; Idei, H.; Feng, Y.; Weller, A.; Fukuda, T.; Mitarai, O.; Murakami, S.; Nakamura, Y.; Hino, T.; Ohno, N.; Okamura, T.; Iio, S.; Chowdhuri, M.; Ezumi, N.; Garcia, L.; Ichimura, M.; Irie, M.; Isayama, Akihiko; Iwamae, Atsushi; Takenaga, Hidenobu; Urano, Hajime

    2008-10-01

    Remarkable progress in the physical parameters of net-current free plasmas has been made in the Large Helical Device (LHD) since the last Fusion Energy Conference in Chengdu, 2006 (O. Motojima et al., Nucl. Fusion 47 (2007) S668). The beta value reached 5 % and a high beta state beyond 4.5% from the diamagnetic measurement has been maintained for longer than 100 times the energy confinement time. The density and temperature regimes also have been extended. The central density has exceeded 1.0x10 21 m -3 due to the formation of an Internal Diffusion Barrier (IDB). The ion temperature has reached 6.8 keV at the density of 2x10 19 m -3 , which is associated with the suppression of ion heat conduction loss. Although these parameters have been obtained in separated discharges, each fusion-reactor relevant parameter has elucidated the potential of net-current free heliotron plasmas. Diversified studies in recent LHD experiments are reviewed in this paper. (author)

  15. Large step-down DC-DC converters with reduced current stress

    International Nuclear Information System (INIS)

    Ismail, Esam H.

    2009-01-01

    In this paper, several DC-DC converters with large voltage step-down ratios are introduced. A simple modification in the output section of the conventional buck and quadratic converters can effectively extend the duty-cycle range. Only two additional components (an inductor and diode) are necessary for extending the duty-cycle range. The topologies presented in this paper show an improvement in the duty-cycle (about 40%) over the conventional buck and quadratic converters. Consequently, they are well suited for extreme step-down voltage conversion ratio applications. With extended duty-cycle, the current stress on all components is reduced, leading to a significant improvement of the system losses. The principle of operation, theoretical analysis, and comparison of circuit performances with other step-down converters is discussed regarding voltage and current stress. Experimental results of one prototype rated 40-W and operating at 100 kHz are provided in this paper to verify the performance of this new family of converters. The efficiency of the proposed converters is higher than the quadratic converters

  16. Fractional Modeling of the AC Large-Signal Frequency Response in Magnetoresistive Current Sensors

    Directory of Open Access Journals (Sweden)

    Sergio Iván Ravelo Arias

    2013-12-01

    Full Text Available Fractional calculus is considered when derivatives and integrals of non-integer order are applied over a specific function. In the electrical and electronic domain, the transfer function dependence of a fractional filter not only by the filter order n, but additionally, of the fractional order α is an example of a great number of systems where its input-output behavior could be more exactly modeled by a fractional behavior. Following this aim, the present work shows the experimental ac large-signal frequency response of a family of electrical current sensors based in different spintronic conduction mechanisms. Using an ac characterization set-up the sensor transimpedance function  is obtained considering it as the relationship between sensor output voltage and input sensing current,[PLEASE CHECK FORMULA IN THE PDF]. The study has been extended to various magnetoresistance sensors based in different technologies like anisotropic magnetoresistance (AMR, giant magnetoresistance (GMR, spin-valve (GMR-SV and tunnel magnetoresistance (TMR. The resulting modeling shows two predominant behaviors, the low-pass and the inverse low-pass with fractional index different from the classical integer response. The TMR technology with internal magnetization offers the best dynamic and sensitivity properties opening the way to develop actual industrial applications.

  17. Operational Experience and Consolidations for the Current Lead Control Valves of the Large Hadron Collider

    CERN Document Server

    Perin, A; Pirotte, O; Krieger, B; Widmer, A

    2012-01-01

    The Large Hadron Collider superconducting magnets are powered by more than 1400 gas cooled current leads ranging from 120 A to 13000 A. The gas flow required by the leads is controlled by solenoid proportional valves with dimensions from DN 1.8 mm to DN 10 mm. During the first months of operation, signs of premature wear were found in the active parts of the valves. This created major problems for the functioning of the current leads threatening the availability of the LHC. Following the detection of the problems, a series of measures were implemented to keep the LHC running, to launch a development program to solve the premature wear problem and to prepare for a global consolidation of the gas flow control system. This article describes first the difficulties encountered and the measures taken to ensure a continuous operation of the LHC during the first year of operation. The development of new friction free valves is then presented along with the consolidation program and the test equipment developed to val...

  18. Wideband Precision Current Transformer for the Magnet Current of the Beam Extraction Kicker Magnet of the Large Hadron Collider

    CERN Document Server

    Gräwer, G

    2004-01-01

    The LHC beam extraction system is composed of 15 fast kicker magnets per beam to extract the particles in one turn of the collider and to safely dispose them on external absorbers. Each magnet is powered by a separate pulse generator. The generator produces a magnet current pulse with 3 us rise time, 20 kA amplitude and 1.8 ms fall time, of which 90 us are needed to dump the beam. The beam extraction system requires a high level of reliability. To detect any change in the magnet current characteristics, which might indicate a slow degradation of the pulse generator, a high precision wideband current transformer will be installed. For redundancy reasons, the results obtained with this device will be cross-checked with a Rogowski coil, installed adjacent to the transformer. A prototype transformer has been successfully tested at nominal current levels and showed satisfactory results compared with the output of a high frequency resistive coaxial shunt. The annular core of the ring type transformer is composed of...

  19. Survey of large-amplitude flapping motions in the midtail current sheet

    Directory of Open Access Journals (Sweden)

    V. A. Sergeev

    2006-08-01

    Full Text Available We surveyed fast current sheet crossings (flapping motions over the distance range 10–30 RE in the magnetotail covered by the Geotail spacecraft. Since the local tilts of these dynamic sheets are large and variable in these events, we compare three different methods of evaluating current sheet normals using 4-s/c Cluster data and define the success criteria for the single-spacecraft-based method (MVA to obtain the reliable results. Then, after identifying more than ~1100 fast CS crossings over a 3-year period of Geotail observations in 1997–1999, we address their parameters, spatial distribution and activity dependence. We confirm that over the entire distance covered and LT bins, fast crossings have considerable tilts in the YZ plane (from estimated MVA normals which show a preferential appearance of one (YZ kink-like mode that is responsible for these severe current sheet perturbations. Their occurrence is highly inhomogeneous; it sharply increases with radial distance and has a peak in the tail center (with some duskward shift, resembling the occurrence of the BBFs, although there is no one-to-one local correspondence between these two phenomena. The crossing durations typically spread around 1 min and decrease significantly where the high-speed flows are registered. Based on an AE index superposed epoch study, the flapping motions prefer to appear during the substorm expansion phase, although a considerable number of events without any electrojet and auroral activity were also observed. We also present statistical distributions of other parameters and briefly discuss what could be possible mechanisms to generate the flapping motions.

  20. Toxicity of seven priority hazardous and noxious substances (HNSs) to marine organisms: Current status, knowledge gaps and recommendations for future research

    International Nuclear Information System (INIS)

    Rocha, A. Cristina S.; Reis-Henriques, Maria Armanda; Galhano, Victor; Ferreira, Marta; Guimarães, Laura

    2016-01-01

    Shipping industry and seaborne trade have rapidly increased over the last fifty years, mainly due to the continuous increasing demand for chemicals and fuels. Consequently, despite current regulations, the occurrence of accidental spills poses an important risk. Hazardous and noxious substances (HNSs) have been raising major concern among environmental managers and scientific community for their heterogeneity, hazardous potential towards aquatic organisms and associated social-economic impacts. A literature review on ecotoxicological hazards to aquatic organisms was conducted for seven HNSs: acrylonitrile, n-butyl acrylate, cyclohexylbenzene, hexane, isononanol, trichloroethylene and xylene. Information on the mechanisms of action of the selected HNS was also reviewed. The main purpose was to identify: i) knowledge gaps in need of being addressed in future research; and ii) a set of possible biomarkers suitable for ecotoxicological assessment and monitoring in both estuarine and marine systems. Main gaps found concern the scarcity of information available on ecotoxicological effects of HNS towards marine species and their poorly understood mode of action in wildlife. Differences were found between the sensitivity of freshwater and seawater organisms, so endpoints produced in the former may not be straightforwardly employed in evaluations for the marine environment. The relationship between sub-individual effects and higher level detrimental alterations (e.g. behavioural, morphological, reproductive effects and mortality) are not fully understood. In this context, a set of biomarkers associated to neurotoxicity, detoxification and anti-oxidant defences is suggested as potential indicators of toxic exposure/effects of HNS in marine organisms. Overall, to support the development of contingency plans and the establishment of environmental safety thresholds, it will be necessary to undertake targeted research on HNS ecotoxicity in the marine environment. Research should

  1. Toxicity of seven priority hazardous and noxious substances (HNSs) to marine organisms: Current status, knowledge gaps and recommendations for future research

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, A. Cristina S., E-mail: cristinasrocha@gmail.com; Reis-Henriques, Maria Armanda; Galhano, Victor; Ferreira, Marta, E-mail: marta.ferreira@usp.ac.fj; Guimarães, Laura

    2016-01-15

    Shipping industry and seaborne trade have rapidly increased over the last fifty years, mainly due to the continuous increasing demand for chemicals and fuels. Consequently, despite current regulations, the occurrence of accidental spills poses an important risk. Hazardous and noxious substances (HNSs) have been raising major concern among environmental managers and scientific community for their heterogeneity, hazardous potential towards aquatic organisms and associated social-economic impacts. A literature review on ecotoxicological hazards to aquatic organisms was conducted for seven HNSs: acrylonitrile, n-butyl acrylate, cyclohexylbenzene, hexane, isononanol, trichloroethylene and xylene. Information on the mechanisms of action of the selected HNS was also reviewed. The main purpose was to identify: i) knowledge gaps in need of being addressed in future research; and ii) a set of possible biomarkers suitable for ecotoxicological assessment and monitoring in both estuarine and marine systems. Main gaps found concern the scarcity of information available on ecotoxicological effects of HNS towards marine species and their poorly understood mode of action in wildlife. Differences were found between the sensitivity of freshwater and seawater organisms, so endpoints produced in the former may not be straightforwardly employed in evaluations for the marine environment. The relationship between sub-individual effects and higher level detrimental alterations (e.g. behavioural, morphological, reproductive effects and mortality) are not fully understood. In this context, a set of biomarkers associated to neurotoxicity, detoxification and anti-oxidant defences is suggested as potential indicators of toxic exposure/effects of HNS in marine organisms. Overall, to support the development of contingency plans and the establishment of environmental safety thresholds, it will be necessary to undertake targeted research on HNS ecotoxicity in the marine environment. Research should

  2. Multipacting in a coaxial coupler with bias voltage for SRF operation with a large beam current

    Science.gov (United States)

    Liu, Z.-K.; Wang, Ch.; Chang, F.-Y.; Chang, L.-H.; Chang, M.-H.; Chen, L.-J.; Chung, F.-T.; Lin, M.-C.; Lo, C.-H.; Tsai, C.-L.; Tsai, M.-H.; Yeh, M.-S.; Yu, T.-C.

    2016-09-01

    A superconducting radio-frequency (SRF) module is commonly used for a high-energy accelerator; its purpose is to provide energy to the particle beam. Because of the low power dissipation and smaller impedance of a higher-order mode for this module, it can provide more power to the particle beam with better stability through decreasing the couple bunch instability. A RF coupler is necessary to transfer the high power from a RF generator to the cavity. A coupler of coaxial type is a common choice. With high-power operation, it might suffer from multipacting, which is a resonance phenomenon due to re-emission of secondary electrons. Applying a bias voltage between inner and outer conductors of the coaxial coupler might increase or decrease the strength of the multipacting effect. We studied the effect of a bias voltage on multipacting using numerical simulation to track the motion of the electrons. The simulation results and an application for SRF operation with a large beam current are presented in this paper.

  3. RECONNECTION PROPERTIES OF LARGE-SCALE CURRENT SHEETS DURING CORONAL MASS EJECTION ERUPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, B. J.; Kazachenko, M. D. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Edmondson, J. K. [Climate and Space Sciences and Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States); Guidoni, S. E. [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-07-20

    We present a detailed analysis of the properties of magnetic reconnection at large-scale current sheets (CSs) in a high cadence version of the Lynch and Edmondson 2.5D MHD simulation of sympathetic magnetic breakout eruptions from a pseudostreamer source region. We examine the resistive tearing and break-up of the three main CSs into chains of X- and O-type null points and follow the dynamics of magnetic island growth, their merging, transit, and ejection with the reconnection exhaust. For each CS, we quantify the evolution of the length-to-width aspect ratio (up to ∼100:1), Lundquist number (∼10{sup 3}), and reconnection rate (inflow-to-outflow ratios reaching ∼0.40). We examine the statistical and spectral properties of the fluctuations in the CSs resulting from the plasmoid instability, including the distribution of magnetic island area, mass, and flux content. We show that the temporal evolution of the spectral index of the reconnection-generated magnetic energy density fluctuations appear to reflect global properties of the CS evolution. Our results are in excellent agreement with recent, high-resolution reconnection-in-a-box simulations even though our CSs’ formation, growth, and dynamics are intrinsically coupled to the global evolution of sequential sympathetic coronal mass ejection eruptions.

  4. Projecting changes in the distribution and productivity of living marine resources: A critical review of the suite of modelling approaches used in the large European project VECTORS

    Science.gov (United States)

    Peck, Myron A.; Arvanitidis, Christos; Butenschön, Momme; Canu, Donata Melaku; Chatzinikolaou, Eva; Cucco, Andrea; Domenici, Paolo; Fernandes, Jose A.; Gasche, Loic; Huebert, Klaus B.; Hufnagl, Marc; Jones, Miranda C.; Kempf, Alexander; Keyl, Friedemann; Maar, Marie; Mahévas, Stéphanie; Marchal, Paul; Nicolas, Delphine; Pinnegar, John K.; Rivot, Etienne; Rochette, Sébastien; Sell, Anne F.; Sinerchia, Matteo; Solidoro, Cosimo; Somerfield, Paul J.; Teal, Lorna R.; Travers-Trolet, Morgan; van de Wolfshaar, Karen E.

    2018-02-01

    We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of single life stages or the whole life cycle of species, 3) food web models, and 4) end-to-end models. Single pressures are rare and, in the future, models must be able to examine multiple factors affecting living marine resources such as interactions between: i) climate-driven changes in temperature regimes and acidification, ii) reductions in water quality due to eutrophication, iii) the introduction of alien invasive species, and/or iv) (over-)exploitation by fisheries. Statistical (correlative) approaches can be used to detect historical patterns which may not be relevant in the future. Advancing predictive capacity of changes in distribution and productivity of living marine resources requires explicit modelling of biological and physical mechanisms. New formulations are needed which (depending on the question) will need to strive for more realism in ecophysiology and behaviour of individuals, life history strategies of species, as well as trophodynamic interactions occurring at different spatial scales. Coupling existing models (e.g. physical, biological, economic) is one avenue that has proven successful. However, fundamental advancements are needed to address key issues such as the adaptive capacity of species/groups and ecosystems. The continued development of end-to-end models (e.g., physics to fish to human sectors) will be critical if we hope to assess how multiple pressures may interact to cause changes in living marine resources including the ecological and economic costs and trade-offs of different spatial management strategies. Given the strengths and weaknesses of the various types of models reviewed here, confidence in projections of changes in the

  5. Efficient Preparation of Streptochlorin from Marine Streptomyces sp. SYYLWHS-1-4 by Combination of Response Surface Methodology and High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Lin Li

    2016-05-01

    Full Text Available Since first isolated from the lipophilic extract of Streptomyces sp. SF2583, streptochlorin, has attracted a lot of attention because of its various pharmacological properties, such as antibiotic, antiallergic, antitumor, and anti-inflammatory activities. For the efficient preparation of streptochlorin from a producing strain Streptomyces sp. SYYLWHS-1-4, we developed a combinative method by using response surface methodology (RSM and high-speed counter-current chromatography (HSCCC. In the fermentation process, we used RSM to optimize the condition for the efficient accumulation of streptochlorin, and the optimal parameters were: yeast extract 1.889 g/L, soluble starch 8.636 g/L, K2HPO4 0.359 g/L, CaCl2 2.5 g/L, MgSO4 0.625 g/L, marine salt 25 g/L, medium volume 50%, initial pH value 7.0, temperature 27.5 °C, which enhanced streptochlorin yield by 17.7-fold. During the purification process, the preparative HSCCC separation was performed using a petroleum ether–ethyl acetate–methanol–water (9:0.8:5:5, v/v/v/v biphasic solvent system, where 300 mg of crude sample yielded 16.5 mg streptochlorin with over 95% purity as determined by UPLC. Consequently, the combination method provided a feasible strategy for highly effective preparation of streptochlorin, which ensured the supply of large amounts of streptochlorin for in vivo pharmacological assessments or other requirements.

  6. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Martinus S.; de Vries, Marjella J.; van Oel, Pieter R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  7. Treatment Options for Paediatric Anaplastic Large Cell Lymphoma (ALCL: Current Standard and beyond

    Directory of Open Access Journals (Sweden)

    Nina Prokoph

    2018-03-01

    Full Text Available Anaplastic Lymphoma Kinase (ALK-positive Anaplastic Large Cell Lymphoma (ALCL, remains one of the most curable cancers in the paediatric setting; multi-agent chemotherapy cures approximately 65–90% of patients. Over the last two decades, major efforts have focused on improving the survival rate by intensification of combination chemotherapy regimens and employing stem cell transplantation for chemotherapy-resistant patients. More recently, several new and ‘renewed’ agents have offered the opportunity for a change in the paradigm for the management of both chemo-sensitive and chemo-resistant forms of ALCL. The development of ALK inhibitors following the identification of the EML4-ALK fusion gene in Non-Small Cell Lung Cancer (NSCLC has opened new possibilities for ALK-positive ALCL. The uniform expression of CD30 on the cell surface of ALCL has given the opportunity for anti-CD30 antibody therapy. The re-evaluation of vinblastine, which has shown remarkable activity as a single agent even in the face of relapsed disease, has led to the consideration of a revised approach to frontline therapy. The advent of immune therapies such as checkpoint inhibition has provided another option for the treatment of ALCL. In fact, the number of potential new agents now presents a real challenge to the clinical community that must prioritise those thought to offer the most promise for the future. In this review, we will focus on the current status of paediatric ALCL therapy, explore how new and ‘renewed’ agents are re-shaping the therapeutic landscape for ALCL, and identify the strategies being employed in the next generation of clinical trials.

  8. Solid Waste Transportation through Ocean Currents: Marine Debris Sightings and their Waste Quantification at Port Dickson Beaches, Peninsular Malaysia

    OpenAIRE

    Chong Jing Yi; Narayanan Kannan

    2016-01-01

    Four beaches at Port Dickson, Peninsular Malaysia, namely Saujana Beach, Nelayan Beach, Bagan Pinang Beach and Cermin beach have been sampled for marine debris from 7th June 2014 until 26th July 2014, on every Saturday. These beaches face the Strait of Malacca with a coastline stretching 18 km each. Our observations revealed a total debris items of 13193 in those beaches. The top three items of highest frequency were cigarette butts, foamed fragments and food wrappers. Plastic debris scaled h...

  9. Current status and future prospects for the assessment of marine and coastal ecosystem services: a systematic review.

    Science.gov (United States)

    Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis

    2013-01-01

    Research on ecosystem services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial ecosystem services highlighting a knowledge gap on marine and coastal ecosystem services (MCES) and an urgent need to assess them. We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal ecosystem services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each ecosystem service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved ecosystem service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. This review summarizes the state of available information related to ecosystem services associated with marine and coastal ecosystems. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies.

  10. Current Status and Future Prospects for the Assessment of Marine and Coastal Ecosystem Services: A Systematic Review

    Science.gov (United States)

    Liquete, Camino; Piroddi, Chiara; Drakou, Evangelia G.; Gurney, Leigh; Katsanevakis, Stelios; Charef, Aymen; Egoh, Benis

    2013-01-01

    Background Research on ecosystem services has grown exponentially during the last decade. Most of the studies have focused on assessing and mapping terrestrial ecosystem services highlighting a knowledge gap on marine and coastal ecosystem services (MCES) and an urgent need to assess them. Methodology/Principal Findings We reviewed and summarized existing scientific literature related to MCES with the aim of extracting and classifying indicators used to assess and map them. We found 145 papers that specifically assessed marine and coastal ecosystem services from which we extracted 476 indicators. Food provision, in particular fisheries, was the most extensively analyzed MCES while water purification and coastal protection were the most frequently studied regulating and maintenance services. Also recreation and tourism under the cultural services was relatively well assessed. We highlight knowledge gaps regarding the availability of indicators that measure the capacity, flow or benefit derived from each ecosystem service. The majority of the case studies was found in mangroves and coastal wetlands and was mainly concentrated in Europe and North America. Our systematic review highlighted the need of an improved ecosystem service classification for marine and coastal systems, which is herein proposed with definitions and links to previous classifications. Conclusions/Significance This review summarizes the state of available information related to ecosystem services associated with marine and coastal ecosystems. The cataloging of MCES indicators and the integrated classification of MCES provided in this paper establish a background that can facilitate the planning and integration of future assessments. The final goal is to establish a consistent structure and populate it with information able to support the implementation of biodiversity conservation policies. PMID:23844080

  11. Current direction, marine toxic substances, and wind wave spectra data from moored current meter casts and other instruments in the Gulf of Mexico as part of the Brine Disposal project, 1977-09-15 to 1979-06-30 (NODC Accession 7900295)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, marine toxic substances, and wind wave spectra data were collected using moored current meter casts and other instruments in the Gulf of Mexico...

  12. Current direction, marine toxic substances, and other data from current meters and grab casts from the GUSS III and other platforms in support of the Brine Disposal project from 1977-10-20 to 1979-04-16 (NODC Accession 8000029)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, marine toxic substances, and other data from were collected from current meters and grab casts from the GUSS III and other platforms from 20...

  13. Current direction, marine toxic substances, and wind wave spectra data from moored current meter casts and other instruments in the Gulf of Mexico as part of the Brine Disposal project, 1977-12-22 to 1979-09-30 (NODC Accession 7900336)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, marine toxic substances, and wind wave spectra data were collected using moored current meter casts and other instruments in the Gulf of Mexico...

  14. Current meter and marine toxic substances data from moored current meter casts and other instruments in the North Pacific Ocean as part of the Deep Ocean Mining and Environmental Study (DOMES) project, 1975-08-29 to 1977-12-01 (NODC Accession 7800741)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter and marine toxic substances data were collected using moored current meter casts and other instruments in the North Pacific Ocean from August 29, 1975...

  15. Cloning, Stem Cells, and the Current National Debate: Incorporating Ethics into a Large Introductory Biology Course

    Science.gov (United States)

    Fink, Rachel D.

    2002-01-01

    Discussing the ethical issues involved in topics such as cloning and stem cell research in a large introductory biology course is often difficult. Teachers may be wary of presenting material biased by personal beliefs, and students often feel inhibited speaking about moral issues in a large group. Yet, to ignore what is happening "out there"…

  16. Production of a high-current microsecond electron beam with a large cross section

    International Nuclear Information System (INIS)

    Abdullin, E.N.; Belomytsev, S.Ya.; Bugaev, S.P.; Gorbachev, S.I.; Zaslavskii, V.M.; Zorin, V.P.; Koval'chuk, B.M.; Loginov, S.V.; Matyukov, Yu.N.; Rasputin, R.M.; Tolkachev, V.S.; Shchanin, P.M.

    1991-01-01

    Obtaining high-current wide-aperture electron beams is an important problem in the development of laser technology for controlled nuclear fusion and for solving ecological and technological problems. The main scheme for producing such beams involves the use of generators with intermediate energy storage devices and burst-emission vacuum diodes. Beam pinching is prevented by using an external magnetic field or sectioning the diode into magnetically insulated diodes with currents lower than the limiting current. The length of the electron-current pulse varies from tens to hundreds of nano-seconds and is limited by the parameters of the intermediate storage device. Here the authors study the formation of a high-current electron beam with a square cross section and a current of the order of the limiting current of the diode in the absence of an external magnetic field as well as a 'fast' storage device in the power supply circuit. These conditions as a whole correspond to a simpler electron-source circuit, but the beam forming becomes more complicated. The reason for this is that there is no external magnetic field and that the role of plasma processes in the diode is enhanced by the greater length of the electron-current pulses

  17. Chemical, zooplankton, and marine toxic substances data from moored current meter casts and other instruments in the Gulf of Mexico during the Brine Disposal project, 1978-06-02 to 1979-06-02 (NODC Accession 8000002)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, zooplankton, and marine toxic substances data were collected using moored current meter casts and other instruments in the Gulf of Mexico from June 2, 1978...

  18. Chemical, benthic organisms, zooplankton, marine toxic substances, and other data from moored current meter casts and other instruments in the Gulf of Mexico during the Brine Disposal project, 1979-08-30 to 1981-09-21 (NODC Accession 8200012)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, marine toxic substances, benthic organisms, zooplankton, and other data were collected using moored current meter casts and other instruments in the Gulf...

  19. The next 16 higher spin currents and three-point functions in the large N = 4 holography

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Changhyun; Kim, Dong-gyu; Kim, Man Hea [Kyungpook National University, Department of Physics, Taegu (Korea, Republic of)

    2017-08-15

    By using the known operator product expansions (OPEs) between the lowest 16 higher spin currents of spins (1, (3)/(2), (3)/(2), (3)/(2), (3)/(2), 2,2,2,2,2,2, (5)/(2), (5)/(2), (5)/(2), (5)/(2), 3) in an extension of the large N = 4 linear superconformal algebra, one determines the OPEs between the lowest 16 higher spin currents in an extension of the large N = 4 nonlinear superconformal algebra for generic N and k. The Wolf space coset contains the group G = SU(N + 2) and the affine Kac-Moody spin 1 current has the level k. The next 16 higher spin currents of spins (2, (5)/(2), (5)/(2), (5)/(2), (5)/(2), 3,3,3,3,3,3, (7)/(2), (7)/(2), (7)/(2), (7)/(2), 4) arise in the above OPEs. The most general lowest higher spin 2 current in this multiplet can be determined in terms of affine Kac-Moody spin (1)/(2), 1 currents. By careful analysis of the zero mode (higher spin) eigenvalue equations, the three-point functions of bosonic higher spin 2, 3, 4 currents with two scalars are obtained for finite N and k. Furthermore, we also analyze the three-point functions of bosonic higher spin 2, 3, 4 currents in the extension of the large N = 4 linear superconformal algebra. It turns out that the three-point functions of higher spin 2, 3 currents in the two cases are equal to each other at finite N and k. Under the large (N, k) 't Hooft limit, the two descriptions for the three-point functions of higher spin 4 current coincide with each other. The higher spin extension of SO(4) Knizhnik Bershadsky algebra is described. (orig.)

  20. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    OpenAIRE

    Krol, Martinus S.; de Vries, Marjella J.; van Oel, P.R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts of small reservoirs are subject to climate change. Using a case-study on North-East Brazil, this paper shows that climate change impacts on water availability may be severe, and impacts on distrib...

  1. Analysis of current distribution in a large superconductor; Chodendo dotai nai no denryu bunpu kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Hamajima, K.; Alamgir, A.K.M.; Harada, N.; Tsuda, M. [Yamaguchi Univ., Yamaguchi (Japan); Ono, M.; Takano, H. [Toshiba Corp., Tokyo (Japan)

    2000-04-25

    An imbalanced current distribution is often observed in cable-in-conduit (CIC) superconductors, which are composed of multistaged, triplet type sub-cables, and deteriorates the performance of the coils. Therefore, it is very important to analyze the current distribution in a superconductor and find out methods to obtain a homogeneous current distribution in the conductor. We apply a magnetic flux conservation in a loop contoured by electric center lines of filaments in two arbitrary strands located on adjacent layers in a coaxial multilayer superconductor, and then analyze the current distribution in the conductor. A generalized formula governing the current distribution can be described as explicit functions of the superconductor construction parameters, such as twist pitch, twist direction and radius of each layer. It is shown that we can obtain a homogeneous current distribution using this fundamental formula, which is a function of the twist pitches of layers. Moreover, it is demonstrated that we can control current distribution in the coaxial superconductor. (author)

  2. A propidium monoazide–quantitative PCR method for the detection and quantification of viable Enterococcus faecalis in large-volume samples of marine waters

    KAUST Repository

    Salam, Khaled W.; El-Fadel, Mutasem E.; Barbour, Elie K.; Saikaly, Pascal

    2014-01-01

    The development of rapid detection assays of cell viability is essential for monitoring the microbiological quality of water systems. Coupling propidium monoazide with quantitative PCR (PMA-qPCR) has been successfully applied in different studies for the detection and quantification of viable cells in small-volume samples (0.25-1.00 mL), but it has not been evaluated sufficiently in marine environments or in large-volume samples. In this study, we successfully integrated blue light-emitting diodes for photoactivating PMA and membrane filtration into the PMA-qPCR assay for the rapid detection and quantification of viable Enterococcus faecalis cells in 10-mL samples of marine waters. The assay was optimized in phosphate-buffered saline and seawater, reducing the qPCR signal of heat-killed E. faecalis cells by 4 log10 and 3 log10 units, respectively. Results suggest that high total dissolved solid concentration (32 g/L) in seawater can reduce PMA activity. Optimal PMA-qPCR standard curves with a 6-log dynamic range and detection limit of 102 cells/mL were generated for quantifying viable E. faecalis cells in marine waters. The developed assay was compared with the standard membrane filter (MF) method by quantifying viable E. faecalis cells in seawater samples exposed to solar radiation. The results of the developed PMA-qPCR assay did not match that of the standard MF method. This difference in the results reflects the different physiological states of E. faecalis cells in seawater. In conclusion, the developed assay is a rapid (∼5 h) method for the quantification of viable E. faecalis cells in marine recreational waters, which should be further improved and tested in different seawater settings. © 2014 Springer-Verlag Berlin Heidelberg.

