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Sample records for submergence vehicle alvin

  1. Navigation Upgrades to the National Deep Submergence Facility Vehicles D.S.V. Alvin, Jason 2, and the DSL-120A

    Science.gov (United States)

    Whitcomb, L. L.; Kinsey, J. C.; Yoerger, D. R.; Taylor, C. L.; Bowen, A. D.; Walden, B. B.; Fornari, D. J.

    2003-12-01

    We report on recently completed enhancements to the navigation systems employed on the 4500m submersible Alvin and the 6500m ROV Jason 2 and DSL-120A sonar system of the UNOLS National Deep Submergence Facility (NDSF) of the Woods Hole Oceanographic Institution (WHOI). Over the last two years we have significantly improved the accuracy and update rate of the six degree-of-freedom vehicle position and velocity navigation data available for these vehicles, thus improving the quantitative accuracy of acoustic surveys, optical surveys, and sampling operations. The navigation upgrades have also enabled improvements in the closed-loop dynamic positioning accuracy of the Jason 2 ROV, thus improving the vehicle tracking precision during survey and sampling operations. We have sought to employ more a uniform suite of navigation instruments, navigation data processing software systems, and data logging format standards for NDSF vehicles to improve the utility and ease-of-use of data by science users. Improved navigation instruments deployed on each of these vehicles in 2001 and 2002 include the following: (a) A 1200 KHz Bottom Lock Doppler Sonar (RDInstruments Inc.) providing three dimensional vehicle velocity information with respect to the ocean floor and the water column at an update rate of up to 10 Hz, providing a single-ping beam-velocity error standard deviation of 0.3% for a nominal advance velocity of 1 meter/sec. (b) A north-seeking fiber-optic gyroscope (IXSEA Inc.) providing true-north heading, pitch, and roll with a rated accuracy of 0.1 degree. Improved navigation data processing software systems deployed on these vehicles in 2001 and 2002 includes Dvlnav, an interactive navigation program developed at JHU for precision navigation of underwater vehicles and submersibles. DVLNAV employs a variety of sensors including bottom lock Doppler sonar, long baseline (LBL) acoustic navigation, gyro compasses, magnetic compasses, depth sensors, altimeters, and (when

  2. Being There & Getting Back Again: Half a Century of Deep Ocean Research & Discovery with the Human Occupied Vehicle "Alvin"

    Science.gov (United States)

    German, C. R.; Fornari, D. J.; Fryer, P.; Girguis, P. R.; Humphris, S. E.; Kelley, D. S.; Tivey, M.; Van Dover, C. L.; Von Damm, K.

    2012-12-01

    In 2013, Alvin returns to service after significant observational and operational upgrades supported by the NSF, NAVSEA & NOAA. Here we review highlights of the first half-century of deep submergence science conducted by Alvin, describe some of the most significant improvements for the new submarine and discuss the importance of these new capabilities for 21st century ocean science and education. Alvin has a long history of scientific exploration, discovery and intervention at the deep seafloor: in pursuit of hypothesis-driven research and in response to human impacts. One of Alvin's earliest achievements, at the height of the Cold War, was to help locate & recover an H-bomb in the Mediterranean, while the last dives completed, just ahead of the current refit, were to investigate the impacts of the Deep Water Horizon oil spill. Alvin has excelled in supporting a range of Earth & Life Science programs including, in the late 1970s, first direct observations and sampling of deep-sea hydrothermal vents and the unusual fauna supported by microbial chemosynthesis. The 1980s saw expansion of Alvin's dive areas to newly discovered hot-springs in the Atlantic & NE Pacific, Alvin's first dives to the wreck of RMS Titanic and its longest excursions away from WHOI yet, via Loihi Seamount (Hawaii) to the Mariana Trench. The 1990s saw Alvin's first event-response dives to sites where volcanic eruptions had just occurred at the East Pacific Rise & Juan de Fuca Ridge while the 2000s saw Alvin discover novel off-axis venting at Lost City. Observations from these dives fundamentally changed our views of volcanic and microbial processes within young ocean crust and even the origins of life! In parallel, new deep submergence capabilities, including manipulative experiments & sensor development, relied heavily on testing using Alvin. Recently, new work has focused on ocean margins where fluid flow from the seafloor results in the release of hydrocarbons and other chemical species that

  3. Upgrades to NDSF Vehicle Camera Systems and Development of a Prototype System for Migrating and Archiving Video Data in the National Deep Submergence Facility Archives at WHOI

    Science.gov (United States)

    Fornari, D.; Howland, J.; Lerner, S.; Gegg, S.; Walden, B.; Bowen, A.; Lamont, M.; Kelley, D.

    2003-12-01

    In recent years, considerable effort has been made to improve the visual recording capabilities of Alvin and ROV Jason. This has culminated in the routine use of digital cameras, both internal and external on these vehicles, which has greatly expanded the scientific recording capabilities of the NDSF. The UNOLS National Deep Submergence Facility (NDSF) archives maintained at Woods Hole Oceanograpic Institution (WHOI) are the repository for the diverse suite of photographic still images (both 35mm and recently digital), video imagery, vehicle data and navigation, and near-bottom side-looking sonar data obtained by the facility vehicles. These data comprise a unique set of information from a wide range of seafloor environments over the more than 25 years of NDSF operations in support of science. Included in the holdings are Alvin data plus data from the tethered vehicles- ROV Jason, Argo II, and the DSL-120 side scan sonar. This information conservatively represents an outlay in facilities and science costs well in excess of \\$100 million. Several archive related improvement issues have become evident over the past few years. The most critical are: 1. migration and better access to the 35mm Alvin and Jason still images through digitization and proper cataloging with relevant meta-data, 2. assessing Alvin data logger data, migrating data on older media no longer in common use, and properly labeling and evaluating vehicle attitude and navigation data, 3. migrating older Alvin and Jason video data, especially data recorded on Hi-8 tape that is very susceptible to degradation on each replay, to newer digital format media such as DVD, 4. improving the capabilities of the NDSF archives to better serve the increasingly complex needs of the oceanographic community, including researchers involved in focused programs like Ridge2000 and MARGINS, where viable distributed databases in various disciplinary topics will form an important component of the data management structure

  4. New Web Services for Broader Access to National Deep Submergence Facility Data Resources Through the Interdisciplinary Earth Data Alliance

    Science.gov (United States)

    Ferrini, V. L.; Grange, B.; Morton, J. J.; Soule, S. A.; Carbotte, S. M.; Lehnert, K.

    2016-12-01

    The National Deep Submergence Facility (NDSF) operates the Human Occupied Vehicle (HOV) Alvin, the Remotely Operated Vehicle (ROV) Jason, and the Autonomous Underwater Vehicle (AUV) Sentry. These vehicles are deployed throughout the global oceans to acquire sensor data and physical samples for a variety of interdisciplinary science programs. As part of the EarthCube Integrative Activity Alliance Testbed Project (ATP), new web services were developed to improve access to existing online NDSF data and metadata resources. These services make use of tools and infrastructure developed by the Interdisciplinary Earth Data Alliance (IEDA) and enable programmatic access to metadata and data resources as well as the development of new service-driven user interfaces. The Alvin Frame Grabber and Jason Virtual Van enable the exploration of frame-grabbed images derived from video cameras on NDSF dives. Metadata available for each image includes time and vehicle position, data from environmental sensors, and scientist-generated annotations, and data are organized and accessible by cruise and/or dive. A new FrameGrabber web service and service-driven user interface were deployed to offer integrated access to these data resources through a single API and allows users to search across content curated in both systems. In addition, a new NDSF Dive Metadata web service and service-driven user interface was deployed to provide consolidated access to basic information about each NDSF dive (e.g. vehicle name, dive ID, location, etc), which is important for linking distributed data resources curated in different data systems.

  5. AT26-12 Alvin Science Verification Cruise (EM122)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over the past four years, HOV Alvin has undergone a suite of enhancements including a new pressure hull with improved visibility and ergonomics, new digital imaging...

  6. Remote Sensing of Submerged Aquatic Vegetation in a Shallow Non-Turbid River Using an Unmanned Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Kyle F. Flynn

    2014-12-01

    Full Text Available A passive method for remote sensing of the nuisance green algae Cladophora glomerata in rivers is presented using an unmanned aerial vehicle (UAV. Included are methods for UAV operation, lens distortion correction, image georeferencing, and spectral analysis to support algal cover mapping. Eighteen aerial photography missions were conducted over the summer of 2013 using an off-the-shelf UAV and three-band, wide-angle, red, green, and blue (RGB digital camera sensor. Images were post-processed, mosaicked, and georeferenced so automated classification and mapping could be completed. An adaptive cosine estimator (ACE and spectral angle mapper (SAM algorithm were used to complete the algal identification. Digital analysis of optical imagery correctly identified filamentous algae and background coverage 90% and 92% of the time, and tau coefficients were 0.82 and 0.84 for ACE and SAM, respectively. Thereafter, algal cover was characterized for a one-kilometer channel segment during each of the 18 UAV flights. Percent cover ranged from <5% to >50%, and increased immediately after vernal freshet, peaked in midsummer, and declined in the fall. Results indicate that optical remote sensing with UAV holds promise for completing spatially precise, and multi-temporal measurements of algae or submerged aquatic vegetation in shallow rivers with low turbidity and good optical transmission.

  7. Localization and Tracking of Submerged Phytoplankton Bloom Patches by an Autonomous Underwater Vehicle

    Science.gov (United States)

    Godin, M. A.; Ryan, J. P.; Zhang, Y.; Bellingham, J. G.

    2012-12-01

    Observing plankton in their drifting frame of reference permits effective studies of marine ecology from the perspective of microscopic life itself. By minimizing variation caused simply by advection, observations in a plankton-tracking frame of reference focus measurement capabilities on the processes that influence the life history of populations. Further, the patchy nature of plankton populations motivates use of sensor data in real-time to resolve patch boundaries and adapt observing resources accordingly. We have developed capabilities for population-centric plankton observation and sampling by autonomous underwater vehicles (AUVs). Our focus has been on phytoplankton populations, both because of their ecological significance - as the core of the oceanic food web and yet potentially harmful under certain bloom conditions, as well as the accessibility of their signal to simple optical sensing. During the first field deployment of these capabilities in 2010, we tracked a phytoplankton patch containing toxigenic diatoms and found that their toxicity correlated with exposure to resuspended sediments. However, this first deployment was labor intensive as the AUV drove in a pre-programmed pattern centered around a patch-marking drifter; it required a boat deployment of the patch-marking drifter and required full-time operators to periodically estimate of the position of the patch with respect to the drifter and adjust the AUV path accordingly. In subsequent field experiments during 2011 and 2012, the Tethys-class long-range AUVs ran fully autonomous patch tracking algorithms which detected phytoplankton patches and continually updated estimates of each patch center by driving adaptive patterns through the patch. Iterations of the algorithm were generated to overcome the challenges of tracking advecting and evolving patches while minimizing human involvement in vehicle control. Such fully autonomous monitoring will be necessary to perform long-term in

  8. Knowledge and Reality: Essays in Honor of Alvin Plantinga [review

    OpenAIRE

    Rehnman, Sebastian

    2009-01-01

    Open access article. Published by Taylor & Francis. According to the Philosophical Lexicon, to ‘planting’ is to ‘use twentieth-century fertilizer to encourage new shoots from eleventh-century ideas which everyone thought had gone to seed.’ Although the prominent US philosopher Alvin Plantinga cannot be said to use medieval ideas in any historically informed sense, he has certainly fertilized contemporary metaphysics, epistemology, and philosophy of religion. His philosophy was given a comp...

  9. Acoustical characteristic predictions of a multi-layer system of a submerged vehicle hull mounted sonar simplified to an infinite planar model

    Directory of Open Access Journals (Sweden)

    Sung-Hee Kim

    2012-06-01

    Full Text Available Hull Mounted Sonar (HMS is a long range submerged vehicle's hull-mounted passive sonar system which detects low-frequency noise caused by machineries of enemy ships or submerged vehicles. The HMS needs a sound absorption /insulation multi-layer structure to shut out the self-noise from own machineries and to amplify signals from outside. Therefore, acoustic analysis of the multi-layer system should be performed when the HMS is designed. This paper simplified the HMS multi-layer system to be an infinite planar multi-layer model. Also, main excitations that influence the HMS were classified into mechanical, plane wave and turbulent flow excitation, and the investigations for each excitation were performed for various models. Stiffened multi-layer analysis for mechanical excitation and general multi-layer analysis for turbulent flow excitation were developed. The infinite planar multi-layer analysis was expected to be more useful for preliminary design stage of HMS system than the infinite cylindrical model because of short analysis time and easiness of parameter study.

  10. Alvin W. Gouldner and industrial sociology at Columbia University.

    Science.gov (United States)

    Chriss, J J

    2001-01-01

    Alvin W. Gouldner (1920--1980) was a prolific sociologist of the post-World War II era who spent the early part of his career (the 1950s) in the field of industrial sociology. A case study of Gouldner's early life and career is useful insofar as it intertwines with the development of industrial sociology as a distinct subfield within sociology. Through this analysis we are also better able to understand how and in what ways a burgeoning organizational studies program developed at Columbia University during the 1940s. This analysis of the historical and cultural contexts within which Gouldner came to prominence as an industrial sociologist at Columbia, and the intellectual program that resulted, can also help shed light on more recent trends in organizational studies. Copyright 2001 John Wiley & Sons, Inc.

  11. El modelo epistemológico de Alvin Plantinga. Un comentario sobre "Warranted Christian Belief"

    OpenAIRE

    Maraya, E.A. (Erlito A.)

    2006-01-01

    This article shows the epistemological model proposed by Alvin Plantinga towards the knowledge of God. This model is con-fronted with the ones proposed by Thomas Aquinas and Calvin. The author reaches the conclusion that they are different, incom-patible models.

  12. US State Submerged Lands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Submerged Lands Act (43 U.S.C. Section 1301 et seq.) grants coastal states title to natural resources located within their coastal submerged lands and navigable...

  13. Submerged AUV Charging Station

    Science.gov (United States)

    Jones, Jack A.; Chao, Yi; Curtin, Thomas

    2014-01-01

    Autonomous Underwater Vehicles (AUVs) are becoming increasingly important for military surveillance and mine detection. Most AUVs are battery powered and have limited lifetimes of a few days to a few weeks. This greatly limits the distance that AUVs can travel underwater. Using a series of submerged AUV charging stations, AUVs could travel a limited distance to the next charging station, recharge its batteries, and continue to the next charging station, thus traveling great distances in a relatively short time, similar to the Old West “Pony Express.” One solution is to use temperature differences at various depths in the ocean to produce electricity, which is then stored in a submerged battery. It is preferred to have the upper buoy submerged a reasonable distance below the surface, so as not to be seen from above and not to be inadvertently destroyed by storms or ocean going vessels. In a previous invention, a phase change material (PCM) is melted (expanded) at warm temperatures, for example, 15 °C, and frozen (contracted) at cooler temperatures, for example, 8 °C. Tubes containing the PCM, which could be paraffin such as pentadecane, would be inserted into a container filled with hydraulic oil. When the PCM is melted (expanded), it pushes the oil out into a container that is pressurized to about 3,000 psi (approx equals 20.7 MPa). When a valve is opened, the high-pressure oil passes through a hydraulic motor, which turns a generator and charges a battery. The low-pressure oil is finally reabsorbed into the PCM canister when the PCM tubes are frozen (contracted). Some of the electricity produced could be used to control an external bladder or a motor to the tether line, such that depth cycling is continued for a very long period of time. Alternatively, after the electricity is generated by the hydraulic motor, the exiting low-pressure oil from the hydraulic motor could be vented directly to an external bladder on the AUV, such that filling of the bladder

  14. A Needs Assessment Study and Curriculum Development for a Public and Private Security Program at Alvin Community College.

    Science.gov (United States)

    Bethscheider, John

    A needs assessment for a community college curriculum in public and private security was conducted by surveying 50 high schools, four-year colleges, and private security agencies in the Alvin Community College area; 36 institutions responded. Findings revealed: most have a designated director of their security program; most would rather hire the…

  15. Alvin (Al) Sieff: Thoughts About and Lessons from a Great Engineer

    Science.gov (United States)

    Tauber, Michael

    2010-01-01

    Alvin (Al) Seiff was known as a world-class atmospheric scientist during the last three decades of his life. Equally deserving, however, were his prior achievements as an innovative engineer, an exceptional technical manager, and a mentor of young engineers at NASA Ames Research Center. This paper outlines Al's role in developing Ames ballistic range facilities, probably the most advanced in the world at that time, and his seminal 1963 report that contained the concepts used to reconstruct the atmospheres of Mars, Venus, Jupiter and Titan. Also discussed is my affiliation with Al after he hired me in 1962, including our joint work on Mars missions and investigating the feasibility that a Jupiter probe could survive entry, work that eventually led to the development of the Galileo probe. Finally, suggestions are offered for speeding the analysis and design of thermal protection systems based on lessons learned from successful probes and landers.