  3. A propidium monoazide–quantitative PCR method for the detection and quantification of viable Enterococcus faecalis in large-volume samples of marine waters

    KAUST Repository

    Salam, Khaled W.

    2014-08-23

    The development of rapid detection assays of cell viability is essential for monitoring the microbiological quality of water systems. Coupling propidium monoazide with quantitative PCR (PMA-qPCR) has been successfully applied in different studies for the detection and quantification of viable cells in small-volume samples (0.25-1.00 mL), but it has not been evaluated sufficiently in marine environments or in large-volume samples. In this study, we successfully integrated blue light-emitting diodes for photoactivating PMA and membrane filtration into the PMA-qPCR assay for the rapid detection and quantification of viable Enterococcus faecalis cells in 10-mL samples of marine waters. The assay was optimized in phosphate-buffered saline and seawater, reducing the qPCR signal of heat-killed E. faecalis cells by 4 log10 and 3 log10 units, respectively. Results suggest that high total dissolved solid concentration (32 g/L) in seawater can reduce PMA activity. Optimal PMA-qPCR standard curves with a 6-log dynamic range and detection limit of 102 cells/mL were generated for quantifying viable E. faecalis cells in marine waters. The developed assay was compared with the standard membrane filter (MF) method by quantifying viable E. faecalis cells in seawater samples exposed to solar radiation. The results of the developed PMA-qPCR assay did not match that of the standard MF method. This difference in the results reflects the different physiological states of E. faecalis cells in seawater. In conclusion, the developed assay is a rapid (∼5 h) method for the quantification of viable E. faecalis cells in marine recreational waters, which should be further improved and tested in different seawater settings. © 2014 Springer-Verlag Berlin Heidelberg.

  4. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.

    2016-11-15

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  5. Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

    KAUST Repository

    Williamson, David H.; Harrison, Hugo B.; Almany, Glenn R.; Berumen, Michael L.; Bode, Michael; Bonin, Mary C.; Choukroun, Severine; Doherty, Peter J.; Frisch, Ashley J.; Saenz-Agudelo, Pablo; Jones, Geoffrey P.

    2016-01-01

    Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

  6. Keeping the ‘Great’ in the Great Barrier Reef: large-scale governance of the Great Barrier Reef Marine Park

    Directory of Open Access Journals (Sweden)

    Louisa S. Evans

    2014-08-01

    Full Text Available As part of an international collaboration to compare large-scale commons, we used the Social-Ecological Systems Meta-Analysis Database (SESMAD to systematically map out attributes of and changes in the Great Barrier Reef Marine Park (GBRMP in Australia. We focus on eight design principles from common-pool resource (CPR theory and other key social-ecological systems governance variables, and explore to what extent they help explain the social and ecological outcomes of park management through time. Our analysis showed that commercial fisheries management and the re-zoning of the GBRMP in 2004 led to improvements in ecological condition of the reef, particularly fisheries. These boundary and rights changes were supported by effective monitoring, sanctioning and conflict resolution. Moderate biophysical connectivity was also important for improved outcomes. However, our analysis also highlighted that continued challenges to improved ecological health in terms of coral cover and biodiversity can be explained by fuzzy boundaries between land and sea, and the significance of external drivers to even large-scale social-ecological systems (SES. While ecological and institutional fit in the marine SES was high, this was not the case when considering the coastal SES. Nested governance arrangements become even more important at this larger scale. To our knowledge, our paper provides the first analysis linking the re-zoning of the GBRMP to CPR and SES theory. We discuss important challenges to coding large-scale systems for meta-analysis.

  7. Near-Earth Magnetic Field Effects of Large-Scale Magnetospheric Currents

    DEFF Research Database (Denmark)

    Lühr, Hermann; Xiong, Chao; Olsen, Nils

    2017-01-01

    . Significant progress in interpreting the magnetic fields from the different sources has been achieved thanks to magnetic satellite missions like Ørsted, CHAMP and now Swarm. Of particular interest for this article is a proper representation of the magnetospheric ring current effect. Uncertainties in modelling...... its effect still produce the largest residuals between observations and present-day geomagnetic field models. A lot of progress has been achieved so far, but there are still open issues like the characteristics of the partial ring current. Other currents discussed are those flowing......Magnetospheric currents play an important role in the electrodynamics of near-Earth space. This has been the topic of many space science studies. Here we focus on the magnetic fields they cause close to Earth. Their contribution to the geomagnetic field is the second largest after the core field...

  8. A Low Heat Inleak Cryogenic Station for Testing HTS Current Leads for the Large Hadron Collider

    CERN Document Server

    Ballarino, A; Gomes, P; Métral, L; Serio, L; Suraci, A

    1999-01-01

    The LHC will be equipped with about 8000 superconducting magnets of all types. The total current to be transported into the cryogenic enclosure amounts to some 3360 kA. In order to reduce the heat load into the liquid helium, CERN intends to use High Temperature Superconducting (HTS) material for leads having current ratings up to 13 kA. The resistive part of the leads is cooled by forced flow of gaseous helium between 20 K and 300 K. The HTS part of the lead is immersed in a 4.5 K liquid helium bath, operates in self cooling conditions and is hydraulically separated from the resistive part. A cryogenic test station has been designed and built in order to assess the thermal and electrical performances of 13 kA prototype current leads. We report on the design, commissioning and operation of the cryogenic test station and illustrate its performance by typical test results of HTS current leads.

  9. Conceptual design of current lead for large scale high temperature superconducting rotating machine

    International Nuclear Information System (INIS)

    Le, T. D.; Kim, J. H.; Park, S. I.; Kim, H. M.

    2014-01-01

    High-temperature superconducting (HTS) rotating machines always require an electric current of from several hundreds to several thousand amperes to be led from outside into cold region of the field coil. Heat losses through the current leads then assume tremendous importance. Consequently, it is necessary to acquire optimal design for the leads which would achieve minimum heat loss during operation of machines for a given electrical current. In this paper, conduction cooled current lead type of 10 MW-Class HTS rotating machine will be chosen, a conceptual design will be discussed and performed relied on the least heat lost estimation between conventional metal lead and partially HTS lead. In addition, steady-state thermal characteristic of each one also is considered and illustrated.

  10. Reorganization of a large marine ecosystem due to atmospheric and anthropogenic pressure: a discontinuous regime shift in the Central Baltic Sea

    DEFF Research Database (Denmark)

    Moellmann, C; Diekmann, Rabea; Muller-Karulis, B

    2009-01-01

    the Baltic Sea, the largest brackish water body in the world ocean, and its ecosystems are strongly affected by atmospheric and anthropogenic drivers. Here, we present results of an analysis of the state and development of the Central Baltic Sea ecosystem integrating hydroclimatic, nutrient, phyto......Marine ecosystems such as the Baltic Sea are currently under strong atmospheric and anthropogenic pressure. Besides natural and human-induced changes in climate, major anthropogenic drivers such as overfishing and anthropogenic eutrophication are significantly affecting ecosystem structure...

  11. Large Current Modulation and Spin-Dependent Tunneling of Vertical Graphene/MoS$_{2}$ Heterostructures

    OpenAIRE

    Myoung, Nojoon; Seo, Kyungchul; Lee, Seung Joo; Ihm, Gukhyung

    2013-01-01

    Vertical graphene heterostructures have been introduced as an alternative architecture for electronic devices by using quantum tunneling. Here, we present that the current on/off ratio of vertical graphene field-effect transistors is enhanced by using an armchair graphene nanoribbon as an electrode. Moreover, we report spin-dependent tunneling current of the graphene/MoS2 heterostructures. When an atomically thin MoS2 layer sandwiched between graphene electrodes becomes magnetic, Dirac fermio...

  12. Fast-wave current drive modelling for large non-circular tokamaks

    International Nuclear Information System (INIS)

    Batchelor, D.B.; Goldfinger, R.C.; Jaeger, E.F.; Carter, M.D.; Swain, D.W.; Ehst, D.; Karney, C.F.F.

    1990-01-01

    It is widely recognized that a key element in the development of an attractive tokamak reactor, and in the successful achievement of the mission of ITER, is the development of an efficient steady-state current drive technique. Fast waves in the ion cyclotron range of frequencies hold the promise to drive steady-state currents with the required efficiency and to effectively heat the plasma to ignition. Advantages over other heating and current drive techniques include low cost per watt and the ability to penetrate to the center of high-density plasmas. The primary issues that must be resolved are: can an antenna array be designed to radiate the required spectrum of waves and have adequate coupling properties? Will the rf power be efficiently absorbed by electrons in the desired velocity range without unacceptable parasitic damping by fuel ions or α particles? What will the efficiency of current drive be when toroidal effects such as trapped particles are included? Can a practical rf system be designed and integrated into the device? We have addressed these issues by performing extensive calculations with ORION, a 2-D code, and the ray tracing code RAYS, which calculate wave propagation, absorption and current drive in tokamak geometry, and with RIP, a 2-D code that self-consistently calculates current drive with MHD equilibrium. An important figure of merit in this context is the integrated, normalized current drive efficiency. The calculations that we present here emphasize the ITER device. We consider a low-frequency scenario such that no ion resonances appear in the machine, and a high-frequency scenario such that the deuterium second harmonic resonance is just outside the plasma and the tritium second harmonic is in the plasma, midway between the magnetic axis and the inside edge. In both cases electron currents are driven by combined TTMP and Landau damping of the fast waves

  13. Near-Earth Magnetic Field Effects of Large-Scale Magnetospheric Currents

    Science.gov (United States)

    Luehr, Hermann; Xiong, Chao; Olsen, Nils; Le, Guan

    2016-01-01

    Magnetospheric currents play an important role in the electrodynamics of near- Earth space. This has been the topic of many space science studies. Here we focus on the magnetic fields they cause close to Earth. Their contribution to the geomagnetic field is the second largest after the core field. Significant progress in interpreting the magnetic fields from the different sources has been achieved thanks to magnetic satellite missions like Ørsted, CHAMP and now Swarm. Of particular interest for this article is a proper representation of the magnetospheric ring current effect. Uncertainties in modelling its effect still produce the largest residuals between observations and present-day geomagnetic field models. A lot of progress has been achieved so far, but there are still open issues like the characteristics of the partial ring current. Other currents discussed are those flowing in the magnetospheric tail. Also their magnetic contribution at LEO orbits is non-negligible. Treating them as an independent source is a more recent development, which has cured some of the problems in geomagnetic field modelling. Unfortunately there is no index available for characterizing the tail current intensity. Here we propose an approach that may help to properly quantify the magnetic contribution from the tail current for geomagnetic field modelling. Some open questions that require further investigation are mentioned at the end.

  14. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    OpenAIRE

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-01

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was perfor...

  15. Regional modeling of large wildfires under current and potential future climates in Colorado and Wyoming, USA

    Science.gov (United States)

    West, Amanda; Kumar, Sunil; Jarnevich, Catherine S.

    2016-01-01

    Regional analysis of large wildfire potential given climate change scenarios is crucial to understanding areas most at risk in the future, yet wildfire models are not often developed and tested at this spatial scale. We fit three historical climate suitability models for large wildfires (i.e. ≥ 400 ha) in Colorado andWyoming using topography and decadal climate averages corresponding to wildfire occurrence at the same temporal scale. The historical models classified points of known large wildfire occurrence with high accuracies. Using a novel approach in wildfire modeling, we applied the historical models to independent climate and wildfire datasets, and the resulting sensitivities were 0.75, 0.81, and 0.83 for Maxent, Generalized Linear, and Multivariate Adaptive Regression Splines, respectively. We projected the historic models into future climate space using data from 15 global circulation models and two representative concentration pathway scenarios. Maps from these geospatial analyses can be used to evaluate the changing spatial distribution of climate suitability of large wildfires in these states. April relative humidity was the most important covariate in all models, providing insight to the climate space of large wildfires in this region. These methods incorporate monthly and seasonal climate averages at a spatial resolution relevant to land management (i.e. 1 km2) and provide a tool that can be modified for other regions of North America, or adapted for other parts of the world.

  16. Marine fog: a review

    Science.gov (United States)

    Koračin, Darko; Dorman, Clive E.; Lewis, John M.; Hudson, James G.; Wilcox, Eric M.; Torregrosa, Alicia

    2014-01-01

    The objective of this review is to discuss physical processes over a wide range of spatial scales that govern the formation, evolution, and dissipation of marine fog. We consider marine fog as the collective combination of fog over the open sea along with coastal sea fog and coastal land fog. The review includes a history of sea fog research, field programs, forecasting methods, and detection of sea fog via satellite observations where similarity in radiative properties of fog top and the underlying sea induce further complexity. The main thrust of the study is to provide insight into causality of fog including its initiation, maintenance, and destruction. The interplay between the various physical processes behind the several stages of marine fog is among the most challenging aspects of the problem. An effort is made to identify this interplay between processes that include the microphysics of fog formation and maintenance, the influence of large-scale circulation and precipitation/clouds, radiation, turbulence (air-sea interaction), and advection. The environmental impact of marine fog is also addressed. The study concludes with an assessment of our current knowledge of the phenomenon, our principal areas of ignorance, and future lines of research that hold promise for advances in our understanding.

  17. Design optimization of 600 A-13 kA current leads for the Large Hadron Collider project at CERN

    CERN Document Server

    Spiller, D M; Al-Mosawl, M K; Friend, C M; Thacker, P; Ballarino, A

    2001-01-01

    The requirements of the Large Hadron Collider project at CERN for high-temperature superconducting (HTS) current leads have been widely publicized. CERN require hybrid current leads of resistive and HTS materials with current ratings of 600 A, 6 kA and 13 kA. BICC General Superconductors, in collaboration with the University of Southampton, have developed and manufactured prototype current leads for the Large Hadron Collider project. The resistive section consists of a phosphorus de-oxidized copper conductor and heat exchanger and the HTS section is constructed from BICC General's (Pb, Bi)2223 tapes with a reduced thermal conductivity Ag alloy sheath. We present the results of the materials optimization studies for the resistive and the HTS sections. Some results of the acceptance tests at CERN are discussed. (9 refs).

  18. Large-R jets in Atlas Tile Calorimeter current and upgraded geometry

    CERN Document Server

    Cecchini, Vincent Egidio

    2017-01-01

    This report describes a comparative study of two different geometries of the Atlas Tile Calorimeter to assess the performance of an increased granularity upgrade. The current geometry is compared to the upgraded one, needed because of the luminosity increase in the High-Luminosity LHC. Those geometries had been simulated in Geant4 to provide Monte-Carlo events simulations allowing us to compare the behaviour of the upgraded geometry with the current one. Data analysis is made from this simulation to compare the behaviour of the reconstructed jets substructure in the two different geometries.

  19. The study of dynamics of electrons in the presence of large current densities

    International Nuclear Information System (INIS)

    Garcia, G.

    2007-11-01

    The runaway electron effect is considered in different fields: nuclear fusion, or the heating of the solar corona. In this thesis, we are interested in runaway electrons in the ionosphere. We consider the issue of electrons moving through an ionospheric gas of positive ions and neutrals under the influence of a parallel electric field. We develop a kinetic model of collisions including electrons/electrons, electrons/ions and electrons/neutrals collisions. We use a Fokker-Planck approach to describe binary collisions between charged particles with a long-range interaction. A computational example is given illustrating the approach to equilibrium and the impact of the different terms. Then, a static electric field is applied in a new sample run. In this run, the electrons move in the z direction, parallel to the electric field. The first results show that all the electron distribution functions are non-Maxwellian. Furthermore, runaway electrons can carry a significant part of the total current density up to 20% of the total current density. Nevertheless, we note that the divergence free of the current density is not conserved. We introduce major changes in order to take into account the variation of the different moments of the ion distribution functions. We observe that the electron distribution functions are still non-Maxwellian. Runaway electrons are created and carry the current density. The core distribution stay at rest. As these electrons undergo less collisions, they increase the plasma conductivity. We make a parametric study. We fit the electron distribution function by two Maxwellian. We show that the time to reach the maximal current density is a key point. Thus, when we increase this time, we modify the temperatures. The current density plays a primary role. When the current density increases, all the moments of the distributions increase: electron density and mean velocity of the suprathermal distribution and the electron temperature of the core and

  20. The Safety and Efficacy of a Sustainable Marine Extract for the Treatment of Thinning Hair: A Summary of New Clinical Research and Results from a Panel Discussion on the Problem of Thinning Hair and Current Treatments.

    Science.gov (United States)

    Hornfeldt, Carl S; Holland, Mark; Bucay, Vivian W; Roberts, Wendy E; Waldorf, Heidi A; Dayan, Steven H

    2015-09-01

    Alopecia and thinning hair are highly prevalent conditions affecting a large proportion of men and women. Diffused hair loss is often more difficult to diagnose in women, mostly due to over-reliance on the assumption of hormonal influences, and it is commonly treated with a multi-therapy approach. Clinical studies have demonstrated the effectiveness of a nutraceutical supplement to provide essential nutrients that aid in stimulating existing hair growth and reducing hair shedding. The supplement Viviscal® contains a proprietary blend of proteins, lipids, and glycosaminoglycans derived from sustainable marine sources. We present here a summary of studies that have examined the safety and efficacy of this nutraceutical; as well as discussions on hair loss and current therapies from a recently convened expert panel in dermatology and plastic surgery.

  1. A hydrological budget (2002-2008) for a large subtropical wetland ecosystem indicates marine groundwater discharge accompanies diminished freshwater flow

    Science.gov (United States)

    Saha, Amartya K.; Moses, Christopher S.; Price, Rene M.; Engel, Victor; Smith, Thomas J.; Anderson, Gordon

    2012-01-01

    Water budget parameters are estimated for Shark River Slough (SRS), the main drainage within Everglades National Park (ENP) from 2002 to 2008. Inputs to the water budget include surface water inflows and precipitation while outputs consist of evapotranspiration, discharge to the Gulf of Mexico and seepage losses due to municipal wellfield extraction. The daily change in volume of SRS is equated to the difference between input and outputs yielding a residual term consisting of component errors and net groundwater exchange. Results predict significant net groundwater discharge to the SRS peaking in June and positively correlated with surface water salinity at the mangrove ecotone, lagging by 1 month. Precipitation, the largest input to the SRS, is offset by ET (the largest output); thereby highlighting the importance of increasing fresh water inflows into ENP for maintaining conditions in terrestrial, estuarine, and marine ecosystems of South Florida.

  2. Large benefits to marine fisheries of meeting the 1.5°C global warming target.

    Science.gov (United States)

    Cheung, William W L; Reygondeau, Gabriel; Frölicher, Thomas L

    2016-12-23

    Translating the Paris Agreement to limit global warming to 1.5°C above preindustrial level into impact-related targets facilitates communication of the benefits of mitigating climate change to policy-makers and stakeholders. Developing ecologically relevant impact-related targets for marine ecosystem services, such as fisheries, is an important step. Here, we use maximum catch potential and species turnover as climate-risk indicators for fisheries. We project that potential catches will decrease by more than 3 million metric tons per degree Celsius of warming. Species turnover is more than halved when warming is lowered from 3.5° to 1.5°C above the preindustrial level. Regionally, changes in maximum catch potential and species turnover vary across ecosystems, with the biggest risk reduction in the Indo-Pacific and Arctic regions when the Paris Agreement target is achieved. Copyright © 2016, American Association for the Advancement of Science.

  3. Right-handed charged currents in the era of the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Alioli, S. [CERN Theory Division,CH-1211, Geneva 23 (Switzerland); Cirigliano, V. [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States); Dekens, W. [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States); New Mexico Consortium, Los Alamos Research Park,Los Alamos, NM 87544 (United States); Vries, J. de [Nikhef, Theory Group,Science Park 105, 1098 XG, Amsterdam (Netherlands); Mereghetti, E. [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States)

    2017-05-16

    We discuss the phenomenology of right-handed charged currents in the framework of the Standard Model Effective Field Theory, in which they arise due to a single gauge-invariant dimension-six operator. We study the manifestations of the nine complex couplings of the W to right-handed quarks in collider physics, flavor physics, and low-energy precision measurements. We first obtain constraints on the couplings under the assumption that the right-handed operator is the dominant correction to the Standard Model at observable energies. We subsequently study the impact of degeneracies with other Beyond-the-Standard-Model effective interactions and identify observables, both at colliders and low-energy experiments, that would uniquely point to right-handed charged currents.

  4. Large current modulation and spin-dependent tunneling of vertical graphene/MoS2 heterostructures.

    Science.gov (United States)

    Myoung, Nojoon; Seo, Kyungchul; Lee, Seung Joo; Ihm, G

    2013-08-27

    Vertical graphene heterostructures have been introduced as an alternative architecture for electronic devices by using quantum tunneling. Here, we present that the current on/off ratio of vertical graphene field-effect transistors is enhanced by using an armchair graphene nanoribbon as an electrode. Moreover, we report spin-dependent tunneling current of the graphene/MoS2 heterostructures. When an atomically thin MoS2 layer sandwiched between graphene electrodes becomes magnetic, Dirac fermions with different spins feel different heights of the tunnel barrier, leading to spin-dependent tunneling. Our finding will develop the present graphene heterostructures for electronic devices by improving the device performance and by adding the possibility of spintronics based on graphene.

  5. Large critical current density improvement in Bi-2212 wires through the groove-rolling process

    International Nuclear Information System (INIS)

    Malagoli, A; Bernini, C; Braccini, V; Romano, G; Putti, M; Chaud, X; Debray, F

    2013-01-01

    Recently there has been a growing interest in Bi-2212 superconductor round wire for high magnetic field use despite the fact that an increase of the critical current is still needed to boost its successful use in such applications. Recent studies have demonstrated that the main obstacle to current flow, especially in long wires, is the residual porosity inside these powder-in-tube processed conductors that develops from bubble agglomeration when the Bi-2212 melts. In this work we tried to overcome this issue affecting the wire densification by changing the deformation process. Here we show the effects of groove rolling versus the drawing process on the critical current density J C and on the microstructure. In particular, groove-rolled multifilamentary wires show a J C increased by a factor of about 3 with respect to drawn wires prepared with the same Bi-2212 powder and architecture. We think that this approach in the deformation process is able to produce the required improvements both because the superconducting properties are enhanced and because it makes the fabrication process faster and cheaper. (paper)

  6. Eliminating large-scale magnetospheric current perturbations from long-term geomagnetic observatory data

    Science.gov (United States)

    Pick, L.; Korte, M. C.

    2016-12-01

    Magnetospheric currents generate the largest external contribution to the geomagnetic field observed on Earth. Of particular importance is the solar-driven effect of the ring current whose fluctuations overlap with internal field secular variation (SV). Recent core field models thus co-estimate this effect but their validity is limited to the last 15 years offering satellite data. We aim at eliminating magnetospheric modulation from the whole geomagnetic observatory record from 1840 onwards in order to obtain clean long-term SV that will enhance core flow and geodynamo studies.The ring current effect takes form of a southward directed external dipole field aligned with the geomagnetic main field axis. Commonly the Dst index (Sugiura, 1964) is used to parametrize temporal variations of this dipole term. Because of baseline instabilities, the alternative RC index was derived from hourly means of 21 stations spanning 1997-2013 (Olsen et al., 2014). We follow their methodology based on annual means from a reduced station set spanning 1960-2010. The absolute level of the variation so determined is "hidden" in the static lithospheric offsets taken as quiet-time means. We tackle this issue by subtracting crustal biases independently calculated for each observatory from an inversion of combined Swarm satellite and observatory data.Our index reproduces the original annual RC index variability with a reasonable offset of -10 nT in the reference time window 2000-2010. Prior to that it depicts a long-term trend consistent with the external dipole term from COV-OBS (Gillet et al., 2013), being the only long-term field model available for comparison. Sharper variations that are better correlated with the Ap index than the COV-OBS solution lend support to the usefulness of our initial modeling approach. Following a detailed sensitivity study of station choice future work will focus on increasing the resolution from annual to hourly means.

  7. Assessing the role of large herbivores in the structuring and functioning of freshwater and marine angiosperm ecosystems

    NARCIS (Netherlands)

    Bakker, Elisabeth S.; Pagès, Jordi F.; Arthur, Rohan; Alcoverro, Teresa

    2016-01-01

    While large herbivores can have strong impacts on terrestrial ecosystems, much less is known of their role in aquatic systems. We reviewed the literature to determine: (1) which large herbivores (>10 kg) have a (semi-)aquatic lifestyle and are important consumers of submerged vascular plants, (2)

  8. A route to explosive large-scale magnetic reconnection in a super-ion-scale current sheet

    Directory of Open Access Journals (Sweden)

    K. G. Tanaka

    2009-01-01

    Full Text Available How to trigger magnetic reconnection is one of the most interesting and important problems in space plasma physics. Recently, electron temperature anisotropy (αeo=Te⊥/Te|| at the center of a current sheet and non-local effect of the lower-hybrid drift instability (LHDI that develops at the current sheet edges have attracted attention in this context. In addition to these effects, here we also study the effects of ion temperature anisotropy (αio=Ti⊥/Ti||. Electron anisotropy effects are known to be helpless in a current sheet whose thickness is of ion-scale. In this range of current sheet thickness, the LHDI effects are shown to weaken substantially with a small increase in thickness and the obtained saturation level is too low for a large-scale reconnection to be achieved. Then we investigate whether introduction of electron and ion temperature anisotropies in the initial stage would couple with the LHDI effects to revive quick triggering of large-scale reconnection in a super-ion-scale current sheet. The results are as follows. (1 The initial electron temperature anisotropy is consumed very quickly when a number of minuscule magnetic islands (each lateral length is 1.5~3 times the ion inertial length form. These minuscule islands do not coalesce into a large-scale island to enable large-scale reconnection. (2 The subsequent LHDI effects disturb the current sheet filled with the small islands. This makes the triggering time scale to be accelerated substantially but does not enhance the saturation level of reconnected flux. (3 When the ion temperature anisotropy is added, it survives through the small island formation stage and makes even quicker triggering to happen when the LHDI effects set-in. Furthermore the saturation level is seen to be elevated by a factor of ~2 and large-scale reconnection is achieved only in this case. Comparison with two-dimensional simulations that exclude the LHDI effects confirms that the saturation level

  9. Biomass Gasification - A synthesis of technical barriers and current research issues for deployment at large scale

    Energy Technology Data Exchange (ETDEWEB)

    Heyne, Stefan [Chalmers Univ. of Technology, Gothenburg (Sweden); Liliedahl, Truls [KTH, Royal Inst. of Technology, Stockholm (Sweden); Marklund, Magnus [Energy Technology Centre, Piteaa (Sweden)

    2013-09-01

    Thermal gasification at large scale for cogeneration of power and heat and/or production of fuels and materials is a main pathway for a sustainable deployment of biomass resources. However, so far no such full scale production exists and biomass gasification projects remain at the pilot or demonstration scale. This report focuses on the key critical technology challenges for the large-scale deployment of the following biomass-based gasification concepts: Direct Fluidized Bed Gasification (FBG), Entrained Flow Gasification (EFG) and indirect Dual Fluidized Bed Gasification (DFBG). The main content in this report is based on responses from a number of experts in biomass gasification obtained from a questionnaire. The survey was composed of a number of more or less specific questions on technical barriers as to the three gasification concepts considered. For formalising the questionnaire, the concept of Technology Readiness Level (TRL 1-9) was used for grading the level of technical maturity of the different sub-processes within the three generic biomass gasification technologies. For direct fluidized bed gasification (FBG) it is mentioned that the technology is already available at commercial scale as air-blown technology and thus that air-blown FBG gasification may be reckoned a mature technology. The remaining technical challenge is the conversion to operation on oxygen with the final goal of producing chemicals or transport fuels. Tar reduction, in particular, and gas cleaning and upgrading in general are by far the most frequently named technical issues considered problematic. Other important aspects are problems that may occur when operating on low-grade fuels - i.e. low-cost fuels. These problems include bed agglomeration/ash sintering as well as alkali fouling. Even the preparation and feeding of these low-grade fuels tend to be problematic and require further development to be used on a commercial scale. Furthermore, efficient char conversion is mentioned by

  10. Current knowledge of the South East Asian large branchiopod Crustacea (Anostraca, Notostraca, Laevicaudata, Spinicaudata, Cyclestherida

    Directory of Open Access Journals (Sweden)

    D. Christopher Rogers

    2013-08-01

    Full Text Available The large branchiopod crustaceans (fairy shrimp, tadpole shrimp and clam shrimp of South East (SE Asia have only recently been examined with scientific vigor. Although more than 70 species have been reported for Asia and Indonesia, only six native taxa and one introduced species are known from SE Asia. The majority of records are from Thailand, with fewer than three records each from Laos, Myanmar, Malaysia, Cambodia, Vietnam, and Singapore. Eleven genera reported from adjacent regions may potentially occur in SE Asia. Spinicaudatan clam shrimp have been collected from Thailand and Cambodia, but have not been identified beyond genus. Four of the five native fairy shrimp species are endemic to SE Asia. The limited distributions of these few taxa suggest that this region has a distinct branchiopod fauna. In addition, we present new species and records of clam shrimp from Thailand. Future survey efforts will undoubtedly reveal additional taxa.

  11. The potential of large critical currents in the high Tc oxides

    International Nuclear Information System (INIS)

    Deutcher, G.