  16. Fundamentalism on stilts: A response to Alvin Platinga�s reformed epistemology

    Directory of Open Access Journals (Sweden)

    Jaco S. Gericke

    2009-09-01

    Full Text Available During the greater part of the 20th century, biblical scholarship and the philosophy of religion were not considered to have much in common. However, towards the end of the millennium, a movement of a few Christian philosophers of religion called �Reformed Epistemology� (RE suggested the need for interdisciplinary dialogue. With Alvin Plantinga as primary representative, these philosophers claimed to be concerned with what they considered to be the lack of philosophical reflection on the foundations of historical criticism and its non-traditional findings. In this article, the author (qua biblical scholar suggests that Plantinga�s arguments have not been taken seriously because of his fundamentalism and the resulting failure to grasp the nature and contents of the hermeneutical debates that have raged within biblical theology for the past 200 years.

  17. Cars submerged in water.

    NARCIS (Netherlands)

    2010-01-01

    Crashes in which cars are submerged in deep water or in a ditch are often complicated and serious. Considering their severity and the fact that approximately half the fatalities in this crash type are not due to drowning but to injury, preventive measures are to be preferred above measures that have

  18. ALVIN investigation of an active propagating rift system, Galapagos 95.5° W

    Science.gov (United States)

    Hey, R.N.; Sinton, J.M.; Kleinrock, M.C.; Yonover, R.N.; MacDonald, K.C.; Miller, S.P.; Searle, R.C.; Christie, D.M.; Atwater, T.M.; Sleep, Norman H.; Johnson, H. Paul; Neal, C.A.

    1992-01-01

    ALVIN investigations have defined the fine-scale structural and volcanic patterns produced by active rift and spreading center propagation and failure near 95.5° W on the Galapagos spreading center. Behind the initial lithospheric rifting, which is propagating nearly due west at about 50 km m.y.−1, a triangular block of preexisting lithosphere is being stretched and fractured, with some recent volcanism along curving fissures. A well-organized seafloor spreading center, an extensively faulted and fissured volcanic ridge, develops ~ 10 km (~ 200,000 years) behind the tectonic rift tip. Regional variations in the chemical compositions of the youngest lavas collected during this program contrast with those encompassing the entire 3 m.y. of propagation history for this region. A maximum in degree of magmatic differentiation occurs about 9 km behind the propagating rift tip, in a region of diffuse rifting. The propagating spreading center shows a gentle gradient in magmatic differentiation culminating at the SW-curving spreading center tip. Except for the doomed rift, which is in a constructional phase, tectonic activity also dominates over volcanic activity along the failing spreading system. In contrast to the propagating rift, failing rift lavas show a highly restricted range of compositions consistent with derivation from a declining upwelling zone accompanying rift failure. The lithosphere transferred from the Cocos to the Nazca plate by this propagator is extensively faulted and characterized by ubiquitous talus in one of the most tectonically disrupted areas of seafloor known. The pseudofault scarps, where the preexisting lithosphere was rifted apart, appear to include both normal and propagator lavas and are thus more lithologically complex than previously thought. Biological communities, probably vestimentiferan tubeworms, occur near the top of the outer pseudofault scarp, although no hydrothermal venting was observed.

  19. The JASON Remotely Operated Vehicle System

    Science.gov (United States)

    1993-02-01

    Project FAMOUS were the French bathyscaph ARCHIMEDE and the submersible CYANA as well as the American submersible ALVIN (ref. 6). In all, forty-two dives...their thrust characteristics and improved their low-level control over the thrusters broad dynamic range (ref. 31). During the JASON vehicle design a...his console is the JASON control box (figure 12). On the left is a grip control for thrusting JASON up or down. Next to it is a push button for

  20. Optimization of submerged vane parameters

    Indian Academy of Sciences (India)

    Submerged vanes are airfoils which are in general placed at certain angle with respect to the flow direction in a channel to induce artificial circulations downstream. By virtue of these artificially generated circulations, submerged vanes were utilized to protect banks of rivers against erosion, to control shifting of rivers, to avoid ...

  1. Optimization of submerged vane parameters

    Indian Academy of Sciences (India)

    H Sharma

    velocities simulated from CFD using standard k-x model were very much in accordance with what it was measured by Wang and Odgaard [4]. Thus, model can be used to study the turbulence characteristics around submerged vanes and to predict various parameters downstream of the submerged vanes. After the model ...

  2. Oceanographic data collected during the Gulf of Alaska 2004 Expedition (alaska2004) on RV Atlantis in Gulf of Alaska from July 30, 2004 - August 23, 2004 (NODC Accession 0072310)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2004 Gulf of Alaska Seamount Expedition will use the deep submergence vehicle (DSV) Alvin to explore five large seamounts. Giacomini, Pratt, Welker, Denson, and...

  3. Dive site geology: DSV ALVIN (2006) and ROV JASON II (2007) dives to the middle-lower continental slope, northern Gulf of Mexico

    Science.gov (United States)

    Roberts, H. H.; Shedd, W.; Hunt, J., Jr.

    2010-11-01

    Use of DSV ALVIN (2006) and ROV JASON II (2007) provided access to never observed or sampled sites of fluid-gas expulsion from the little-studied middle and lower continental slope of the northern Gulf of Mexico (below water depths of 1000 m). Dives were focused on 15 locations selected by 3-D seismic surface attributes and shallow subsurface geologic analyses. The linkage between highly positive seafloor reflectivity and hard bottoms proved to be an efficient indicator of potential sites of interest. Through observation and sampling of reflective sites, starting in the mid-1980s, it has become apparent that most hard bottoms on the northern Gulf's continental slope are created by the precipitation of authigenic carbonates at hydrocarbon seep sites. Access to the Bureau of Ocean Energy Management, Regulation and Enforcement's extraordinary archive of slope-wide 3-D seismic data made efficient site selection possible. From thousands of sites that display the characteristics of fluid-gas expulsion, 15 were observed and sampled during the 2006 and 2007 cruises. Water depths in which these 15 sites were located ranged from ∼2750 to ∼970 m. All sites exhibited evidence of hydrocarbon seepage or more rapid venting. Chemosynthetic organisms, authigenic carbonates, barite, gas hydrates, highly anoxic surface sediments, brine pools, and hydrocarbon-laced brine flows were identified and sampled. High-resolution acoustic Autonomous Underwater Vehicle (AUV) data, including multibeam bathymetry, side-scan sonar swaths, and chirp sonar subbottom profiles, were collected at four locations (AC601, WR269, GC852, and AT340). Data sets from the 2006 and 2007 dives resulted in a greatly improved understanding of both cross-slope and along-slope variability in the characteristics of fluid-gas expulsion sites and associated habitats. Our studies confirmed the importance of fluid-gas expulsion processes for sustaining chemosynthetic communities and impacting seabed geology on the

  4. Explosion proof vehicle for tank inspection

    Science.gov (United States)

    Zollinger, William T [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Bauer, Scott G [Idaho Falls, ID

    2012-02-28

    An Explosion Proof Vehicle (EPV) having an interior substantially filled with an inert fluid creating an interior pressure greater than the exterior pressure. One or more flexible tubes provide the inert fluid and one or more electrical conductors from a control system to the vehicle. The vehicle is preferably used in subsurface tank inspection, whereby the vehicle is submerged in a volatile fluid.

  5. Drought and submergence tolerance in plants

    Science.gov (United States)

    Du, Hewei; Zhou, Yufan; Oksenberg, Nir; Ronald, Pamela

    2017-11-14

    The invention provides methods of genetically modified plants to increase tolerance to drought and/or submergence. The invention additionally provides plants having increased drought and/or submergence tolerance engineered using such methods.

  6. Submerged membrane distillation for desalination of water

    KAUST Repository

    Francis, Lijo

    2016-10-27

    Submerged membrane modules for use for desalination of water are disclosed. In one or more aspects, the membrane modules can be submerged either in a feed solution tank or the feed solution can pass through the lumen side of the membrane submerged within the tank. The feed solution can be a water-based feed stream containing an amount of salt.

  7. A “basicalidade” da crença em Deus segundo Alvin Plantinga: uma apresentação

    Directory of Open Access Journals (Sweden)

    Guilherme V. R. de Carvalho

    2009-05-01

    Full Text Available O artigo apresenta a defesa da racionalidade da crença em Deus desenvolvida pelo filósofo reformado Alvin Plantinga, a partir de sua redefinição como “crença apropriadamente básica”. Após uma breve introdução, que situa a epistemologia religiosa de Plantinga no contexto das transformações recentes no campo da filosofia analítica da religião, expõe-se a crítica de Plantinga ao fundacionalismo clássico, cujo colapso teria reaberto a viabilidade epistemológica da crença em Deus. Segue-se a defesa plantingiana da crença em Deus como crença apropriadamente básica, que teria bases experienciais identificáveis, mas dispensaria qualquer evidência ou demonstração racional, mostrando a orientação firme da construção plantingiana em direção a uma forma plenamente externalista de epistemologia. O final do artigo oferece uma breve reflexão sobre o significado cultural e espiritual da epistemologia reformada de Plantinga.Palavras-chave: Crença; Epistemologia; Externalismo; Fé e razão; Filosofia reformada; Fundacionalismo.ABSTRACTThe article presents a defense of the rationality of the belief in God, developed by reformed philosopher Alvin Plantinga, who redefined it as a “properly basic belief”. After a brief introduction to place Plantinga’s religious epistemology in the context of recent transformations in the field of analytical philosophy of religion, Plantinga’s critique to classic foundationalism, whose collapse opened the epistemological viability of belief in God, is exposed. Then, the article focuses on the Plantingian defense of belief in God as a properly basic belief, nased on identifiable experiential grounds but independent from all evidence or rational demonstration, thus showing the firm orientation of Plantinga’s construction towards a fully externalist form of epistemology. The conclusion offers a short reflection on the cultural and spiritual meaning of Plantinga’s reformed epistemology

  8. Ühe maketinäituse lugu / Alvin Järving, Larissa Kondina, Johan Tali ...[jt.] ; üles kirjutanud Maris Kerge

    Index Scriptorium Estoniae

    2011-01-01

    Näitus "Viini Eksiilid. Helisev arhitektuur" kinos Helios 10-18.09.2011 Tallinna arhitektuuribiennaali raames. Näitusel osalevad arhitektid Alvin Järving, Larissa Kondina, Joanna-Maria Helinurm, Johan Tali, Kadri Kerge, Kadri Tamre, Siim Tuksam ja Sille Pihlak, kes on äsja lõpetanud või õpivad Viini Rakenduskunsti Ülikooli (Universität für Angewandte Kunst Wien) arhitektuurikoolis. Näitusel osalejate mõtteid

  9. Workshop on ROVs and deep submergence

    Science.gov (United States)

    The deep-submergence community has an opportunity on March 6 to participate in a unique teleconferencing demonstration of a state-of-the-art, remotely operated underwater research vehicle known as the Jason-Medea System. Jason-Medea has been developed over the past decade by scientists, engineers, and technicians at the Deep Submergence Laboratory at Woods Hole Oceanographic Institution. The U.S. Navy, the Office of the Chief of Naval Research, and the National Science Foundation are sponsoring the workshop to explore the roles that modern computational, communications, and robotics technologies can play in deep-sea oceanographic research.Through the cooperation of Electronic Data Systems, Inc., the Jason Foundation, and Turner Broadcasting System, Inc., 2-1/2 hours of air time will be available from 3:00 to 5:30 PM EST on March 6. Twenty-seven satellite downlink sites will link one operating research vessel and the land-based operation with workshop participants in the United States, Canada, the United Kingdom, and Bermuda. The research ship Laney Chouest will be in the midst of a 3-week educational/research program in the Sea of Cortez, between Baja California and mainland Mexico. This effort is focused on active hydrothermal vents driven by heat flow from the volcanically active East Pacific Rise, which underlies the sediment-covered Guaymas Basin. The project combines into a single-operation, newly-developed robotic systems, state-of-the-art mapping and sampling tools, fiber-optic data transmission from the seafloor, instantaneous satellite communication from ship to shore, and a sophisticated array of computational and telecommunications networks. During the workshop, land-based scientists will observe and participate directly with their seagoing colleagues as they conduct seafloor research.

  10. Reflexivity in Qualitative Social Research: Bridging the Gap between Theory and Practice with Alvin Gouldner’s Reflexive Sociology

    Directory of Open Access Journals (Sweden)

    Elisabeth Simburgüer

    2014-01-01

    Full Text Available La reflexividad se ha puesto de moda en las Ciencias Sociales. En este artículo ofrezco una discusión crítica del concepto de reflexi - vidad y su uso en la investigación social cualitativa en contextos educativos. Argumento que uno de los dilemas en una gran canti - dad de literatura sobre la materia radica en la frecuente ausencia de discusión que permita entender en qué medida las aspiracio - nes reflexivas de los académicos en sus investigaciones pueden llevarse a cabo en la práctica académica. Con base en lo expuesto por Alvin Gouldner, el artículo plantea una manera diferente de enmarcar la reflexividad en la investigación cualitativa, de modo que sirva de puente entre la teoría y la reflexividad en la univer - sidad; asimismo, formula preguntas importantes sobre las impli - caciones de la reflexividad o de su ausencia. Con fundamento en entrevistas cualitativas a académicos, efectuadas en el Reino Unido y Chile, señalo una amplia investigación acerca de la labor académica y la identidad. Para concluir, sugiero que las discusio - nes sobre la puesta en práctica de las aspiraciones para ser un(a académico(a reflexivo(a deben partir del análisis colectivo de las estructuras actuales de la mercantilización de la educación supe - rior y la forma en que estas pueden limitar la práctica académica reflexiva en la universidad.

  11. Measurement of Submerged Oil/Gas Leaks using ROV Video

    Science.gov (United States)

    Shaffer, Franklin; de Vera, Giorgio; Lee, Kenneth; Savas, Ömer

    2013-11-01

    Drilling for oil or gas in the Gulf of Mexico is increasing rapidly at depths up to three miles. The National Commission on the Deepwater Horizon Oil Leak concluded that inaccurate estimates of the leak rate from the Deepwater Horizon caused an inadequate response and attempts to cap the leak to fail. The first response to a submerged oil/gas leak will be to send a Remotely Operated Vehicle (ROV) down to view the leak. During the response to the Deepwater Horizon crisis, the authors Savas and Shaffer were members of the Flow Rate Technical Group's Plume Team who used ROV video to develop the FRTG's first official estimates of the oil leak rate. Savas and Shaffer developed an approach using the larger, faster jet features (e.g., turbulent eddies, vortices, entrained particles) in the near-field developing zone to measure discharge rates. The authors have since used the Berkeley Tow Tank to test this approach on submerged dye-colored water jets and compressed air jets. Image Correlation Velocimetry has been applied to measure the velocity of visible features. Results from tests in the Berkeley Tow Tank and submerged oil jets in the OHMSETT facility will be presented.

  12. Flow and scour around vertical submerged structures

    Indian Academy of Sciences (India)

    Although past investigations establish the effect of various parameters on scour around vertical submerged structures for live and clear water condition, yet further studies are required to analyze the scour around group of submerged structures for various bed sediments, understand the flow physics around the group and ...

  13. Iodine Removal Efficiency in Non-Submerged and Submerged Self-Priming Venturi Scrubber

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Majid; Yan, Changqi; Sun, Zhongning; Gu, Haifeng; Wang, Junlong; Mehboob; Khurram [Harbin Engineering Univ., Harbin (China)

    2013-04-15

    The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na{sub 2}S{sub 2}O{sub 3}) in water to remove the gaseous iodine (I{sub 2}) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

  14. IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

    Directory of Open Access Journals (Sweden)

    MAJID ALI

    2013-04-01

    Full Text Available The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH and sodium thiosulphate (Na2S2O3 in water to remove the gaseous iodine (I2 from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

  15. Impeller Submergence Depth for Stirred Tanks

    Directory of Open Access Journals (Sweden)

    Thiyam T. Devi

    2011-11-01

    Full Text Available Impeller submergence governs the performance of mixing tanks employed in oxygen transfer operation. Present work experimentally investigates the effect of impeller submergence depths on oxygen transfer and corresponding power consumption. It has been found that at higher range of impeller submergence, mixing tanks consume less power and gives higher values of oxygen transfer coefficient. Optimal range of submergence depth is 0.7 to 0.9 times the impeller diameter. Copyright ©2011 BCREC UNDIP. All rights reserved.(Received: 4th March 2011; Revised: 12nd July 2011; Accepted: 14th July 2011[How to Cite: T.T. Devi, A.P. Sinha, M. Thakre, and B. Kumar. (2011. Impeller Submergence Depth for Stirred Tanks. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 123-128. doi:10.9767/bcrec.6.2.826.123-128][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.826.123-128 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/826] | View in 

  16. Laser Beam Submerged Arc Hybrid Welding

    Science.gov (United States)

    Reisgen, Uwe; Olschok, Simon; Jakobs, Stefan; Schleser, Markus; Mokrov, Oleg; Rossiter, Eduardo

    The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.

  17. Multielement stoichiometry of submerged macrophytes across Yunnan plateau lakes (China)

    National Research Council Canada - National Science Library

    Xing, Wei; Wu, Haoping; Shi, Qiao; Hao, Beibei; Liu, Han; Wang, Zhixiu; Liu, Guihua

    2015-01-01

    .... We predicted that tissue element composition in submerged macrophytes is affected by lake trophic level and taxonomy, and submerged macrophytes have weak stoichiometric homeostasis for all above 16 elements...

  18. Oxygen dynamics in submerged rice (Oryza sativa L.)

    DEFF Research Database (Denmark)

    Colmer, Timothy D.; Pedersen, Ole

    2008-01-01

    Complete submergence of plants prevents direct O2 and CO2 exchange with air. Underwater photosynthesis can result in marked diurnal changes in O2 supply to submerged plants. Dynamics in pO2 had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O2 loss...

  19. Benthic bacterial diversity in submerged sinkhole ecosystems.

    Science.gov (United States)

    Nold, Stephen C; Pangborn, Joseph B; Zajack, Heidi A; Kendall, Scott T; Rediske, Richard R; Biddanda, Bopaiah A

    2010-01-01

    Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities.

  20. Production of extracellular aspartic protease in submerged ...

    African Journals Online (AJOL)

    Yomi

    29(1): 1-6. Fraile ER, Bernardinelli SE, Handel M, Jauregui AM (1978). Selección de cepas de Mucor sp productoras de enzimas coagulantes de leche. Rev. Arg. Microbiol. 10(2): 65-69. Ghareib M, Hamdy HS, Khalil AA (2001). Production of intracellular milk clotting enzyme in submerged cultures of Fusarium subglutinans.

  1. Topology optimization for submerged buoyant structures

    NARCIS (Netherlands)

    Picelli, R.; van Dijk, R.; Vicente, W.M.; Pavanello, R.; Langelaar, M.; van Keulen, A.

    2017-01-01

    This paper presents an evolutionary structural topology optimization method for the design of completely submerged buoyant modules with design-dependent fluid pressure loading. This type of structure is used to support offshore rig installation and pipeline transportation at all water depths. The

  2. Production of extracellular aspartic protease in submerged ...

    African Journals Online (AJOL)

    Fungal milk-clotting enzymes have gained value as bovine Chymosin substitutes in the cheese industry. In this work, the effects of culture conditions on the production of extracellular milk clotting enzymes from Mucor mucedo DSM 809 in submerged fermentation were studied. The maximum activity was observed after 48 h ...

  3. Pump Coastdown with the Submerged Flywheel

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyun-Gi; Seo, KyoungWoo; Kim, Seong Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Many research reactors are generally designed as open pool types in consideration of the heat removal of the nuclear fuels, reactor operation and accessibility. Reactor structure assembly is generally placed at the pool bottom as shown in Fig. 1. Primary cooling system pump circulates the coolant from the reactor structure to the heat exchanger in order to continuously remove the heat generated from the reactor core in the research reactor as shown in Fig. 1. The secondary cooling system releases the transferred heat to the atmosphere by the cooling tower. Coastdown flow rate of the primary cooling system pump with the submerged flywheel are calculated analytically in case of the accident situation. Coastdown flow rate is maintained until almost 80 sec when the pump stops normally. But, coastdown flow rate is rapidly decreased when the flywheel is submerged because of the friction load on the flywheel surface.

  4. Coastline Protection by a Submerged Breakwater

    Science.gov (United States)

    Valentine, B. D.; Hayatdavoodi, M.; Ertekin, R. C.

    2016-02-01

    Coastal communities are in danger of the impact caused by storm surge and waves. Storm surge brings the water level to a higher elevation and farther inland. This rise in water level increases the chance of a higher number and larger set of waves approaching shorelines, and it can potentially devastate the coastal infrastructure. In this study, we evaluate the performance of a submerged, horizontal breakwater located near shore. Unlike other types of breakwaters, such as the ones that extend to the surface, either fixed or floating, a submerged horizontal breakwater does not create any visual distraction or limit most of the recreational and commercial activities in the nearshore areas. The Level I Green-Naghdi (GN) nonlinear water wave equations are utilized here to study the wave transformation over a submerged breakwater that is located in shallow water. The GN theory is based on the theory of directed fluid sheets and assumes an incompressible and inviscid fluid; no assumption on the rotationality of the flow is required. In this approach, the nonlinear boundary conditions and the averaged conservation laws are satisfied exactly. The reflection and transmission coefficients due to nonlinear shallow water waves are determined implementing two approaches which use Goda's (1976) and Grue's (1992) methods. The results are compared with the existing laboratory experiments, and close agreement is observed overall. Preliminary results of the performance of the breakwater on dissipating storm waves during Hurricane Ike (2008), approaching the shore of Galveston, Texas, are presented.

  5. IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

    OpenAIRE

    Ali, Majid; CHANGQI, YAN; ZHONGNING, SUN; HAIFENG, GU; JUNLONG, WANG; MEHBOOB, KHURRAM

    2013-01-01

    The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na2S2O3) in water to remove the gaseous iodine (I2) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine...

  6. Submergence tolerance in Hordeum marinum

    DEFF Research Database (Denmark)

    Pedersen, Ole; Malik, Al I.; Colmer, Timothy D.

    2010-01-01

    Floodwaters differ markedly in dissolved CO(2), yet the effects of CO(2) on submergence responses of terrestrial plants have rarely been examined. The influence of dissolved CO(2) on underwater photosynthesis and growth was evaluated for three accessions of the wetland plant Hordeum marinum Huds......) movement, would all contribute to submergence tolerance in H. marinum. The present study demonstrates that dissolved CO(2) levels can determine submergence tolerance of terrestrial plants. So, submergence experiments should be conducted with defined CO(2) concentrations and enrichment might be needed...

  7. Calibration of submerged multi-sluice gates

    Directory of Open Access Journals (Sweden)

    Mohamed F. Sauida

    2014-09-01

    The main objective of this work is to study experimentally and verify empirically the different parameters affecting the discharge through submerged multiple sluice gates (i.e., the expansion ratios, gates operational management, etc.. Using multiple regression analysis of the experimental results, a general equation for discharge coefficient is developed. The results show, that the increase in the expansion ratio and the asymmetric operation of gates, give higher values for the discharge coefficient. The obtained predictions of the discharge coefficient using the developed equations are compared to the experimental data. The present developed equations showed good consistency and high accuracy.

  8. Damage detection in submerged plates using ultrasonic guided waves

    Indian Academy of Sciences (India)

    Suitable ultrasonic guided wave modes with optimum scanning capabilities have been generated and identified in submerged plate system. Finally, the propagation of selected modes through submerged notched plates is investigated. Sensitivity of leaky waves to the notches has been studied. The methodology would help ...

  9. Automating a submerged pump method for operating oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Popa, I.

    1984-01-01

    The basic parameters of wells which operate in a mode of submerged operation are presented. The basic systems for measuring and testing the parameters of submerged operation are described. Worldwide experience in solving this particular problem is analyzed. Romanian (SRR) use of systems for automation, remote signaling and remote management is examined.

  10. Impacts of climate change on submerged and emergent wetland plants

    Science.gov (United States)

    Frederick T. Short; Sarian Kosten; Pamela A. Morgan; Sparkle L Malone; Gregg E. Moore

    2016-01-01

    Submerged and emergent wetland plant communities are evaluated for their response to global climate change (GCC), focusing on seagrasses, submerged freshwater plants, tidal marsh plants, freshwater marsh plants and mangroves. Similarities and differences are assessed in plant community responses to temperature increase, CO2increase, greater UV-B exposure, sea...

  11. Identification of a novel submergence response gene regulated by ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-12-07

    Dec 7, 2016 ... 3Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangzte University,. Jingzhou 434025, P.R. .... intolerance to submergence) and M202(Sub1A) by qRT-. PCR. We identified a novel gene responsive to submergence, called RS1. The expression patterns of.

  12. Identification of a novel submergence response gene regulated by ...

    African Journals Online (AJOL)

    Our results also show that RS1 is highly expressed under submergence, drought, and NaCl stresses, but not under cold or dehydration stress. Hormone ABA treatment induces, whereas GA treatment decreases, RS1 expression. The RS1 and Sub1A genes are co-regulated under submergence. Overexpression of RS1 in ...

  13. Laser-matter Interaction with Submerged Samples

    Energy Technology Data Exchange (ETDEWEB)

    Mariella, R; Rubenchik, A; Norton, M; Donohue, G; Roberts, K

    2010-03-25

    With the long-term goal in mind of investigating if one could possibly design a 'universal solid-sample comminution technique' for debris and rubble, we have studied pulsed-laser ablation of solid samples that were contained within a surrounding fluid. Using pulses with fluences between 2 J and 0.3 J, wavelengths of 351 and 527 nm, and samples of rock, concrete, and red brick, each submerged in water, we have observed conditions in which {micro}m-scale particles can be preferentially generated in a controlled manner, during the laser ablation process. Others have studied laser peening of metals, where their attention has been to the substrate. Our study uses non-metallic substrates and analyzes the particles that are ablated from the process. The immediate impact of our investigation is that laser-comminution portion of a new systems concept for chemical analysis has been verified as feasible.

  14. Submerged arc welding of heavy plate

    Science.gov (United States)

    Wilson, R. A.

    1972-01-01

    The submerged arc process is particularly suitable for heavy plate welding because of its ability to combine very high deposit rates along with excellent quality. It does these things without the smoke and spatter often accompanying other processes. It is available today in several forms that are pointed to the fabricators of heavy sections with long, short or round about welds. Tandem arc full automatic equipment is particularly suitable for those long heavy welds where speed and deposit rate are of the first order. An attachment called long stick-out which makes use of the IR drop on long electrode extensions can be included on this equipment to increase deposition rates 50% or more.

  15. Modeling tabular icebergs submerged in the ocean

    Science.gov (United States)

    Stern, A. A.; Adcroft, A.; Sergienko, O.; Marques, G.

    2017-08-01

    Large tabular icebergs calved from Antarctic ice shelves have long lifetimes (due to their large size), during which they drift across large distances, altering ambient ocean circulation, bottom-water formation, sea-ice formation, and biological primary productivity in the icebergs' vicinity. However, despite their importance, the current generation of ocean circulation models usually do not represent large tabular icebergs. In this study, we develop a novel framework to model large tabular icebergs submerged in the ocean. In this framework, tabular icebergs are represented by pressure-exerting Lagrangian elements that drift in the ocean. The elements are held together and interact with each other via bonds. A breaking of these bonds allows the model to emulate calving events (i.e., detachment of a tabular iceberg from an ice shelf) and tabular icebergs breaking up into smaller pieces. Idealized simulations of a calving tabular iceberg, its drift, and its breakup demonstrate capabilities of the developed framework.

  16. Crassulacean acid metabolism in submerged aquatic plants

    Science.gov (United States)

    Keeley, Jon E.; Sybesme, C.

    1984-01-01

    CO2-fixation in the dark is known to occur in various organs of many plants. However, only in species possessing crassulacean acid metabolism (CAM) does dark CO2-fixation contribute substantially to the carbon economy of the plant. Until very recently CAM was known only from terrestrial species, largely drought adapted succulents. The discovery of CAM in the submerged aquatic fern ally Isoetes howellii (Isoetaceae)(Keeley 1981) adds a new dimension to our understanding of crassulacean acid metabolism. In this paper I will summarize 1) the evidence of CAM in Isoetes howellii, 2) the data on the distribution of CAM in aquatic species, and 3) the work to date on the functional significance of CAM in aquatic species.

  17. Submerged membrane distillation for seawater desalination

    KAUST Repository

    Francis, Lijo

    2014-08-11

    A submerged membrane distillation (SMD) process for fresh water production from Red Sea water using commercially available hollow fiber membranes has been successfully employed and compared with the conventional direct contact membrane distillation (DCMD) process. The hollow fiber membranes have been characterized for its morphology using field effect scanning electron microscope. In SMD process, a bunch of hollow fiber membranes are glued together at both ends to get a simplified open membrane module assembly submerged into the coolant tank equipped with a mechanical stirrer. Hot feed stream is allowed to pass through the lumen side of the membrane using a feed pump. Continuous stirring at the coolant side will reduce the temperature and concentration polarization. During the conventional DCMD process, using feed-coolant streams with co-current and counter-current flows has been tested and the results are compared in this study. In SMD process, a water vapor flux of 10.2 kg m-2 h-1 is achieved when using a feed inlet temperature of 80°C and coolant temperature of 20°C. Under the same conditions, during conventional DCMD process, a water vapor flux of 11.6 and 10.1 kg m-2 h-1 were observed during counter-current and co-current flow streams, respectively. Results show that the water production in the SMD process is comparable with the conventional DCMD process, while the feed-coolant flow streams are in the co-current direction. During conventional DCMD operation, a 15% increase in the water production is observed when feed-coolant streams are in the counter-current direction compared to the co-current direction. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  18. Durability performance of submerged concrete structures - phase 2.

    Science.gov (United States)

    2015-09-01

    This project determined that severe corrosion of steel can occur in the submerged : portions of reinforced concrete structures in marine environments. Field studies of decommissioned : pilings from Florida bridges revealed multiple instances of stron...

  19. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  20. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  1. Marine algal flora of submerged Angria Bank (Arabian Sea)

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Reddy, C.R.K.; Ambiye, V.

    Submerged Angria Bank was surveyed for the deep water marine algal flora. About 57 species were reported from this bank for the first time. Rhodophyta dominated (30 species) followed by Chlorophyta (18 species) and Phaeophyta (9 species). A few...

  2. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Biotic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  3. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  4. Supporting Calculations For Submerged Bed Scrubber Condensate Disposal Preconceptual Study

    Energy Technology Data Exchange (ETDEWEB)

    Pajunen, A. J.; Tedeschi, A. R.

    2012-09-18

    This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Preconceptual Study report The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments.

  5. Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

    Directory of Open Access Journals (Sweden)

    Malay Kumar ADAK

    2011-06-01

    Full Text Available The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation. It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield. The detrimental effects of the complete submergence were recorded in generation of sucrose, starch, sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control (i.e. non-submerged condition. The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity. Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity. However, under normal or control condition, there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity. Still, photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield. Finally, plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues. It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity (number of panicles, in this case as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.

  6. Incipient motion of sediment in presence of submerged flexible vegetation

    OpenAIRE

    Wang, Hao; Tang, Hong-Wu; Zhao, Han-Qing; Xuan-yu ZHAO; Lü, Sheng-qi

    2015-01-01

    The presence of submerged vegetation on river beds can change the water flow structure and alter the state of sediment motion. In this study, the incipient motion of sediment in the presence of submerged flexible vegetation in open channels was investigated in a laboratory experiment. The vegetation was simulated with flexible rubber cylinders arranged in parallel arrays. The effect of the vegetation density, water depth, and sediment grain size on the incipient motion was investigated. The e...

  7. Heat transfer model for quenching by submerging

    Energy Technology Data Exchange (ETDEWEB)

    Passarella, D N; Varas, F [Departamento de Matematica Aplicada II, E.T.S. de Ing. de Telecomunicacion, Universidad de Vigo, Campus Marcosende, 36310 Vigo (Spain); MartIn, E B, E-mail: diego@dma.uvigo.es, E-mail: fvaras@uvigo.es, E-mail: emortega@uvigo.es [Area de Mecanica de Fluidos, E.T.S. de Ing. Industriales, Universidad de Vigo, Campus Marcosende, 36310 Vigo (Spain)

    2011-05-01

    In quenching by submerging the workpiece is cooled due to vaporization, convective flow and interaction of both mechanisms. The dynamics of these phenomena is very complex and the corresponding heat fluxes are strongly dependent on local flow variables such as velocity of fluid and vapor fraction. This local dependence may produce very different cooling rates along the piece, responsible for inappropriate metallurgical transformations, variability of material properties and residual stresses. In order to obtain an accurate description of cooling during quenching, a mathematical model of heat transfer is presented here. The model is based on the drift-flux mixture-model for multiphase flows, including an equation of conservation of energy for the liquid phase and specific boundary conditions that account for evaporation and presence of vapor phase on the surface of the piece. The model was implemented on Comsol Multiphysics software. Generation of appropriate initial and boundary conditions, as well as numerical resolution details, is briefly discussed. To test the model, a simple flow condition was analyzed. The effect of vapor fraction on heat transfer is assessed. The presence of the typical vapor blanket and its collapse can be recovered by the model, and its effect on the cooling rates on different parts of the piece is analyzed. Comparisons between numerical results and data from literature are made.

  8. Modeling of Combined Phenomena Affecting an AUV Stealth Vehicle

    Directory of Open Access Journals (Sweden)

    Miroslaw Gerigk

    2016-12-01

    Full Text Available In the paper some results of research connected with modeling the basic stealth characteristics of an AUV vehicle are presented. First of all a general approach to design of the stealth AUV autonomous underwater vehicles under consideration is introduced. Then the AUV stealth vehicle concept is briefly described. Next a method of modeling of the stealth characteristics is briefly described. As an example of the stealth characteristics investigations some results of modeling the boundary layer and wake are presented. Some remarks regarding the behavior of the AUV stealth vehicle in the submerged conditions are given. The final conclusions are presented.