    1993-01-01

    The potential for high critical current densities is examined. on a thermodynamical basis, the energy scale for vortex pinning can be derived for instance from a measurement of the width of the critical region. This energy scale is of the order of 0.2 eV in YBCO, which is sufficient for practical applications. Another important parameter is the short coherence length. The inner plane length, of the order of a few lattice spacing, is favorable for pinning by point defects. But the very short outer plane length gives rise to anomalous magnetic behavior, unfavorable for high-field applications at high temperature; this is true in particular in most anisotropic oxides, such as the Bi compounds (author)

  12. A 1200 Year Alkenone-based Reconstruction of Sea Surface Temperature and Marine Productivity in the Southern California Current System from the Medieval Climate Anomaly to Present

    Science.gov (United States)

    O'Mara, N. A.; Kelly, C. S.; Herbert, T.

    2017-12-01

    Laminated sediment cores taken from the San Lazaro Basin (SLB) (25.18N, 112.66W) located off the coast of Baja California in the subtropical eastern Pacific were geochemically analyzed for alkenone and sterol biomarkers to reconstruct sea surface temperature (SST) and marine productivity from 850-1980 CE. High sedimentation rates, low bottom water dissolved oxygen, and high marine productivity in combination with the San Lazaro Basin's location within the dynamic transition zone between the tropical and subtropical eastern Pacific, make it a prime location to study variability of tropical and subtropical modes of climate variability. This study focuses on the impacts and variability of the El Niño Southern Oscillation and the Pacific Decadal Oscillation on the subtropical eastern Pacific. SST and coccolithophore productivity (n=730) for 2 mm sections of sediment corresponding to 1 measurement every 1.8 years were reconstructed using the Uk'37 unsaturation index and C37 alkenone concentration. The high resolution of this record allowed for the analysis of variability of SST and productivity on decadal timescales. Brassicasterol concentrations were calculated for a limited number of samples (n=44) to assess diatom productivity. High spectral power was found at periods of 20-30 years in SST and productivity records indicating a strong influence of the PDO on the SLB, making this the first marine based record directly relevant to PDO reconstructions that continuously spans the last millennium. Cool and productive (warm and less productive) waters were observed in the southern California Current in the Medieval Climate Anomaly 900-1200 CE (Little Ice Age 1400-1800 CE) supporting previous reconstructions that warmer (cooler) SST are linked to both reduced (enhanced) phytoplankton productivity. Additionally, cool (warm) SST were also associated with dry (wet) conditions in the American Southwest indicating that changes in the PDO has had a significant impact on drought

  13. Long-time and large-distance asymptotic behavior of the current-current correlators in the non-linear Schroedinger model

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Terras, V. [CNRS, ENS Lyon (France). Lab. de Physique

    2010-12-15

    We present a new method allowing us to derive the long-time and large-distance asymptotic behavior of the correlations functions of quantum integrable models from their exact representations. Starting from the form factor expansion of the correlation functions in finite volume, we explain how to reduce the complexity of the computation in the so-called interacting integrable models to the one appearing in free fermion equivalent models. We apply our method to the time-dependent zero-temperature current-current correlation function in the non-linear Schroedinger model and compute the first few terms in its asymptotic expansion. Our result goes beyond the conformal field theory based predictions: in the time-dependent case, other types of excitations than the ones on the Fermi surface contribute to the leading orders of the asymptotics. (orig.)

  14. Long-time and large-distance asymptotic behavior of the current-current correlators in the non-linear Schroedinger model

    International Nuclear Information System (INIS)

    Kozlowski, K.K.; Terras, V.

    2010-12-01

    We present a new method allowing us to derive the long-time and large-distance asymptotic behavior of the correlations functions of quantum integrable models from their exact representations. Starting from the form factor expansion of the correlation functions in finite volume, we explain how to reduce the complexity of the computation in the so-called interacting integrable models to the one appearing in free fermion equivalent models. We apply our method to the time-dependent zero-temperature current-current correlation function in the non-linear Schroedinger model and compute the first few terms in its asymptotic expansion. Our result goes beyond the conformal field theory based predictions: in the time-dependent case, other types of excitations than the ones on the Fermi surface contribute to the leading orders of the asymptotics. (orig.)

  15. Sustainable production of toxin free marine microalgae biomass as fish feed in large scale open system in the Qatari desert.

    Science.gov (United States)

    Das, Probir; Thaher, Mahmoud Ibrahim; Hakim, Mohammed Abdul Quadir Mohd Abdul; Al-Jabri, Hareb Mohammed S J

    2015-09-01

    Mass cultivation of microalgae biomass for feed should be cost effective and toxin free. Evaporation loss in Qatar can be as high as 2 cm/d. Hence, production of marine microalgae biomass in Qatar would also require mitigating water loss as there was only very limited groundwater reserve. To address these issues, a combination of four growth conditions were applied to a 25,000 L raceway pond: locally isolated microalgae strain was selected which could grow in elevated salinity; strain that did not require silica and vitamins; volume of the culture would increase over time keeping denser inoculum in the beginning, and evaporation water loss would be balanced by adding seawater only. A local saline tolerant Nannochloropsis sp. was selected which did not require silica and vitamins. When the above conditions were combined in the pond, average areal biomass productivities reached 20.37 g/m(2)/d, and the culture was not contaminated by any toxic microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Persistent marine debris

    International Nuclear Information System (INIS)

    Levy, E.M.

    1992-01-01

    In this paper the distribution of persistent marine debris, adrift on world oceans and stranded on beaches globally, is reviewed and related to the known inputs and transport by the major surface currents. Since naturally occurring processes eventually degrade petroleum in the environment, international measures to reduce the inputs have been largely successful in alleviating oil pollution on a global, if not on a local, scale. Many plastics, however, are so resistant to natural degradation that merely controlling inputs will be insufficient, and more drastic and costly measures will be needed to cope with the emerging global problem posed by these materials

  17. Numerical Analysis of Consolidation Settlement and Creep Deformation of Artificial Island Revetment Structure in a Large-Scale Marine Reclamation Land Project

    Directory of Open Access Journals (Sweden)

    Jie Zhao

    2015-09-01

    Full Text Available In order to analyze the influential factors of soft foundation settlement in a marine reclamation land project, the consolidation settlement and pore pressure dissipation of the entire area are numerically simulated using Soft-Soil- Creep Model, in which the PLAXIS finite element software for professional geotechnical engineering is applied and empirical data of Japanese Kansai’s airport project are used. Moreover, the figures of settlement and pore pressure results in the different basic period are drawn, and the corresponding analysis conclusions are ob-tained based on the comparison among the results from the computational parameters of depth. In addition,, the influence rules of various parameters on settlement results is concluded through running the parameter sensitivity analysis in Soft-Soil-Creep Model, and the experience and conclusions can be for reference in the design and con-struction of similar large-scale marine reclamation land project. Also the empirical value method of the creep index has not been applied widely. Further research needs to be done.

  18. Evaluating large-scale blood transfusion therapy for the current Ebola epidemic in Liberia.

    Science.gov (United States)

    Gutfraind, Alexander; Meyers, Lauren Ancel

    2015-04-15

    To combat the 2014-2015 Ebola virus disease (EVD) epidemic in West Africa, the World Health Organization urged the rapid evaluation of convalescent whole blood (CWB) and plasma (CP) transfusion therapy. However, the feasibility and likely impacts of broad implementation of transfusions are yet unknown. We extended an Ebola virus transmission model published by the Centers for Disease Control and Prevention to include hospital-based convalescent donations and transfusions. Using recent epidemiological estimates for EVD in Liberia and assuming that convalescent transfusions reduce the case-fatality rate to 12.5% (range, 7.5%-17.5%), we projected the impacts of a countrywide ramp-up of transfusion therapy. Under the 10% case-hospitalization rate estimated for Liberia in September 2014, large-scale CP therapy is expected to save 3586 lives by October 2015 (3.1% mortality reduction; 95% confidence interval [CI], .52%-4.5%). Under a higher 30% hospitalization rate, CP transfusions are expected to save 151 lives (0.9% of the total; 95% CI, .21%-11%). Transfusion therapy for EVD is a low-cost measure that can potentially save many lives in West Africa but will not measurably influence the prevalence. Under all scenarios considered, CP transfusions are predicted to achieve greater reductions in mortality than CWB. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Linac beam dynamics calculations for low-current large-emittance beams

    International Nuclear Information System (INIS)

    Swain, G.R.; Butler, H.S.

    1992-01-01

    The beam in PILAC, a superconducting linac for pions proposed at LAUFF, will have a lager momentum spread (7% dp/p) and occupy a larger transverse space (13 cm dia. bore) than is usual in high-beta linacs. To find the effects of this large phase space, a cavity element is being added to the MOTER code. With this addition, pions and other particles may be tracked through the injection line and the PILAC linac. In one option, the particles may be cell by cell through a multicell cavity using formulas. The formulas are derived by integrating the energy gain and transverse impulse from the fields in a cell along the path of the particle. What is new in this analysis is that the transverse momentum is considered to be a significant part of the total momentum. The effect of a difference in velocity from the design velocity of the structure is considered. In another option still under development, field information is specified, and the particles may be tracked by stepwise integration

  20. Lagrangian current measurements and large-scale long-term dispersion rates (Sofar float experiment)

    International Nuclear Information System (INIS)

    Gurbutt, F.A.

    1984-01-01

    Activity entering the water from a deep-sea disposal of radioactive waste package will be dispersed through the ocean both by the long-term circulation pattern and the eddy (mixing) motions. Sofar floats are thought to be the most cost-effective way of obtaining direct information on the circulation over a few years and the only way to obtain information, in the Lagrangian framework, on the statistics of the eddy movements. The Sofar float experiment seeks to answer questions including: (a) What is the magnitude of space and time variability of the horizontal eddy kinetic energy in the eastern bassin and is it consistent with that found in the western basin of the North Atlantic. (b) Is the deep flow inferred from incoherent arrays of moored current meters correct. The report covers the preparation stage for the Sofar float experiment whick takes place from autumn 1984 to 1986. It describes the recent results from the western North Atlantic, the design of the new deep Sofar float, the testing of the float including the range at which these new floats can be heard, the experimental design and expected results

  1. Preparative separation of sulfur-containing diketopiperazines from marine fungus Cladosporium sp. using high-speed counter-current chromatography in stepwise elution mode.

    Science.gov (United States)

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-09

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  2. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Binbin Gu

    2015-01-01

    Full Text Available High-speed counter-current chromatography (HSCCC was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs (including two new compounds cladosporin A (1 and cladosporin B (3, and a known compound haematocin (2 from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v and (2:1:2:1, v/v, in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  3. Large-eddy-simulation approach in understanding flow structures of 2D turbulent density currents over sloping surfaces

    Science.gov (United States)

    Nayamatullah, M.; Rao Pillalamarri, Narasimha; Bhaganagar, Kiran

    2018-04-01

    A numerical investigation was performed to understand the flow dynamics of 2D density currents over sloping surfaces. Large eddy simulation was conducted for lock-exchange (L-E) release currents and overflows. 2D Navier-Stokes equations were solved using the Boussinesq approximation. The effects of the lock aspect-ratio (height/length of lock), slope, and Reynolds number on the flow structures and turbulence mixing have been analyzed. Results have confirmed buoyancy within the head of the two-dimensional currents is not conserved which contradicts the classical thermal theory. The lock aspect-ratio dictates the fraction of initial buoyancy which is carried by the head of the current at the beginning of the slumping (horizontal) and accelerating phase (over a slope), which has important implications on turbulence kinetic energy production, and hence mixing in the current. For L-E flows over a slope, increasing slope angle enhances the turbulence production. Increasing slope results in shear reversal within the density current resulting in shear-instabilities. Differences in turbulence production mechanisms and flow structures exist between the L-E and constant-flux release currents resulting in significant differences in the flow characteristics between different releases.

  4. Measurements of the large-scale direct-current Earth potential and possible implications for the geomagnetic dynamo.

    Science.gov (United States)

    1985-07-05

    The magnitude of the large-scale direct-current earth potential was measured on a section of a recently laid transatlantic telecommunications cable. Analysis of the data acquired on the 4476-kilometer cable yielded a mean direct-current potential drop of less than about 0.072 +/- 0.050 millivolts per kilometer. Interpreted in terms of a generation of the potential by the earth's geodynamo, such a small value of the mean potential implies that the toroidal and poloidal magnetic fields of the dynamo are approximately equal at the core-mantle boundary.

  5. Large dunes on the outer shelf off the Zambezi Delta, Mozambique: evidence for the existence of a Mozambique Current

    Science.gov (United States)

    Flemming, Burghard W.; Kudrass, Hermann-Rudolf

    2018-02-01

    The existence of a continuously flowing Mozambique Current, i.e. a western geostrophic boundary current flowing southwards along the shelf break of Mozambique, was until recently accepted by oceanographers studying ocean circulation in the south-western Indian Ocean. This concept was then cast into doubt based on long-term current measurements obtained from current-meter moorings deployed across the northern Mozambique Channel, which suggested that southward flow through the Mozambique Channel took place in the form of successive, southward migrating and counter-clockwise rotating eddies. Indeed, numerical modelling found that, if at all, strong currents on the outer shelf occurred for not more than 9 days per year. In the present study, the negation of the existence of a Mozambique Current is challenged by the discovery of a large (50 km long, 12 km wide) subaqueous dune field (with up to 10 m high dunes) on the outer shelf east of the modern Zambezi River delta at water depths between 50 and 100 m. Being interpreted as representing the current-modified, early Holocene Zambezi palaeo-delta, the dune field would have migrated southwards by at least 50 km from its former location since sea level recovered to its present-day position some 7 ka ago and after the former delta had been remoulded into a migrating dune field. Because a large dune field composed of actively migrating bedforms cannot be generated and maintained by currents restricted to a period of only 9 days per year, the validity of those earlier modelling results is questioned for the western margin of the flow field. Indeed, satellite images extracted from the Perpetual Ocean display of NASA, which show monthly time-integrated surface currents in the Mozambique Channel for the 5 month period from June-October 2006, support the proposition that strong flow on the outer Mozambican shelf occurs much more frequently than postulated by those modelling results. This is consistent with more recent modelling

  6. Natural radionuclides tracing in marine surface waters along the northern coast of Oman Sea by combining the radioactivity analysis, oceanic currents and the SWAN model results

    International Nuclear Information System (INIS)

    Zare, Mohammad Reza; Mostajaboddavati, Mojtaba; Kamali, Mahdi; Tari, Marziyeh; Mosayebi, Sanaz; Mortazavi, Mohammad Seddigh

    2015-01-01

    Highlights: • This study estimates radioactive pollution diffusion in coastline of the Oman Sea. • 36 high volume surface water samples were analyzed using a portable HPGe detector. • Oceanic currents in the northern coast of Oman Sea were investigated. • The spectral wave model SWAN was used for wave parameters simulation. • Currents and preferable wave directions were coupled with higher radioactivity. - Abstract: This study aims to establish a managed sampling plan for rapid estimate of natural radio-nuclides diffusion in the northern coast of the Oman Sea. First, the natural radioactivity analysis in 36 high volume surface water samples was carried out using a portable high-resolution gamma-ray spectrometry. Second, the oceanic currents in the northern coast were investigated. Then, the third generation spectral SWAN model was utilized to simulate wave parameters. Direction of natural radioactivity propagation was coupled with the preferable wave vectors and oceanic currents direction that face to any marine pollution, these last two factors will contribute to increase or decrease of pollution in each grid. The results were indicated that the natural radioactivity concentration between the grids 8600 and 8604 is gathered in the grid 8600 and between the grids 8605 and 8608 is propagated toward middle part of Oman Sea

  7. Modeling the condensation of sulfuric acid and water on the cylinder liner of a large two-stroke marine diesel engine

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Faurskov; Mayer, Stefan; Eskildsen, Svend S.

    2018-01-01

    Corrosive wear of cylinder liners in large two-stroke marine diesel engines that burn heavy fuel oil containing sulfur is coupled to the formation of gaseous sulfur trioxide (SO3) and subsequent combined condensation of sulfuric acid (H2SO4) and water (H2O) vapor. The present work seeks to address...... vapor liquid equilibrium. By assuming homogenous cylinder gas mixtures condensation is modeled using a convective heat and mass transfer analogy combined with realistic liner temperature profiles. Condensation of water is significantly altered by the liner temperature and charge air humidity while...... how fuel sulfur content, charge air humidity and liner temperature variations affects the deposition of water and sulfuric acid at low load operation. A phenomenological engine model is applied to simulate the formation of cylinder/bulk gas combustion products and dew points comply with H2O–H2SO4...

  8. A comprehensive Two-Fluid Model for Cavitation and Primary Atomization Modelling of liquid jets - Application to a large marine Diesel injector

    International Nuclear Information System (INIS)

    Habchi, Chawki; Bohbot, Julien; Schmid, Andreas; Herrmann, Kai

    2015-01-01

    In this paper, a comprehensive two-fluid model is suggested in order to compute the in-nozzle cavitating flow and the primary atomization of liquid jets, simultaneously. This model has been applied to the computation of a typical large marine Diesel injector. The numerical results have shown a strong correlation between the in-nozzle cavitating flow and the ensuing spray orientation and atomization. Indeed, the results have confirmed the existence of an off-axis liquid core. This asymmetry is likely to be at the origin of the spray deviation observed experimentally. In addition, the primary atomization begins very close to the orifice exit as in the experiments, and the smallest droplets are generated due to cavitation pocket shape oscillations located at the same side, inside the orifice. (paper)

  9. A comprehensive Two-Fluid Model for Cavitation and Primary Atomization Modelling of liquid jets - Application to a large marine Diesel injector

    Science.gov (United States)

    Habchi, Chawki; Bohbot, Julien; Schmid, Andreas; Herrmann, Kai

    2015-12-01

    In this paper, a comprehensive two-fluid model is suggested in order to compute the in-nozzle cavitating flow and the primary atomization of liquid jets, simultaneously. This model has been applied to the computation of a typical large marine Diesel injector. The numerical results have shown a strong correlation between the in-nozzle cavitating flow and the ensuing spray orientation and atomization. Indeed, the results have confirmed the existence of an off-axis liquid core. This asymmetry is likely to be at the origin of the spray deviation observed experimentally. In addition, the primary atomization begins very close to the orifice exit as in the experiments, and the smallest droplets are generated due to cavitation pocket shape oscillations located at the same side, inside the orifice.

  10. Improved protection system for phase faults on marine vessels based on ratio between negative sequence and positive sequence of the fault current

    DEFF Research Database (Denmark)

    Ciontea, Catalin-Iosif; Hong, Qiteng; Booth, Campbell

    2018-01-01

    algorithm is implemented in a programmable digital relay embedded in a hardware-in-the-loop (HIL) test set-up that emulates a typical maritime feeder using a real-time digital simulator. The HIL set-up allows testing of the new protection method under a wide range of faults and network conditions......This study presents a new method to protect the radial feeders on marine vessels. The proposed protection method is effective against phase–phase (PP) faults and is based on evaluation of the ratio between the negative sequence and positive sequence of the fault currents. It is shown...... that the magnitude of the introduced ratio increases significantly during the PP fault, hence indicating the fault presence in an electric network. Here, the theoretical background of the new method of protection is firstly discussed, based on which the new protection algorithm is described afterwards. The proposed...

  11. Trends in Cable Magnetization and Persistent Currents during the Production of the Main Dipoles of the Large Hadron Collider

    CERN Document Server

    Bellesia, B; Granata, V; Le Naour, S; Oberli, L; Sanfilippo, S; Santoni, C; Scandale, Walter; Schwerg, N; Todesco, Ezio; Völlinger, C

    2005-01-01

    The production of more than 60% of superconducting cables for the main dipoles of the Large Hadron Collider has been completed. The results of the measurements of cable magnetization and the dependence on the manufacturers are presented. The strand magnetization produces field errors that have been measured in a large number of dipoles (approximately 100 to date) tested in cold conditions. We examine here the correlation between the available magnetic measurements and the large database of cable magnetization. The analysis is based on models documented elsewhere in the literature. Finally, a forecast of the persistent current effects to be expected in the LHC main dipoles is presented, and the more critical parameters for beam dynamics are singled out.

  12. Mapping geological structures in bedrock via large-scale direct current resistivity and time-domain induced polarization tomography

    DEFF Research Database (Denmark)

    Rossi, Matteo; Olsson, Per-Ivar; Johansson, Sara

    2017-01-01

    -current resistivity distribution of the subsoil and the phase of the complex conductivity using a constant-phase angle model. The joint interpretation of electrical resistivity and induced-polarization models leads to a better understanding of complex three-dimensional subsoil geometries. The results have been......An investigation of geological conditions is always a key point for planning infrastructure constructions. Bedrock surface and rock quality must be estimated carefully in the designing process of infrastructures. A large direct-current resistivity and time-domain induced-polarization survey has......, there are northwest-trending Permian dolerite dykes that are less deformed. Four 2D direct-current resistivity and time-domain induced-polarization profiles of about 1-km length have been carefully pre-processed to retrieve time-domain induced polarization responses and inverted to obtain the direct...

  13. Suspended sediment dynamics in a large-scale turbidity current: Direct measurements from the deep-water Congo Canyon

    Science.gov (United States)

    Simmons, S.; Azpiroz, M.; Cartigny, M.; Clare, M. A.; Parsons, D. R.; Sumner, E.; Talling, P. J.

    2016-12-01

    Turbidity currents that transport sediment to the deep ocean deposit a greater volume of sediment than any other process on Earth. To date, only a handful of studies have directly measured turbidity currents, with flow durations ranging from a few minutes to a few hours. Our understanding of turbidity current dynamics is therefore largely derived from scaled laboratory experiments and numerical modelling. Recent years have seen the first field-scale measurements of depth-resolved velocity profiles, but sediment concentration (a key parameter for turbidity currents) remains elusive. Here, we present high resolution measurements of deep-water turbidity currents from the Congo Canyon; one of the world's largest submarine canyons. Direct measurements using acoustic Doppler current profilers (ADCPs) show that flows can last for many days, rather than hours as seen elsewhere, and provide the first quantification of concentration and grain size within deep-water turbidity currents.Velocity and backscatter were measured at 5 second intervals by an ADCP suspended 80 m above the canyon floor, at 2000 m water depth. A novel inversion method using multiple ADCP frequencies enabled quantification of sediment concentration and grain size within the flows. We identify high concentrations of coarse sediment within a thin frontal cell, which outruns a thicker, trailing body. Thus, the flows grow in length while propagating down-canyon. This is distinct from classical models and other field-scale measurements of turbidity currents. The slow-moving body is dominated by suspended fine-grained sediment. The body mixes with the surrounding fluid leaving diffuse clouds of sediment that persist for days after initial entrainment. Ambient tidal flow also controls the mixing within the body and the surrounding fluid. Our results provide a new quantification of suspended sediment within flows and the interaction with the surrounding fluid.

  14. Economic Impact of Large-Scale Deployment of Offshore Marine and Hydrokinetic Technology in Oregon Coastal Counties

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, T. [Bureau of Ocean Energy Management (BOEM), Washington, DC (United States); Tegen, S. [Bureau of Ocean Energy Management (BOEM), Washington, DC (United States); Beiter, P. [Bureau of Ocean Energy Management (BOEM), Washington, DC (United States)

    2015-03-01

    To begin understanding the potential economic impacts of large-scale WEC technology, the Bureau of Ocean Energy Management (BOEM) commissioned the National Renewable Energy Laboratory (NREL) to conduct an economic impact analysis of largescale WEC deployment for Oregon coastal counties. This report follows a previously published report by BOEM and NREL on the jobs and economic impacts of WEC technology for the entire state (Jimenez and Tegen 2015). As in Jimenez and Tegen (2015), this analysis examined two deployment scenarios in the 2026-2045 timeframe: the first scenario assumed 13,000 megawatts (MW) of WEC technology deployed during the analysis period, and the second assumed 18,000 MW of WEC technology deployed by 2045. Both scenarios require major technology and cost improvements in the WEC devices. The study is on very large-scale deployment so readers can examine and discuss the potential of a successful and very large WEC industry. The 13,000-MW is used as the basis for the county analysis as it is the smaller of the two scenarios. Sensitivity studies examined the effects of a robust in-state WEC supply chain. The region of analysis is comprised of the seven coastal counties in Oregon—Clatsop, Coos, Curry, Douglas, Lane, Lincoln, and Tillamook—so estimates of jobs and other economic impacts are specific to this coastal county area.

  15. Large and growing environmental reservoirs of Deca-BDE present an emerging health risk for fish and marine mammals

    International Nuclear Information System (INIS)

    Ross, Peter S.; Couillard, Catherine M.; Ikonomou, Michael G.; Johannessen, Sophia C.; Lebeuf, Michel; Macdonald, Robie W.; Tomy, Gregg T.

    2009-01-01

    Polybrominated diphenyl ethers (PBDEs) have been the subject of intense scientific and regulatory scrutiny during recent years. Of the three commercial forms (Penta, Octa and Deca) of PBDEs that have been widely used as flame retardants in textiles, furniture upholstery, plastics, and electronics, only Deca-BDE remains on the general market in North America, while a recent ruling of the European Court spells an impending end to its use in Europe. We review here highlights of aquatic research documenting the rapid emergence of PBDEs as a high priority environmental concern in Canada. PBDEs are being introduced in large quantities to the aquatic environment through sewage discharge and atmospheric deposition. In certain environmental compartments, the single congener BDE-209, the main ingredient in the Deca-BDE formulation, has surpassed the legacy PCBs and DDT as the top contaminant by concentration. Limited biomagnification of BDE-209 in aquatic food webs reflects its high log K ow and preferential partitioning into the particle phase. As a result, large environmental reservoirs of BDE-209 are being created in sediments, and these may present a long-term threat to biota: BDE-209 breaks down into more persistent, more bioaccumulative, more toxic, and more mobile PBDE congeners in the environment

  16. Large and growing environmental reservoirs of Deca-BDE present an emerging health risk for fish and marine mammals.

    Science.gov (United States)

    Ross, Peter S; Couillard, Catherine M; Ikonomou, Michael G; Johannessen, Sophia C; Lebeuf, Michel; Macdonald, Robie W; Tomy, Gregg T

    2009-01-01

    Polybrominated diphenyl ethers (PBDEs) have been the subject of intense scientific and regulatory scrutiny during recent years. Of the three commercial forms (Penta, Octa and Deca) of PBDEs that have been widely used as flame retardants in textiles, furniture upholstery, plastics, and electronics, only Deca-BDE remains on the general market in North America, while a recent ruling of the European Court spells an impending end to its use in Europe. We review here highlights of aquatic research documenting the rapid emergence of PBDEs as a high priority environmental concern in Canada. PBDEs are being introduced in large quantities to the aquatic environment through sewage discharge and atmospheric deposition. In certain environmental compartments, the single congener BDE-209, the main ingredient in the Deca-BDE formulation, has surpassed the legacy PCBs and DDT as the top contaminant by concentration. Limited biomagnification of BDE-209 in aquatic food webs reflects its high log K(ow) and preferential partitioning into the particle phase. As a result, large environmental reservoirs of BDE-209 are being created in sediments, and these may present a long-term threat to biota: BDE-209 breaks down into more persistent, more bioaccumulative, more toxic, and more mobile PBDE congeners in the environment.

  17. Marine electrical practice

    CERN Document Server

    Watson, G O

    1991-01-01

    Marine Engineering Series: Marine Electrical Practice, Sixth Edition focuses on changes in the marine industry, including the application of programmable electronic systems, generators, and motors. The publication first ponders on insulation and temperature ratings of equipment, protection and discrimination, and AC generators. Discussions focus on construction, shaft-drive generators, effect of unbalanced loading, subtransient and transient reactance, protection discrimination, fault current, measurement of ambient air temperature, and basis of machine ratings. The text then examines AC switc

  18. Life-cycle and genome of OtV5, a large DNA virus of the pelagic marine unicellular green alga Ostreococcus tauri.

    Directory of Open Access Journals (Sweden)

    Evelyne Derelle

    Full Text Available Large DNA viruses are ubiquitous, infecting diverse organisms ranging from algae to man, and have probably evolved from an ancient common ancestor. In aquatic environments, such algal viruses control blooms and shape the evolution of biodiversity in phytoplankton, but little is known about their biological functions. We show that Ostreococcus tauri, the smallest known marine photosynthetic eukaryote, whose genome is completely characterized, is a host for large DNA viruses, and present an analysis of the life-cycle and 186,234 bp long linear genome of OtV5. OtV5 is a lytic phycodnavirus which unexpectedly does not degrade its host chromosomes before the host cell bursts. Analysis of its complete genome sequence confirmed that it lacks expected site-specific endonucleases, and revealed the presence of 16 genes whose predicted functions are novel to this group of viruses. OtV5 carries at least one predicted gene whose protein closely resembles its host counterpart and several other host-like sequences, suggesting that horizontal gene transfers between host and viral genomes may occur frequently on an evolutionary scale. Fifty seven percent of the 268 predicted proteins present no similarities with any known protein in Genbank, underlining the wealth of undiscovered biological diversity present in oceanic viruses, which are estimated to harbour 200Mt of carbon.

  19. Fault Ride Through Capability Enhancement of a Large-Scale PMSG Wind System with Bridge Type Fault Current Limiters

    Directory of Open Access Journals (Sweden)

    ALAM, M. S.