  9. Determining the Discharge Rate from a Submerged Oil Leaks using ROV Video and CFD study

    Science.gov (United States)

    Saha, Pankaj; Shaffer, Frank; Shahnam, Mehrdad; Savas, Omer; Devites, Dave; Steffeck, Timothy

    2016-11-01

    The current paper reports a technique to measure the discharge rate by analyzing the video from a Remotely Operated Vehicle (ROV). The technique uses instantaneous images from ROV video to measure the velocity of visible features (turbulent eddies) along the boundary of an oil leak jet and subsequently classical theory of turbulent jets is imposed to determine the discharge rate. The Flow Rate Technical Group (FRTG) Plume Team developed this technique that manually tracked the visible features and produced the first accurate government estimates of the oil discharge rate from the Deepwater Horizon (DWH). For practical application this approach needs automated control. Experiments were conducted at UC Berkeley and OHMSETT that recorded high speed, high resolution video of submerged dye-colored water or oil jets and subsequently, measured the velocity data employing LDA and PIV software. Numerical simulation have been carried out using experimental submerged turbulent oil jets flow conditions employing LES turbulence closure and VOF interface capturing technique in OpenFOAM solver. The CFD results captured jet spreading angle and jet structures in close agreement with the experimental observations. The work was funded by NETL and DOI Bureau of Safety and Environmental Enforcement (BSEE).

  10. Vehicle to Vehicle Services

    DEFF Research Database (Denmark)

    Brønsted, Jeppe Rørbæk

    2008-01-01

    As computing devices, sensors, and actuators pervade our surroundings, new applications emerge with accompanying research challenges. In the transportation domain vehicles are being linked by wireless communication and equipped with an array of sensors and actuators that make is possible to provide...... location aware infotainment, increase safety, and lessen environmental strain. This dissertation is about service oriented architecture for pervasive computing with an emphasis on vehicle to vehicle applications. If devices are exposed as services, applications can be created by composing a set of services...... and governing the flow of data among them. In pervasive computing, composing services is, however, not the whole story. To fully realize their potential, applications must also deal with challenges such as device heterogeneity, context awareness, openendedness, and resilience to dynamism in network connectivity...

  11. Submerged cultivation of medicinal mushrooms: bioprocesses and products (review).

    Science.gov (United States)

    Elisashvili, Vladimir

    2012-01-01

    Medicinal mushrooms belonging to higher Basidiomycetes are an immensely rich yet largely untapped resource of useful, easily accessible, natural compounds with various biological activities that may promote human well-being. The medicinal properties are found in various cellular components and secondary metabolites (polysaccharides, proteins and their complexes, phenolic compounds, polyketides, triterpenoids, steroids, alkaloids, nucleotides, etc.), which have been isolated and identified from the fruiting bodies, culture mycelium, and culture broth of mushrooms. Some of these compounds have cholesterol-lowering, anti-diabetic, antioxidant, antitumor, immunomodulating, antimicrobial, and antiviral activities ready for industrial trials and further commercialization, while others are in various stages of development. Recently, the submerged cultivation of medicinal mushrooms has received a great deal of attention as a promising and reproducible alternative for the efficient production of mushroom mycelium and metabolites. Submerged cultivation of mushrooms has significant industrial potential, but its success on a commercial scale depends on increasing product yields and development of novel production systems that address the problems associated with this technique of mushroom cultivation. In spite of many researchers' efforts for the production of bioactive metabolites by mushrooms, the physiological and engineering aspects of submerged cultures are still far from being thoroughly studied. The vast majority of studies have focused on polysaccharide and ganoderic acid production in submerged cultivation of medicinal mushrooms, and very little has been written so far on the antioxidant and hemagglutinating activity of submerged mushroom cultures. The purpose of this review is to provide an update of the present state of the art and future prospects of submerged cultivation of medicinal mushrooms to produce mycelium and bioactive metabolites, and to make a

  12. Rice SUB1A constrains remodelling of the transcriptome and metabolome during submergence to facilitate post-submergence recovery.

    Science.gov (United States)

    Locke, Anna M; Barding, Gregory A; Sathnur, Sumukh; Larive, Cynthia K; Bailey-Serres, Julia

    2017-11-02

    The rice (Oryza sativa L.) ethylene-responsive transcription factor gene SUB1A-1 confers tolerance to prolonged, complete submergence by limiting underwater elongation growth. Upon desubmergence, SUB1A-1 genotypes rapidly recover photosynthetic function and recommence development towards flowering. The underpinnings of the transition from stress amelioration to the return to homeostasis are not well known. Here, transcriptomic and metabolomic analyses were conducted to identify mechanisms by which SUB1A improves physiological function over the 24 hr following a sublethal submergence event. Evaluation of near-isogenic genotypes after submergence and over a day of reaeration demonstrated that SUB1A transiently constrains the remodelling of cellular activities associated with growth. SUB1A influenced the abundance of ca. 1,400 transcripts and had a continued impact on metabolite content, particularly free amino acids, glucose, and sucrose, throughout the recovery period. SUB1A promoted recovery of metabolic homeostasis but had limited influence on mRNAs associated with growth processes and photosynthesis. The involvement of low energy sensing during submergence and recovery was supported by dynamics in trehalose-6-phosphate and mRNAs encoding key enzymes and signalling proteins, which were modulated by SUB1A. This study provides new evidence of convergent signalling pathways critical to the rapidly reversible management of carbon and nitrogen metabolism in submergence resilient rice. © 2017 John Wiley & Sons Ltd.

  13. Peculiarities of thermal dissociation of oxides during submerged arc welding

    Directory of Open Access Journals (Sweden)

    Leonid Zhdanov

    2013-12-01

    Full Text Available A method of settlement of the process of thermal dissociation of oxides in reaction zone during the submerged arc welding and welding deposition is presented. Combined non-linear equations for definition of gas-vapour mixture composition were developed. They describe the dissociation of MeO, MeO2 and Me2O3 types of oxides. Calculations of the processes of oxide dissociation were performed for the oxides that are commonly included into welding fluxes. Their results and analysis are presented. The method proposed appeared to be adequate and applicable for analysis of processes during submerged arc operation that run in the gas phase.

  14. EAARL-B Submerged Topography—Saint Croix, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A submerged topography digital elevation model (DEM) mosaic for a portion of the submerged environs of Saint Croix, U.S. Virgin Islands, was produced from remotely...

  15. EAARL-B Submerged Topography--Saint Thomas, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A submerged topography Digital Elevation Model (DEM) mosaic for a portion of the submerged environs of Saint Thomas, U.S. Virgin Islands, was produced from remotely...

  16. Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

    NARCIS (Netherlands)

    Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

    2014-01-01

    Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged

  17. Invasive Crayfish Threaten the Development of Submerged Macrophytes in Lake Restoration

    NARCIS (Netherlands)

    Wal, van der J.E.M.; Dorenbosch, M.; Immers, A.K.; Vidal Forteza, C.; Geurts Van Kessel, J.M.M.; Peeters, E.T.H.M.; Koese, B.; Bakker, E.S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous

  18. Invasive crayfish threaten the development of submerged macrophytes in lake restoration

    NARCIS (Netherlands)

    Van der Wal, J.E.M.; Dorenbosch, M.; Immers, A.; Vidal Forteza, C.; Geurts, J.J.M.; Peeters, E.T.H.M.; Koese, B.; Bakker, E.S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous

  19. Through-flow of water in leaves of a submerged plant is influenced by the apical opening

    DEFF Research Database (Denmark)

    Pedersen, Ole; Jørgensen, Lise Bolt; Sand-Jensen, Kaj

    1997-01-01

    Submerged plant, apical opening, hydathode, Sparganium, hydraulic architecture, leaf specific conductivity......Submerged plant, apical opening, hydathode, Sparganium, hydraulic architecture, leaf specific conductivity...

  20. Hydrogen mitigation in submerged arc welding

    Science.gov (United States)

    Klimowicz, Steven

    With the role of hydrogen in weld metal well understood in its relation to cold cracking, there has been a push to produce welds with lower and lower diffusible hydrogen contents. The push for lower diffusible hydrogen contents has placed pressure on consumables manufactures to create consumables that can achieve the requirements for lower diffusible hydrogen content. Currently EM12K flux is produced so that it can achieve below 4 ml of diffusible hydrogen for every 100g of weld metal deposited (ml/100g) for submerged arc welding (SAW). The recent trend for industry is to preferentially achieve diffusible hydrogen contents below 3 ml/100g. Making it necessary to find a way to modify the flux to achieve a lower diffusible hydrogen content for the welds it produces. To achieve this goal a two phase plan was developed. The first phase was to characterize the entire welding system for hydrogen. Since the goal of the project is hydrogen mitigation, any amount of hydrogen that could be reduced is helpful and therefore must first be discovered. Sources of hydrogen may be found by analyzing the welding wire and base metal, as well as breaking the flux down into its components and production steps. The wire was analyzed for total hydrogen content as was the base metal. The flux and its components were analyzed using differential thermal analysis-simultaneous thermal analysis (DTA-STA) and later vacuum degassing for moisture content. The analysis of the wire showed that the copper coating on the wire was the largest contributor of hydrogen. There was lubricant present on the wire surface as well, but it did not contribute as much as the copper coating. It was found that a simple low temperature baking of the wire was enough to remove the lubricant and coating moisture. The base metal was found to have a similar total hydrogen content to that of the wire. The breakdown of the flux and production process for moisture content analysis revealed that the production process

  1. Predicting the location and spatial extent of submerged coral reef habitat in the Great Barrier Reef world heritage area, Australia.

    Science.gov (United States)

    Bridge, Tom; Beaman, Robin; Done, Terry; Webster, Jody

    2012-01-01

    Coral reef communities occurring in deeper waters have received little research effort compared to their shallow-water counterparts, and even such basic information as their location and extent are currently unknown throughout most of the world. Using the Great Barrier Reef as a case study, habitat suitability modelling is used to predict the distribution of deep-water coral reef communities on the Great Barrier Reef, Australia. We test the effectiveness of a range of geophysical and environmental variables for predicting the location of deep-water coral reef communities on the Great Barrier Reef. Great Barrier Reef, Australia. Maximum entropy modelling is used to identify the spatial extent of two broad communities of habitat-forming megabenthos phototrophs and heterotrophs. Models were generated using combinations of geophysical substrate properties derived from multibeam bathymetry and environmental data derived from Bio-ORACLE, combined with georeferenced occurrence records of mesophotic coral communities from autonomous underwater vehicle, remotely operated vehicle and SCUBA surveys. Model results are used to estimate the total amount of mesophotic coral reef habitat on the GBR. Our models predict extensive but previously undocumented coral communities occurring both along the continental shelf-edge of the Great Barrier Reef and also on submerged reefs inside the lagoon. Habitat suitability for phototrophs is highest on submerged reefs along the outer-shelf and the deeper flanks of emergent reefs inside the GBR lagoon, while suitability for heterotrophs is highest in the deep waters along the shelf-edge. Models using only geophysical variables consistently outperformed models incorporating environmental data for both phototrophs and heterotrophs. Extensive submerged coral reef communities that are currently undocumented are likely to occur throughout the Great Barrier Reef. High-quality bathymetry data can be used to identify these reefs, which may play an

  2. Predicting the location and spatial extent of submerged coral reef habitat in the Great Barrier Reef world heritage area, Australia.

    Directory of Open Access Journals (Sweden)

    Tom Bridge

    Full Text Available AIM: Coral reef communities occurring in deeper waters have received little research effort compared to their shallow-water counterparts, and even such basic information as their location and extent are currently unknown throughout most of the world. Using the Great Barrier Reef as a case study, habitat suitability modelling is used to predict the distribution of deep-water coral reef communities on the Great Barrier Reef, Australia. We test the effectiveness of a range of geophysical and environmental variables for predicting the location of deep-water coral reef communities on the Great Barrier Reef. LOCATION: Great Barrier Reef, Australia. METHODS: Maximum entropy modelling is used to identify the spatial extent of two broad communities of habitat-forming megabenthos phototrophs and heterotrophs. Models were generated using combinations of geophysical substrate properties derived from multibeam bathymetry and environmental data derived from Bio-ORACLE, combined with georeferenced occurrence records of mesophotic coral communities from autonomous underwater vehicle, remotely operated vehicle and SCUBA surveys. Model results are used to estimate the total amount of mesophotic coral reef habitat on the GBR. RESULTS: Our models predict extensive but previously undocumented coral communities occurring both along the continental shelf-edge of the Great Barrier Reef and also on submerged reefs inside the lagoon. Habitat suitability for phototrophs is highest on submerged reefs along the outer-shelf and the deeper flanks of emergent reefs inside the GBR lagoon, while suitability for heterotrophs is highest in the deep waters along the shelf-edge. Models using only geophysical variables consistently outperformed models incorporating environmental data for both phototrophs and heterotrophs. MAIN CONCLUSION: Extensive submerged coral reef communities that are currently undocumented are likely to occur throughout the Great Barrier Reef. High

  3. Proposed gas generation assembly would recover deeply submerged objects

    Science.gov (United States)

    Sprague, C. W.

    1968-01-01

    Gas generation system, used for recovery of submerged objects, generates hydrogen gas by the reaction of sodium with sea water. The assembly consists of flooded flotation tanks cabled together, equipped with relief valves to equalize pressure as the array ascends and hydrostatic pressure diminishes, and carrying remotely activated welding units.

  4. Implementation of Submerged Arc Welding Training. Final Report.

    Science.gov (United States)

    Bowick, Earl; Todd, John

    A unit on submerged arc welding (SAW) was developed and integrated into the welding program at Seattle Central Community College (Washington) during the period December 1983 through May 1984. During this time, 10 major users of SAW in the area were contacted and mailed questionnaires. Follow up consisted of telephone calls and personal contact as…

  5. Benthic Bacterial Diversity in Submerged Sinkhole Ecosystems▿ †

    Science.gov (United States)

    Nold, Stephen C.; Pangborn, Joseph B.; Zajack, Heidi A.; Kendall, Scott T.; Rediske, Richard R.; Biddanda, Bopaiah A.

    2010-01-01

    Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities. PMID:19880643

  6. Effects of submerged and anaerobic fermentations on cassava flour ...

    African Journals Online (AJOL)

    Oke Oluwatoyin Victoria

    2015-03-18

    Mar 18, 2015 ... Cassava tubers for processing into cassava flour, Lafun a Nigerian locally fermented product was subjected to two different types of fermentations: submerged and anaerobic fermentation for 72 h. Physicochemical changes that occurred during fermentation and their influence on the functional, rheological ...

  7. Reactive oxygen species mediate growth and death in submerged plants

    Directory of Open Access Journals (Sweden)

    Bianka eSteffens

    2013-06-01

    Full Text Available Aquatic and semi-aquatic plants are well adapted to survive partial or complete submergence which is commonly accompanied by oxygen deprivation. The gaseous hormone ethylene controls a number of adaptive responses to submergence including adventitious root growth and aerenchyma formation. Reactive oxygen species (ROS act as signaling intermediates in ethylene-controlled submergence adaptation and possibly also independent of ethylene. ROS levels are controlled by synthesis, enzymatic metabolism and nonenzymatic scavenging. While the actors are by and large known, we still have to learn about altered ROS at the subcellular level and how they are brought about, and the signaling cascades that trigger a specific response. This review briefly summarizes our knowledge on the contribution of ROS to submergence adaptation and describes spectrophotometrical, histochemical and live cell imaging detection methods that have been used to study changes in ROS abundance. Electron paramagnetic resonance (EPR spectroscopy is introduced as a method that allows identification and quantification of specific ROS in cell compartments. The use of advanced technologies such as EPR spectroscopy will be necessary to untangle the intricate and partially interwoven signaling networks of ethylene and ROS.

  8. Surface Intermediate Zone of Submerged Turbulent Buoyant Jet in Current

    DEFF Research Database (Denmark)

    Chen, H. B.; Larsen, Torben

    1995-01-01

    This paper deals with the intermediate zone between the jet and plume stages of a submerged buoyant discharge from sea outfall in current. The stability criteria, plume width and height after the intermediate zone and the dilution within the intermediate region have been studied theoretically and...

  9. Effects of prolonged elevated water salinity on submerged ...

    African Journals Online (AJOL)

    environmental change, global warming. * To whom all correspondence should be addressed. e-mail: ian.russell@sanparks.org. Received 9 March 2017; accepted in revised form 10 October 2017. INTRODUCTION. Estuarine submerged macrophyte communities can be highly variable at both spatial and temporal scales, ...

  10. Protein enrichment of cassava peel by submerged fermentation ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... Key words: Cassava peel, Trichoderma viride, enzyme, submerged fermentation, protein, amino acids. INTRODUCTION. Protein-energy malnutrition remains a major public health problem in many developing countries and there is the need to increase daily intake of protein, especially animal protein, using ...

  11. Relationships between the biomass of waterfowl and submerged ...

    African Journals Online (AJOL)

    The Wilderness Lakes system, comprising three estuarine lakes (Eilandvlei, Langvlei and Rondevlei), supports a diverse waterbird community, which includes 12 duck species and the abundant Red-knobbed Coot Fulica cristata. Biannual counts of waterfowl (ducks and Red-knobbed Coot) and assessments of submerged ...

  12. Protein enrichment of cassava peel by submerged fermentation with ...

    African Journals Online (AJOL)

    Protein enrichment of cassava peel by submerged fermentation with Trichoderma viride (ATCC 36316). OO Ezekiel, OC Aworh, HP Blaschek, TC Ezeji. Abstract. Cassava (Manihot esculenta Crantz) peel is one of the solid wastes produced as a consequence of cassava processing. It is low in protein but contains a large ...

  13. Nitrification in a submerged attached growth bioreactor using Luffa ...

    African Journals Online (AJOL)

    A laboratory-scale submerged attached growth bioreactor using Luffa cylindrica as support material for the immobilization of nitrifying bacteria was applied for polishing the effluent of an UASB reactor treating domestic wastewater under the tropical conditions of northeast Brazil, in the City of Campina Grande (7o 13' 11” ...

  14. Effects of submerged vegetation on water clarity across climates

    NARCIS (Netherlands)

    Kosten, S.; Lacerot, G.; Jeppesen, E.; Motta Marques, D.M.L.; Nes, van E.H.; Mazzeo, N.; Scheffer, M.

    2009-01-01

    A positive feedback between submerged vegetation and water clarity forms the backbone of the alternative state theory in shallow lakes. The water clearing effect of aquatic vegetation may be caused by different physical, chemical, and biological mechanisms and has been studied mainly in temperate

  15. Underwater Vehicle

    National Research Council Canada - National Science Library

    Dick, James L

    2007-01-01

    There is thus provided an underwater vehicle having facility for maneuvering alongside a retrieving vehicle, as by manipulation of bow and stern planes, for engaging a hull surface of the retrieving...

  16. Applying the seedling-emergence method under waterlogged conditions to detect the seed bank of aquatic plants in submerged sediments

    NARCIS (Netherlands)

    Boedeltje, G; ter Heerdt, GNJ; Bakker, JP

    Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings

  17. Methods for geothermal reservoir detection emphasizing submerged environments

    Energy Technology Data Exchange (ETDEWEB)

    Case, C.W.; Wilde, P.

    1976-05-21

    This report has been prepared for the California State Lands Commission to aid them in evaluating exploration programs for geothermal reservoirs, particularly in submerged land environments. Three charts show: (1) a logical progression of specific geologic, geochemical, and geophysical exploration techniques for detecting geothermal reservoirs in various geologic environments with emphasis on submerged lands, (2) various exploration techniques which can be used to develop specific information in geothermal areas, and (3) if various techniques will apply to geothermal exploration according to a detailed geologic classification. A narrative in semi-outline form supplements these charts, providing for each technique; a brief description, advantages, disadvantages, special geologic considerations, and specific references. The specific geologic situation will control the exploration criterion to be used for reservoir detection. General guidelines are established which may be of use in evaluating such a program, but the optimum approach will vary with each situation.

  18. Antitumor activity of submerged biomass of Hericium erinaceus

    OpenAIRE

    Avtonomova, A.; Bakanov, A.; Vinokurov, V.; Bukhman, V.; Krasnopolskaya, L.

    2011-01-01

    Submerged cultivation of Hericium erinaceus in various media has been studied. The yield of biomass was shown to depend mainly on the carbon source, whereas the content of watersoluble polysaccharides depended primarily on the nitrogen source. Using optimal medium composition, the biomass yield of 22-23 g/l in 7 days was achieved. The antitumor activity was studied in vivo with using 2 tumor strains. The inhibition ratio of tumor in these experience reached 86%. An exposure of mice with tumor...

  19. Submerged beachrock preservation in the context of wave ravinement

    Science.gov (United States)

    Pretorius, Lauren; Green, Andrew N.; Andrew Cooper, J.

    2018-02-01

    This study examines a Holocene-aged submerged shoreline, Limestone Reef, located in the shallow subtidal zone of South Africa's east coast. It comprises an elongate, coast-oblique, slab-like outcrop of beachrock situated above the contemporary fair-weather wave base. It is currently undergoing mechanical disintegration. Its unique and rare preservation in a high-energy setting affords an opportunity to examine the mechanical processes occurring during wave ravinement associated with rising sea level. The submerged shoreline and the adjacent shoreface were examined using high-resolution seismic reflection, side-scan sonar and shallow-water multibeam echosounding techniques. Limestone Reef rests on top of unconsolidated Holocene deposits. The structure's surface is characterised by reef-perpendicular gullies with rubble derived from the slab fringing its seaward edge. Limestone Reef slopes gently seawards and has a steep landward-facing edge where gullies are most prominently developed. Teardrop-shaped rippled scour depressions, marked by high backscatter, are located seawards of the submerged shoreline. These elongate in a seaward direction and are filled with bioclastic gravels and residual rubble from Limestone Reef. The gullies in the upstanding structure are indicative of wave plucking and abrasion of the shoreline. The material exposed by the rippled scour depressions is identical to that comprising the postglacial ravinement surface identified in the offshore stratigraphy. These deposits are considered to represent the contemporary, actively forming wave ravinement surface. The results suggest that wave ravinement of submerged shorelines is a discontinuous process dominated by the seaward entrainment of material from its landward edge controlled by high-energy drawback during storm surges. The ravinement process appears to operate at the seasonal scale and averages out over the long-term millennial scale for the continuous surface.

  20. Submerged Pagodas of Mahabalipuram - Study based on underwater investigations

    Digital Repository Service at National Institute of Oceanography (India)

    Sundaresh; Gaur, A.S.; Tripati, S.; Vora, K.H.; Rao, K.M.

    - gested that this place could have served as an ancient port (Dayalan, 1992). Mahabalipuram was well known to earlier mariners as 'Seven Pagodas' since the 1 7h century AD. it is generally believed that out of 7 temples originally con- structed, all... based on the local traditions and available literature. The local tradition and the people of Mahabalipuram believe that five temples similar to the Shore Temple have been submerged in the sea. On the basis of local traditions Ancient Tamil...

  1. Instrumentation, control, and automation for submerged anaerobic membrane bioreactors

    OpenAIRE

    Robles Martínez, Ángel; Durán Pinzón, Freddy; Ruano García, María Victoria; Ribes Bertomeu, José; Rosado Muñoz, Alfredo; SECO TORRECILLAS, AURORA; Ferrer, J.

    2015-01-01

    A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON® , Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on off and PID algorithms were implemented to control the follo...

  2. Foreign Vehicles

    Science.gov (United States)

    1994-04-01

    3 4.19 Broadband Electromagnetic Interference ...... ........ 3 4.20 Gun Control Systems for Vehicle-Mounted Weapons...accordance with TOP 2-2-61333. 4.20 Gun Control Systems for Vehicle-Mounted Weapons. Characterize the angular-displacement type control handle used in tank...Main Weapon Firing Tests. Determine the ability of the test vehicle’s main armament and fire/ gun control system to hit its target. a. Artillery

  3. On the submerging of a spherical intruder into granular beds

    Science.gov (United States)

    Wu, Chuan-Yu; Zhang, Ling; Chen, Lan

    2017-06-01

    Granular materials are complex systems and their mechanical behaviours are determined by the material properties of individual particles, the interaction between particles and the surrounding media, which are still incompletely understood. Using an advanced discrete element method (DEM), we simulate the submerging process of a spherical projectile (an intruder) into granular materials of various properties with a zero penetration velocity (i.e. the intruder is touching the top surface of the granular bed and released from stationary) and examine its settling behaviour. By systematically changing the density and size of the intruder and the particle density (i.e. the density of the particles in the granular bed), we find that the intruder can sink deep into the granular bed even with a zero penetration velocity. Furthermore, we confirm that under certain conditions the granular bed can behave like a Newtonian liquid and the submerging intruder can reach a constant velocity, i.e. the terminal velocity, identical to the settling of a sphere in a liquid, as observed experimentally. A mathematical model is also developed to predict the maximum penetration depth of the intruder. The model predictions are compared with experimental data reported in the literature,good agreement was obtained, demonstrating the model can accurately predict the submerging behaviour of the intruder in the granular media.

  4. Research efforts for detection and recovery of submerged oil

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, K. [United States Coast Guard, Groton, CT (United States). Research and Development Center

    2009-07-01

    Submerged oil can sink and destroy shellfish and other marine populations in addition to causing closure of water intakes at industrial facilities and power plants. However, current methods to find and recover oil from spills involving submerged oil are inadequate. The underwater environment presents major challenges such as poor visibility, difficulty in tracking oil spill movement, colder temperatures, inadequate containment methods and problems with the equipment's interaction with water. This paper reported on a multi-year project launched by the Research and Development Center of the United States Coast Guard to develop a complete approach for spills of submerged oil. The project involved detection technologies and recovery methods for oil on the bottom of any body of water. Proof of concept (POC) and prototype tests of potential detection technologies were evaluated during tests at the Ohmsett facility in Leonardo, New Jersey. The technologies included sonar, laser fluorometry, real-time mass spectrometry and in-situ fluorometry. This paper described the development of a complete specification for an integrated recovery system along with a plan for future development. 9 refs., 2 tabs., 11 figs.

  5. Production of Alpha Amylase by Bacillus cereus in Submerged Fermentation

    Directory of Open Access Journals (Sweden)

    Helen H. Raplong

    2014-09-01

    Full Text Available Microorganisms have the ability to secrete enzymes when they are grown in the presence of certain substrates. Amylases are among the most important industrial enzymes and are of great significance in biotechnological studies. Bacteria belonging to the genus Bacillus were isolated using mannitol egg yolk polymyxin B (MYP agar a highly selective media for Bacillus cereus isolation. The isolates were tested for α-amylase production on nutrient agar supplemented with starch and in submerged fermentation. The bacteria isolated and identified (using the Microgen Bacillus identification kit were all Bacillus cereus and SB2 had the largest zone of hydrolysis of 12mm on nutrient agar supplemented with starch as well as the highest enzyme activity of 1.62U/ml. Amylase activity of 2.56U/ml was obtained after 24 hours incubation in submerged fermentation. When amylase enzyme production parameters where optimized, maximum amylase activity was obtained at a pH of 6.5, temperature of 350C, incubation time of 24 hours and 4% inoculums concentration. Bacillus cereus SB2 is a potential isolate for alpha-amylase production with soluble starch as the sole carbon source in submerged fermentation.

  6. On the submerging of a spherical intruder into granular beds

    Directory of Open Access Journals (Sweden)

    Wu Chuan-Yu

    2017-01-01

    Full Text Available Granular materials are complex systems and their mechanical behaviours are determined by the material properties of individual particles, the interaction between particles and the surrounding media, which are still incompletely understood. Using an advanced discrete element method (DEM, we simulate the submerging process of a spherical projectile (an intruder into granular materials of various properties with a zero penetration velocity (i.e. the intruder is touching the top surface of the granular bed and released from stationary and examine its settling behaviour. By systematically changing the density and size of the intruder and the particle density (i.e. the density of the particles in the granular bed, we find that the intruder can sink deep into the granular bed even with a zero penetration velocity. Furthermore, we confirm that under certain conditions the granular bed can behave like a Newtonian liquid and the submerging intruder can reach a constant velocity, i.e. the terminal velocity, identical to the settling of a sphere in a liquid, as observed experimentally. A mathematical model is also developed to predict the maximum penetration depth of the intruder. The model predictions are compared with experimental data reported in the literature,good agreement was obtained, demonstrating the model can accurately predict the submerging behaviour of the intruder in the granular media.

  7. Research on water-exit and take-off process for Morphing Unmanned Submersible Aerial Vehicle

    Science.gov (United States)

    Hu, Jun-hua; Xu, Bao-wei; Feng, Jin-fu; Qi, Duo; Yang, Jian; Wang, Cong

    2017-04-01

    This paper presents a theoretic implementation method of Morphing Unmanned Submersible Aerial Vehicle (MUSAV), which can both submerge in the water and fly in the air. Two different shapes are put forward so that the vehicle can suit both submergence and flight, considering the tremendous differences between hydrodynamic configuration and aerodynamic configuration of a vehicle. The transition of the two shapes can be achieved by using morphing technology. The water-to-air process, including water-exit, morphing, take-off and steady flight, is analyzed. The hydrodynamic and aerodynamic model of the vehicle exiting the water surface obliquely and then taking off into the air has been founded. The control strategy after morphing is analyzed and the control method is given. Numerical method is used to validate the motion model of the water-exit process. Results of simulations show the validity of the proposed model and the feasibility of MUSAV in theory.

  8. Antioxidant Properties of the Edible Basidiomycete Armillaria mellea in Submerged Cultures

    OpenAIRE

    Lung, Ming-Yeou; Chang, Yu-Cheng

    2011-01-01

    Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from dried mycelia (MEM) and mycelia-free broth (MEB) and hot water extracts from dried mycelia (HWEM) by A. mellea submerged cultures show good antioxidant properties as ...

  9. Enhanced effects of biotic interactions on predicting multispecies spatial distribution of submerged macrophytes after eutrophication

    OpenAIRE

    Song, Kun; Cui, Yichong; Zhang, Xijin; Pan, Yingji; Xu, Junli; Xu, Kaiqin; Da, Liangjun

    2017-01-01

    Abstract Water eutrophication creates unfavorable environmental conditions for submerged macrophytes. In these situations, biotic interactions may be particularly important for explaining and predicting the submerged macrophytes occurrence. Here, we evaluate the roles of biotic interactions in predicting spatial occurrence of submerged macrophytes in 1959 and 2009 for Dianshan Lake in eastern China, which became eutrophic since the 1980s. For the four common species occurred in 1959 and 2009,...

  10. GigaUnit Transplant System: A New Mechanical Tool for Transplanting Submerged Aquatic Vegetation

    National Research Council Canada - National Science Library

    Shafer, Deborah J

    2008-01-01

    Submerged aquatic vegetation (SAV) performs many important ecosystem functions, including wave attenuation and sediment stabilization, water quality improvement, primary production, food web support for secondary consumers...

  11. Restoring Ecological Function to a Submerged Salt Marsh

    Science.gov (United States)

    Stagg, C.L.; Mendelssohn, I.A.

    2010-01-01

    Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase marsh surface elevation, thus ameliorating effects of excessive inundation. Although this technique is growing in popularity, the restoration of ecological function after sediment addition has received little attention. To determine if sediment subsidized salt marshes are functionally equivalent to natural marshes, we examined above- and belowground primary production in replicated restored marshes receiving four levels of sediment addition (29-42 cm North American Vertical Datum of 1988 [NAVD 88]) and in degraded and natural ambient marshes (4-22 cm NAVD 88). Moderate intensities of sediment-slurry addition, resulting in elevations at the mid to high intertidal zone (29-36 cm NAVD 88), restored ecological function to degraded salt marshes. Sediment additions significantly decreased flood duration and frequency and increased bulk density, resulting in greater soil drainage and redox potential and significantly lower phytotoxic sulfide concentrations. However, ecological function in the restored salt marsh showed a sediment addition threshold that was characterized by a decline in primary productivity in areas of excessive sediment addition and high elevation (>36 cm NAVD 88). Hence, the addition of intermediate levels of sediment to submerging salt marshes increased marsh surface elevation, ameliorated impacts of prolonged inundation, and increased primary productivity. However, too much sediment resulted in diminished ecological function that was equivalent to the submerged or degraded system. ?? 2010 Society for Ecological Restoration International.

  12. Enhanced Sorbitol Production under Submerged Fermentation using Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Khan Nadiya Jan

    2017-04-01

    Full Text Available Background and Objective: Sorbitol is a non-toxic and slightly hygroscopic compound with different applications. Zymomonas mobiles produces sorbitol from sucrose or mixtures of glucose and fructose (formation is coupled with the dehydrogenation of glucose to glucono-δ- lactone. Recombinant Zymomonas mobilis may produce sorbitol and gluconic acid from glucose and fructose using different divalent metal ions with reduced the ethanol yield andsignificantly increased yield of sorbitol. Current study envisaged to alter the media components, physical process parameters and supplementation of amino acids for enhanced sorbitol production.Material and Methods: Several process variables were evaluated on sorbitol production including carbon sources (glucose, fructose, maltose, sucrose, carbon concentrations (5, 10, 20 and 25 g l-1, nitrogen sources (peptone, tryptone, yeast extract, beef extract and organic nitrogen mix, temperatures (25, 29, 33, 37, 41°C, pH (6, 6.5, 7 , 7.5 ,8, agitation rate (50, 100, 150, 200 rpm and amino acids (cysteine, cystine, tryptophanin batch cultivation ofLactobacillus plantarum NCIM 2912. Shake flask cultivation performed under optimum conditions like temperature 37°C, pH 7.0 and agitation rate of 150 rpm, resulted in enhanced sorbitol production. Comparative study of sorbitol production in solid state fermentation and submerged fermentation was also evaluated.Results and Conclusion: Batch cultivation under submerged conditions further performed in 7.5-l lab scale bioreactor (working volume 3.0-l under optimized conditions resulted in maximum cell biomass of 8.95±0.03 g g-1 and a sorbitol content of 9.78±0.04 g l-1 after 42.0 h of fermentation. Scale up study on bioreactor resulted in maximum sorbitol yield (Yp/x and productivity of 1.11 g g-1 and 0.50 g l-1 h under submerged fermentation, respectively.Conflict of interest: The authors declare no conflict of interest.