    2018-02-01

    Full Text Available In this paper, bridge type fault current limiter (BFCL is proposed as a potential solution to the fault problems of permanent magnet synchronous generator (PMSG based large-scale wind energy system. As PMSG wind system is more vulnerable to disturbances, it is essential to guarantee the stability during severe disturbances by enhancing the fault ride through capability. BFCL controller has been designed to insert resistance and inductance during the inception of system disturbances in order to limit fault current. Constant capacitor voltage has been maintained by the grid voltage source converter (GVSC controller while current extraction or injection has been achieved by machine VSC (MVSC controller. Symmetrical and unsymmetrical faults have been applied in the system to show the effectiveness of the proposed BFCL solution. PMSG wind system, BFCL and their controllers have been implemented by real time hardware in loop (RTHIL setup with real time digital simulator (RTDS and dSPACE. Another significant feature of this work is that the performance of the proposed BFCL is compared with that of series dynamic braking resistor (SDBR. Comparative RTHIL implementation results show that the proposed BFCL is very efficient in improving system fault ride through capability by limiting the fault current and outperforms SDBR.

  20. Large Eddy Simulation study of the development of finite-channel lock-release currents at high Grashof numbers

    Science.gov (United States)

    Ooi, Seng-Keat

    2005-11-01

    Lock-exchange gravity current flows produced by the instantaneous release of a heavy fluid are investigated using 3-D well resolved Large Eddy Simulation simulations at Grashof numbers up to 8*10^9. It is found the 3-D simulations correctly predict a constant front velocity over the initial slumping phase and a front speed decrease proportional to t-1/3 (the time t is measured from the release) over the inviscid phase, in agreement with theory. The evolution of the current in the simulations is found to be similar to that observed experimentally by Hacker et al. (1996). The effect of the dynamic LES model on the solutions is discussed. The energy budget of the current is discussed and the contribution of the turbulent dissipation to the total dissipation is analyzed. The limitations of less expensive 2D simulations are discussed; in particular their failure to correctly predict the spatio-temporal distributions of the bed shear stresses which is important in determining the amount of sediment the gravity current can entrain in the case in advances of a loose bed.

  1. Osedax borings in fossil marine bird bones

    Science.gov (United States)

    Kiel, Steffen; Kahl, Wolf-Achim; Goedert, James L.

    2011-01-01

    The bone-eating marine annelid Osedax consumes mainly whale bones on the deep-sea floor, but recent colonization experiments with cow bones and molecular age estimates suggesting a possible Cretaceous origin of Osedax indicate that this worm might be able grow on a wider range of substrates. The suggested Cretaceous origin was thought to imply that Osedax could colonize marine reptile or fish bones, but there is currently no evidence that Osedax consumes bones other than those of mammals. We provide the first evidence that Osedax was, and most likely still is, able to consume non-mammalian bones, namely bird bones. Borings resembling those produced by living Osedax were found in bones of early Oligocene marine flightless diving birds (family Plotopteridae). The species that produced these boreholes had a branching filiform root that grew to a length of at least 3 mm, and lived in densities of up to 40 individuals per square centimeter. The inclusion of bird bones into the diet of Osedax has interesting implications for the recent suggestion of a Cretaceous origin of this worm because marine birds have existed continuously since the Cretaceous. Bird bones could have enabled this worm to survive times in the Earth's history when large marine vertebrates other than fish were rare, specifically after the disappearance of large marine reptiles at the end-Cretaceous mass extinction event and before the rise of whales in the Eocene.

  2. Open Data, Jupyter Notebooks and Geospatial Data Standards Combined - Opening up large volumes of marine and climate data to other communities

    Science.gov (United States)

    Clements, O.; Siemen, S.; Wagemann, J.

    2017-12-01

    The EU-funded Earthserver-2 project aims to offer on-demand access to large volumes of environmental data (Earth Observation, Marine, Climate data and Planetary data) via the interface standard Web Coverage Service defined by the Open Geospatial Consortium. Providing access to data via OGC web services (e.g. WCS and WMS) has the potential to open up services to a wider audience, especially to users outside the respective communities. Especially WCS 2.0 with its processing extension Web Coverage Processing Service (WCPS) is highly beneficial to make large volumes accessible to non-expert communities. Users do not have to deal with custom community data formats, such as GRIB for the meteorological community, but can directly access the data in a format they are more familiar with, such as NetCDF, JSON or CSV. Data requests can further directly be integrated into custom processing routines and users are not required to download Gigabytes of data anymore. WCS supports trim (reduction of data extent) and slice (reduction of data dimension) operations on multi-dimensional data, providing users a very flexible on-demand access to the data. WCPS allows the user to craft queries to run on the data using a text-based query language, similar to SQL. These queries can be very powerful, e.g. condensing a three-dimensional data cube into its two-dimensional mean. However, the more processing-intensive the more complex the query. As part of the EarthServer-2 project, we developed a python library that helps users to generate complex WCPS queries with Python, a programming language they are more familiar with. The interactive presentation aims to give practical examples how users can benefit from two specific WCS services from the Marine and Climate community. Use-cases from the two communities will show different approaches to take advantage of a Web Coverage (Processing) Service. The entire content is available with Jupyter Notebooks, as they prove to be a highly beneficial tool

  3. Comparative Study on Assimilating Remote Sensing High Frequency Radar Surface Currents at an Atlantic Marine Renewable Energy Test Site

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2017-12-01

    Full Text Available A variety of data assimilation approaches have been applied to enhance modelling capability and accuracy using observations from different sources. The algorithms have varying degrees of complexity of implementation, and they improve model results with varying degrees of success. Very little work has been carried out on comparing the implementation of different data assimilation algorithms using High Frequency radar (HFR data into models of complex inshore waters strongly influenced by both tides and wind dynamics, such as Galway Bay. This research entailed implementing four different data assimilation algorithms: Direct Insertion (DI, Optimal Interpolation (OI, Nudging and indirect data assimilation via correcting model forcing into a three-dimensional hydrodynamic model and carrying out detailed comparisons of model performances. This work will allow researchers to directly compare four of the most common data assimilation algorithms being used in operational coastal hydrodynamics. The suitability of practical data assimilation algorithms for hindcasting and forecasting in shallow coastal waters subjected to alternate wetting and drying using data collected from radars was assessed. Results indicated that a forecasting system of surface currents based on the three-dimensional model EFDC (Environmental Fluid Dynamics Code and the HFR data using a Nudging or DI algorithm was considered the most appropriate for Galway Bay. The largest averaged Data Assimilation Skill Score (DASS over the ≥6 h forecasting period from the best model NDA attained 26% and 31% for east–west and north–south surface velocity components respectively. Because of its ease of implementation and its accuracy, this data assimilation system can provide timely and useful information for various practical coastal hindcast and forecast operations.

  4. Characterizing the relative contributions of large vessels to total ocean noise fields: a case study using the Gerry E. Studds Stellwagen Bank National Marine Sanctuary.

    Science.gov (United States)

    Hatch, Leila; Clark, Christopher; Merrick, Richard; Van Parijs, Sofie; Ponirakis, Dimitri; Schwehr, Kurt; Thompson, Michael; Wiley, David

    2008-11-01

    In 2006, we used the U.S. Coast Guard's Automatic Identification System (AIS) to describe patterns of large commercial ship traffic within a U.S. National Marine Sanctuary located off the coast of Massachusetts. We found that 541 large commercial vessels transited the greater sanctuary 3413 times during the year. Cargo ships, tankers, and tug/tows constituted 78% of the vessels and 82% of the total transits. Cargo ships, tankers, and cruise ships predominantly used the designated Boston Traffic Separation Scheme, while tug/tow traffic was concentrated in the western and northern portions of the sanctuary. We combined AIS data with low-frequency acoustic data from an array of nine autonomous recording units analyzed for 2 months in 2006. Analysis of received sound levels (10-1000 Hz, root-mean-square pressure re 1 microPa +/- SE) averaged 119.5 +/- 0.3 dB at high-traffic locations. High-traffic locations experienced double the acoustic power of less trafficked locations for the majority of the time period analyzed. Average source level estimates (71-141 Hz, root-mean-square pressure re 1 microPa +/- SE) for individual vessels ranged from 158 +/- 2 dB (research vessel) to 186 +/- 2 dB (oil tanker). Tankers were estimated to contribute 2 times more acoustic power to the region than cargo ships, and more than 100 times more than research vessels. Our results indicate that noise produced by large commercial vessels was at levels and within frequencies that warrant concern among managers regarding the ability of endangered whales to maintain acoustic contact within greater sanctuary waters.

  5. Characterizing Marine Soundscapes.

    Science.gov (United States)

    Erbe, Christine; McCauley, Robert; Gavrilov, Alexander

    2016-01-01

    The study of marine soundscapes is becoming widespread and the amount of data collected is increasing rapidly. Data owners (typically academia, industry, government, and defense) are negotiating data sharing and generating potential for data syntheses, comparative studies, analyses of trends, and large-scale and long-term acoustic ecology research. A problem is the lack of standards and commonly agreed protocols for the recording of marine soundscapes, data analysis, and reporting that make a synthesis and comparison of results difficult. We provide a brief overview of the components in a marine soundscape, the hard- and software tools for recording and analyzing marine soundscapes, and common reporting formats.

  6. High speed, intermediate resolution, large area laser beam induced current imaging and laser scribing system for photovoltaic devices and modules

    Science.gov (United States)

    Phillips, Adam B.; Song, Zhaoning; DeWitt, Jonathan L.; Stone, Jon M.; Krantz, Patrick W.; Royston, John M.; Zeller, Ryan M.; Mapes, Meghan R.; Roland, Paul J.; Dorogi, Mark D.; Zafar, Syed; Faykosh, Gary T.; Ellingson, Randy J.; Heben, Michael J.

    2016-09-01

    We have developed a laser beam induced current imaging tool for photovoltaic devices and modules that utilizes diode pumped Q-switched lasers. Power densities on the order of one sun (100 mW/cm2) can be produced in a ˜40 μm spot size by operating the lasers at low diode current and high repetition rate. Using galvanostatically controlled mirrors in an overhead configuration and high speed data acquisition, large areas can be scanned in short times. As the beam is rastered, focus is maintained on a flat plane with an electronically controlled lens that is positioned in a coordinated fashion with the movements of the mirrors. The system can also be used in a scribing mode by increasing the diode current and decreasing the repetition rate. In either mode, the instrument can accommodate samples ranging in size from laboratory scale (few cm2) to full modules (1 m2). Customized LabVIEW programs were developed to control the components and acquire, display, and manipulate the data in imaging mode.

  7. Events Calendar: Smithsonian Marine Ecosystems Exhibit: Smithsonian Marine

    Science.gov (United States)

    current Smithsonian research on the plants and animals of the Indian River Lagoon and marine environments Station (SMS) at Fort Pierce Smithsonian Marine Station at Fort Pierce Website Search Box History Modeling Ecosystems Virtual Tour Facebook Instagram Twitter SMS Home › Smithsonian Marine

  8. On the field-to-current conversion factors for large bipolar lightning discharge events in winter thunderstorms in Japan

    Science.gov (United States)

    Chen, Long; Zhang, Qilin; Hou, Wenhao; Tao, Yulang

    2015-07-01

    In this paper we have simulated the far-field waveform characteristic of large bipolar events (LBEs) occurred in winter thunderstorms in Japan and compared the field-to-current conversion factors (FCCFs) of LBEs with that of the lightning cloud-to-ground (CG) return stroke (RS) in summer thunderstorm. As for the physical process of LBEs, Wu et al. (2014) considered that LBEs may be very similar to the typical lightning RS (RS-like process) or caused by an initial continuous current pulse (ICC-like process) in upward lightning flashes. We assume that the lightning channel length of LBEs ranges from 500 m to 1000 m, and the height of tall object struck by LBEs is from 100 m to 300 m. By using the bouncing wave model, we found that only when the injected current waveform of LBEs is characterized with a symmetric Gaussian pulse, the simulated far-field waveform of LBEs both for RS-like process and ICC-like process is similar to that observed by Wu et al. (2014). For striking tall objects with heights from 100 m and 300 m, the FCCFs of LBEs are positively correlated with its channel length and derivatives of injected current waveform, and the FCCF for RS-like process is about similar to that for ICC-like process. However, the FCCFs of LBEs are very different from lightning RS in summer thunderstorm; that is to say, the FCCFs developed for the well-known lightning RS in summer thunderstorm are not suitable for LBEs.

  9. Maximum swimming speeds of sailfish and three other large marine predatory fish species based on muscle contraction time and stride length: a myth revisited

    Directory of Open Access Journals (Sweden)

    Morten B. S. Svendsen

    2016-10-01

    Full Text Available Billfishes are considered to be among the fastest swimmers in the oceans. Previous studies have estimated maximum speed of sailfish and black marlin at around 35 m s−1 but theoretical work on cavitation predicts that such extreme speed is unlikely. Here we investigated maximum speed of sailfish, and three other large marine pelagic predatory fish species, by measuring the twitch contraction time of anaerobic swimming muscle. The highest estimated maximum swimming speeds were found in sailfish (8.3±1.4 m s−1, followed by barracuda (6.2±1.0 m s−1, little tunny (5.6±0.2 m s−1 and dorado (4.0±0.9 m s−1; although size-corrected performance was highest in little tunny and lowest in sailfish. Contrary to previously reported estimates, our results suggest that sailfish are incapable of exceeding swimming speeds of 10-15 m s−1, which corresponds to the speed at which cavitation is predicted to occur, with destructive consequences for fin tissues.

  10. Larval abundances of rockfishes that were historically targeted by fishing increased over 16 years in association with a large marine protected area.

    Science.gov (United States)

    Thompson, Andrew R; Chen, Dustin C; Guo, Lian W; Hyde, John R; Watson, William

    2017-09-01

    Marine protected areas (MPAs) can facilitate recovery of diminished stocks by protecting reproductive adults. To effectively augment fisheries, however, reproductive output must increase within the bounds of MPAs so that larvae can be exported to surrounding areas and seed the region. In response to dramatic declines of rockfishes ( Sebastes spp.) in southern California by the late 1990s two large MPAs, the Cowcod Conservation Areas (CCAs), were established in 2001. To evaluate whether the CCAs affected rockfish productivity we evaluated the dynamics of 8 species that were, and 7 that were not, historically targeted by fishing. Abundances of 6/8 targeted and 4/7 non-targeted species increased regionally from 1998 to 2013. These upturns were probably affected by environmental conditions in addition to changes in fishing pressure as the presence of most species correlated negatively with temperature, and temperature was lower than the historic average in 11/15 years. Seventy-five per cent of the targeted, but none of the non-targeted species increased at a greater rate inside than outside the CCAs while controlling for environmental factors. Results indicate that management actions, coupled with favourable environmental conditions, facilitated the resurgence of multiple rockfish species that were targeted by intense fishing effort for decades.

  11. Improvement of a high current DC power supply system for testing the large scaled superconducting cables and magnets

    International Nuclear Information System (INIS)

    Yamada, Shuichi; Chikaraishi, Hirotaka; Tanahashi, Shugo

    1993-11-01

    A dc 75 kA power supply system was constructed to test the superconducting (SC) R and D cables and magnets for the Large Helical Device. It consists of three 25 kA unit banks. A unit bank has two double-star-rectifier connections with the inter-phase reactors. A digital feedback control method is applied to the automatic current regulation (ACR) in each unit bank. For shortening the dead time of the feedback process, a new algorithm of a digital phase controller for the ACR is investigated. A Bode diagram of the feedback process is directly measured. It is confirmed that the dead time of the feedback process is reduced to one sixth, and that the feedback gain of PID compensation is improved by a factor of two from the original method. (author)

  12. Novel failure mechanism and improvement for split-gate trench MOSFET with large current under unclamped inductive switch stress

    Science.gov (United States)

    Tian, Ye; Yang, Zhuo; Xu, Zhiyuan; Liu, Siyang; Sun, Weifeng; Shi, Longxing; Zhu, Yuanzheng; Ye, Peng; Zhou, Jincheng

    2018-04-01

    In this paper, a novel failure mechanism under unclamped inductive switch (UIS) for Split-Gate Trench Metal Oxide Semiconductor Field Effect Transistor (MOSFET) with large current is investigated. The device sample is tested and analyzed in detail. The simulation results demonstrate that the nonuniform potential distribution of the source poly should be responsible for the failure. Three structures are proposed and verified available to improve the device UIS ruggedness by TCAD simulation. The best one of the structures the device with source metal inserting into source poly through contacts in the field oxide is carried out and measured. The results demonstrate that the optimized structure can balance the trade-off between the UIS ruggedness and the static characteristics.

  13. Marine heatwaves off eastern Tasmania: Trends, interannual variability, and predictability

    Science.gov (United States)

    Oliver, Eric C. J.; Lago, Véronique; Hobday, Alistair J.; Holbrook, Neil J.; Ling, Scott D.; Mundy, Craig N.

    2018-02-01

    Surface waters off eastern Tasmania are a global warming hotspot. Here, mean temperatures have been rising over several decades at nearly four times the global average rate, with concomitant changes in extreme temperatures - marine heatwaves. These changes have recently caused the marine biodiversity, fisheries and aquaculture industries off Tasmania's east coast to come under stress. In this study we quantify the long-term trends, variability and predictability of marine heatwaves off eastern Tasmania. We use a high-resolution ocean model for Tasmania's eastern continental shelf. The ocean state over the 1993-2015 period is hindcast, providing daily estimates of the three-dimensional temperature and circulation fields. Marine heatwaves are identified at the surface and subsurface from ocean temperature time series using a consistent definition. Trends in marine heatwave frequency are positive nearly everywhere and annual marine heatwave days and penetration depths indicate significant positive changes, particularly off southeastern Tasmania. A decomposition into modes of variability indicates that the East Australian Current is the dominant driver of marine heatwaves across the domain. Self-organising maps are used to identify 12 marine heatwave types, each with its own regionality, seasonality, and associated large-scale oceanic and atmospheric circulation patterns. The implications of this work for marine ecosystems and their management were revealed through review of past impacts and stakeholder discussions regarding use of these data.

  14. Spatial genetic structure in Beta vulgaris subsp. maritima and Beta macrocarpa reveals the effect of contrasting mating system, influence of marine currents, and footprints of postglacial recolonization routes.

    Science.gov (United States)

    Leys, Marie; Petit, Eric J; El-Bahloul, Yasmina; Liso, Camille; Fournet, Sylvain; Arnaud, Jean-François

    2014-05-01

    Understanding the factors that contribute to population genetic divergence across a species' range is a long-standing goal in evolutionary biology and ecological genetics. We examined the relative importance of historical and ecological features in shaping the present-day spatial patterns of genetic structure in two related plant species, Beta vulgaris subsp. maritima and Beta macrocarpa. Using nuclear and mitochondrial markers, we surveyed 93 populations from Brittany (France) to Morocco - the southern limit of their species' range distribution. Whereas B. macrocarpa showed a genotypic structure and a high level of genetic differentiation indicative of selfing, the population genetic structure of B. vulgaris subsp. maritima was consistent with an outcrossing mating system. We further showed (1) a strong geographic clustering in coastal B. vulgaris subsp. maritima populations that highlighted the influence of marine currents in shaping different lineages and (2) a peculiar genetic structure of inland B. vulgaris subsp. maritima populations that could indicate the admixture of distinct evolutionary lineages and recent expansions associated with anthropogenic disturbances. Spatial patterns of nuclear diversity and differentiation also supported a stepwise recolonization of Europe from Atlantic-Mediterranean refugia after the last glacial period, with leading-edge expansions. However, cytoplasmic diversity was not impacted by postglacial recolonization: stochastic long-distance seed dispersal mediated by major oceanic currents may mitigate the common patterns of reduced cytoplasmic diversity observed for edge populations. Overall, the patterns we documented here challenge the general view of reduced genetic diversity at the edge of a species' range distribution and provide clues for understanding how life-history and major geographic features interact to shape the distribution of genetic diversity.

  15. Current deformation in the Tibetan Plateau: a stress gauge in the large-scale India-Asia collision tectonics

    Science.gov (United States)

    Capitanio, F. A.

    2017-12-01

    The quantification of the exact tectonic forces budget on Earth has remained thus far elusive. Geodetic velocities provide relevant constraints on the current dynamics of the coupling between collision and continental tectonics, however in the Tibetan plateau these support contrasting, non-unique models. Here, we compare numerical models of coupled India-Asia plate convergence, collision and continent interiors tectonics to the geodetically-constrained motions in the Tibetan Plateau to provide a quantitative assessment of the driving forces of plate tectonics in the area. The models develop a range of long-term evolutions remarkably similar to the Asian tectonics in the Cenozoic, reproducing the current large-scale motions pattern under a range of conditions. Balancing the convergent margin forces, following subduction, and the far-field forcing along the trail of the subducting continent, the geodetic rates in the Tibetan Plateau can be matched. The comparisons support the discussion on the likely processes at work, allowing inferences on the drivers of plateau formation and its role on the plate margin-interiors tectonics. More in general, the outcomes highlight the unique role of the Tibetan Plateau as a pressure gauge for the tectonic forces on Earth.

  16. Current-induced magnetization switching in atom-thick tungsten engineered perpendicular magnetic tunnel junctions with large tunnel magnetoresistance.

    Science.gov (United States)

    Wang, Mengxing; Cai, Wenlong; Cao, Kaihua; Zhou, Jiaqi; Wrona, Jerzy; Peng, Shouzhong; Yang, Huaiwen; Wei, Jiaqi; Kang, Wang; Zhang, Youguang; Langer, Jürgen; Ocker, Berthold; Fert, Albert; Zhao, Weisheng

    2018-02-14

    Perpendicular magnetic tunnel junctions based on MgO/CoFeB structures are of particular interest for magnetic random-access memories because of their excellent thermal stability, scaling potential, and power dissipation. However, the major challenge of current-induced switching in the nanopillars with both a large tunnel magnetoresistance ratio and a low junction resistance is still to be met. Here, we report spin transfer torque switching in nano-scale perpendicular magnetic tunnel junctions with a magnetoresistance ratio up to 249% and a resistance area product as low as 7.0 Ω µm 2 , which consists of atom-thick W layers and double MgO/CoFeB interfaces. The efficient resonant tunnelling transmission induced by the atom-thick W layers could contribute to the larger magnetoresistance ratio than conventional structures with Ta layers, in addition to the robustness of W layers against high-temperature diffusion during annealing. The critical switching current density could be lower than 3.0 MA cm -2 for devices with a 45-nm radius.

  17. The marine renewable energies file

    International Nuclear Information System (INIS)

    2009-01-01

    A set of articles addresses several aspects and issues related to the development of renewable marine energies: the objectives defined by the French government and the European Union in terms of share of renewable energies in energy consumption, some existing projects, the definition and assessment of the different renewable marine energies (offshore wind energy, sea thermal energy, sea current energy, sea tide energy, sea wave energy, marine biomass, osmotic energy), the need for a national strategy according to two researchers belonging to IFREMER, the implementation of the first offshore test platform by the Ecole Centrale de Nantes, the role of the ADEME (financial support, marketing studies, legislation, definition of a national programme), the recommendation by the European Commission of a large scale offshore wind energy development, the activities of EDF and Total in the field of marine energy, the problems faced by the first French offshore wind generator project, the actions undertaken in La Reunion in the field of sea thermal energy, and the opportunities in the use of micro-algae for hydrogen, bio-fuel or biogas production

  18. A Catalogue of marine biodiversity indicators

    Directory of Open Access Journals (Sweden)

    Heliana Teixeira

    2016-11-01

    Full Text Available A Catalogue of Marine Biodiversity Indicators was developed with the aim of providing the basis for assessing the environmental status of the marine ecosystems. Useful for the implementation of the Marine Strategy Framework Directive (MSFD, this catalogue allows the navigation of a database of indicators mostly related to biological diversity, non-indigenous species, food webs, and seafloor integrity. Over 600 indicators were compiled, which were developed and used in the framework of different initiatives (e.g. EU policies, research projects and in national and international contexts (e.g. Regional Seas Conventions, and assessments in non-European seas. The catalogue reflects the current scientific capability to address environmental assessment needs by providing a broad coverage of the most relevant indicators for marine biodiversity and ecosystem integrity.The available indicators are reviewed according to their typology, data requirements, development status, geographical coverage, relevance to habitats or biodiversity components, and related human pressures. Through this comprehensive overview, we discuss the potential of the current set of indicators in a wide range of contexts, from large-scale to local environmental programs, and we also address shortcomings in light of current needs.Developed by the DEVOTES Project, the catalogue is freely available through the DEVOTool software application, which provides browsing and query options for the associated metadata. The tool allows extraction of ranked indicator lists best fulfilling selected criteria, enabling users to search for suitable indicators to address a particular biodiversity component, ecosystem feature, habitat or pressure in a marine area of interest.This tool is useful for EU Member States, Regional Sea Conventions, the European Commission, non-governmental organizations, managers, scientists and any person interested in marine environmental assessment. It allows users to

  19. A Catalogue of Marine Biodiversity Indicators

    KAUST Repository

    Teixeira, Heliana; Berg, Torsten; Uusitalo, Laura; Fü rhaupter, Karin; Heiskanen, Anna Stiina; Mazik, Krysia; Lynam, Christopher P.; Neville, Suzanna; Rodriguez, J. German; Papadopoulou, Nadia; Moncheva, Snejana; Churilova, Tanya; Kryvenko, Olga; Krause-Jensen, Dorte; Zaiko, Anastasija; Verí ssimo, Helena; Pantazi, Maria; Carvalho, Susana; Patrí cio, Joana; Uyarra, Maria C.; Borja, À ngel

    2016-01-01

    A Catalogue of Marine Biodiversity Indicators was developed with the aim of providing the basis for assessing the environmental status of the marine ecosystems. Useful for the implementation of the Marine Strategy Framework Directive (MSFD), this catalogue allows the navigation of a database of indicators mostly related to biological diversity, non-indigenous species, food webs, and seafloor integrity. Over 600 indicators were compiled, which were developed and used in the framework of different initiatives (e.g., EU policies, research projects) and in national and international contexts (e.g., Regional Seas Conventions, and assessments in non-European seas). The catalogue reflects the current scientific capability to address environmental assessment needs by providing a broad coverage of the most relevant indicators for marine biodiversity and ecosystem integrity. The available indicators are reviewed according to their typology, data requirements, development status, geographical coverage, relevance to habitats or biodiversity components, and related human pressures. Through this comprehensive overview, we discuss the potential of the current set of indicators in a wide range of contexts, from large-scale to local environmental programs, and we also address shortcomings in light of current needs. Developed by the DEVOTES Project, the catalogue is freely available through the DEVOTool software application, which provides browsing and query options for the associated metadata. The tool allows extraction of ranked indicator lists best fulfilling selected criteria, enabling users to search for suitable indicators to address a particular biodiversity component, ecosystem feature, habitat, or pressure in a marine area of interest. This tool is useful for EU Member States, Regional Sea Conventions, the European Commission, non-governmental organizations, managers, scientists, and any person interested in marine environmental assessment. It allows users to build

  20. A Catalogue of Marine Biodiversity Indicators

    KAUST Repository

    Teixeira, Heliana

    2016-11-04

    A Catalogue of Marine Biodiversity Indicators was developed with the aim of providing the basis for assessing the environmental status of the marine ecosystems. Useful for the implementation of the Marine Strategy Framework Directive (MSFD), this catalogue allows the navigation of a database of indicators mostly related to biological diversity, non-indigenous species, food webs, and seafloor integrity. Over 600 indicators were compiled, which were developed and used in the framework of different initiatives (e.g., EU policies, research projects) and in national and international contexts (e.g., Regional Seas Conventions, and assessments in non-European seas). The catalogue reflects the current scientific capability to address environmental assessment needs by providing a broad coverage of the most relevant indicators for marine biodiversity and ecosystem integrity. The available indicators are reviewed according to their typology, data requirements, development status, geographical coverage, relevance to habitats or biodiversity components, and related human pressures. Through this comprehensive overview, we discuss the potential of the current set of indicators in a wide range of contexts, from large-scale to local environmental programs, and we also address shortcomings in light of current needs. Developed by the DEVOTES Project, the catalogue is freely available through the DEVOTool software application, which provides browsing and query options for the associated metadata. The tool allows extraction of ranked indicator lists best fulfilling selected criteria, enabling users to search for suitable indicators to address a particular biodiversity component, ecosystem feature, habitat, or pressure in a marine area of interest. This tool is useful for EU Member States, Regional Sea Conventions, the European Commission, non-governmental organizations, managers, scientists, and any person interested in marine environmental assessment. It allows users to build

  1. Review of the Current Body Fat Taping Method and Its Importance in Ascertaining Fitness Levels in the United States Marine Corps

    Science.gov (United States)

    2015-06-01

    exercises include isometric movements such as the “tummy tightner” and the back flexor (Figure 2). 12 Figure 1. A Female Marine...a 20-foot rope climb, was to test an individual’s strength . The third event required a Marine to run 50 yards in a zig-zag pattern followed by a...assumption that such women would have greater strength and stamina with regard to physical fitness (Institute of Medicine 1998, 34). In 1987, DODI

  2. Spatial variation in foraging behaviour of a marine top predator (Phoca vitulina determined by a large-scale satellite tagging program.

    Directory of Open Access Journals (Sweden)

    Ruth J Sharples

    Full Text Available The harbour seal (Phoca vitulina is a widespread marine predator in Northern Hemisphere waters. British populations have been subject to rapid declines in recent years. Food supply or inter-specific competition may be implicated but basic ecological data are lacking and there are few studies of harbour seal foraging distribution and habits. In this study, satellite tagging conducted at the major seal haul outs around the British Isles showed both that seal movements were highly variable among individuals and that foraging strategy appears to be specialized within particular regions. We investigated whether these apparent differences could be explained by individual level factors: by modelling measures of trip duration and distance travelled as a function of size, sex and body condition. However, these were not found to be good predictors of foraging trip duration or distance, which instead was best predicted by tagging region, time of year and inter-trip duration. Therefore, we propose that local habitat conditions and the constraints they impose are the major determinants of foraging movements. Specifically the distance to profitable feeding grounds from suitable haul-out locations may dictate foraging strategy and behaviour. Accounting for proximity to productive foraging resources is likely to be an important component of understanding population processes. Despite more extensive offshore movements than expected, there was also marked fidelity to the local haul-out region with limited connectivity between study regions. These empirical observations of regional exchange at short time scales demonstrates the value of large scale electronic tagging programs for robust characterization of at-sea foraging behaviour at a wide spatial scale.

  3. Analyzing the optimization of an organic Rankine cycle system for recovering waste heat from a large marine engine containing a cooling water system

    International Nuclear Information System (INIS)

    Yang, Min-Hsiung; Yeh, Rong-Hua

    2014-01-01

    Highlights: • Employing the thermodynamic analysis and a heat-transfer method, an ORC optimization is presented. • An optimal objective parameter evaluation of six working fluids is presented. • Refrigerants with superior thermodynamic properties do not necessary have excellent performance. • Cylinder jacket water temperature strongly affects optimal evaporation temperature. - Abstract: In this study, six working fluids with zero ozone depletion potential and low global warming potential are used in an organic Rankine cycle (ORC) system to recover waste heat from cylinder jacket water of large marine diesel engines. Thermodynamic analysis and a finite-temperature-difference heat-transfer method are developed to evaluate the thermal efficiency, total heat-exchanger area, objective parameter, and exergy destruction of the ORC system. The optimal evaporation and condensation temperatures for achieving the maximal objective parameter, the ratio of net power output to the total heat-transfer area of heat exchangers, of an ORC system are investigated. The results show that, among the working fluids, R600a performs the best in the optimal objective parameter evaluation followed by R1234ze, R1234yf, R245fa, R245ca, and R1233zd at evaporation temperatures ranging from 58 °C to 68 °C and condensation temperatures ranging from 35 °C to 45 °C. The optimal operating temperatures and corresponding thermal efficiency and exergy destruction are proposed. Furthermore, the influences of inlet temperatures on cylinder jacket water and cooling water in the ORC are presented for recovering waste heat. The results of this work were verified with theoretical solutions and experimental results in the literature and it was revealed that they were consistent with them

  4. A new nonlinear blind source separation method with chaos indicators for decoupling diagnosis of hybrid failures: A marine propulsion gearbox case with a large speed variation

    International Nuclear Information System (INIS)

    Li, Zhixiong; Peng, Z

    2016-01-01

    The normal operation of propulsion gearboxes ensures the ship safety. Chaos indicators could efficiently indicate the state change of the gearboxes. However, accurate detection of gearbox hybrid faults using Chaos indicators is a challenging task and the detection under speed variation conditions is attracting considerable attentions. Literature review suggests that the gearbox vibration is a kind of nonlinear mixture of variant vibration sources and the blind source separation (BSS) is reported to be a promising technique for fault vibration analysis, but very limited work has addressed the nonlinear BSS approach for hybrid faults decoupling diagnosis. Aiming to enhance the fault detection performance of Chaos indicators, this work presents a new nonlinear BSS algorithm for gearbox hybrid faults detection under a speed variation condition. This new method appropriately introduces the kernel spectral regression (KSR) framework into the morphological component analysis (MCA). The original vibration data are projected into the reproducing kernel Hilbert space (RKHS) where the instinct nonlinear structure in the original data can be linearized by KSR. Thus the MCA is able to deal with nonlinear BSS in the KSR space. Reliable hybrid faults decoupling is then achieved by this new nonlinear MCA (NMCA). Subsequently, by calculating the Chaos indicators of the decoupled fault components and comparing them with benchmarks, the hybrid faults can be precisely identified. Two specially designed case studies were implemented to evaluate the proposed NMCA-Chaos method on hybrid gear faults decoupling diagnosis. The performance of the NMCA-Chaos was compared with state of art techniques. The analysis results show high performance of the proposed method on hybrid faults detection in a marine propulsion gearbox with large speed variations.

  5. Extension of operation regimes and investigation of three-dimensional current-less plasmas in the Large Helical Device

    International Nuclear Information System (INIS)

    Kaneko, O.

    2012-11-01

    The Large Helical Device (LHD) has shown the advantages of heliotron plasma for fusion reactor from operational point of view not only such as disruption free and steady state operation, but also as high density and stable high beta operation. Since the last Fusion Energy Conference in Daejon in 2010 (Yamada, 2011 Nucl. Fusion 51 094021), physical understanding as well as parameter improvement of net-current free helical plasmas has progressed successively. The current efforts are focused on optimization of plasma edge condition to extend the operation regime towards higher ion temperature and more stable high density. In LHD a part of open helical divertors are being modified to the baffle-structured closed ones to aim at active control of the edge plasma. It has been demonstrated that the neutral pressure in the closed helical divertor was more than 10 times higher than that in the open helical divertor. The central ion temperature has exceeded 7 keV. This high-T i plasma was obtained by a carbon pellet injection and the kinetic-energy confinement was improved by a factor of 1.5. Transport analysis of the high-T i plasmas has shown that the ion-thermal conductivity and the viscosity reduced after the pellet injection. Study of physics in 3-D geometry is highlighted in the topics of the response to Resonant Magnetic Perturbation such as ELM mitigation and divertor detachment. Novel approaches of non-local and non-diffusive transport have also been advanced. In this paper, highlighted results in these two years are overviewed. (author)

  6. Are we missing the boat? Current uses of long-term biological monitoring data in the evaluation and management of marine protected areas.

    Science.gov (United States)

    Addison, P F E; Flander, L B; Cook, C N

    2015-02-01

    Protected area management agencies are increasingly using management effectiveness evaluation (MEE) to better understand, learn from and improve conservation efforts around the globe. Outcome assessment is the final stage of MEE, where conservation outcomes are measured to determine whether management objectives are being achieved. When quantitative monitoring data are available, best-practice examples of outcome assessments demonstrate that data should be assessed against quantitative condition categories. Such assessments enable more transparent and repeatable integration of monitoring data into MEE, which can promote evidence-based management and improve public accountability and reporting. We interviewed key informants from marine protected area (MPA) management agencies to investigate how scientific data sources, especially long-term biological monitoring data, are currently informing conservation management. Our study revealed that even when long-term monitoring results are available, management agencies are not using them for quantitative condition assessment in MEE. Instead, many agencies conduct qualitative condition assessments, where monitoring results are interpreted using expert judgment only. Whilst we found substantial evidence for the use of long-term monitoring data in the evidence-based management of MPAs, MEE is rarely the sole mechanism that facilitates the knowledge transfer of scientific evidence to management action. This suggests that the first goal of MEE (to enable environmental accountability and reporting) is being achieved, but the second and arguably more important goal of facilitating evidence-based management is not. Given that many MEE approaches are in their infancy, recommendations are made to assist management agencies realize the full potential of long-term quantitative monitoring data for protected area evaluation and evidence-based management. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Reconstruction of a Large-scale Pre-flare Coronal Current Sheet Associated with a Homologous X-shaped Flare

    Science.gov (United States)

    Jiang, Chaowei; Yan, Xiaoli; Feng, Xueshang; Duan, Aiying; Hu, Qiang; Zuo, Pingbing; Wang, Yi

    2017-11-01

    As a fundamental magnetic structure in the solar corona, electric current sheets (CSs) can form either prior to or during a solar flare, and they are essential for magnetic energy dissipation in the solar corona because they enable magnetic reconnection. However, the static reconstruction of a CS is rare, possibly due to limitations that are inherent in the available coronal field extrapolation codes. Here we present the reconstruction of a large-scale pre-flare CS in solar active region 11967 using an MHD-relaxation model constrained by the SDO/HMI vector magnetogram. The CS is associated with a set of peculiar homologous flares that exhibit unique X-shaped ribbons and loops occurring in a quadrupolar magnetic configuration.This is evidenced by an ’X’ shape, formed from the field lines traced from the CS to the photosphere. This nearly reproduces the shape of the observed flare ribbons, suggesting that the flare is a product of the dissipation of the CS via reconnection. The CS forms in a hyperbolic flux tube, which is an intersection of two quasi-separatrix layers. The recurrence of the X-shaped flares might be attributed to the repetitive formation and dissipation of the CS, as driven by the photospheric footpoint motions. These results demonstrate the power of a data-constrained MHD model in reproducing a CS in the corona as well as providing insight into the magnetic mechanism of solar flares.

  8. Marine Renewable Energy Seascape

    Directory of Open Access Journals (Sweden)

    Alistair G.L. Borthwick

    2016-03-01

    Full Text Available Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation measures. Ocean energy has huge potential, but there are major interdisciplinary problems to be overcome regarding technology, cost reduction, investment, environmental impact, governance, and so forth. This article briefly reviews ocean energy production from offshore wind, tidal stream, ocean current, tidal range, wave, thermal, salinity gradients, and biomass sources. Future areas of research and development are outlined that could make exploitation of the marine renewable energy (MRE seascape a viable proposition; these areas include energy storage, advanced materials, robotics, and informatics. The article concludes with a sustainability perspective on the MRE seascape encompassing ethics, legislation, the regulatory environment, governance and consenting, economic, social, and environmental constraints. A new generation of engineers is needed with the ingenuity and spirit of adventure to meet the global challenge posed by MRE.

  9. Large current MOSFET on photonic silicon-on-insulator wafers and its monolithic integration with a thermo-optic 2 × 2 Mach-Zehnder switch.

    Science.gov (United States)

    Cong, G W; Matsukawa, T; Chiba, T; Tadokoro, H; Yanagihara, M; Ohno, M; Kawashima, H; Kuwatsuka, H; Igarashi, Y; Masahara, M; Ishikawa, H

    2013-03-25

    n-channel body-tied partially depleted metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated for large current applications on a silicon-on-insulator wafer with photonics-oriented specifications. The MOSFET can drive an electrical current as large as 20 mA. We monolithically integrated this MOSFET with a 2 × 2 Mach-Zehnder interferometer optical switch having thermo-optic phase shifters. The static and dynamic performances of the integrated device are experimentally evaluated.

  10. Marine ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Studies on marine ecology included marine pollution; distribution patterns of Pu and Am in the marine waters, sediments, and organisms of Bikini Atoll and the influence of physical, chemical, and biological factors on their movements through marine biogeochemical systems; transfer and dispersion of organic pollutants from an oil refinery through coastal waters; transfer of particulate pollutants, including sediments dispersed during construction of offshore power plants; and raft culture of the mangrove oysters

  11. Impact of large-scale circulation changes in the North Atlantic sector on the current and future Mediterranean winter hydroclimate

    Science.gov (United States)

    Barcikowska, Monika J.; Kapnick, Sarah B.; Feser, Frauke

    2018-03-01

    The Mediterranean region, located in the transition zone between the dry subtropical and wet European mid-latitude climate, is very sensitive to changes in the global mean climate state. Projecting future changes of the Mediterranean hydroclimate under global warming therefore requires dynamic climate models to reproduce the main mechanisms controlling regional hydroclimate with sufficiently high resolution to realistically simulate climate extremes. To assess future winter precipitation changes in the Mediterranean region we use the Geophysical Fluid Dynamics Laboratory high-resolution general circulation model for control simulations with pre-industrial greenhouse gas and aerosol concentrations which are compared to future scenario simulations. Here we show that the coupled model is able to reliably simulate the large-scale winter circulation, including the North Atlantic Oscillation and Eastern Atlantic patterns of variability, and its associated impacts on the mean Mediterranean hydroclimate. The model also realistically reproduces the regional features of daily heavy rainfall, which are absent in lower-resolution simulations. A five-member future projection ensemble, which assumes comparatively high greenhouse gas emissions (RCP8.5) until 2100, indicates a strong winter decline in Mediterranean precipitation for the coming decades. Consistent with dynamical and thermodynamical consequences of a warming atmosphere, derived changes feature a distinct bipolar behavior, i.e. wetting in the north—and drying in the south. Changes are most pronounced over the northwest African coast, where the projected winter precipitation decline reaches 40% of present values. Despite a decrease in mean precipitation, heavy rainfall indices show drastic increases across most of the Mediterranean, except the North African coast, which is under the strong influence of the cold Canary Current.

  12. Marine pollution

    International Nuclear Information System (INIS)

    Albaiges, J.

    1989-01-01

    This book covers the following topics: Transport of marine pollutants; Transformation of pollutants in the marine environment; Biological effects of marine pollutants; Sources and transport of oil pollutants in the Persian Gulf; Trace metals and hydrocarbons in Syrian coastal waters; and Techniques for analysis of trace pollutants

  13. Marine Mineral Exploration

    DEFF Research Database (Denmark)

    in EEZ areas are fairly unknown; many areas need detailed mapping and mineral exploration, and the majority of coastal or island states with large EEZ areas have little experience in exploration for marine hard minerals. This book describes the systematic steps in marine mineral exploration....... Such exploration requires knowledge of mineral deposits and models of their formation, of geophysical and geochemical exploration methods, and of data evaluation and interpretation methods. These topics are described in detail by an international group of authors. A short description is also given of marine...

  14. Seawater and marine sidements

    International Nuclear Information System (INIS)

    Eicke, H.F.

    1985-01-01

    The Deutsches Hydrographisches Institut (DHI) is responsible for monitoring the radioactive substances (such as Cs-137, Cs-134, Sr-90, H-3, Pu-239, Pu-240) in the seawater and marine sediments along the Federal German seacoasts, of the fishing grounds of the Federal German offshore fishery industry, and of marine currents moving towards these fishing grounds. The DHI has been carrying out this task since 1965, activities being placed under the responsibility of the DHI Department for Marine Radioactivity, which since 1960 is a directing centre within the Government's system for environmental radioactivity monitoring. (orig./DG) [de

  15. Precision measurement of the cross section of charged-current and neutral current processes at large Q2 at HERA with the polarized-electron beam

    International Nuclear Information System (INIS)

    Tran, Trong Hieu

    2010-03-01

    The inclusive cross sections for both charged and neutral current processes have been measured in interactions of longitudinally polarized electrons (positrons) with unpolarized protons using the full data samples collected by H1 at HERA-II. The data taken at a center-of-mass energy of 319 GeV correspond to an integrated luminosity of 149.1 pb -1 and 180.0 pb -1 for e - p and e + p collisions, representing an increase in statistics of a factor of 10 and 2, respectively, over the data from HERA-I. The measured double differential cross sections d 2 σ/dxdQ 2 cover more than two orders of magnitude in both Q 2 , the negative four-momentum transfer squared, up to 30000 GeV 2 , and Bjorken x, down to 0.003. The cross section data are compared to predictions of the Standard Model which is able to provide a good description of the data. The polarization asymmetry as a function of Q 2 is measured with improved precision, confirming the previous observation of P violation effect in neutral current ep scattering at distances down to 10 -18 m. The total cross sections of the charged current process, for Q 2 > 400 GeV 2 and inelasticity y ± beams and different polarization values. Together with the corresponding cross section obtained from the previously published unpolarized data, the polarization dependence of the charged current cross section is measured and found to be in agreement with the Standard Model prediction with the absence of right-handed charged current. The cross sections are combined with previously published data from H1 to obtain the most precise unpolarized measurements. These are used to extract the structure function xF 3 γZ which is sensitive to the valence quark distributions down to low x values. The new cross sections have also been used in a combined electroweak and QCD fit to significantly improve the light quark couplings to the Z-boson than those obtained based on the HERA-I data alone. (orig.)

  16. Data integration for European marine biodiversity research: creating a database on benthos and plankton to study large-scale patterns and long-term changes

    NARCIS (Netherlands)

    Vandepitte, L.; Vanhoorne, B.; Kraberg, A.; Anisimova, N.; Antoniadou, C.; Araújo, R.; Bartsch, I.; Beker, B.; Benedetti-Cecchi, L.; Bertocci, I.; Cochrane, S.J.; Cooper, K.; Craeymeersch, J.A.; Christou, E.; Crisp, D.J.; Dahle, S.; de Boissier, M.; De Kluijver, M.; Denisenko, S.; De Vito, D.; Duineveld, G.; Escaravage, V.L.; Fleischer, D.; Fraschetti, S.; Giangrande, A.; Heip, C.H.R.; Hummel, H.; Janas, U.; Karez, R.; Kedra, M.; Kingston, P.; Kuhlenkamp, R.; Libes, M.; Martens, P.; Mees, J.; Mieszkowska, N.; Mudrak, S.; Munda, I.; Orfanidis, S.; Orlando-Bonaca, M.; Palerud, R.; Rachor, E.; Reichert, K.; Rumohr, H.; Schiedek, D.; Schubert, P.; Sistermans, W.C.H.; Sousa Pinto, I.S.; Southward, A.J.; Terlizzi, A.; Tsiaga, E.; Van Beusekom, J.E.E.; Vanden Berghe, E.; Warzocha, J.; Wasmund, N.; Weslawski, J.M.; Widdicombe, C.; Wlodarska-Kowalczuk, M.; Zettler, M.L.

    2010-01-01

    The general aim of setting up a central database on benthos and plankton was to integrate long-, medium- and short-term datasets on marine biodiversity. Such a database makes it possible to analyse species assemblages and their changes on spatial and temporal scales across Europe. Data collation

  17. Marine genomics

    DEFF Research Database (Denmark)

    Oliveira Ribeiro, Ângela Maria; Foote, Andrew David; Kupczok, Anne

    2017-01-01

    Marine ecosystems occupy 71% of the surface of our planet, yet we know little about their diversity. Although the inventory of species is continually increasing, as registered by the Census of Marine Life program, only about 10% of the estimated two million marine species are known. This lag......-throughput sequencing approaches have been helping to improve our knowledge of marine biodiversity, from the rich microbial biota that forms the base of the tree of life to a wealth of plant and animal species. In this review, we present an overview of the applications of genomics to the study of marine life, from...

  18. 78 FR 33357 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2013-06-04

    ... confidence in these values is unknown. Table 3--Marine Mammal Density Estimates Density Species (animals/km\\2... unintentional taking of marine animals occurring incidental to the shock testing which involved large explosives... Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Conducting...

  19. Modelling of Combustion and Pollutant Formation in a Large, Two-Stroke Marine Diesel Engine using Integrated CFD-Skeletal Chemical Mechanism

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Karvounis, Nikolas; Schramm, Jesper

    In this reported work, simulation studies of in-cylinder diesel combustion and pollutant formation processesin a two-stroke, low-speed uniflow-scavenged marine diesel engine are presented. Numerical computation is performed by integrating chemical kinetics into CFD computations. In order...... to minimize the computational runtime, an in-house skeletal n-heptane chemical mechanism is coupled with the CFD model. This surrogate fuel model comprises 89 reactions with 32 species essential to diesel ignition/combustion processes as well as the formation of soot precursors and nitrogen monoxide (NO......). Prior to the marine engine simulation,coupling of the newly developed surrogate fuel model and a revised multi-step soot model [1] is validated on the basis of optical diagnostics measurement obtained at varying ambient pressure levels [2]. It is demonstrated that the variation of ignition delay times...

  20. Numerical investigation of soot formation and oxidation processes under large two-stroke marine diesel engine-like conditions using integrated CFD-chemical kinetics

    DEFF Research Database (Denmark)

    Pang, Kar Mun; Karvounis, Nikolas; Walther, Jens Honore

    2016-01-01

    n-heptane mechanism and a revised multi-step soot model using laser extinction measurements of diesel soot obtained at different ambient pressure levels in an optical accessible, constant volume chamber experiment. It is revealed that ignition delay times and liftoff lengths generated using the new......In this reported work, multi-dimensional computational fluid dynamics studies of diesel combustion and soot formation processes in a constant volume combustion chamber and a marine diesel engine are carried out. The key interest here is firstly to validate the coupling of a newly developed skeletal...... using the revised soot model agrees reasonably well with the measurements in terms of peak values. The numerical model is subsequently applied to investigate the flame development, soot/nitrogen monoxide formation and heat transfer in a two-stroke, low-speed uniflow-scavenged marine diesel engine...

  1. Global mismatch between fishing dependency and larval supply from marine reserves

    Science.gov (United States)

    Andrello, Marco; Guilhaumon, François; Albouy, Camille; Parravicini, Valeriano; Scholtens, Joeri; Verley, Philippe; Barange, Manuel; Sumaila, U. Rashid; Manel, Stéphanie; Mouillot, David

    2017-07-01

    Marine reserves are viewed as flagship tools to protect exploited species and to contribute to the effective management of coastal fisheries. Yet, the extent to which marine reserves are globally interconnected and able to effectively seed areas, where fisheries are most critical for food and livelihood security is largely unknown. Using a hydrodynamic model of larval dispersal, we predict that most marine reserves are not interconnected by currents and that their potential benefits to fishing areas are presently limited, since countries with high dependency on coastal fisheries receive very little larval supply from marine reserves. This global mismatch could be reversed, however, by placing new marine reserves in areas sufficiently remote to minimize social and economic costs but sufficiently connected through sea currents to seed the most exploited fisheries and endangered ecosystems.

  2. The effect of plasma minor-radius expansion in the current build-up phase of a large tokamak

    International Nuclear Information System (INIS)

    Kobayashi, Tomofumi; Tazima, Teruhiko; Tani, Keiji; Tamura, Sanae

    1977-03-01

    A plasma simulation code has been developed to study the plasma current build-up process in JT-60. Plasma simulation is made with a model which represents well overall plasma behavior of the present-day tokamaks. The external electric circuit is taken into consideration in simulation calculation. An emphasis is placed on the simulation of minor-radius expansion of the plasma and behavior of neutral particles in the plasma during current build-up. A calculation with typical parameters of JT-60 shows a week skin distribution in the current density and the electron temperature, if the minor radius of the plasma expands with build-up of the plasma current. (auth.)

  3. Marine medicinal glycomics

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Pomin

    2014-01-01

    Full Text Available Glycomics is an international initiative aimed to understand the structure and function of the glycans from a given type of cell, tissue, organism, kingdom or even environment, as found under certain conditions. Glycomics is one of the latest areas of intense biological research. Glycans of marine sources are unique in terms of structure and function. They differ considerably from those of terrestrial origin. This review discusses the most known marine glycans of potential therapeutic properties. They are chitin, chitosan, and sulfated polysaccharides named glycosaminoglycans, sulfated fucans and sulfated galactans. Their medical actions are very broad. When certain structural requirements are found, these glycans can exhibit beneficial effects in inflammation, coagulation, thrombosis, cancer growth/metastasis and vascular biology. Both structure and therapeutic mechanisms of action of these marine glycans are discussed here in straight context with the current glycomic age through a project suggestively named Marine Medicinal Glycomics.

  4. From Discovery to Production: Biotechnology of Marine Fungi for the Production of New Antibiotics

    Science.gov (United States)

    Silber, Johanna; Kramer, Annemarie; Labes, Antje; Tasdemir, Deniz

    2016-01-01

    Filamentous fungi are well known for their capability of producing antibiotic natural products. Recent studies have demonstrated the potential of antimicrobials with vast chemodiversity from marine fungi. Development of such natural products into lead compounds requires sustainable supply. Marine biotechnology can significantly contribute to the production of new antibiotics at various levels of the process chain including discovery, production, downstream processing, and lead development. However, the number of biotechnological processes described for large-scale production from marine fungi is far from the sum of the newly-discovered natural antibiotics. Methods and technologies applied in marine fungal biotechnology largely derive from analogous terrestrial processes and rarely reflect the specific demands of the marine fungi. The current developments in metabolic engineering and marine microbiology are not yet transferred into processes, but offer numerous options for improvement of production processes and establishment of new process chains. This review summarises the current state in biotechnological production of marine fungal antibiotics and points out the enormous potential of biotechnology in all stages of the discovery-to-development pipeline. At the same time, the literature survey reveals that more biotechnology transfer and method developments are needed for a sustainable and innovative production of marine fungal antibiotics. PMID:27455283

  5. The low-latitude boundary layer at mid-altitiudes: Relation to large-scale Birkeland currents

    International Nuclear Information System (INIS)

    Woch, J.; Yamauchi, M.; Lundin, R.; Potemra, T.A.; Zanetti, L.J.

    1993-01-01

    In this work the authors seek to test a projected relationship between the low latitude boundary layer (LLBL) and field aligned currents (FAC), or Birkeland currents. They use the procedure developed by Woch and Lundin for identifying LLBL boundaries. They look for correlations between properties of the FAC and properties of the LLBL. Their results show that in most cases the FAC observed are totally inside the region which exhibits LLBL plasma precipitation. The authors argue that within the biases to their data because of its source, and relative sensitivities, their conclusions support earlier work which argues for the LLBL acting as a source region for FAC features

  6. University of Washington/ Northwest National Marine Renewable Energy Center Tidal Current Technology Test Protocol, Instrumentation, Design Code, and Oceanographic Modeling Collaboration: Cooperative Research and Development Final Report, CRADA Number CRD-11-452

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Frederick R. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-11-01

    The University of Washington (UW) - Northwest National Marine Renewable Energy Center (UW-NNMREC) and the National Renewable Energy Laboratory (NREL) will collaborate to advance research and development (R&D) of Marine Hydrokinetic (MHK) renewable energy technology, specifically renewable energy captured from ocean tidal currents. UW-NNMREC is endeavoring to establish infrastructure, capabilities and tools to support in-water testing of marine energy technology. NREL is leveraging its experience and capabilities in field testing of wind systems to develop protocols and instrumentation to advance field testing of MHK systems. Under this work, UW-NNMREC and NREL will work together to develop a common instrumentation system and testing methodologies, standards and protocols. UW-NNMREC is also establishing simulation capabilities for MHK turbine and turbine arrays. NREL has extensive experience in wind turbine array modeling and is developing several computer based numerical simulation capabilities for MHK systems. Under this CRADA, UW-NNMREC and NREL will work together to augment single device and array modeling codes. As part of this effort UW NNMREC will also work with NREL to run simulations on NREL's high performance computer system.

  7. Marine Planning for Potential Wave Energy Facility Placement Amongst a Crowded Sea of Existing Resource Uses

    Science.gov (United States)

    Feist, B. E.; Fuller, E.; Plummer, M. L.

    2016-12-01

    Conversion to renewable energy sources is a logical response to increasing pressure to reduce greenhouse gas emissions. Ocean wave energy is the least developed renewable energy source, despite having the highest energy per unit area. While many hurdles remain in developing wave energy, assessing potential conflicts and evaluating tradeoffs with existing uses is essential. Marine planning encompasses a broad array of activities that take place in and affect large marine ecosystems, making it an ideal tool for evaluating wave energy resource use conflicts. In this study, we focus on the potential conflicts between wave energy conversion (WEC) facilities and existing marine uses in the context of marine planning, within the California Current Large Marine Ecosystem. First, we evaluated wave energy facility development using the Wave Energy Model (WEM) of the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) toolkit. Second, we ran spatial analyses on model output to identify conflicts with existing marine uses including AIS based vessel traffic, VMS and observer based measures of commercial fishing effort, and marine conservation areas. We found that regions with the highest wave energy potential were distant from major cities and that infrastructure limitations (cable landing sites) restrict integration with existing power grids. We identified multiple spatial conflicts with existing marine uses; especially shipping vessels and various commercial fishing fleets, and overlap with marine conservation areas varied by conservation designation. While wave energy generation facilities may be economically viable in the California Current, this viability must be considered within the context of the costs associated with conflicts that arise with existing marine uses. Our analyses can be used to better inform placement of WEC devices (as well as other types of renewable energy facilities) in the context of marine planning by accounting for economic tradeoffs

  8. Unusually large 210Po deficiencies relative to 210Pb in the Kuroshio Current of the East China and Philippine seas

    International Nuclear Information System (INIS)

    Yoshiyuki Nozaki; Naoko Ikuta; Mayumi Yashima

    1990-01-01

    Three vertical water profiles of 210 Pb and 210 Po have been measured in the East China and Philippine seas. All the profiles show a large 210 Po deficiency of ∼ 8 dpm/cm 2 relative to 210 Pb in the top ∼ 1,000 m of the water column. Based on the 210 Po deficiency, the steady state flux for 210 Po removal from the surface water is estimated to be 14 dpm cm -2 /yr. The 210 Po/ 210 Pb ratio of sinking particles will be too high unless an additional source of 210 Pb into the surface is accounted for. Thus the large 210 Po deficit is probably caused by the increased atmospheric input of 210 Pb without any significant 210 Po, which is focused in the Kuroshio region by isopycnal transport, and the preferential scavenging of 210 Po relative to 210 Pb by settling particles. The transient model calculations indicate that the model can account for the observed high excess 210 Pb inventory and large 210 Po deficiency in the water column if focusing of atmospherically derived 210 Pb in the Kuroshio water is a factor of 2-3 more than the local input. Such lateral redistribution by the western North Pacific gyre circulation is not inconsistent with the deeper penetration and the high water column inventories of anthropogenic substances observed in this region

  9. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high ... or by any means without permission in writing from the copyright holder. ..... Journal of Chemical Engineering Research and Design 82 ... Indian Ocean Marine Science Association Technical.

  10. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  11. Investigation of the current situation of massive blood transfusion in different surgical departments: a large multicenter study in China

    OpenAIRE

    Sun, Yang; Jin, Zhan-Kui; Xu, Cui-Xiang; Dang, Qian-Li; Zhang, Li-Jie; Chen, Hong-Nan; Song, Yao-Jun; Yang, Jiang-Cun

    2015-01-01

    Objective: This study aims to learn about the current situation of surgical massive blood transfusion of different surgical departments in China’s Tertiary hospitals, which could provide the basis for the formulation of guidelines on massive blood transfusion. Method: A multicenter retrospective research on the application status of blood constituents during massive blood transfusion was conducted and a comparative analyses of survival and length of hospitalization in patients from different ...