  13. Thickness mapping of submerged portions of a BWR torus using an ROV

    Energy Technology Data Exchange (ETDEWEB)

    Somers, T. (Marquest Group, Inc., Bourne, MA (United States)); Bagley, J.G. (Ebasco Quality Services, South Kearny, NJ (United States))

    1992-01-01

    A methodology has been developed for establishing an ultrasonic baseline of the submerged portions of a boiling water reactor torus shell. A remotely operated vehicle (ROV) is equipped to deliver an array of ultrasonic thickness transducers to within a fixed stand-off from the shell. The position of the transducers at each ultrasound reading is measured and recorded using a precision acoustic navigation system. The resulting thickness contour map makes it possible to visualize the condition of the torus shell and provides quantitative documentation of shell thickness at a large number of known locations. The navigation system can be reinstalled in the future so that by comparing future thickness readings acquired at the same location, it is possible to create a map of the rate of change in shell thickness. An ultrasonic thickness survey was conducted recently using a preliminary version of such a system. The experience gained in performing this survey has been incorporated in the design of a full-scale prototype system, which is currently under development. This system will include such features as automatic control of the ROV based on the acoustic navigation data, generation of three-dimensional thickness maps, and remote control of the data acquisition process from outside the radiation area.

  14. [Genetic algorithm for fermentation kinetics of submerged fermentation by Morchella].

    Science.gov (United States)

    Wang, Ying; Piao, Meizi; Sun, Yonghai

    2008-08-01

    Fermentation kinetics is important for optimizing control and up-scaling fermentation process. We studied submerged fermentation kinetics of Morchella. Applying the genetic Algorithm in the Matlab software platform, we compared suitability of the Monod and Logistic models, both are commonly used in process of fungal growth, to describe Morchella growth kinetics. Meanwhile, we evaluated parameters involved in the models for Morchella growth, EPS production and substrate consumption. The results indicated that Logistic model fit better with the experimental data. The average error of this model was 5.8%. This kinetics model can be useful for optimizing and up-scaling fungal fermentation process.

  15. Liquid Film Diffusion on Reaction Rate in Submerged Biofilters

    DEFF Research Database (Denmark)

    Christiansen, Pia; Hollesen, Line; Harremoës, Poul

    1995-01-01

    Experiments were carried out in order to investigate the influence of liquid film diffusion on reaction rate in a submerged biofilter with denitrification and in order to compare with a theoretical study of the mass transfer coefficient. The experiments were carried out with varied flow, identified...... by the empty bed velocity of inflow and recirculation, respectively 1.3, 2.8, 5.6 and 10.9 m/h. The filter material consisted of 3 mm biostyren spheres. The results indicate that the influence of liquid film diffusion on reaction rate can be ignored....

  16. Slag Metal Reactions during Submerged Arc Welding of Alloy Steels

    Science.gov (United States)

    Mitra, U.; Eagar, T. W.

    1984-01-01

    The transfer of Cr, Si, Mn, P, S, C, Ni, and Mo between the slag and the weld pool has been studied for submerged arc welds made with calcium silicate and manganese silicate fluxes. The results show a strong interaction between Cr and Si transfer but no interaction with Mn. The manganese silicate flux produces lower residual sulfur while the calcium silicate fluxes are more effective for removal of phosphorus. The effective oxygen reaction temperature lies between 1700 and 2000 °C for all elements studied. Evidence of Cr and Mn loss by metal vaporization is also presented.

  17. Abandoned vehicles

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  18. Cathodic disbonding of organic coatings on submerged steel

    Energy Technology Data Exchange (ETDEWEB)

    Knudsen, Ole oeystein

    1998-12-31

    In offshore oil production, submerged steel structures are commonly protected by an organic coating in combination with cathodic protection. The main advantage is that the coating decreases the current demand for cathodic protection. But the coating degrades with time. This thesis studies one of the most important mechanisms for coating degradation in seawater, cathodic disbonding. Seven commercial coatings and two model coatings with various pigmentations have been studied. Parameter studies, microscopy and studies of free films were used in the mechanism investigations. Exposure to simulated North Sea conditions was used in the performance studies. The effect of aluminium and glass barrier pigments on cathodic disbonding was investigated. The mechanism for the effect of the aluminium pigments on cathodic disbonding was also investigated. The transport of charge and oxygen to the steel/coating interface during cathodic disbonding was studied for two epoxy coatings. Cathodic disbonding, blistering and current demand for cathodic protection was measured for nine commercial coatings for submerged steel structures, using the ASTM-G8 standard test and a long term test under simulated North Sea conditions. The relevance of the ASTM-G8 test as a prequalification test was evaluated. 171 refs., 40 figs., 6 tabs.

  19. Period Doubling in Bubbling from a Submerged Nozzle

    Science.gov (United States)

    Dennis, Jordan; Grace, Laura; Lehman, Susan

    The timing of bubbles rising from a nozzle submerged in a viscous solution was measured to examine the period-doubling route to chaos in this system. A narrow nozzle was submerged in a mixture of water and glycerin, and nitrogen was supplied to the nozzle at a varying flow rate. The bubbles were detected using a laser and photodiode system; when the bubbles rise through the laser beam, they scatter the light so that the signal at the photodiode decreases. The period between bubbles as well as the duration of each bubble (a function of bubble size and bubble velocity) was determined, and examined as the nitrogen flow rate increased, for solutions with five different concentrations of glycerin. Bubbles were also recorded visually using a high-speed camera. Within the flow rates tested, we observed a bifurcation of the period to period-2 behavior for all solutions tested, and a further bifurcation to period-4 for all solutions except pure glycerin. The solution viscosity affected both the onset of the bifurcation and the precise bubble behavior during the bifurcation. Unusually, a short period/long period pair of bubbles recurring at a regular interval was sometimes observed in the low flow regime which is typically period-1, an observation which requires further investigation. Research supported by NSF DMR 1560093.

  20. Magnetic imaging of a submerged Roman harbour, Caesarea Maritima, Israel

    Science.gov (United States)

    Boyce, J. I.; Reinhardt, E. G.; Raban, A.; Pozza, M. R.

    2003-04-01

    The harbour built by King Herod's engineers at Caesarea represented a major advance in Roman harbour construction that incorporated the use of large (390 m^3), form-filled hydraulic concrete blocks to build an extensive foundation for the harbour moles and breakwater barriers. Marine geophysical surveys were recently conducted across the submerged harbour in an attempt to map the configuration of the buried concrete foundation. A total of 107 line km of high-resolution marine magnetic surveys (nominal 15 m line separations) and bathymetry data were acquired over a 1 km^2 area of the submerged harbour using an Overhauser marine magnetometer, integrated DGPS and single-beam (200 KHz) echosounder. The feasibility of magnetic detection of the concrete was established before the survey by magnetic susceptibility testing of concrete core samples. All concrete samples contained appreciable amounts of fe-oxide-rich volcanic ash ('pozzolana') and showed uniformly high susceptibility values (k > 10^-^4 cgs) when compared to harbour bottom sediments and building stones (k construction of the harbour moles and quays.

  1. THE INFLUENCE OF SUBMERGED MACROPHYTES ON SEDIMENTARY DIATOM ASSEMBLAGES(1).

    Science.gov (United States)

    Vermaire, Jesse C; Prairie, Yves T; Gregory-Eaves, Irene

    2011-12-01

    Submerged macrophytes are a central component of lake ecosystems; however, little is known regarding their long-term response to environmental change. We have examined the potential of diatoms as indicators of past macrophyte biomass. We first sampled periphyton to determine whether habitat was a predictor of diatom assemblage. We then sampled 41 lakes in Quebec, Canada, to evaluate whether whole-lake submerged macrophyte biomass (BiomEpiV) influenced surface sediment diatom assemblages. A multivariate regression tree (MRT) was used to construct a semiquantitative model to reconstruct past macrophyte biomass. We determined that periphytic diatom assemblages on macrophytes were significantly different from those on wood and rocks (ANOSIM R = 0.63, P macrophyte, nutrient-limited lakes (BiomEpiV ≥525 μg · L(-1) ; total phosphorus [TP] macrophyte, nutrient-limited lakes (BiomEpiV eutrophic lakes (TP ≥35 μg · L(-1) ; six lakes). A semiquantitative model correctly predicted the MRT group of the lake 71% of the time (P macrophytes have a significant influence on diatom community structure and that sedimentary diatom assemblages can be used to infer past macrophyte abundance. © 2011 Phycological Society of America.

  2. Wait or escape? Contrasting submergence tolerance strategies of Rorippa amphibia, Rorippa sylvestris and their hybrid

    NARCIS (Netherlands)

    Akman, M.; Bhikharie, A.V.; McLean, E.H.; Boonman, A.; Visser, E.J.W.; Schranz, M.E.; van Tienderen, P.H.

    2012-01-01

    Background and Aims Differential responses of closely related species to submergence can provide insight into the evolution and mechanisms of submergence tolerance. Several traits of two wetland species from habitats with contrasting flooding regimes, Rorippa amphibia and Rorippa sylvestris, as well

  3. Growth rate, protein:RNA ratio and stoichiometric homeostasis of submerged macrophytes under eutrophication stress

    OpenAIRE

    Xing W.; Shi Q.; Liu H.; Liu G.

    2016-01-01

    Growth rate hypothesis (GRH) and stoichiometric homeostasis of photoautotrophs have always been questioned. However, little is known about GRH and stoichiometric homeostasis of aquatic plants, especially submerged macrophytes. Therefore, we aim to test the GRH and explore stoichiometric homeostasis of four freshwater submerged macrophytes under eutrophication stress. At the single species level and the multi-species level, N:P ratios ...

  4. Evidence of shoreline shift on the northern Saurashtra coast: Study based on the submerged temple complex at Pindara

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh

    . It is difficult to assign a particular reason for the submergence of the temple in discussion, however minor sea level rise and seismic activity might have played a vital role in submergence of the temple complex....

  5. Submerged beach ridge lineation and associated sedentary fauna in the innershelf of Gopalpur Coast, Orissa, Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, K.M.; Murthy, K.S.R.; Reddy, N.P.C.; Subrahmanyam, A.S.; Lakshminarayana, S.; Rao, M.M.M.; Sarma, K.V.L.N.S.; Premkumar, M.K.; Sree, A.; Bapuji, M.

    . (e - mail: kmrao@kadali.nio.org) RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 81, NO. 7, 10 OCTOBER 2001 829 mic profiling to locate the submerged roc k outcrops. Though the submerged topographic features were r e por - ted by some...

  6. EAARL-B Submerged Topography–Saint Croix, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A submerged topography Digital Elevation Model (DEM) mosaic for a portion of the submerged environs of Saint Croix, U.S. Virgin Islands, was produced from remotely...

  7. THE STUDY ON THE DURABILITY OF SUBMERGED STRUCTURE DISPLACEMENT DUE TO CONCRETE FAILURE

    Directory of Open Access Journals (Sweden)

    M. Mohd

    2016-09-01

    Full Text Available Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures.

  8. [Effects of light on submerged macrophytes in eutrophic water: research progress].

    Science.gov (United States)

    Li-Sha, Zou; Ze-Yu, Nie; Xiao-Yan, Yao; Ji-Yan, Shi

    2013-07-01

    The restoration of submerged macrophytes is the key to remediate eutrophic water and maintain the health of aquatic ecosystem, while light is the main limiting factor. This paper summarized the factors affecting the light extinction in water and the mechanisms of light intensity affecting the physiology of submerged macrophytes, with the focuses on the metabolic mechanisms of carbon, nitrogen, and phosphorus, the responses of antioxidant enzyme system, and the feedbacks of pigment composition and concentration in the common submerged macrophytes under low light stress. Several engineering techniques applied in the ecological restoration of submerged macrophytes were presented, and the framework of the restoration of submerged macrophytes in eutrophic water was proposed. Some problems in current research and several suggestions on future research were addressed, which could help the related research and engineering practices.

  9. Pimestavalt valge - nagu piim / Alvin Wiberg

    Index Scriptorium Estoniae

    Wiberg, Alvin

    2007-01-01

    Kunstnikud Patric Leo ja Maria Hurtig ehitasid Stockholmi lõunaosa vanast piimapoest endale kodu ja ateljee. Pimestavalt valged seinad ja laed, otstarbekad lahendused ja tippklassi tehnika. 10 värv. ill.

  10. Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods

    DEFF Research Database (Denmark)

    Herzog, Max; Konnerup, Dennis; Pedersen, Ole

    2018-01-01

    Floods and salinization of agricultural land adversely impact global rice production. We investigated whether gas films on leaves of submerged rice delay salt entry during saline submergence. Two-week-old plants with leaf gas films (+GF) or with gas films experimentally removed (-GF) were submerg...

  11. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-11

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  12. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  13. Critical Assessment of Temperature Distribution in Submerged Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Vineet Negi

    2013-01-01

    Full Text Available Temperature distribution during any welding process holds the key for understanding and predicting several important welding attributes like heat affected zone, microstructure of the weld, residual stress, and distortion during welding. The accuracy of the analytical approaches for modeling temperature distribution during welding has been constrained by oversimplified assumptions regarding boundary conditions and material properties. In this paper, an attempt has been made to model the temperature distribution during submerged arc welding process using finite element modeling technique implemented in ANSYS v12. In the present analysis, heat source is assumed to be double-ellipsoidal with Gaussian volumetric heat generation. Furthermore, variation of material properties with temperature and both convective and radiant heat loss boundary condition have been considered. The predicted temperature distribution is then validated against the experimental results obtained by thermal imaging of the welded plate, and they are found to be in a good agreement.

  14. Arc characteristics of submerged arc welding with stainless steel wire

    Science.gov (United States)

    Li, Ke; Wu, Zhi-sheng; Liu, Cui-rong; Chen, Feng-hua

    2014-08-01

    The arc characteristics of submerged arc welding (SAW) with stainless steel wire were studied by using Analysator Hannover (AH). The tests were carried out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution (PDD) curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.

  15. Numerical study on tsunami hazard mitigation using a submerged breakwater.

    Science.gov (United States)

    Ha, Taemin; Yoo, Jeseon; Han, Sejong; Cho, Yong-Sik

    2014-01-01

    Most coastal structures have been built in surf zones to protect coastal areas. In general, the transformation of waves in the surf zone is quite complicated and numerous hazards to coastal communities may be associated with such phenomena. Therefore, the behavior of waves in the surf zone should be carefully analyzed and predicted. Furthermore, an accurate analysis of deformed waves around coastal structures is directly related to the construction of economically sound and safe coastal structures because wave height plays an important role in determining the weight and shape of a levee body or armoring material. In this study, a numerical model using a large eddy simulation is employed to predict the runup heights of nonlinear waves that passed a submerged structure in the surf zone. Reduced runup heights are also predicted, and their characteristics in terms of wave reflection, transmission, and dissipation coefficients are investigated.

  16. Numerical Study on Tsunami Hazard Mitigation Using a Submerged Breakwater

    Directory of Open Access Journals (Sweden)

    Taemin Ha

    2014-01-01

    Full Text Available Most coastal structures have been built in surf zones to protect coastal areas. In general, the transformation of waves in the surf zone is quite complicated and numerous hazards to coastal communities may be associated with such phenomena. Therefore, the behavior of waves in the surf zone should be carefully analyzed and predicted. Furthermore, an accurate analysis of deformed waves around coastal structures is directly related to the construction of economically sound and safe coastal structures because wave height plays an important role in determining the weight and shape of a levee body or armoring material. In this study, a numerical model using a large eddy simulation is employed to predict the runup heights of nonlinear waves that passed a submerged structure in the surf zone. Reduced runup heights are also predicted, and their characteristics in terms of wave reflection, transmission, and dissipation coefficients are investigated.

  17. Phytoremediation of arsenic in submerged soil by wetland plants.

    Science.gov (United States)

    Jomjun, Nateewattana; Siripen, Trichaiyaporn; Maliwan, Saeouy; Jintapat, Nateewattana; Prasak, Thavornyutikarn; Somporn, Choonluchanon; Petch, Pengchai

    2011-01-01

    Wetland aquatic plants including Canna glauca L., Colocasia esculenta L. Schott, Cyperus papyrus L. and Typha angustifolia L. were used in the phytoremediation of submerged soil polluted by arsenic (As). Cyperus papyrus L. was noticed as the largest biomass producer which has arsenic accumulation capacity of 130-172 mg As/kg plant. In terms of arsenic removal rate, however, Colocasia esculenta L. was recognized as the largest and fastest arsenic remover in this study. Its arsenic removal rate was 68 mg As/m2/day while those rates of Canna glauca L., Cyperus papyrus L. and Typha angustifolia L. were 61 mg As/m2/day, 56 mg As/m2/day, and 56 mg As/m2/day, respectively. Although the 4 aquatic plants were inferior in arsenic accumulation, their high arsenic removal rates were observed. Phytostabilization should be probable for the application of these plants.