  12. Improved Marine Waters Monitoring

    Science.gov (United States)

    Palazov, Atanas; Yakushev, Evgeniy; Milkova, Tanya; Slabakova, Violeta; Hristova, Ognyana

    2017-04-01

    IMAMO - Improved Marine Waters Monitoring is a project under the Programme BG02: Improved monitoring of marine waters, managed by Bulgarian Ministry of environment and waters and co-financed by the Financial Mechanism of the European Economic Area (EEA FM) 2009 - 2014. Project Beneficiary is the Institute of oceanology - Bulgarian Academy of Sciences with two partners: Norwegian Institute for Water Research and Bulgarian Black Sea Basin Directorate. The Project aims to improve the monitoring capacity and expertise of the organizations responsible for marine waters monitoring in Bulgaria to meet the requirements of EU and national legislation. The main outcomes are to fill the gaps in information from the Initial assessment of the marine environment and to collect data to assess the current ecological status of marine waters including information as a base for revision of ecological targets established by the monitoring programme prepared in 2014 under Art. 11 of MSFD. Project activities are targeted to ensure data for Descriptors 5, 8 and 9. IMAMO aims to increase the institutional capacity of the Bulgarian partners related to the monitoring and assessment of the Black Sea environment. The main outputs are: establishment of real time monitoring and set up of accredited laboratory facilities for marine waters and sediments chemical analysis to ensure the ability of Bulgarian partners to monitor progress of subsequent measures undertaken.

  13. Large-scale nuclear structure calculations for spin-dependent WIMP scattering with chiral effective field theory currents

    OpenAIRE

    Klos, P.; Menéndez, J.; Gazit, D.; Schwenk, A.

    2013-01-01

    We perform state-of-the-art large-scale shell-model calculations of the structure factors for elastic spin-dependent WIMP scattering off 129,131Xe, 127I, 73Ge, 19F, 23Na, 27Al, and 29Si. This comprehensive survey covers the non-zero-spin nuclei relevant to direct dark matter detection. We include a pedagogical presentation of the formalism necessary to describe elastic and inelastic WIMP-nucleus scattering. The valence spaces and nuclear interactions employed have been previously used in nucl...

  14. Injuries by marine and freshwater stingrays: history, clinical aspects of the envenomations and current status of a neglected problem in Brazil.

    Science.gov (United States)

    Junior, Vidal Haddad; Cardoso, João Luiz Costa; Neto, Domingos Garrone

    2013-07-29

    Stingrays are a group of rays - cartilaginous fish related to sharks - that have whiplike tails with barbed, usually venomous spines and are found around the world, especially the marine species. Despite recent reports of accidents involving these fish, they are not aggressive, reacting only when stepped on or improperly handled. Injuries by stingrays are seldom mentioned by historians, although they have always been present in riverine communities of inland waters and in South American coasts. Indeed, envenomations by stingrays are quite common in freshwater and marine fishing communities. Although having high morbidity, such injuries are neglected because they have low lethality and usually occur in remote areas, which favor the use of folk remedies. In the present review article, historical aspects of injuries caused by stingrays in Brazil and their distribution on the coast of São Paulo state and riverine communities of the North, Midwest and Southeast regions were studied. In addition, other aspects were analyzed such as clinical features, therapeutic methods, preventive measures and trends in occurrence of these accidents in the country, particularly in areas in which freshwater stingrays had not been previously registered, being introduced after breaching of natural barriers.

  15. Theory and Practice of Marine Regional Management in China

    Institute of Scientific and Technical Information of China (English)

    Shangjie; JI; Qunzhen; QU

    2014-01-01

    With the development of marine economy in coastal provinces and cities,there comes a series of environmental problems. Marine regional management,as a completely new marine management mode,transforms traditional management mode and can protect marine ecosystem. Thus,the marine regional management is feasible and applicable in China. This paper firstly discussed connotation and development of the marine regional management in China and pointed that the marine regional management is integrated management of a certain marine region. Next,it summarized characteristics of the marine regional management at current stage,for example,land-based pollution of trans-geographic system and marine management under regional government cooperative mechanism. Finally,it came up with recommendations including combining theory and practice of the marine regional management,and establishing marine regional management system as soon as possible,to realize benign interaction and sustainable development of marine economy and ecological environment.

  16. Hungarian Marfan family with large FBN1 deletion calls attention to copy number variation detection in the current NGS era

    Science.gov (United States)

    Ágg, Bence; Meienberg, Janine; Kopps, Anna M.; Fattorini, Nathalie; Stengl, Roland; Daradics, Noémi; Pólos, Miklós; Bors, András; Radovits, Tamás; Merkely, Béla; De Backer, Julie; Szabolcs, Zoltán; Mátyás, Gábor

    2018-01-01

    Copy number variations (CNVs) comprise about 10% of reported disease-causing mutations in Mendelian disorders. Nevertheless, pathogenic CNVs may have been under-detected due to the lack or insufficient use of appropriate detection methods. In this report, on the example of the diagnostic odyssey of a patient with Marfan syndrome (MFS) harboring a hitherto unreported 32-kb FBN1 deletion, we highlight the need for and the feasibility of testing for CNVs (>1 kb) in Mendelian disorders in the current next-generation sequencing (NGS) era. PMID:29850152

  17. A new large egg type from the marine live feed calanoid copepod Acartia tonsa (Dana)-Perspectives for selective breeding of designer feed for hatcheries

    DEFF Research Database (Denmark)

    Hammervold, Stian Halsen; Glud, Ronnie N.; Evjemo, Jan Ove

    2015-01-01

    correspondingly large, and the copepods remained large when developing into adulthood. The fact that copepods hatched from large eggs were fertile indicates no chromosomal abnormalities and suggests that this egg type represents the upper tail end of eggs in a classical normal distribution of size vs. frequency...

  18. Methods of Model Reduction for Large-Scale Biological Systems: A Survey of Current Methods and Trends.

    Science.gov (United States)

    Snowden, Thomas J; van der Graaf, Piet H; Tindall, Marcus J

    2017-07-01

    Complex models of biochemical reaction systems have become increasingly common in the systems biology literature. The complexity of such models can present a number of obstacles for their practical use, often making problems difficult to intuit or computationally intractable. Methods of model reduction can be employed to alleviate the issue of complexity by seeking to eliminate those portions of a reaction network that have little or no effect upon the outcomes of interest, hence yielding simplified systems that retain an accurate predictive capacity. This review paper seeks to provide a brief overview of a range of such methods and their application in the context of biochemical reaction network models. To achieve this, we provide a brief mathematical account of the main methods including timescale exploitation approaches, reduction via sensitivity analysis, optimisation methods, lumping, and singular value decomposition-based approaches. Methods are reviewed in the context of large-scale systems biology type models, and future areas of research are briefly discussed.

  19. Assessment of current state of the art in modeling techniques and analysis methods for large space structures

    Science.gov (United States)

    Noor, A. K.

    1983-01-01

    Advances in continuum modeling, progress in reduction methods, and analysis and modeling needs for large space structures are covered with specific attention given to repetitive lattice trusses. As far as continuum modeling is concerned, an effective and verified analysis capability exists for linear thermoelastic stress, birfurcation buckling, and free vibration problems of repetitive lattices. However, application of continuum modeling to nonlinear analysis needs more development. Reduction methods are very effective for bifurcation buckling and static (steady-state) nonlinear analysis. However, more work is needed to realize their full potential for nonlinear dynamic and time-dependent problems. As far as analysis and modeling needs are concerned, three areas are identified: loads determination, modeling and nonclassical behavior characteristics, and computational algorithms. The impact of new advances in computer hardware, software, integrated analysis, CAD/CAM stems, and materials technology is also discussed.

  20. Smithsonian Marine Station (SMS) at Fort Pierce

    Science.gov (United States)

    share current Smithsonian research on the plants and animals of the Indian River Lagoon and marine Smithsonian Marine Station at Fort Pierce Website Search Box Search Field: SMS Website Search Twitter SMS Home › Welcome to the Smithsonian Marine Station Homepage slideshow Who We Are... The

  1. The Source Book of Marine Sciences.

    Science.gov (United States)

    Beakley, John C.; And Others

    Included is a teachers resource collection of 42 marine science activities for high school students. Both the biological and the physical factors of the marine environment are investigated, including the study of tides, local currents, microscope measuring, beaches, turbidity, sea water solids, pH, and salinity, marine bacteriology, microbiology,…

  2. Large-scale integration of renewable and distributed generation of electricity in Spain: Current situation and future needs

    International Nuclear Information System (INIS)

    Cossent, Rafael; Gómez, Tomás; Olmos, Luis

    2011-01-01

    Similar to other European countries, mechanisms for the promotion of electricity generation from renewable energy sources (RESs) and combined heat and power (CHP) production have caused a significant growth in distributed generation (DG) in Spain. Low DG/RES penetration levels do not have a major impact on electricity systems. However, several problems arise as DG shares increase. Smarter distribution grids are deemed necessary to facilitate DG/RES integration. This involves modifying the way distribution networks are currently planned and operated. Furthermore, DG and demand should also adopt a more active role. This paper reviews the current situation of DG/RES in Spain including penetration rates, support payments for DG/RES, level of market integration, economic regulation of Distribution System Operators (DSOs), smart metering implementation, grid operation and planning, and incentives for DSO innovation. This paper identifies several improvements that could be made to the treatment of DG/RES. Key aspects of an efficient DG/RES integration are identified and several regulatory changes specific to the Spanish situation are recommended. - Highlights: ► Substantial DG/RES penetration levels are foreseen for the coming years in Spain. ► Integrating such amount of DG/RES in electricity markets and networks is challenging. ► We review key regulatory aspects that may affect DG/RES integration in Spain. ► Several recommendations aimed at easing DG/RES integration in Spain are provided. ► Market integration and the transition towards smarter grids are deemed key issues.

  3. Modelling tide-driven currents and residual eddies in the Gulf of Kachchh and their seasonal variability: A marine environmental planning perspective

    Digital Repository Service at National Institute of Oceanography (India)

    Babu, M.T.; Vethamony, P.; Desa, E.

    showed very good agreement with the measured currents. The study suggests that though the currents of GoK are predominantly tide-driven, they respond significantly to the seasonally changing wind system. Strong southwesterly winds enhance the flood tidal...

  4. Marine fungi: A critique

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, S.; Raghukumar, C.

    in the sea have been ignored to a large extent. However, several instances of terrestrial species of fungi, active in marine environment have been reported. The arguments to support the view that terrestrial species of fungi by virtue of their physiological...

  5. L'intervention sous-marine : situation actuelle et perspectives d'avenir Underwater Operations and Techniques: Current Situation and Future Outlook

    Directory of Open Access Journals (Sweden)

    Bertrand A. R. V.

    2006-11-01

    Full Text Available A l'occasion de la Conférence Internationale de Paris sur la Pénétration sous-marine(6-8 décembre 1982, cet article fait le point sur les différents moyens d'intervention sous-marine disponibles à ce jour (plongeurs, engins télécommandés, sous-marins à pression atmosphérique et sur un certain nombre de problèmes technologiques communs (matériaux, télémanipulation, navigation, sources d'énergie. Ce domaine est encore en pleine évolution et fait appel aux récentes innovations technologiques. Bien que les engins télécommandés semblent avoir actuellement la faveur des industriels, les autres moyens restent d'avenir prometteur, la complémentarité devant remplacer dans le futur la concurrence La résurrection de l'Argyronète qui doit devenir en 1985 un banc d'essais des nouvelles techniques est le témoignage de l'activité de ce secteur industriel. This article is based on the International Symposium in Paris on Underwater Operations and Techniques 6-9 December 1982. It reviews the different methods now available for underwater operations (divers, remote-controlled vehicles, atmospheric-pressure submarines and various technological problems common to all of them (materials, remote manipulation, navigating, power sources. This field is evolving rapidly and makes use of the most recent technological innovations. Although remote-controlled vehicles now seem to be favored by industrialists, the other methods still have a promising future, and the complementariness of these methods can be expected to replace rivalry among them. The resurrection of the Argyronète project, which should become a test bench for new techniques in 1985, is a good illustration of the activity going on in this industrial sector.

  6. Extremophiles in an Antarctic Marine Ecosystem

    Directory of Open Access Journals (Sweden)

    Iain Dickinson

    2016-01-01

    Full Text Available Recent attempts to explore marine microbial diversity and the global marine microbiome have indicated a large proportion of previously unknown diversity. However, sequencing alone does not tell the whole story, as it relies heavily upon information that is already contained within sequence databases. In addition, microorganisms have been shown to present small-to-large scale biogeographical patterns worldwide, potentially making regional combinations of selection pressures unique. Here, we focus on the extremophile community in the boundary region located between the Polar Front and the Southern Antarctic Circumpolar Current in the Southern Ocean, to explore the potential of metagenomic approaches as a tool for bioprospecting in the search for novel functional activity based on targeted sampling efforts. We assessed the microbial composition and diversity from a region north of the current limit for winter sea ice, north of the Southern Antarctic Circumpolar Front (SACCF but south of the Polar Front. Although, most of the more frequently encountered sequences  were derived from common marine microorganisms, within these dominant groups, we found a proportion of genes related to secondary metabolism of potential interest in bioprospecting. Extremophiles were rare by comparison but belonged to a range of genera. Hence, they represented interesting targets from which to identify rare or novel functions. Ultimately, future shifts in environmental conditions favoring more cosmopolitan groups could have an unpredictable effect on microbial diversity and function in the Southern Ocean, perhaps excluding the rarer extremophiles.

  7. Marine Renewable Energies

    DEFF Research Database (Denmark)

    Azzellino, Arianna; Conley, Daniel; Vicinanza, Diego

    2013-01-01

    Countries with coastlines may have valuable renewable energy resources in the form of tides, currents, waves, and offshorewind.The potential to gather energy from the sea has recently gained interest in several nations, so Marine Renewable Energy Installations (hereinafter MREIs) will likely become...

  8. Concurrent Validity and Feasibility of Short Tests Currently Used to Measure Early Childhood Development in Large Scale Studies.

    Directory of Open Access Journals (Sweden)

    Marta Rubio-Codina

    Full Text Available In low- and middle-income countries (LIMCs, measuring early childhood development (ECD with standard tests in large scale surveys and evaluations of interventions is difficult and expensive. Multi-dimensional screeners and single-domain tests ('short tests' are frequently used as alternatives. However, their validity in these circumstances is unknown. We examined the feasibility, reliability, and concurrent validity of three multi-dimensional screeners (Ages and Stages Questionnaires (ASQ-3, Denver Developmental Screening Test (Denver-II, Battelle Developmental Inventory screener (BDI-2 and two single-domain tests (MacArthur-Bates Short-Forms (SFI and SFII, WHO Motor Milestones (WHO-Motor in 1,311 children 6-42 months in Bogota, Colombia. The scores were compared with those on the Bayley Scales of Infant and Toddler Development (Bayley-III, taken as the 'gold standard'. The Bayley-III was given at a center by psychologists; whereas the short tests were administered in the home by interviewers, as in a survey setting. Findings indicated good internal validity of all short tests except the ASQ-3. The BDI-2 took long to administer and was expensive, while the single-domain tests were quickest and cheapest and the Denver-II and ASQ-3 were intermediate. Concurrent validity of the multi-dimensional tests' cognitive, language, and fine motor scales with the corresponding Bayley-III scale was low below 19 months. However, it increased with age, becoming moderate-to-high over 30 months. In contrast, gross motor scales' concurrence was high under 19 months and then decreased. Of the single-domain tests, the WHO-Motor had high validity with gross motor under 16 months, and the SFI and SFII expressive scales showed moderate correlations with language under 30 months. Overall, the Denver-II was the most feasible and valid multi-dimensional test and the ASQ-3 performed poorly under 31 months. By domain, gross motor development had the highest concurrence

  9. An investigation of the field-aligned currents associated with a large-scale ULF wave using data from CUTLASS and FAST

    Directory of Open Access Journals (Sweden)

    H. C. Scoffield

    2005-02-01

    Full Text Available On 14 December 1999, a large-scale ULF wave event was observed by the Hankasalmi radar of the SuperDARN chain. Simultaneously, the FAST satellite passed through the Hankasalmi field-of-view, measuring the magnetic field oscillations of the wave at around 2000km altitude, along with the precipitating ion and electron populations associated with these fields. A simple field line resonance model of the wave has been created and scaled using the wave's spatial and temporal characteristics inferred from SuperDARN and IMAGE magnetometer data. Here the model calculated field-aligned current is compared with field-aligned currents derived from the FAST energetic particle spectra and magnetic field measurements. This comparison reveals the small-scale structuring and energies of the current carriers in a large-scale Alfvén wave, a topic, which at present, is of considerable theoretical interest. When FAST traverses a region of the wave involving low upward field-aligned current densities, the current appears to be carried by unstructured downgoing electrons of energies less than 30eV. A downward current region appears to be carried partially by upgoing electrons below the FAST energy detection threshold, but also consists of a mixture of hotter downgoing magnetospheric electrons and upgoing ionospheric electrons of energies <30eV, with the hotter upgoing electrons presumably representing those upgoing electrons which have been accelerated by the wave field above the low energy detection threshold of FAST. A stronger interval of upward current shows that small-scale structuring of scale ~50km has been imposed on the current carriers, which are downgoing magnetospheric electrons of energy 0-500eV.

  10. A large-eddy simulation study of wake propagation and power production in an array of tidal-current turbines.

    Science.gov (United States)

    Churchfield, Matthew J; Li, Ye; Moriarty, Patrick J

    2013-02-28

    This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally periodic precursor simulation is performed to create turbulent flow data. Then those data are used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modelled using rotating actuator lines, and the finite-volume method is used to solve the governing equations. In studying the wakes created by the turbines, we observed that the vertical shear of the inflow combined with wake rotation causes lateral wake asymmetry. Also, various turbine configurations are simulated, and the total power production relative to isolated turbines is examined. We found that staggering consecutive rows of turbines in the simulated configurations allows the greatest efficiency using the least downstream row spacing. Counter-rotating consecutive downstream turbines in a non-staggered array shows a small benefit. This work has identified areas for improvement. For example, using a larger precursor domain would better capture elongated turbulent structures, and including salinity and temperature equations would account for density stratification and its effect on turbulence. Additionally, the wall shear stress modelling could be improved, and more array configurations could be examined.

  11. High power rf amplifiers for accelerator applications: The large orbit gyrotron and the high current, space charge enhanced relativistic klystron

    International Nuclear Information System (INIS)

    Stringfield, R.M.; Fazio, M.V.; Rickel, D.G.; Kwan, T.J.T.; Peratt, A.L.; Kinross-Wright, J.; Van Haaften, F.W.; Hoeberling, R.F.; Faehl, R.; Carlsten, B.; Destler, W.W.; Warner, L.B.

    1991-01-01

    Los Alamos is investigating a number of high power microwave (HPM) sources for their potential to power advanced accelerators. Included in this investigation are the large orbit gyrotron amplifier and oscillator (LOG) and the relativistic klystron amplifier (RKA). LOG amplifier development is newly underway. Electron beam power levels of 3 GW, 70 ns duration, are planned, with anticipated conversion efficiencies into RF on the order of 20 percent. Ongoing investigations on this device include experimental improvement of the electron beam optics (to allow injection of a suitable fraction of the electron beam born in the gun into the amplifier structure), and computational studies of resonator design and RF extraction. Recent RKA studies have operated at electron beam powers into the device of 1.35 GW in microsecond duration pulses. The device has yielded modulated electron beam power approaching 300 MW using 3-5 kW of RF input drive. RF powers extracted into waveguide have been up to 70 MW, suggesting that more power is available from the device than has been converted to-date in the extractor

  12. An N-methyl-D-aspartate receptor mediated large, low-frequency, spontaneous excitatory postsynaptic current in neonatal rat spinal dorsal horn neurons.

    Science.gov (United States)

    Thomson, L M; Zeng, J; Terman, G W

    2006-09-01

    Examples of spontaneous oscillating neural activity contributing to both pathological and physiological states are abundant throughout the CNS. Here we report a spontaneous oscillating intermittent synaptic current located in lamina I of the neonatal rat spinal cord dorsal horn. The spontaneous oscillating intermittent synaptic current is characterized by its large amplitude, slow decay time, and low-frequency. We demonstrate that post-synaptic N-methyl-D-aspartate receptors (NMDARs) mediate the spontaneous oscillating intermittent synaptic current, as it is inhibited by magnesium, bath-applied d-2-amino-5-phosphonovalerate (APV), or intracellular MK-801. The NR2B subunit of the NMDAR appears important to this phenomenon, as the NR2B subunit selective NMDAR antagonist, alpha-(4-hydroxphenyl)-beta-methyl-4-benzyl-1-piperidineethanol tartrate (ifenprodil), also partially inhibited the spontaneous oscillating intermittent synaptic current. Inhibition of spontaneous glutamate release by the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or the mu-opioid receptor agonist [D-Ala2, N-Me-Phe4, Gly5] enkephalin-ol (DAMGO) inhibited the spontaneous oscillating intermittent synaptic current frequency. Marked inhibition of spontaneous oscillating intermittent synaptic current frequency by tetrodotoxin (TTX), but not post-synaptic N-(2,6-dimethylphenylcarbamoylmethyl)triethylammonium bromide (QX-314), suggests that the glutamate release important to the spontaneous oscillating intermittent synaptic current is dependent on active neural processes. Conversely, increasing dorsal horn synaptic glutamate release by GABAA or glycine inhibition increased spontaneous oscillating intermittent synaptic current frequency. Moreover, inhibiting glutamate transporters with threo-beta-benzyloxyaspartic acid (DL-TBOA) increased spontaneous oscillating intermittent synaptic current frequency and decay time. A possible functional role of this spontaneous NMDAR

  13. The role of upper mantle mineral phase transitions on the current structure of large-scale Earth's mantle convection.

    Science.gov (United States)

    Thoraval, C.

    2017-12-01

    Describing the large-scale structures of mantle convection and quantifying the mass transfer between upper and lower mantle request to account for the role played by mineral phase transitions in the transition zone. We build a density distribution within the Earth mantle from velocity anomalies described by global seismic tomographic models. The density distribution includes thermal anomalies and topographies of the phase transitions at depths of 410 and 660 km. We compute the flow driven by this density distribution using a 3D spherical circulation model, which account for depth-dependent viscosity. The dynamic topographies at the surface and at the CMB and the geoid are calculated as well. Within the range of viscosity profiles allowing for a satisfying restitution of the long wavelength geoid, we perform a parametric study to decipher the role of the characteristics of phase diagrams - mainly the Clapeyron's slopes - and of the kinetics of phase transitions, which may modify phase transition topographies. Indeed, when a phase transition is delayed, the boundary between two mineral phases is both dragged by the flow and interfere with it. The results are compared to recent estimations of surface dynamic topography and to the phase transition topographies as revealed by seismic studies. The consequences are then discussed in terms of structure of mantle flow. Comparisons between various tomographic models allow us to enlighten the most robust features. At last, the role played by the phase transitions on the lateral variations of mass transfer between upper and lower mantle are quantified by comparison to cases with no phase transitions and confronted to regional tomographic models, which reflect the variability of the behaviors of the descending slabs in the transition zone.

  14. Developement of a large proton accelerator for innovative researches; development of low energy high current beam transport system

    Energy Technology Data Exchange (ETDEWEB)

    Ko, In Soo; Namkung, Won; Cho, M. H.; Kim, K. N.; Kim, J. H.; Bae, Y. S.; Kim, Y.; Kim, K. H.; Shim, K. Y. [Pohang University of Science and Technology, Pohang (Korea)

    2001-04-01

    We have designed the beam transport system to connect the ion source and the RFQ. In this design, we have finalized the positions of solenoids and various beam diagnostic device. We have finalize the physical and mechanical designs of solenoids, and these designs are already adopted to produce the actual solenoids. We have also studied about EPICS, Experimental Physics and Industrial Control System, to control a stepper motor as a tuner of the RFQ designed for KOMACEPICS is a real time control system for a large scale system such as accelerators and tokamaks. The purpose of this thesis is to establish a test system based on the EPICS. A Sun UtraSPARC 5 workstation is used as the Operator Interface(OPI) console, and a VME chassis contained a Motorola MVME162 single board computer is used as the Input/Output Controller(IOC). A stepper motor controller is connected to the IOC via an RS-232C as a field bus. The EPICS base, extensions, and the real time OS vxWorks are installed on the workstation. The real time OS image can be downloaded to the IOC via the FTP when the test station is started. We have installed an IOC application as a device and driver support layer for the serial communication with an RS-232C on the workstation. We have designed the IOC database configuration files and a graphic user interface style OPI panel which was programmed by the MEDM. With this OPI, we can control the stepper motor using EPICS. 17 refs., 33 figs., 9 tabs. (Author)

  15. Large-Scale Laboratory Experiments of Initiation of Motion and Burial of Objects under Currents and Waves

    Science.gov (United States)

    Landry, B. J.; Wu, H.; Wenzel, S. P.; Gates, S. J.; Fytanidis, D. K.; Garcia, M. H.

    2017-12-01

    Unexploded ordnances (UXOs) can be found at the bottom of coastal areas as the residue of military wartime activities, training or accidents. These underwater objects are hazards for humans and the coastal environment increasing the need for addressing the knowledge gaps regarding the initiation of motion, fate and transport of UXOs under currents and wave conditions. Extensive experimental analysis was conducted for the initiation of motion of UXOs under various rigid bed roughness conditions (smooth PVC, pitted steel, marbles, gravels and bed of spherical particles) for both unidirectional and oscillatory flows. Particle image velocimetry measurements were conducted under both flow conditions to resolve the flow structure estimate the critical flow conditions for initiation of motion of UXOs. Analysis of the experimental observations shows that the geometrical characteristics of the UXOs, their properties (i.e. volume, mass) and their orientation with respect to the mean flow play an important role on the reorientation and mobility of the examined objects. A novel unified initiation of motion diagram is proposed using an effective/unified hydrodynamic roughness and a new length scale which includes the effect of the projected area and the bed-UXO contact area. Both unidirectional and oscillatory critical flow conditions collapsed into a single dimensionless diagram highlighting the importance and practical applicability of the proposed work. In addition to the rigid bed experiments, the burial dynamics of proud UXOs on a mobile sand bed were also examined. The complex flow-bedform-UXOs interactions were evaluated which highlighted the effect of munition density on burial rate and final burial depth. Burial dynamics and mechanisms for motion were examined for various UXOs types, and results show that, for the case of the low density UXOs under energetic conditions, lateral transport coexists with burial. Prior to burial, UXO re-orientation was also observed

  16. Marine Science

    African Journals Online (AJOL)

    between humans and the coastal and marine environment. ... The journal has a new and more modern layout, published online only, and the editorial .... the population structure of Platorchestia fayetta sp. nov. and their interaction with the.

  17. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the ... tidal height and amplitude can influence light penetra- ...... to environmental parameters in cage culture area of Sepanggar Bay, Malaysia.

  18. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ... consist of special issues on major events or important thematic issues. ... of sources, including plant and animal by- products.

  19. Marine biotoxins

    National Research Council Canada - National Science Library

    2004-01-01

    ... (ciguatera fish poisoning). It discusses in detail the causative toxins produced by marine organisms, chemical structures and analytical methods, habitat and occurrence of the toxin-producing organisms, case studies and existing regulations...

  20. Marine Science

    African Journals Online (AJOL)

    pod diversity and distribution are important especially since studies on marine biodiversity are scarce .... Method II –. Zamoum &. Furla (2012) protocol. Method III. – Geist et al (2008) protocol ..... Public Library Of Science One 8: 51273.

  1. Marine pollution

    International Nuclear Information System (INIS)

    Clark, R.B.

    1992-01-01

    The effects of petroleum, waste materials, halogenated hydrocarbons, radioactivity and heat on the marine ecosystem, the fishing industry and human health are discussed using the example of the North Sea. (orig.) [de

  2. Marine Science

    African Journals Online (AJOL)

    No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form ... to optimize nucleic acid extraction protocols from marine gastropods, present an ...... Greenfield., Gomez E, Harvell CD, Sale PF, Edwards.

  3. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high ..... circulation patterns include the nutrient-rich Somali ...... matical Structures in Computer Science 24: e240311.

  4. Marine insects

    National Research Council Canada - National Science Library

    Cheng, Lanna

    1976-01-01

    .... Not only are true insects, such as the Collembola and insect parasites of marine birds and mammals, considered, but also other kinds of intertidal air-breathing arthropods, notably spiders, scorpions...

  5. Marine Science

    African Journals Online (AJOL)

    Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue .... shell growth is adversely affected. ... local stressors in action, such as ocean acidification ..... that the distribution of many intertidal sessile animals.

  6. The O(α{sub s}{sup 2}) heavy quark corrections to charged current deep-inelastic scattering at large virtualities

    Energy Technology Data Exchange (ETDEWEB)

    Blümlein, Johannes, E-mail: Johannes.Bluemlein@desy.de [Deutsches Elektronen–Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Hasselhuhn, Alexander [Deutsches Elektronen–Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Pfoh, Torsten [Deutsches Elektronen–Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

    2014-04-15

    We calculate the O(α{sub s}{sup 2}) heavy flavor corrections to charged current deep-inelastic scattering at large scales Q{sup 2}≫m{sup 2}. The contributing Wilson coefficients are given as convolutions between massive operator matrix elements and massless Wilson coefficients. Foregoing results in the literature are extended and corrected. Numerical results are presented for the kinematic region of the HERA data.