  18. Minimizing downstream scour due to submerged hydraulic jump using corrugated

    Directory of Open Access Journals (Sweden)

    Hossam Mohamed Ali

    2014-12-01

    Full Text Available Local scour downstream of hydraulic structures due to hydraulic jump is considered one of the tedious and complicated problems facing their stability. Throughout this paper, an experimental study was conducted to study the effect of using different spaced corrugated aprons on the downstream local scour due to submerged jump. Sixty runs were carried out in a horizontal rectangular flume to determine the optimal corrugation wavelength which minimizing the scour. A case of flat apron included to estimate the influence of corrugated aprons on scour holes dimensions. Two types of non-cohesive soil were used. Experiments were performed for a range of Froude numbers between 1.68 and 9.29. The results showed that using spaced triangular corrugated aprons minimize the scour depth and length of fine sand by average percentage of 63.4% and 30.2%, respectively and for coarse sand by 44.2% and 20.6% in comparing with classical jump.

  19. Microbial production of four biodegradable siderophores under submerged fermentation.

    Science.gov (United States)

    Fazary, Ahmed E; Al-Shihri, Ayed S; Alfaifi, Mohammad Y; Saleh, Kamel A; Alshehri, Mohammed A; Elbehairi, Serag Eldin I; Ju, Yi-Hsu

    2016-07-01

    Four siderophore analogues were isolated and purified from Escherichia coli, Bacillus spp. ST13, and Streptomyces pilosus microorganisms under some specific submerged fermentation conditions. In order to evaluate the highest production of this siderophore analogues through the growth, a rapid spectrophotometric screening semi-quantitative method was used, in which interestingly the analogues were isolated in its own form not its iron chelate. After chromatographic separation, the chemical structures of the isolated and purified siderophores were illustrated using detailed spectroscopic techniques. The biodegradation studies were done on that four novel isolated and purified siderophores following OECD protocols. In addition, the bioactivities of these siderophores and their iron complexes were examined and evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Development of Submerged Entry Nozzles that Resist Clogging

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Jeffrey D. Smith; Kent D. Peasle

    2002-10-14

    Accretion formation and the associated clogging of SENs is a major problem for the steel industry leading to decreased strand speed, premature changing of SENs or strand termination and the associated reductions in productivity, consistency, and steel quality. A program to evaluate potentially clog resistance materials was initiated at the University of Missouri-Rolla. The main objective of the research effort was to identify combinations of steelmaking and refractory practices that would yield improved accretion resistance for tundish nozzles and submerged entry nozzles. A number of tasks were identified during the initial kick-off meeting and each was completed with two exceptions, the thermal shock validation and the industrial trials. Not completing these two tasks related to not having access to industrial scale production facilities. Though much of the results and information generated in the project is of proprietary nature.

  1. Slag-metal equilibrium during submerged arc welding

    Science.gov (United States)

    Chai, C. S.; Eagar, T. W.

    1981-09-01

    A thermodynamic model of the equilibria existing between the slag and the weld metal during submerged arc welding is presented. As formulated, the model applies only to fused neutral fluxes containing less than 20 pct CaF2, however some results indicate that the model may be useful in more general cases as well. The model is shown to be capable of predicting the gain or loss of both Mn and Si over a wide range of baseplate, electrode and flux compositions. At large deviations from the predicted equilibrium, the experimental results indicate considerable variability in the amount of Mn or Si transferred between the slag and metal phases, while closer to the calculated equilibrium, the extent of metal transfer becomes more predictable. The variability in metal transfer rate at large deviations from equilibrium may be explained by variations between the bulk and the surface concentrations of Mn and Si in both metal and slag phases.

  2. Endodontic Treatment in Submerged Roots: A Case Report

    Directory of Open Access Journals (Sweden)

    Hemalatha Pameshwar Hiremath

    2010-06-01

    Full Text Available Alveolar ridge resorption has long been considered an unavoidable consequence of tooth extraction. While the extent and pattern of resorption is variable among individuals, there is a progressive loss of ridge contour as a result of physiologic bone remodeling. Even today, with best modalities of tooth preservation, there is a group of elderly individuals who do not benefit from modern preventive practices and who now present a dilemma in terms of maintaining the masticatory apparatus necessary for nutrition. Even with excellent dental care, such patients experience abrasion of the natural tooth crowns with age, and embedded roots are left within the alveolar bone. According to old concepts of dental care, extraction of these roots would have been recommended, but today’s goal of excellence in endodontics dictates otherwise. We report a case in which vital and non-vital root submergence was carried out to prevent alveolar ridge reduction.

  3. Development of New Submergence Tolerant Rice Variety for Bangladesh Using Marker-Assisted Backcrossing

    Directory of Open Access Journals (Sweden)

    Khandakar Md Iftekharuddaula

    2015-01-01

    Full Text Available Submergence tolerant high yielding rice variety was developed using BR11 as a recipient parent applying foreground, phenotypic and background selection approaches. Recombinant selection was found essential to minimize linkage drag by BC2F2 generation. Without recombinant selection, the introgression size in the backcross recombinant lines (BRLs was approximately 15 Mb on the carrier chromosome. The BRLs were found submergence tolerance compared to the check varieties under complete submergence for two weeks at Bangladesh Rice Research Institute, and produced higher yield compared to the isogenic Sub1-line under controlled submerged condition. The BRL IR85260-66-654-Gaz2 was released as BRRI dhan52 in 2010, which was the first high yielding submergence tolerant variety in Bangladesh. BRRI dhan52 produced grain yield ranging from 4.2 to 5.2 t/hm2 under different flash flood prone areas of Bangladesh in three consecutive seasons. The study demonstrated the efficiency of recombinant selection and better adaptability of the newly released submergence tolerant high yielding variety in flash flood prone different areas of the country with respect to submergence tolerance and yield potential.

  4. Physiological and transcriptomic characterization of submergence and reoxygenation responses in soybean seedlings.

    Science.gov (United States)

    Tamang, Bishal G; Magliozzi, Joseph O; Maroof, M A Saghai; Fukao, Takeshi

    2014-10-01

    Complete inundation at the early seedling stage is a common environmental constraint for soybean production throughout the world. As floodwaters subside, submerged seedlings are subsequently exposed to reoxygenation stress in the natural progression of a flood event. Here, we characterized the fundamental acclimation responses to submergence and reoxygenation in soybean at the seedling establishment stage. Approximately 90% of seedlings succumbed during 3 d of inundation under constant darkness, whereas 10 d of submergence were lethal to over 90% of seedlings under 12 h light/12 h dark cycles, indicating the significance of underwater photosynthesis in seedling survival. Submergence rapidly decreased the abundance of carbohydrate reserves and ATP in aerial tissue of seedlings although chlorophyll breakdown was not observed. The carbohydrate and ATP contents were recovered upon de-submergence, but sudden exposure to oxygen also induced lipid peroxidation, confirming that reoxygenation induced oxidative stress. Whole transcriptome analysis recognized genome-scale reconfiguration of gene expression that regulates various signalling and metabolic pathways under submergence and reoxygenation. Comparative analysis of differentially regulated genes in shoots and roots of soybean and other plants defines conserved, organ-specific and species-specific adjustments which enhance adaptability to submergence and reoxygenation through different metabolic pathways. © 2014 John Wiley & Sons Ltd.

  5. Submergence induced changes of molecular species in membrane lipids in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Mulan Wang

    2016-06-01

    Full Text Available The composition of membrane lipids is sensitive to environmental stresses. Submergence is a type of stress often encountered by plants. However, how the molecular species of membrane lipids respond to submergence has not yet been characterised. In this study, we used a lipidomic approach to profile the molecular species of membrane lipids in whole plants of Arabidopsis thaliana that were completely submerged for three days. The plants survived one day of submergence, after which, we found that the total membrane lipids were only subtly decreased, showing significant decreases of monogalactosyldiacylglycerol (MGDG and phosphatidylcholine (PC and an increase of phosphatidic acid (PA; however, the basic lipid composition was retained. In contrast, three days of submergence caused plants to die, and the membranes deteriorated via the rapid loss of 96% of lipid content together with a 229% increase in PA. The turnover of molecular species from PG and MGDG to PA indicated that submergence-induced lipid changes occurred through PA-mediated degradation. In addition, molecular species of extraplastidic PG degraded sooner than plastidic ones, lyso-phospholipids exhibited various patterns of change, and the double-bond index (DBI remained unchanged until membrane deterioration. Our results revealed the unique changes of membrane lipids upon submergence and suggested that the major cause of the massive lipid degradation could be anoxia.

  6. The Performance and Fouling Control of Submerged Hollow Fiber (HF Systems: A Review

    Directory of Open Access Journals (Sweden)

    Ebrahim Akhondi

    2017-07-01

    Full Text Available The submerged membrane filtration concept is well-established for low-pressure microfiltration (MF and ultrafiltration (UF applications in the water industry, and has become a mainstream technology for surface-water treatment, pretreatment prior to reverse osmosis (RO, and membrane bioreactors (MBRs. Compared to submerged flat sheet (FS membranes, submerged hollow fiber (HF membranes are more common due to their advantages of higher packing density, the ability to induce movement by mechanisms such as bubbling, and the feasibility of backwashing. In view of the importance of submerged HF processes, this review aims to provide a comprehensive landscape of the current state-of-the-art systems, to serve as a guide for further improvements in submerged HF membranes and their applications. The topics covered include recent developments in submerged hollow fiber membrane systems, the challenges and developments in fouling-control methods, and treatment protocols for membrane permeability recovery. The highlighted research opportunities include optimizing the various means to manipulate the hydrodynamics for fouling mitigation, developing online monitoring devices, and extending the submerged HF concept beyond filtration.

  7. Oxygen absorption by adventitious roots promotes the survival of completely submerged terrestrial plants.

    Science.gov (United States)

    Ayi, Qiaoli; Zeng, Bo; Liu, Jianhui; Li, Siqi; van Bodegom, Peter M; Cornelissen, Johannes H C

    2016-04-10

    Flooding imposes stress upon terrestrial plants because it results in oxygen deficiency, which is considered a major problem for submerged plants. A common response of terrestrial plants to flooding is the formation of aquatic adventitious roots. Some studies have shown that adventitious roots on submerged plants are capable of absorbing water and nutrients. However, there is no experimental evidence for the possible oxygen uptake function of adventitious roots or for how important this function might be for the survival of plants during prolonged submergence. This study aims to investigate whether adventitious roots absorb oxygen from the water column, and whether this new function is beneficial to the survival of completely submerged plants. TakingAlternanthera philoxeroides(Mart.) Griseb. as a representative species, the profiling of the underwater oxygen gradient towards living and dead adventitious roots on completely submerged plants was conducted, the oxygen concentration in stem nodes with and without adventitious roots was measured, and the growth, survival and non-structural carbohydrate content of completely submerged plants with and without adventitious roots was investigated. Oxygen profiles in the water column of adventitious roots showed that adventitious roots absorbed oxygen from water. It is found that the oxygen concentration in stem nodes having adventitious roots was higher than that in stem nodes without adventitious roots, which implies that the oxygen absorbed by adventitious roots from water was subsequently transported from the roots to other plant tissues. Compared with plants whose adventitious roots had been pruned, those with intact adventitious roots had slower leaf shedding, slower plant mass reduction, more efficient carbohydrate economy and prolonged survival when completely submerged. The adventitious roots ofA. philoxeroidesformed upon submergence can absorb oxygen from ambient water, thereby alleviating the adverse effects of

  8. Interaction of Submerged Breakwater by a Solitary Wave Using WC-SPH Method

    Directory of Open Access Journals (Sweden)

    Afshin Mansouri

    2014-01-01

    Full Text Available Interaction of a solitary wave and submerged breakwater is studied in a meshless, Lagrangian approach. For this purpose, a two-dimensional smoothed particle hydrodynamics (SPH code is developed. Furthermore, an extensive set of simulations is conducted. In the first step, the generated solitary wave is validated. Subsequently, the interaction of solitary wave and submerged breakwater is investigated thoroughly. Results of the interaction of solitary wave and a submerged breakwater are also shown to be in good agreement with published experimental studies. Afterwards, the effects of the inclination and length of breakwater as well as distance between two breakwaters are evaluated on damping ratio of breakwater.

  9. Oxygen dynamics during submergence in the halophytic stem succulent Halosarcia pergranulata

    DEFF Research Database (Denmark)

    Pedersen, Ole; Vos, Harrie; Colmer, Timothy David

    2006-01-01

    This study elucidated O2 dynamics in shoots and roots of submerged Halosarcia pergranulata (Salicornioideae), a perennial halophytic stem succulent that grows on flood-prone mudflats of salt lakes. Oxygen within shoots and roots was measured using microelectrodes, for plants when waterlogged...... the roots, at least during the first several hours (the time period measured) after submergence or when light periods followed darkness. The influence of light on tissue O2 dynamics was confirmed in an experiment on a submerged plant in a salt lake in south-western Australia. In the late afternoon, partial...

  10. Traction Drive Inverter Cooling with Submerged Liquid Jet Impingement on Microfinned Enhanced Surfaces (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Waye, S.; Narumanchi, S.; Moreno, G.

    2014-09-01

    Jet impingement is one means to improve thermal management for power electronics in electric-drive traction vehicles. Jet impingement on microfin-enhanced surfaces further augments heat transfer and thermal performance. A channel flow heat exchanger from a commercial inverter was characterized as a baseline system for comparison with two new prototype designs using liquid jet impingement on plain and microfinned enhanced surfaces. The submerged jets can target areas with the highest heat flux to provide local cooling, such as areas under insulated-gate bipolar transistors and diode devices. Low power experiments, where four diodes were powered, dissipated 105 W of heat and were used to validate computational fluid dynamics modeling of the baseline and prototype designs. Experiments and modeling used typical automotive flow rates using water-ethylene glycol as a coolant (50%-50% by volume). The computational fluid dynamics model was used to predict full inverter power heat dissipation. The channel flow and jet impingement configurations were tested at full inverter power of 40 to 100 kW (output power) on a dynamometer, translating to an approximate heat dissipation of 1 to 2 kW. With jet impingement, the cold plate material is not critical for the thermal pathway. A high-temperature plastic was used that could eventually be injection molded or formed, with the jets formed from a basic aluminum plate with orifices acting as nozzles. Long-term reliability of the jet nozzles and impingement on enhanced surfaces was examined. For jet impingement on microfinned surfaces, thermal performance increased 17%. Along with a weight reduction of approximately 3 kg, the specific power (kW/kg) increased by 36%, with an increase in power density (kW/L) of 12% compared with the baseline channel flow configuration.

  11. Effects of submergence on growth and survival of saplings of three wetland trees differing in adaptive mechanisms for flood tolerance

    Directory of Open Access Journals (Sweden)

    Fumiko Iwanaga

    2015-04-01

    Full Text Available Aim of study: Withstanding total submergence and reaeration following submergence is essential for the survival and establishment of wetland species. We focused on “LOES–low oxygen escape syndrome” and “LOQS–low oxygen quiescence syndrome” and compared tolerances to total submergence among wetland woody species differing in morphological adaptation to soil flooding. Area of study, materials and methods: This study examined the survival of 2-year-old saplings of Taxodium distichum and Metasequioia glyptostroboides (LOQS species, and Alnus japonica (LOES species, during and after total submergence. Saplings were completely submerged, then de-submerged to determine trends in survival and growth Main results: The M. glyptostroboides and A. japonica saplings could not survive prolonged submergence for more than 8 weeks, whereas saplings of T. distichum survived for over 2 years. Submerged saplings of all species showed no significant growth or modifications in morphology and anatomy under water, such as shoot elongation, adventitious root formation, and/or aerenchyma development. All T. distichum saplings that were de-submerged in the second year had the same pattern of shoot growth regardless of differences in timing and seasonality of de-submergence. Wood formation in T. distichum saplings ceased during submergence and resumed after de-submergence in spring and summer, but not in autumn. Research highlights: T. distichum saplings, which survived longer submergence periods than A. japonica and M. glyptostroboides, had physiological characteristics, such as suspension of growth and metabolism, which allowed survival of protracted total submergence (at least 2 years when saplings were immersed during the dormant stage before leaf flushing.

  12. Outer Continental Shelf Submerged Lands Act Boundary - Atlantic Region NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains the Submerged Lands Act (SLA) boundary line (also known as State Seaward Boundary (SSB), or Fed State Boundary) in ESRI shapefile formats for...

  13. The Development of a Composite Consumable Insert for Submerged ARC Welding

    National Research Council Canada - National Science Library

    1980-01-01

    .... When the submerged arc process was utilized to weld the butt joint in large flat plate structures, the repositioning of the plate for welding of the reverse side was a costly time consuming procedure...