  7. The marine diversity spectrum

    DEFF Research Database (Denmark)

    Reuman, Daniel C.; Gislason, Henrik; Barnes, Carolyn

    2014-01-01

    of taxonomy (all the species in a region regardless of clade) are much less studied but are equally important and will illuminate a different set of ecological and evolutionary processes. We develop and test a mechanistic model of how diversity varies with body mass in marine ecosystems. The model predicts...... the form of the diversity spectrum', which quantifies the distribution of species' asymptotic body masses, is a species analogue of the classic size spectrum of individuals, and which we have found to be a new and widely applicable description of diversity patterns. The marine diversity spectrum...... is predicted to be approximately linear across an asymptotic mass range spanning seven orders of magnitude. Slope -0 center dot 5 is predicted for the global marine diversity spectrum for all combined pelagic zones of continental shelf seas, and slopes for large regions are predicted to lie between -0 center...

  8. Recent Advances in Marine Enzymes for Biotechnological Processes.

    Science.gov (United States)

    Lima, R N; Porto, A L M

    In the last decade, new trends in the food and pharmaceutical industries have increased concern for the quality and safety of products. The use of biocatalytic processes using marine enzymes has become an important and useful natural product for biotechnological applications. Bioprocesses using biocatalysts like marine enzymes (fungi, bacteria, plants, animals, algae, etc.) offer hyperthermostability, salt tolerance, barophilicity, cold adaptability, chemoselectivity, regioselectivity, and stereoselectivity. Currently, enzymatic methods are used to produce a large variety of products that humans consume, and the specific nature of the enzymes including processing under mild pH and temperature conditions result in fewer unwanted side-effects and by-products. This offers high selectivity in industrial processes. The marine habitat has been become increasingly studied because it represents a huge source potential biocatalysts. Enzymes include oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases that can be used in food and pharmaceutical applications. Finally, recent advances in biotechnological processes using enzymes of marine organisms (bacterial, fungi, algal, and sponges) are described and also our work on marine organisms from South America, especially marine-derived fungi and bacteria involved in biotransformations and biodegradation of organic compounds. © 2016 Elsevier Inc. All rights reserved.

  9. Marine biodiversity in Colombia

    International Nuclear Information System (INIS)

    Diaz, Juan Manuel

    2002-01-01

    One decade ago, the seas and oceans were considered biologically less diverse that the terrestrial environment. Now it is known that it is on the contrary; 33 of the 34 categories of animals (phylum), they are represented in the sea, compared with those solely 15 that exist in earth. The investigation about the diversity of life in the sea has been relatively scorned, but there are big benefits that we can wait if this is protected. The captures of fish depend on it; the species captured by the fisheries are sustained of the biodiversity of their trophic chains and habitats. The marine species are probably the biggest reservoir of chemical substances that can be used in pharmaceutical products. The genetic material of some species can be useful in biotechnical applications. The paper treats topics like the current state of the knowledge in marine biodiversity and it is done a diagnostic of the marine biodiversity in Colombia

  10. Optimization of the plasma parameters for the high current and uniform large-scale pulse arc ion source of the VEST-NBI system

    International Nuclear Information System (INIS)

    Jung, Bongki; Park, Min; Heo, Sung Ryul; Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

    2016-01-01

    Highlights: • High power magnetic bucket-type arc plasma source for the VEST NBI system is developed with modifications based on the prototype plasma source for KSTAR. • Plasma parameters in pulse duration are measured to characterize the plasma source. • High plasma density and good uniformity is achieved at the low operating pressure below 1 Pa. • Required ion beam current density is confirmed by analysis of plasma parameters and results of a particle balance model. - Abstract: A large-scale hydrogen arc plasma source was developed at the Korea Atomic Energy Research Institute for a high power pulsed NBI system of VEST which is a compact spherical tokamak at Seoul national university. One of the research target of VEST is to study innovative tokamak operating scenarios. For this purpose, high current density and uniform large-scale pulse plasma source is required to satisfy the target ion beam power efficiently. Therefore, optimizing the plasma parameters of the ion source such as the electron density, temperature, and plasma uniformity is conducted by changing the operating conditions of the plasma source. Furthermore, ion species of the hydrogen plasma source are analyzed using a particle balance model to increase the monatomic fraction which is another essential parameter for increasing the ion beam current density. Conclusively, efficient operating conditions are presented from the results of the optimized plasma parameters and the extractable ion beam current is calculated.

  11. Sea-anemone toxin ATX-II elicits A-fiber-dependent pain and enhances resurgent and persistent sodium currents in large sensory neurons

    Directory of Open Access Journals (Sweden)

    Klinger Alexandra B

    2012-09-01

    Full Text Available Abstract Background Gain-of-function mutations of the nociceptive voltage-gated sodium channel Nav1.7 lead to inherited pain syndromes, such as paroxysmal extreme pain disorder (PEPD. One characteristic of these mutations is slowed fast-inactivation kinetics, which may give rise to resurgent sodium currents. It is long known that toxins from Anemonia sulcata, such as ATX-II, slow fast inactivation and skin contact for example during diving leads to various symptoms such as pain and itch. Here, we investigated if ATX-II induces resurgent currents in sensory neurons of the dorsal root ganglion (DRGs and how this may translate into human sensations. Results In large A-fiber related DRGs ATX-II (5 nM enhances persistent and resurgent sodium currents, but failed to do so in small C-fiber linked DRGs when investigated using the whole-cell patch-clamp technique. Resurgent currents are thought to depend on the presence of the sodium channel β4-subunit. Using RT-qPCR experiments, we show that small DRGs express significantly less β4 mRNA than large sensory neurons. With the β4-C-terminus peptide in the pipette solution, it was possible to evoke resurgent currents in small DRGs and in Nav1.7 or Nav1.6 expressing HEK293/N1E115 cells, which were enhanced by the presence of extracellular ATX-II. When injected into the skin of healthy volunteers, ATX-II induces painful and itch-like sensations which were abolished by mechanical nerve block. Increase in superficial blood flow of the skin, measured by Laser doppler imaging is limited to the injection site, so no axon reflex erythema as a correlate for C-fiber activation was detected. Conclusion ATX-II enhances persistent and resurgent sodium currents in large diameter DRGs, whereas small DRGs depend on the addition of β4-peptide to the pipette recording solution for ATX-II to affect resurgent currents. Mechanical A-fiber blockade abolishes all ATX-II effects in human skin (e.g. painful and itch

  12. Ecosystem size structure response to 21st century climate projection: large fish abundance decreases in the central North Pacific and increases in the California Current.

    Science.gov (United States)

    Woodworth-Jefcoats, Phoebe A; Polovina, Jeffrey J; Dunne, John P; Blanchard, Julia L

    2013-03-01

    Output from an earth system model is paired with a size-based food web model to investigate the effects of climate change on the abundance of large fish over the 21st century. The earth system model, forced by the Intergovernmental Panel on Climate Change (IPCC) Special report on emission scenario A2, combines a coupled climate model with a biogeochemical model including major nutrients, three phytoplankton functional groups, and zooplankton grazing. The size-based food web model includes linkages between two size-structured pelagic communities: primary producers and consumers. Our investigation focuses on seven sites in the North Pacific, each highlighting a specific aspect of projected climate change, and includes top-down ecosystem depletion through fishing. We project declines in large fish abundance ranging from 0 to 75.8% in the central North Pacific and increases of up to 43.0% in the California Current (CC) region over the 21st century in response to change in phytoplankton size structure and direct physiological effects. We find that fish abundance is especially sensitive to projected changes in large phytoplankton density and our model projects changes in the abundance of large fish being of the same order of magnitude as changes in the abundance of large phytoplankton. Thus, studies that address only climate-induced impacts to primary production without including changes to phytoplankton size structure may not adequately project ecosystem responses. © 2012 Blackwell Publishing Ltd.

  13. Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns

    Science.gov (United States)

    Miloslavich, Patricia; Díaz, Juan Manuel; Klein, Eduardo; Alvarado, Juan José; Díaz, Cristina; Gobin, Judith; Escobar-Briones, Elva; Cruz-Motta, Juan José; Weil, Ernesto; Cortés, Jorge; Bastidas, Ana Carolina; Robertson, Ross; Zapata, Fernando; Martín, Alberto; Castillo, Julio; Kazandjian, Aniuska; Ortiz, Manuel

    2010-01-01

    This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of

  14. Marine biodiversity in the Caribbean: regional estimates and distribution patterns.

    Directory of Open Access Journals (Sweden)

    Patricia Miloslavich

    2010-08-01

    Full Text Available This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles and the northern coast of South America (Venezuela-Colombia, while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1 highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2 high variability among collecting methods, (3 limited taxonomic expertise for many groups, and (4 differing levels of activity in the study

  15. Otters, Marine

    Science.gov (United States)

    Estes, James A.; Bodkin, James L.; Ben-David, M.; Perrin, William F.; Würsing, Bernd; Thewissen, J.G.M.

    2009-01-01

    The otters (Mustelidae; Lutrinae) provide an exceptional perspective into the evolution of marine living by mammals. Most extant marine mammals (e.g. the cetaceans, pinnipeds, and sirenians) have been so highly modified by long periods of selection for life in the sea that they bear little resemblance to their terrestrial ancestors. Marine otters, in contrast, are more recent expatriates from freshwater habitats and some species still live in both environments. Contrasts among species within the otters, and among the otters, terrestrial mammals, and the more highly adapted pinnipeds and cetaceans provide powerful insights into mammalian adaptations to life in the sea (Estes, 1989). Among the marine mammals, sea otters (Enhydra lutris, Fig. 1) provide the clearest understanding of consumer-induced effects on ecosystem function. This is due in part to opportunities provided by history and in part to the relative ease with which shallow coastal systems where sea otters live can be observed and studied. Although more difficult to study than sea otters, other otter species reveal the connectivity among the marine, freshwater, and terrestrial systems. These three qualities of the otters – their comparative biology, their role as predators, and their role as agents of ecosystem connectivity – are what make them interesting to marine mammalogy.The following account provides a broad overview of the comparative biology and ecology of the otters, with particular emphasis on those species or populations that live in the sea. Sea otters are features prominently, in part because they live exclusively in the sea whereas other otters have obligate associations with freshwater and terrestrial environments (Kenyon, 1969; Riedman and Estes, 1990).

  16. Technology to prevent deposition of marine organisms by means of electrically conductive coating. Discussions on current and potential distribution by using experiments; Doden tomaku ni yoru kaiyo seibutsu fuchaku boshi gijutsu. Denryu den`i bunpu ni kansuru jikken ni yoru kento

    Energy Technology Data Exchange (ETDEWEB)

    Usami, M; Masaki, T [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Ueda, K

    1996-04-10

    Steel structures in sea water and surface of hulls are deposited with such marine organisms as microorganisms, algae and shellfish. The deposition causes a large problem such as occurrence of abnormal local corrosion in the structures, and increase in cruising resistance in ocean vessels. The present study has introduced a simplified equation of estimation for current and potential distribution in parts coated with an electrically conductive film, and verified its reasonability by an experiment. The equation of estimation was introduced by following a model of current flow in the electrically conductive coating. The experiment has the conductive coating applied to the interior of a concrete water tank with a length of 10.8 m, a width of 5 m and a depth of 3 m to measure potential at different locations. The conductive coating was energized from copper foils attached on each applied face, whereas the current was applied to two faces between the conductive films as a pair among the four coating applied faces to measure potential in each location. A simulated calculation revealed that the potential range in the depth direction is made smaller if specific resistance of the conductive film is decreased, and made greater if increased. Effectiveness of the equation of estimation was verified by an experiment. This method has provided a prospect of achieving optimization of the specification for application of the conductive film. 2 refs., 7 figs.

  17. Marine renewable energies: status and development perspectives

    International Nuclear Information System (INIS)

    2011-01-01

    This document proposes an overview of the marine renewable energy (MRE) market, of the development perspectives, of the industrial, academic and institutional actors, of current technologies and technologies under development, and of French and European research and development programs. These energies comprise: tidal energy, the exploitation of sea temperature differences with respect with depth, wave energy, marine current power energy, osmotic and marine biomass energy

  18. Marine Battlefields

    DEFF Research Database (Denmark)

    Harðardóttir, Sara

    as they are an important food source for various marine animals. For both phytoand zooplankton predation is a major cause of mortality, and strategies for protection or avoidance are important for survival. Diatoms of the genera Nitzschia and Pseudo-nitzschia are known to produce a neuro-toxin, domoic acid (DA). Despite......Phytoplankton species are photosynthetic organisms found in most aquatic habitats. In the ocean, phytoplankton are tremendously important because they produce the energy that forms the base of the marine food web. Zooplankton feed on phytoplankton and mediate the energy to higher trophic levels...

  19. Marine Ecological Environment Management Based on Ecological Compensation Mechanisms

    Directory of Open Access Journals (Sweden)

    Qunzhen Qu

    2016-12-01

    Full Text Available The level of marine environmental management is a key factor in the successful implementation of marine power strategies. The improvement in management levels of marine environments requires innovation in marine management. In other words, the transformation of marine environmental management into marine ecological environment management must be done in order to achieve sustainable development of the marine economy. As an environmental economic policy that combines both administrative and market measures, ecological compensation mechanisms have significant advantages in marine ecological environment management. Based on the study of the current development of ecological compensation mechanisms in China, through the analysis of the connotation of marine ecological civilization, existing marine ecological protection practices and marine environmental management methods, this paper posits that the current marine ecological environment management in China should be established on the basis of ecological compensation mechanisms. At present, a lack of laws and regulations for overall marine ecological environment management is the key factor restricting the practice of marine ecological environment management. Therefore, it is necessary to explore the current path of marine ecological environment management in China from the perspective of the construction of legal system of ecological compensation law, the establishment of ecological compensation fees, ecological taxes and ecological compensation fund systems, and the clear status for a marine ecological management and supervision body.

  20. Evaluating the role of large jellyfish and forage fishes as energy pathways, and their interplay with fisheries, in the Northern Humboldt Current System

    Science.gov (United States)

    Chiaverano, Luciano M.; Robinson, Kelly L.; Tam, Jorge; Ruzicka, James J.; Quiñones, Javier; Aleksa, Katrina T.; Hernandez, Frank J.; Brodeur, Richard D.; Leaf, Robert; Uye, Shin-ichi; Decker, Mary Beth; Acha, Marcelo; Mianzan, Hermes W.; Graham, William M.

    2018-05-01

    Large jellyfish are important consumers of plankton, fish eggs and fish larvae in heavily fished ecosystems worldwide; yet they are seldom included in fisheries production models. Here we developed a trophic network model with 41 functional groups using ECOPATH re-expressed in a donor-driven, end-to-end format to directly evaluate the efficiency of large jellyfish and forage fish at transferring energy to higher trophic levels, as well as the ecosystem-wide effects of varying jellyfish and forage fish consumption rates and fishing rates, in the Northern Humboldt Current system (NHCS) off of Peru. Large jellyfish were an energy-loss pathway for high trophic-level consumers, while forage fish channelized the production of lower trophic levels directly into production of top-level consumers. A simulated jellyfish bloom resulted in a decline in productivity of all functional groups, including forage fish (12%), with the exception of sea turtles. A modeled increase in forage fish consumption rate by 50% resulted in a decrease in large jellyfish productivity (29%). A simulated increase of 40% in forage fish harvest enhanced jellyfish productivity (24%), while closure of all fisheries caused a decline in large jellyfish productivity (26%) and productivity increases in upper level consumers. These outcomes not only suggest that jellyfish blooms and fisheries have important effects on the structure of the NHCS, but they also support the hypothesis that forage fishing provides a competitive release for large jellyfish. We recommend including jellyfish as a functional group in future ecosystem modeling efforts, including ecosystem-based approaches to fishery management of coastal ecosystems worldwide.

  1. Plastics in the Marine Environment.

    Science.gov (United States)

    Law, Kara Lavender

    2017-01-03

    Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence-albeit limited-of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

  2. Plastics in the Marine Environment

    Science.gov (United States)

    Law, Kara Lavender

    2017-01-01

    Plastics contamination in the marine environment was first reported nearly 50 years ago, less than two decades after the rise of commercial plastics production, when less than 50 million metric tons were produced per year. In 2014, global plastics production surpassed 300 million metric tons per year. Plastic debris has been detected worldwide in all major marine habitats, in sizes from microns to meters. In response, concerns about risks to marine wildlife upon exposure to the varied forms of plastic debris have increased, stimulating new research into the extent and consequences of plastics contamination in the marine environment. Here, I present a framework to evaluate the current understanding of the sources, distribution, fate, and impacts of marine plastics. Despite remaining knowledge gaps in mass budgeting and challenges in investigating ecological impacts, the increasing evidence of the ubiquity of plastics contamination in the marine environment, the continued rapid growth in plastics production, and the evidence—albeit limited—of demonstrated impacts to marine wildlife support immediate implementation of source-reducing measures to decrease the potential risks of plastics in the marine ecosystem.

  3. Quench characteristics of Ag/AuBi2223 HTS-stainless steel stack used for the hybrid current leads of the large hadron collider

    CERN Document Server

    Al-Mosawi, M K; Beduz, C; Yang, Y; Ballarino, A

    2008-01-01

    The quench characteristics of Ag/Au sheathed Bi2223 tapes have been investigated in an adiabatic condition and in a configuration similar to that used in hybrid high temperature superconducting current leads, namely the 13000A leads used for the Large Hadron Collider at CERN. A specialised rig was designed and constructed to provide a carefully controlled environment. The samples were prepared from HTS tape soldered onto a stainless steel substrate with a number of temperature sensors at various positions along the length of tape. One end of the lead (cold end) was maintained at 6K using G-M cryo-cooler whereas the temperature of the other end (warm end) can be varied and maintained at temperatures up to 100K. The thermal runaway currents (quench currents) at various warm end temperatures (in the range of 40-100K) were determined. The temperature evolutions at various locations along the tape were recorded at different top end temperatures and currents. The effect of the stainless steel mechanical reinforceme...

  4. Ocean Data Interoperability Platform (ODIP): developing a common framework for global marine data management

    Science.gov (United States)

    Glaves, H. M.

    2015-12-01

    In recent years marine research has become increasingly multidisciplinary in its approach with a corresponding rise in the demand for large quantities of high quality interoperable data as a result. This requirement for easily discoverable and readily available marine data is currently being addressed by a number of regional initiatives with projects such as SeaDataNet in Europe, Rolling Deck to Repository (R2R) in the USA and the Integrated Marine Observing System (IMOS) in Australia, having implemented local infrastructures to facilitate the exchange of standardised marine datasets. However, each of these systems has been developed to address local requirements and created in isolation from those in other regions.Multidisciplinary marine research on a global scale necessitates a common framework for marine data management which is based on existing data systems. The Ocean Data Interoperability Platform project is seeking to address this requirement by bringing together selected regional marine e-infrastructures for the purposes of developing interoperability across them. By identifying the areas of commonality and incompatibility between these data infrastructures, and leveraging the development activities and expertise of these individual systems, three prototype interoperability solutions are being created which demonstrate the effective sharing of marine data and associated metadata across the participating regional data infrastructures as well as with other target international systems such as GEO, COPERNICUS etc.These interoperability solutions combined with agreed best practice and approved standards, form the basis of a common global approach to marine data management which can be adopted by the wider marine research community. To encourage implementation of these interoperability solutions by other regional marine data infrastructures an impact assessment is being conducted to determine both the technical and financial implications of deploying them

  5. Marine Science

    African Journals Online (AJOL)

    Science. The journal has a new and more modern layout, published online only, and the editorial. Board was increased to include more disciplines pertaining to marine sciences. While important chal- lenges still lie ahead, we are steadily advancing our standard to increase visibility and dissemination throughout the global ...

  6. Marine Mammals.

    Science.gov (United States)

    Meith, Nikki

    Marine mammals have not only fascinated and inspired human beings for thousands of years, but they also support a big business by providing flesh for sea-borne factories, sustaining Arctic lifestyles and traditions, and attracting tourists to ocean aquaria. While they are being harpooned, bludgeoned, shot, netted, and trained to jump through…

  7. Marine Science

    African Journals Online (AJOL)

    Mauritius Marine Conservation Society through their. Abstract. While no populations of seals are resident in the tropical Indian Ocean, vagrant animals are occasionally sighted in the region. Here we detail two new sightings of pinnipeds in the Mascarene Islands (Mauritius, Reunion and Rodri- gues) since 1996 and review ...

  8. Marine Science

    African Journals Online (AJOL)

    J O U R N A L O F. Marine Science. Coral reefs of Mauritius in a changing global climate ..... in confined aquifers, and a lesser influence in uncon- fined systems. On the ... massive cloud cover during the critical months, some. 70% bleaching ...

  9. Marine Science

    African Journals Online (AJOL)

    Copy Editor Timothy Andrew. Published ... 2007; Zhou et al., 2009) and they play an important role in the ... At both sites, zonal variation in TMPB was evident with significantly higher C-biomass closer to ... ton is considered to be an essential parameter in eco- systems ...... logical significance of toxic marine dinoflagellates.

  10. Marine Science

    African Journals Online (AJOL)

    sustainable coastal development in the region, as well as contributing to the ... between humans and the coastal and marine environment. ... exploitation for timber, fuel wood, aquaculture, urban. Abstract. Given the high dependence of coastal communities on natural resources, mangrove conservation is a challenge in.

  11. Marine Science

    African Journals Online (AJOL)

    No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means ... USA/Norway ... The last couple of years have been a time of change for the Western Indian Ocean Journal of Marine.

  12. Marine Science

    African Journals Online (AJOL)

    Chief Editor José Paula | Faculty of Sciences of University of Lisbon, Portugal. Copy Editor Timothy Andrew. Published biannually. Aims and scope: The Western Indian Ocean Journal of Marine Science provides an avenue for the wide dissem- ination of high quality research generated in the Western Indian Ocean (WIO) ...

  13. Swept away: ocean currents and seascape features influence genetic structure across the 18,000 Km Indo-Pacific distribution of a marine invertebrate, the black-lip pearl oyster Pinctada margaritifera.

    Science.gov (United States)

    Lal, Monal M; Southgate, Paul C; Jerry, Dean R; Bosserelle, Cyprien; Zenger, Kyall R

    2017-01-10

    Genetic structure in many widely-distributed broadcast spawning marine invertebrates remains poorly understood, posing substantial challenges for their fishery management, conservation and aquaculture. Under the Core-Periphery Hypothesis (CPH), genetic diversity is expected to be highest at the centre of a species' distribution, progressively decreasing with increased differentiation towards outer range limits, as populations become increasingly isolated, fragmented and locally adapted. The unique life history characteristics of many marine invertebrates such as high dispersal rates, stochastic survival and variable recruitment are also likely to influence how populations are organised. To examine the microevolutionary forces influencing population structure, connectivity and adaptive variation in a highly-dispersive bivalve, populations of the black-lip pearl oyster Pinctada margaritifera were examined across its ~18,000 km Indo-Pacific distribution. Analyses utilising 9,624 genome-wide SNPs and 580 oysters, discovered differing patterns of significant and substantial broad-scale genetic structure between the Indian and Pacific Ocean basins. Indian Ocean populations were markedly divergent (F st  = 0.2534-0.4177, p Pacific Ocean oysters, where basin-wide gene flow was much higher (F st  = 0.0007-0.1090, p Pacific Oceans respectively. Evaluation of genetic structure at adaptive loci for Pacific populations (89 SNPs under directional selection; F st  = 0.1012-0.4371, FDR = 0.05), revealed five clusters identical to those detected at neutral SNPs, suggesting environmental heterogeneity within the Pacific. Patterns of structure and connectivity were supported by Mantel tests of isolation by distance (IBD) and independent hydrodynamic particle dispersal simulations. It is evident that genetic structure and connectivity across the natural range of P. margaritifera is highly complex, and produced by the interaction of ocean currents, IBD and seascape

  14. Proceedings of the 2008 marine biodiesel symposium

    International Nuclear Information System (INIS)

    2008-01-01

    In addition to producing lower hydrocarbon emissions, marine biodiesel is biodegradable and does not harm fish. This symposium was held to discuss current marine biodiesel applications and examine methods of increasing the use of biodiesel in marine environments in British Columbia (BC). Biofuel policies and mandates in the province were reviewed, and methods of expanding the biodiesel market were explored. Updates on the use of biodiesel in ferries, tugboats, and smaller marine diesel engine applications were provided. Biodiesel projects in the United States were discussed. The environmental impacts of marine biodiesel were evaluated, and federal policies and standards for biodiesel were also outlined. The symposium was divided into the following 5 main sessions: (1) policy, (2) overviews, (3) using biodiesel in marine engines, (4) biodiesel in larger marine vessels, and (5) biodiesel quality and environmental considerations. The conference featured 13 presentations, of which 4 have been catalogued separately for inclusion in this database. tabs., figs

  15. Salmon Aquaculture and Antimicrobial Resistance in the Marine Environment

    Science.gov (United States)

    Buschmann, Alejandro H.; Tomova, Alexandra; López, Alejandra; Maldonado, Miguel A.; Henríquez, Luis A.; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P.; Cabello, Felipe C.

    2012-01-01

    Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments. PMID:22905164

  16. Salmon aquaculture and antimicrobial resistance in the marine environment.

    Directory of Open Access Journals (Sweden)

    Alejandro H Buschmann

    Full Text Available Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments.

  17. Encyclopedic approach to Marine History of Russia

    Directory of Open Access Journals (Sweden)

    Andrey V. Ishin

    2017-01-01

    Full Text Available Marine direction of foreign policy is for Russia one of key. It is determined geographical position of the Russian state banks of which is washed plenty of Maureies. Also it is related to that considerable part of population lives on the coast of Russian Maureies, and industry, located in an off-shore bar brings, in a large contribution to the economy.Many Russian marine travelers were the discoverers of «new» earths. The contribution of the Russian scientists to the hydrophysical, geological and biological study of Maureies and Oceans is great. Russia possesses a navy, to the constituents approximately one-third of total tonnage of world VMF and one of large in the world a rybopromyslovym fleet. Transport ships under the flag of Russian Federation it is possible to meet planets in the remotest corners. In a number of areas of military shipbuilding and civil shipbuilding Russia had and continues to save priority.Enhanceable interest to the Seas and Oceans found the reflection in the fundamental Russian documents, including, in the Marine doctrine of Russian Federation, ratified Russia President in 2015. In it the value of marine spaces for the Russian state is marked. In the Marine doctrine of Russian Federation is writtenin: «The skilled providing, marine teaching and education play an important role in the increase of efficiency of marine activity. They are directed on preparation, bringing in and maintainance of skilled shots of all levels, maintenance of professionalism, marine traditions and not indifferent relation of citizens to marine history of country, serve positive presentation, propaganda and support of national marine policy, to marine activity and marine service in society».Marine direction, marine science about regions found a reflection in the publications of row of the Russian authors, devoted research of policy of Russia in such regions, as: Black Sea region, Caspian region, Arctic, and also in the series of Encyclopaedias

  18. Wave refraction in the presence of currents and variations of the marine bottom; Refraccion del oleaje en presencia de corrientes y variaciones del fondo marino

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Hernandez, G.; Silva Casarin, R. [Instituto de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2001-03-01

    A method for solving the wave refraction phenomena through a computational model, which solves the wave height and propagation angle from deep to shallow water including wave breaking, is shown. The program considers the shoaling and refraction effects, wave-currents interaction and the non-linearity assumption. The numerical model is based in two principles: the irrotationality of the wave number, which is reduced to the Snell's law for planar bathymetry, and the conservation of wave action, which is reduced to the energy conservation concept when no current interaction occurs. The two-step Lax-Wendroff differential method was used to calculate and solve the entire computational grid. Three different examples that help represent the whole method are shown; the first case is based on an idealized plane and horizontal bathymetry, the second case is the experimental model developed by Berkhoff (1982), and finally the Noda (1974) example is reproduced. [Spanish] Se presenta un modelo numerico para estudiar el fenomeno de la refraccion del oleaje inducida por la presencia de corrientes, cambios batimetricos, rotura y disipacion. El modelo calcula sobre una malla computacional la altura y la direccion local del oleaje. El programa considera los efectos de asomeramiento, refraccion, interaccion oleaje-corriente y su no-linearidad. Los principios que utiliza el modelo son dos; la irrotacionalidad del numero de onda, que para batimetria plana se reduce a la ley de Snell y el principio de conservacion de la accion de ondas, que se simplifica al concepto de la conservacion de la energia cuando no existen corrientes. El metodo diferencial que se utiliza para el calculo e interpolacion de datos sobre la malla de discretizacion es Lax-Wendroff en dos pasos. Se muestran tres casos que ayudan a representar el metodo en su totalidad: el primero se modela con base en una batimetria idealizada, plana y horizontal, el segundo se simula a partir del medolo experimental de

  19. Marine organisms: an alternative source of potentially valuable natural products

    Directory of Open Access Journals (Sweden)

    Alphonse Kelecom

    1991-01-01

    Full Text Available This paper recalls the outcoming of marine natural products research and reviews a selection of marirne bioactive metabolites in current use together with promising trends in marine pharmacology.

  20. Fabrication of a metallic roll stamp with low internal stress and high hardness for large area display applications by a pulse reverse current electroforming process

    International Nuclear Information System (INIS)

    Kim, Joongeok; Han, Jungjin; Kim, Taekyung; Kang, Shinill

    2014-01-01

    With the increasing demand for large scale micro/nano components in the fields of display, energy and electrical devices, etc, the establishment of a roll imprinting process has become a priority. The fabrication of a roll stamp with high dimensional accuracy and uniformity is one of the key issues in the roll imprinting process, because the roll stamp determines the properties of the replicated micro/nano structures. In this study, a method to fabricate a metallic roll stamp with low internal stress, high flatness, and high hardness was proposed by a pulse reverse current (PRC) electroforming process. The effects of PRC electroforming processes on the internal stress, hardness, and grain size of the electroformed stamp were examined, and the optimum process conditions were suggested. As a practical example of the proposed method, various micro-patterns for electronic circuits were fabricated via the roll imprinting process using a PRC electroformed stamp. (paper)

  1. Micro-Mar: a database for dynamic representation of marine microbial biodiversity

    Directory of Open Access Journals (Sweden)

    Rodríguez-Valera Francisco

    2005-09-01

    Full Text Available Abstract Background The cataloging of marine prokaryotic DNA sequences is a fundamental aspect for bioprospecting and also for the development of evolutionary and speciation models. However, large amount of DNA sequences used to quantify prokaryotic biodiversity requires proper tools for storing, managing and analyzing these data for research purposes. Description The Micro-Mar database has been created to collect DNA diversity information from marine prokaryotes for biogeographical and ecological analyses. The database currently includes 11874 sequences corresponding to high resolution taxonomic genes (16S rRNA, ITS and 23S rRNA and many other genes including CDS of marine prokaryotes together with available biogeographical and ecological information. Conclusion The database aims to integrate molecular data and taxonomic affiliation with biogeographical and ecological features that will allow to have a dynamic representation of the marine microbial diversity embedded in a user friendly web interface. It is available online at http://egg.umh.es/micromar/.

  2. Marine Litter, Eutrophication and Noise Assessment Tools

    Science.gov (United States)

    Palazov, Atanas; Velcheva, Maya; Milkova, Tanya; Slabakova, Violeta; Marinova, Veselka

    2017-04-01

    MARLEN - Marine Litter, Eutrophication and Noise Assessment Tools is a project under the Programme BG02.03: Increased capacity for assessing and predicting environmental status in marine and inland waters, managed by Bulgarian Ministry of environment and waters and co-financed by the Financial Mechanism of the European Economic Area (EEA FM) 2009 - 2014. Project Beneficiary is the Institute of oceanology - Bulgarian Academy of Sciences with two partners: Burgas municipality and Bulgarian Black Sea Basin Directorate. Initial assessment of ecological state of Bulgarian marine waters showed lack of data for some descriptors of MSFD. The main goal of MARLEN is to build up tools for assessment of marine environment by implementing new technologies and best practices for addressing three main areas of interest with lack of marine data in particular: a) Marine litter detection and classification in coastal areas; b) Regular near real time surface water eutrophication monitoring on large aquatory; c) Underwater noise monitoring. Developed tools are an important source of real time, near real time and delay mode marine data for Bulgarian Black Sea waters. The partnership within the project increased capacity for environmental assessments and training of personnel and enhances collaboration between scientific institutes, regional and local authorities. Project results supported implementation of MSFD in Bulgarian marine waters for the benefit of coastal population, marine industry, tourism, marine research and marine spatial planning.

  3. Marine Peptides: Bioactivities and Applications

    Directory of Open Access Journals (Sweden)

    Randy Chi Fai Cheung

    2015-06-01

    Full Text Available Peptides are important bioactive natural products which are present in many marine species. These marine peptides have high potential nutraceutical and medicinal values because of their broad spectra of bioactivities. Their antimicrobial, antiviral, antitumor, antioxidative, cardioprotective (antihypertensive, antiatherosclerotic and anticoagulant, immunomodulatory, analgesic, anxiolytic anti-diabetic, appetite suppressing and neuroprotective activities have attracted the attention of the pharmaceutical industry, which attempts to design them for use in the treatment or prevention of various diseases. Some marine peptides or their derivatives have high commercial values and had reached the pharmaceutical and nutraceutical markets. A large number of them are already in different phases of the clinical and preclinical pipeline. This review highlights the recent research in marine peptides and the trends and prospects for the future, with special emphasis on nutraceutical and pharmaceutical development into marketed products.

  4. 18/20 T high magnetic field scanning tunneling microscope with fully low voltage operability, high current resolution, and large scale searching ability.

    Science.gov (United States)

    Li, Quanfeng; Wang, Qi; Hou, Yubin; Lu, Qingyou

    2012-04-01

    We present a home-built 18/20 T high magnetic field scanning tunneling microscope (STM) featuring fully low voltage (lower than ±15 V) operability in low temperatures, large scale searching ability, and 20 fA high current resolution (measured by using a 100 GOhm dummy resistor to replace the tip-sample junction) with a bandwidth of 3.03 kHz. To accomplish low voltage operation which is important in achieving high precision, low noise, and low interference with the strong magnetic field, the coarse approach is implemented with an inertial slider driven by the lateral bending of a piezoelectric scanner tube (PST) whose inner electrode is axially split into two for enhanced bending per volt. The PST can also drive the same sliding piece to inertial slide in the other bending direction (along the sample surface) of the PST, which realizes the large area searching ability. The STM head is housed in a three segment tubular chamber, which is detachable near the STM head for the convenience of sample and tip changes. Atomic resolution images of a graphite sample taken under 17.6 T and 18.0001 T are presented to show its performance. © 2012 American Institute of Physics

  5. Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the Large Helical Device

    International Nuclear Information System (INIS)

    Motojima, O.; Yamada, H.; Komori, A.; Ohyabu, N.; Mutoh, T.; Kaneko, O.; Kawahata, K.; Mito, T.; Ida, K.; Imagawa, S.; Nagayama, Y.; Shimozuma, T.; Watanabe, K.Y.; Masuzaki, S.; Miyazawa, J.; Morisaki, T.; Morita, S.; Ohdachi, S.; Ohno, N.; Saito, K.; Sakakibara, S.; Takeiri, Y.; Tamura, N.; Toi, K.; Tokitani, M.; Yokoyama, M.; Yoshinuma, M.; Ikeda, K.; Isayama, A.; Ishii, K.; Kubo, S.; Murakami, S.; Nagasaki, K.; Seki, T.; Takahata, K.; Takenaga, H.

    2007-01-01

    The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 5 x 10 20 m -3 , which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high β and long pulse

  6. Expanding the World of Marine Bacterial and Archaeal Clades

    Science.gov (United States)

    Yilmaz, Pelin; Yarza, Pablo; Rapp, Josephine Z.; Glöckner, Frank O.

    2016-01-01

    Determining which microbial taxa are out there, where they live, and what they are doing is a driving approach in marine microbial ecology. The importance of these questions is underlined by concerted, large-scale, and global ocean sampling initiatives, for example the International Census of Marine Microbes, Ocean Sampling Day, or Tara Oceans. Given decades of effort, we know that the large majority of marine Bacteria and Archaea belong to about a dozen phyla. In addition to the classically culturable Bacteria and Archaea, at least 50 “clades,” at different taxonomic depths, exist. These account for the majority of marine microbial diversity, but there is still an underexplored and less abundant portion remaining. We refer to these hitherto unrecognized clades as unknown, as their boundaries, names, and classifications are not available. In this work, we were able to characterize up to 92 of these unknown clades found within the bacterial and archaeal phylogenetic diversity currently reported for marine water column environments. We mined the SILVA 16S rRNA gene datasets for sequences originating from the marine water column. Instead of the usual subjective taxa delineation and nomenclature methods, we applied the candidate taxonomic unit (CTU) circumscription system, along with a standardized nomenclature to the sequences in newly constructed phylogenetic trees. With this new phylogenetic and taxonomic framework, we performed an analysis of ICoMM rRNA gene amplicon datasets to gain insights into the global distribution of the new marine clades, their ecology, biogeography, and interaction with oceanographic variables. Most of the new clades we identified were interspersed by known taxa with cultivated members, whose genome sequences are available. This result encouraged us to perform metabolic predictions for the novel marine clades using the PICRUSt approach. Our work also provides an update on the taxonomy of several phyla and widely known marine clades as

  7. Databases of the marine metagenomics

    KAUST Repository

    Mineta, Katsuhiko

    2015-10-28

    The metagenomic data obtained from marine environments is significantly useful for understanding marine microbial communities. In comparison with the conventional amplicon-based approach of metagenomics, the recent shotgun sequencing-based approach has become a powerful tool that provides an efficient way of grasping a diversity of the entire microbial community at a sampling point in the sea. However, this approach accelerates accumulation of the metagenome data as well as increase of data complexity. Moreover, when metagenomic approach is used for monitoring a time change of marine environments at multiple locations of the seawater, accumulation of metagenomics data will become tremendous with an enormous speed. Because this kind of situation has started becoming of reality at many marine research institutions and stations all over the world, it looks obvious that the data management and analysis will be confronted by the so-called Big Data issues such as how the database can be constructed in an efficient way and how useful knowledge should be extracted from a vast amount of the data. In this review, we summarize the outline of all the major databases of marine metagenome that are currently publically available, noting that database exclusively on marine metagenome is none but the number of metagenome databases including marine metagenome data are six, unexpectedly still small. We also extend our explanation to the databases, as reference database we call, that will be useful for constructing a marine metagenome database as well as complementing important information with the database. Then, we would point out a number of challenges to be conquered in constructing the marine metagenome database.

  8. Active Marine Station Metadata

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  9. Antiviral lead compounds from marine sponges

    KAUST Repository

    Sagar, Sunil

    2010-10-11

    Marine sponges are currently one of the richest sources of pharmacologically active compounds found in the marine environment. These bioactive molecules are often secondary metabolites, whose main function is to enable and/or modulate cellular communication and defense. They are usually produced by functional enzyme clusters in sponges and/or their associated symbiotic microorganisms. Natural product lead compounds from sponges have often been found to be promising pharmaceutical agents. Several of them have successfully been approved as antiviral agents for clinical use or have been advanced to the late stages of clinical trials. Most of these drugs are used for the treatment of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The most important antiviral lead of marine origin reported thus far is nucleoside Ara-A (vidarabine) isolated from sponge Tethya crypta. It inhibits viral DNA polymerase and DNA synthesis of herpes, vaccinica and varicella zoster viruses. However due to the discovery of new types of viruses and emergence of drug resistant strains, it is necessary to develop new antiviral lead compounds continuously. Several sponge derived antiviral lead compounds which are hopedto be developed as future drugs are discussed in this review. Supply problems are usually the major bottleneck to the development of these compounds as drugs during clinical trials. However advances in the field of metagenomics and high throughput microbial cultivation has raised the possibility that these techniques could lead to the cost-effective large scale production of such compounds. Perspectives on biotechnological methods with respect to marine drug development are also discussed. 2010 by the authors; licensee MDPI.

  10. Marine Sciences

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    PNL research in the marine sciences is focused on establishing a basic understanding of the mechanisms of stress and tolerance in marine organisms exposed to contaminants. Several environmental stressors had been investigated in earlier energy-related research. In a landmark study, for example, PNL had established that the severity of fish disease caused by the common infectious agent, Flexobacter columnaris, was seriously aggravated by thermal enhancement and certain ecological factors. Subsequent studies demonstrated that the primary immune response in fish, challenged by columnaris, could be permanently suppressed by comparatively low tritium exposures. The research has suggested that a potential exists for a significant biological impact when an aquatic stressor is added to an ambient background of other stressors, which may include heat, heavy metal ions, radiation or infectious microorganisms. More recently, PNL investigators have shown that in response to heavy metal contaminants, animals synthesize specific proteins (metallothioneins), which bind and sequester metals in the animals, thus decreasing metal mobility and effects. Companion studies with host-specific intracellular pathogens are being used to investigate the effects of heavy metals on the synthesis of immune proteins, which mitigate disease processes. The results of these studies aid in predicting the ecological effects of energy-related contaminants on valued fin and shellfish species

  11. Biomarkers of marine pollution and bioremediation

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    species of marine organisms and their bio-magnification across the food chain leading to serious threat to human health. In recent years, levels of contaminants in the marine environment have increased to a large extent as a consequence of vari- ous...

  12. Anticancer Drugs from Marine Flora: An Overview

    OpenAIRE

    Sithranga Boopathy, N.; Kathiresan, K.

    2010-01-01

    Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharide...

  13. Modeling connectivity to identify current and future anthropogenic barriers to movement of large carnivores: A case study in the American Southwest.

    Science.gov (United States)

    McClure, Meredith L; Dickson, Brett G; Nicholson, Kerry L

    2017-06-01

    This study sought to identify critical areas for puma ( Puma concolor ) movement across the state of Arizona in the American Southwest and to identify those most likely to be impacted by current and future human land uses, particularly expanding urban development and associated increases in traffic volume. Human populations in this region are expanding rapidly, with the potential for urban centers and busy roads to increasingly act as barriers to demographic and genetic connectivity of large-bodied, wide-ranging carnivores such as pumas, whose long-distance movements are likely to bring them into contact with human land uses and whose low tolerance both for and from humans may put them at risk unless opportunities for safe passage through or around human-modified landscapes are present. Brownian bridge movement models based on global positioning system collar data collected during bouts of active movement and linear mixed models were used to model habitat quality for puma movement; then, a wall-to-wall application of circuit theory models was used to produce a continuous statewide estimate of connectivity for puma movement and to identify pinch points, or bottlenecks, that may be most at risk of impacts from current and future traffic volume and expanding development. Rugged, shrub- and scrub-dominated regions were highlighted as those offering high quality movement habitat for pumas, and pinch points with the greatest potential impacts from expanding development and traffic, although widely distributed, were particularly prominent to the north and east of the city of Phoenix and along interstate highways in the western portion of the state. These pinch points likely constitute important conservation opportunities, where barriers to movement may cause disproportionate loss of connectivity, but also where actions such as placement of wildlife crossing structures or conservation easements could enhance connectivity and prevent detrimental impacts before they occur.

  14. Economic impacts of marine ecological change

    NARCIS (Netherlands)

    Groeneveld, Rolf A.; Bartelings, Heleen; Börger, Tobias; Bosello, Francesco; Buisman, Erik; Delpiazzo, Elisa; Eboli, Fabio; Fernandes, Jose A.; Hamon, Katell G.; Hattam, Caroline; Loureiro, Maria; Nunes, Paulo A.L.D.; Piwowarczyk, Joanna; Schasfoort, Femke E.; Simons, Sarah L.; Walker, Adam N.

    2018-01-01

    Marine ecological change is likely to have serious potential economic consequences for coastal economies all over the world. This article reviews the current literature on the economic impacts of marine ecological change, as well as a number of recent contributions to this literature carried out

  15. Viruses infecting marine molluscs.

    Science.gov (United States)

    Arzul, Isabelle; Corbeil, Serge; Morga, Benjamin; Renault, Tristan

    2017-07-01

    Although a wide range of viruses have been reported in marine molluscs, most of these reports rely on ultrastructural examination and few of these viruses have been fully characterized. The lack of marine mollusc cell lines restricts virus isolation capacities and subsequent characterization works. Our current knowledge is mostly restricted to viruses affecting farmed species such as oysters Crassostrea gigas, abalone Haliotis diversicolor supertexta or the scallop Chlamys farreri. Molecular approaches which are needed to identify virus affiliation have been carried out for a small number of viruses, most of them belonging to the Herpesviridae and birnaviridae families. These last years, the use of New Generation Sequencing approach has allowed increasing the number of sequenced viral genomes and has improved our capacity to investigate the diversity of viruses infecting marine molluscs. This new information has in turn allowed designing more efficient diagnostic tools. Moreover, the development of experimental infection protocols has answered some questions regarding the pathogenesis of these viruses and their interactions with their hosts. Control and management of viral diseases in molluscs mostly involve active surveillance, implementation of effective bio security measures and development of breeding programs. However factors triggering pathogen development and the life cycle and status of the viruses outside their mollusc hosts still need further investigations. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Marine cloud brightening

    Science.gov (United States)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-01-01

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could—subject to satisfactory resolution of technical and scientific problems identified herein—have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud–albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action

  17. Marine Cloud Brightening

    Energy Technology Data Exchange (ETDEWEB)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, H.; Connolly, P.; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Philip J.; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Robert

    2012-09-07

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could - subject to satisfactory resolution of technical and scientific problems identified herein - have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seedparticle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  18. Marine cloud brightening.

    Science.gov (United States)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, Hugh; Connolly, Paul; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Phillip; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Rob

    2012-09-13

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could-subject to satisfactory resolution of technical and scientific problems identified herein-have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seed-particle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100×100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  19. Effects of Pollution on Marine Organisms.

    Science.gov (United States)

    Mearns, Alan J; Reish, Donald J; Oshida, Philip S; Morrison, Ann Michelle; Rempel-Hester, Mary Ann; Arthur, Courtney; Rutherford, Nicolle; Pryor, Rachel

    2017-10-01

    This review covers selected 2016 articles on the biological effects of pollutants and human physical disturbances on marine and estuarine plants, animals, ecosystems and habitats. The review, based largely on journal articles, covers field and laboratory measurement activities (bioaccumulation of contaminants, field assessment surveys, toxicity testing and biomarkers) as well as pollution issues of current interest including endocrine disrupters, emerging contaminants, wastewater discharges, dredging and disposal etc. Special emphasis is placed on effects of oil spills and marine debris due largely to the 2010 Deepwater Horizon oil blowout in the Gulf of Mexico. Several topical areas reviewed in the past (ballast water and ocean acidification) were dropped this year. The focus of this review is on effects, not pollutant fate and transport. There is considerable overlap across subject areas (e.g.some bioaccumulation papers may be cited in other topical categories). Please use keyword searching of the text to locate related but distributed papers. Use this review only as a guide and please consult the original papers before citing them.

  20. Marine Planning Benefits the Environment

    Science.gov (United States)

    Coastal and Marine Spatial Planning (CMSP) and Ecosystem-Based Management (EBM) are management approaches that allow sustainable coastal and ocean planning. The basic unit of management under CMSP is a large region, with the United States coastlines and Great Lakes divided into ...

  1. Freshwater savings from marine protein consumption

    International Nuclear Information System (INIS)

    Gephart, Jessica A; Pace, Michael L; D’Odorico, Paolo

    2014-01-01

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km 3  yr −1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km 3  yr −1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture. (paper)

  2. The Physics of Marine Biology.

    Science.gov (United States)

    Conn, Kathleen

    1992-01-01

    Discusses ways in which marine biology can be integrated into the physics classroom. Topics suggested for incorporation include the harmonic motion of ocean waves, ocean currents, the interaction of visible light with ocean water, pressure, light absorption, and sound transfer in water. (MDH)

  3. The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds

    Science.gov (United States)

    Miller, Daniel J.; Zhang, Zhibo; Ackerman, Andrew S.; Platnick, Steven; Baum, Bryan A.

    2018-01-01

    Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness (τ) and effective radius (re) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5–10 g/m2. In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic re profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques. PMID:29637042

  4. The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds.

    Science.gov (United States)

    Miller, Daniel J; Zhang, Zhibo; Ackerman, Andrew S; Platnick, Steven; Baum, Bryan A

    2016-04-27

    Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness ( τ ) and effective radius ( r e ) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5-10 g/m 2 . In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic r e profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques.

  5. Turbidity Current Bedforms

    NARCIS (Netherlands)

    Cartigny, Matthieu; Postma, G.

    2017-01-01

    Turbidity currents in the submarine seascape are what river flows are in terrestrial landscapes. While rivers transport sediment from the mountains through valleys towards the sea, turbidity currents transport sediment from the shallow marine realms through canyons towards the deeper abyssal plains.

  6. Atlantic Marine Mammal Assessment Vessel Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in South Atlantic (Florida to Maryland) waters from 1994 to the...

  7. Caribbean Marine Mammal Assessment Vessel Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in Caribbean waters conducted during 2000-2001. These surveys were...

  8. Western Indian Ocean Journal of Marine Science

    African Journals Online (AJOL)

    Western Indian Ocean Journal of Marine Science. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 2 (2004) >. Log in or Register to get access to full text downloads.

  9. Western Indian Ocean Journal of Marine Science

    African Journals Online (AJOL)

    Western Indian Ocean Journal of Marine Science. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 6, No 2 (2008) >. Log in or Register to get access to full text downloads.

  10. Applying Technology to Marine Corps Distance Learning

    National Research Council Canada - National Science Library

    Broihier, Michael

    1997-01-01

    The purpose of this thesis is to investigate the application of technology to distance learning with the intention of recommending to the Marine Corps a feasible migration path away from its current...

  11. Enabling science and technology for marine renewable energy

    International Nuclear Information System (INIS)

    Mueller, Markus; Wallace, Robin

    2008-01-01

    This paper describes some of the key challenges to be met in the development of marine renewable energy technology, from its present prototype form to being a widely deployed contributor to future energy supply. Since 2000, a number of large-scale wave and tidal current prototypes have been demonstrated around the world, but marine renewable energy technology is still 10-15 years behind that of wind energy. UK-based developers are leading the way, with Pelamis from Pelamis Wave Power demonstrated in the open sea, generating electricity into the UK network and securing orders from Portugal. However, having started later, the developing technology can make use of more advanced science and engineering, and it is therefore reasonable to expect rapid progress. Although progress is underway through deployment and testing, there are still key scientific challenges to be addressed in areas including resource assessment and predictability, engineering design and manufacturability, installation, operation and maintenance, survivability, reliability and cost reduction. The research priorities required to meet these challenges are suggested in this paper and have been drawn from current roadmaps and vision documents, including more recent consultations within the community by the UK Energy Research Centre Marine Research Network. Many scientific advances are required to meet these challenges, and their likelihood is explored based on current and future capabilities

  12. Ice forces on marine structures. Volume 2, discussion

    Energy Technology Data Exchange (ETDEWEB)

    Marcellus, R W; Morrison, T B; Allyn, N F.B.; Croasdale, K R; Iyer, H S; Tseng, J

    1988-01-01

    A comprehensive state-of-the-art review is provided of the current methodologies in use for estimating the impact of ice forces on various kinds of marine structures: vertical sided or sloping stationary structures, floating structures, and artificial islands. Introductory chapters present ice statistics from selected Canadian marine regions, the failure modes and mechanical properties of ice, and general principles of ice/structure interactions. The methods for calculating ice loads are basically alternative methods for predicting the behavior of ice under different loading conditions; as such, none of the models have been successful in predicting the behavior of ice under all loading conditions. Currently the only reliable method for accurately predicting ice forces on marine structures is to use large-scale empirical data for ice of the same state as that predicted for design. Extrapolation from ice behavioral data at a smaller scale or ice of a different state is generally required. In comparison to current uncertainties, reasonably accurate estimates of upper bound static ice forces can be made, and a design approach using this upper bound force is appropriate for very massive rigid structures and in designing for overall global stability. The periodicity of ice forces also needs to be considered in terms of dynamic amplification of structure deformation, potential liquefaction of soils, and fatigue life. In certain cases, the deflection of the structure can change the ice failure process and therefore change the level and nature of the ice force. 221 refs., 171 figs., 19 tabs.

  13. Marine environmental monitoring programmes in South Africa: a review

    Directory of Open Access Journals (Sweden)

    H. M. Verheye

    2010-01-01

    Full Text Available South Africa uniquely lies at the junction of two major currents, the Agulhas and the Benguela. The waters overlying the continental shelf exhibit exceptionally high short-, medium- and long-term (days to inter-decadal variability compared with most other shelf areas, and strongly contrasting oceanographic conditions are observed on the east and west coasts. South Africa is rich in fisheries resources and associated environmental data collected over more than a century. The South African marine scientific community has a history of multidisciplinary studies of marine foodwebs, from the driving forces such as wind, currents and solar heating, to the top predators, with the development of kelp bed, sub-tidal reefs and estuarine ecosystem studies in the 1970s; the Benguela Ecology Programme, which ran through four successive five-year stages, focused on the pelagic marine resources. Various approaches have been used to observe the continental shelf at different time and space scales, including: macroscale but frequent satellite imagery, mesoscale environmental and fishery surveys, dedicated crossshelf transects in key areas, measurements of dynamic processes, use of moored buoys and coastal weather stations, and integrated monitoring approaches, including modelling and simulation studies. Between 30 and 50 years of comprehensive marine data now exist, which are proving useful in the application of an ecosystem approach to fisheries monitoring and management, as decadal changes become discernible. These observations need to continue; even though the single-species stock assessment and operational management procedures have not yet formally used environmental factors for fisheries management advice, they help us to understand the factors affecting fish population fluctuations and early life histories and to identify large-scale regime shifts where marine trophic structure and functioning alter to a new state.

  14. Brittany. Brest tackles marine energy

    International Nuclear Information System (INIS)

    Du Guerny, Stanislas

    2015-01-01

    This article illustrates how the Brittany region finances the extension and diversification of the Brest harbour so that it will be able get new contracts and to enable the setting up of plants related to marine energies. Some local actors are already committed in this sector, notably DCNS with the first submerged marine current power installation. Moreover, a contract has been signed between the region and DCNS to develop floating offshore wind energy. Some important local actors are indicated (an existing and a projected techno-pole, Alcatel-Lucent, a research centre). They are located in Rennes, Saint-Malo, Lannion, Lorient or Fougeres

  15. Conservation physiology of marine fishes

    DEFF Research Database (Denmark)

    Jørgensen, Christian; Peck, Myron A.; Antognarelli, Fabio

    2012-01-01

    At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology...... to different extents, ranging from no explicit consideration to detailed physiological mechanisms, and across scales from a single fish to global fishery resources. Biologists from different sub-disciplines are collaborating to rise to the challenge of projecting future changes in distribution and productivity...

  16. Marine renewable energies. Stakes and technical solutions

    International Nuclear Information System (INIS)

    Lacroix, Olivier; Macadre, Laura-Mae

    2012-05-01

    Marine renewable energies are able to supply carbon free energy from various ocean resources (tides, waves, currents, winds, salinity and temperature gradients). This sector, currently at an early stage of deployment, has good prospects of development in the coming years. ENEA releases a report on marine renewable energies giving a transversal vision of the associated stakes and prospects of development. Technical and economic characteristics, maturity level and specificities of each marine energy are analyzed. French and European sources of funding, regulatory framework and potential environmental and social impacts are also reported

  17. Radioactivity of marine environment: pr occupations of the Romanian Institute of Marine Research at Constanta (1977-1995)

    International Nuclear Information System (INIS)

    Bologa, Al.A.; Patrascu, V.

    1996-01-01

    A nuclear laboratory installed in the frame of Romanian Institute of Marine Research has been initially charged with the study of primary plankton productivity as a basic element of bio-productivity using the C-14 method. The results contributed with significant data to complete the ecological picture of the marine environment regarding particularly the nutrient basis of living resources. The laboratory developed its activities by a systematic space-time monitoring of the marine radioactivity making use of a large network of measuring stations extended from Danube mouths through the southern limit of Romanian seashore and occasionally offshore up to 90 miles. Currently, global beta measurements, radiochemical determinations (for Sr-90 for instance) and high resolution gamma spectroscopic measurements (especially on K-40, Cs-134, and Cs-137) are carried out. At the end of 199 a tritium determination chain has been installed to monitor continuously the environment from around Cernavoda NPP across the Dobrogea up to the sea shore. These measurements and studies were made under technical co-operation contracts with IAEA and other national or international organisations while the results were incorporated in two important documents: 'Global Inventory of Radioactivity of Mediterranean Sea (CIESEM/GIRMED)' and 'A Global Data Base of Marine Radioactivity (IAEA/GLOMARD)'

  18. Global patterns of extinction risk in marine and non-marine systems.

    Science.gov (United States)

    Webb, Thomas J; Mindel, Beth L

    2015-02-16

    Despite increasing concern over the effects of human activities on marine ecosystems, extinction in the sea remains scarce: 19-24 out of a total of >850 recorded extinctions implies a 9-fold lower marine extinction rate compared to non-marine systems. The extent of threats faced by marine systems, and their resilience to them, receive considerable attention, but the detectability of marine extinctions is less well understood. Before its extinction or threat status is recorded, a species must be both taxonomically described and then formally assessed; lower rates of either process for marine species could thus impact patterns of extinction risk, especially as species missing from taxonomic inventories may often be more vulnerable than described species. We combine data on taxonomic description with conservation assessments from the International Union for Conservation of Nature (IUCN) to test these possibilities across almost all marine and non-marine eukaryotes. We find that the 9-fold lower rate of recorded extinctions and 4-fold lower rate of ongoing extinction risk across marine species can be explained in part by differences in the proportion of species assessed by the IUCN (3% cf. 4% of non-marine species). Furthermore, once taxonomic knowledge and conservation assessments pass a threshold level, differences in extinction risk between marine and non-marine groups largely disappear. Indeed, across the best-studied taxonomic groups, there is no difference between marine and non-marine systems, with on average between 20% and 25% of species being threatened with extinction, regardless of realm. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  20. Spatial and temporal patterns of stranded intertidal marine debris: is there a picture of global change?

    Science.gov (United States)

    Browne, Mark Anthony; Chapman, M Gee; Thompson, Richard C; Amaral Zettler, Linda A; Jambeck, Jenna; Mallos, Nicholas J

    2015-06-16

    Floating and stranded marine debris is widespread. Increasing sea levels and altered rainfall, solar radiation, wind speed, waves, and oceanic currents associated with climatic change are likely to transfer more debris from coastal cities into marine and coastal habitats. Marine debris causes economic and ecological impacts, but understanding the scope of these requires quantitative information on spatial patterns and trends in the amounts and types of debris at a global scale. There are very few large-scale programs to measure debris, but many peer-reviewed and published scientific studies of marine debris describe local patterns. Unfortunately, methods of defining debris, sampling, and interpreting patterns in space or time vary considerably among studies, yet if data could be synthesized across studies, a global picture of the problem may be avaliable. We analyzed 104 published scientific papers on marine debris in order to determine how to evaluate this. Although many studies were well designed to answer specific questions, definitions of what constitutes marine debris, the methods used to measure, and the scale of the scope of the studies means that no general picture can emerge from this wealth of data. These problems are detailed to guide future studies and guidelines provided to enable the collection of more comparable data to better manage this growing problem.