  14. Meta Modelling of Submerged-Arc Welding Design based on Fuzzy Algorithm

    Science.gov (United States)

    Song, Chang-Yong; Park, Jonghwan; Goh, Dugab; Park, Woo-Chang; Lee, Chang-Ha; Kim, Mun Yong; Kang, Jinseo

    2017-12-01

    Fuzzy algorithm based meta-model is proposed for approximating submerged-arc weld design factors such as weld speed and weld output. Orthogonal array design based on the submerged-arc weld numerical analysis is applied to the proposed approach. The nonlinear finite element analysis is carried out to simulate the submerged-arc weld numerical analysis using thermo-mechanical and temperature-dependent material properties for general mild steel. The proposed meta-model based on fuzzy algorithm design is generated with triangle membership functions and fuzzy if-then rules using training data obtained from the Taguchi orthogonal array design data. The aim of proposed approach is to develop a fuzzy meta-model to effectively approximate the optimized submerged-arc weld factors. To validate the meta-model, the results obtained from the fuzzy meta-model are compared to the best cases from the Taguchi orthogonal array.

  15. Large-Scale Submerged Aquatic Vegetation Restoration in Chesapeake Bay: Status Report, 2003-2006

    National Research Council Canada - National Science Library

    Shafer, Deborah J; Bergstrom, Peter

    2008-01-01

    In 2003, the U.S. Army Engineer Research and Development Center (ERDC) and the National Oceanic and Atmospheric Administration Chesapeake Bay Office began a comprehensive research effort to restore submerged aquatic vegetation (SAV...

  16. Flow Velocity and Morphology of a Submerged Patch of the Aquatic Species

    NARCIS (Netherlands)

    Cornacchia, L.; Licci, S.; van de Koppel, J.; van der Wal, D.; Wharton, G.; Puijalon, S.; Bouma, T.J.

    2016-01-01

    The interaction between macrophytes and hydrodynamic conditions is animportant feature in many aquatic ecosystems. Submerged macrophytes can formmonospecific patches that interact with the flow and alter current velocity; withinthe same vegetation patch, plants are exposed to different levels of

  17. Uncalibrated EAARL-B Submerged Topography--Fort Lauderdale, Florida, 2014 (GEOID12A)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data of a portion of the submerged environs of Fort Lauderdale, Florida, were produced from remotely sensed, geographically referenced elevation...

  18. EAARL-B Submerged Topography - Saint Croix, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII XYZ point cloud data for a portion of the submerged environs of Saint Croix, U.S. Virgin Islands, was produced from remotely sensed, geographically referenced...

  19. EAARL-B Submerged Topography—Crocker Reef, Florida, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII XYZ point cloud data for a portion of the submerged environs of Crocker Reef, Florida, were produced from remotely sensed, geographically referenced elevation...

  20. Calibrated EAARL-B Submerged Topography--Fort Lauderdale, Florida, 2014 (GEOID12A)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data of a portion of the submerged environs of Fort Lauderdale, Florida, were produced from remotely sensed, geographically referenced elevation...

  1. Environmental Assessment: Submerged Aquatic Plant Management of Banks Lake, Banks Lake NWR, Lakeland, Georgia

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Environmental Assessment is an analysis of five alternatives developed to address themanagement of the submerged aquatic plants of Banks Lake on Banks Lake...

  2. Satellite remote sensing of submerged aquatic vegetation distribution and status in the Currituck Sound, NC.

    Science.gov (United States)

    2012-11-01

    Submerged Aquatic Vegetation (SAV) is an important component in any estuarine ecosystem. As such, it is regulated by federal and state agencies as a jurisdictional resource, where impacts to SAV are compensated through mitigation. Historically, tradi...

  3. Root transcript profiling of two Rorippa (brassicaceae) species reveals gene clusters associated with extreme submergence tolerance.

    NARCIS (Netherlands)

    Sasidharan, R.; Mustroph, A.; Boonman, A.; Akman, M.; Ammerlaan, A.M.H.; Breit, T.M.; Schranz, M.E.; Voesenek, L.A.C.J.; Tienderen, van P.H.

    2013-01-01

    Complete submergence represses photosynthesis and aerobic respiration, causing rapid mortality in most terrestrial plants. However, some plants have evolved traits allowing them to survive prolonged flooding, such as species of the genus Rorippa, close relatives of Arabidopsis (Arabidopsis

  4. Root transcript profiling of two Rorippa species reveals gene clusters associated with extreme submergence tolerance

    NARCIS (Netherlands)

    Sasidharan, R.; Mustroph, A.; Boonman, A.; Akman, M.; Ammerlaan, A.M.H.; Breit, T.M.; Schranz, M.E.; Voesenek, L.A.C.J.; van Tienderen, P.H.

    2013-01-01

    Complete submergence represses photosynthesis and aerobic respiration, causing rapid mortality in most terrestrial plants. However, some plants have evolved traits allowing them to survive prolonged flooding, such as species of the genus Rorippa, close relatives of Arabidopsis (Arabidopsis

  5. Swan foraging shapes spatial distribution of two submerged plants, favouring the preferred prey species

    NARCIS (Netherlands)

    Sandsten, H.; Klaassen, M.R.J.

    2008-01-01

    Compared to terrestrial environments, grazing intensity on belowground plant parts may be particularly strong in aquatic environments, which may have great effects on plant-community structure. We observed that the submerged macrophyte, Potamogeton pectinatus, which mainly reproduces with tubers,

  6. EAARL-B Submerged Topography—Saint Thomas, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII XYZ point cloud data for a portion of the submerged environs of Saint Thomas, U.S. Virgin Islands, was produced from remotely sensed, geographically referenced...

  7. Uncalibrated EAARL-B Submerged Topography--Fort Lauderdale, Florida, 2014 (WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data of a portion of the submerged environs of Fort Lauderdale, Florida, were produced from remotely sensed, geographically referenced elevation...

  8. Calibrated EAARL-B Submerged Topography--Fort Lauderdale, Florida, 2014 (WGS84)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data of a portion of the submerged environs of Fort Lauderdale, Florida, were produced from remotely sensed, geographically referenced elevation...

  9. Outer Continental Shelf Submerged Lands Act Boundary - Pacific Region - West Coast NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains the Submerged Lands Act (SLA)boundary line (also known as the State Seaward Boundary (SSB) and Fed State Boundary) for the BOEM Pacific Region...

  10. Process Modeling and Optimization of a Submerged Arc Furnace for Phosphorus Production

    NARCIS (Netherlands)

    Scheepers, E.; Yang, Y.; Adema, A.T.; Boom, R.; Reuter, M.A.

    2010-01-01

    This article presents a process model of a phosphorus-producing, submerged arc furnace. The model successfully incorporates accurate, multifield thermodynamic, kinetic, and industrial data with computational flow dynamic calculations and thus further unifies the sciences of kinetics and equilibrium

  11. EAARL-B Submerged Topography - Saint Croix and Saint Thomas, U.S. Virgin Islands, 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data for part of the submerged environs of Saint Croix and Saint Thomas, U.S. Virgin Islands, were produced from remotely sensed, geographically...

  12. Outer Continental Shelf Submerged Lands Act Boundary - Alaska Region NAD83

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains the Submerged Lands Act (SLA) boundary (also known as State Seaward Boundary (SSB), or Fed State Boundary) in ESRI shapefile format for the...

  13. Tolerance of combined submergence and salinity in the halophytic stem-succulent Tecticornia pergranulata

    DEFF Research Database (Denmark)

    Colmer, T D; Vos, H; Pedersen, Ole

    2009-01-01

    in waters of high salinity. A 'quiescence response', i.e. no shoot growth, would conserve carbohydrates, but tissue sugars still declined with time. A low K(+) : Na(+) ratio, typical for tissues of succulent halophytes, was tolerated even during prolonged submergence, as evidenced by maintenance......BACKGROUND AND AIMS: Habitats occupied by many halophytes are not only saline, but are also prone to flooding. Few studies have evaluated submergence tolerance in halophytes. METHODS: Responses to submergence, at a range of salinity levels, were studied for the halophytic stem-succulent Tecticornia...... pergranulata subsp. pergranulata (syn. Halosarcia pergranulata subsp. pergranulata). Growth and total sugars in succulent stems were assessed as a function of time after submergence. Underwater net photosynthesis, dark respiration, total sugars, glycinebetaine, Na(+), Cl(-) and K(+), in succulent stems, were...

  14. Dynamic Response Analysis of Cable of Submerged Floating Tunnel under Hydrodynamic Force and Earthquake

    Directory of Open Access Journals (Sweden)

    Zhiwen Wu

    2017-01-01

    Full Text Available A simplified analysis model of cable for submerged floating tunnel subjected to parametrically excited vibrations in the ocean environment is proposed in this investigation. The equation of motion of the cable is obtained by a mathematical method utilizing the Euler beam theory and the Galerkin method. The hydrodynamic force induced by earthquake excitations is formulated to simulate real seaquake conditions. The random earthquake excitation in the time domain is formulated by the stochastic phase spectrum method. An analytical model for analyzing the cable for submerged floating tunnel subjected to combined hydrodynamic forces and earthquake excitations is then developed. The sensitivity of key parameters including the hydrodynamic, earthquake, and structural parameters on the dynamic response of the cable is investigated and discussed. The present model enables a preliminary examination of the hydrodynamic and seismic behavior of cable for submerged floating tunnel and can provide valuable recommendations for use in design and operation of anchor systems for submerged floating tunnel.

  15. EAARL-B submerged topography: Barnegat Bay, New Jersey, pre-Hurricane Sandy, 2012

    Science.gov (United States)

    Wright, C. Wayne; Troche, Rodolfo J.; Klipp, Emily S.; Kranenburg, Christine J.; Fredericks, Alexandra M.; Nagle, David B.

    2014-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived submerged topography datasets were produced by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

  16. Metal accumulation by submerged macrophytes in eutrophic lakes at the watershed scale.

    Science.gov (United States)

    Xing, Wei; Wu, Haoping; Hao, Beibei; Liu, Guihua

    2013-10-01

    Metal concentrations (Al, Ba, Ca, K, Li, Mg, Na, Se, Sr and Ti) in submerged macrophytes and corresponding water and sediments were studied in 24 eutrophic lakes along the middle and lower reaches of the Yangtze River (China). Results showed that these eutrophic lakes have high metal concentrations in both water and sediments because of human activities. Average concentrations of Al and Na in tissues of submerged macrophytes were very high in sampled eutrophic lakes. By comparison, Ceratophyllum demersum and Najas marina accumulated more metals (e.g. Ba, Ca, K, Mg, Na, Sr and Ti). Strong positive correlations were found between metal concentrations in tissues of submerged macrophytes, probably because of co-accumulation of metals. The concentrations of Li, Mg, Na and Sr in tissues of submerged macrophytes significantly correlated with their corresponding water values, but not sediment values.

  17. Outer Continental Shelf Submerged Lands Act Boundary - Gulf of Mexico Region NAD27

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set contains the Submerged Lands Act (SLA) boundary line (also known as State Seaward Boundary (SSB), or Fed State Boundary)in ESRI shapefile formats for...

  18. Suitability of seagrasses and submerged aquatic vegetation as indicators of eutrophication

    Science.gov (United States)

    Rooted submerged aquatic vegetation (SAV) encompasses a large diversity of species that range from obligate halophytes such as, seagrasses, to euryhaline species and freshwater obligates. All seagrass and SAV provide key biological functions within the enclosed bays, estuaries, a...

  19. EAARL Submerged Topography - U.S. Virgin Islands 2003

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Stevens, Sara; Yates, Xan; Bonisteel, Jamie M.

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived submerged topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), South Florida-Caribbean Network, Miami, FL; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate bathymetric datasets of a portion of the U.S. Virgin Islands, acquired on April 21, 23, and 30, May 2, and June 14 and 17, 2003. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and

  20. Anatomy of floating and submerged leaves of heterophyllous plant of Nymphaea candida L.

    OpenAIRE

    E.N. Klimenko

    2014-01-01

    The data on anatomy of floating and submerged leaves of heterophyllous aquatic plant Nymphaea candida L. are presented. Anatomy of floating leaves is shown to be different from that of submerged leaves: the absence of stomata, asterosclereids, and differentiated parenchyma, as well as by reduce intercellular volume and leaf width. Common patterns of leaf structure plasticity of aquatic heterophyllous plants in dependence on the environment are discussed.

  1. Aquatic adventitious root development in partially and completely submerged wetland plants Cotula coronopifolia and Meionectes brownii.

    Science.gov (United States)

    Rich, Sarah Meghan; Ludwig, Martha; Colmer, Timothy David

    2012-07-01

    A common response of wetland plants to flooding is the formation of aquatic adventitious roots. Observations of aquatic root growth are widespread; however, controlled studies of aquatic roots of terrestrial herbaceous species are scarce. Submergence tolerance and aquatic root growth and physiology were evaluated in two herbaceous, perennial wetland species Cotula coronopifolia and Meionectes brownii. Plants were raised in large pots with 'sediment' roots in nutrient solution and then placed into individual tanks and shoots were left in air or submerged (completely or partially). The effects on growth of aquatic root removal, and of light availability to submerged plant organs, were evaluated. Responses of aquatic root porosity, chlorophyll and underwater photosynthesis, were studied. Both species tolerated 4 weeks of complete or partial submergence. Extensive, photosynthetically active, aquatic adventitious roots grew from submerged stems and contributed up to 90 % of the total root dry mass. When aquatic roots were pruned, completely submerged plants grew less and had lower stem and leaf chlorophyll a, as compared with controls with intact roots. Roots exposed to the lowest PAR (daily mean 4.7 ± 2.4 µmol m(-2) s(-1)) under water contained less chlorophyll, but there was no difference in aquatic root biomass after 4 weeks, regardless of light availability in the water column (high PAR was available to all emergent shoots). Both M. brownii and C. coronopifolia responded to submergence with growth of aquatic adventitious roots, which essentially replaced the existing sediment root system. These aquatic roots contained chlorophyll and were photosynthetically active. Removal of aquatic roots had negative effects on plant growth during partial and complete submergence.

  2. Agenesis of premolar associated with submerged primary molar and a supernumerary premolar: An unusual case report

    Directory of Open Access Journals (Sweden)

    S. V. S. G. Nirmala

    2012-01-01

    Full Text Available The combination of submerged primary molar, agenesis of permanent successor with a supernumerary in the same place is very rare. The purpose of this article is to report a case of submerged mandibular left second primary molar with supernumerary tooth in the same region along with agenesis of second premolar in an 11-year-old girl, its possible etiological factors, and a brief discussion on treatment options.

  3. Parametric and Nonparametric Analysis of LANDSAT TM and MSS Imagery for Detecting Submerged Plant Communities

    Science.gov (United States)

    Ackleson, S. G.; Klemas, V.

    1984-01-01

    The spatial, spectral and radiometric characteristics of LANDSAT TM and MSS imagery for detecting submerged aquatic vegetation are assessed. The problem is approached from two perspectives; purely stochastic or nonparametric in a radiative sense and theoretical in which radiative transfer equations are used to predict upwelling radiance at satellite altitude. The spectral and radiometric aspects of the theoretical approach are addressed with which a submerged plant canopy is distinguished from a surrounding bottom of sand or mud.

  4. Growth rate, protein:RNA ratio and stoichiometric homeostasis of submerged macrophytes under eutrophication stress

    Directory of Open Access Journals (Sweden)

    Xing W.

    2016-01-01

    Full Text Available Growth rate hypothesis (GRH and stoichiometric homeostasis of photoautotrophs have always been questioned. However, little is known about GRH and stoichiometric homeostasis of aquatic plants, especially submerged macrophytes. Therefore, we aim to test the GRH and explore stoichiometric homeostasis of four freshwater submerged macrophytes under eutrophication stress. At the single species level and the multi-species level, N:P ratios of Potamogeton maackianus, Myriophyllum spicatum, Vallisneria natans and Ceratophyllum demersum had no consistent trends with growth rates. However, protein:RNA ratios of P. maackianus, M. spicatum and V. natans all correlated negatively with growth rates, demonstrating GRH can apply to freshwater submerged macrophytes, even though they are threatening by eutrophication stress. Protein:RNA ratios positively correlated with N:P ratios in culture media and tissues in submerged macrophytes except in P. maackianus (30d, suggesting effects of varying N:P ratios in culture media on protein:RNA ratios are basically in concert with tissue N:P ratios under short-time eutrophication stress. Stoichiometric homeostasis coefficients (HN:P indicated submerged macrophytes have weak homeostasis. Stoichiometric homeostasis of V. natans was stronger than those of P. maackianus, M. spicatum and C. demersum. The differences in GRH and homeostasis of the four submerged macrophytes may be due to species traits.

  5. Structural and Acoustic Responses of a Submerged Stiffened Conical Shell

    Directory of Open Access Journals (Sweden)

    Meixia Chen

    2014-01-01

    Full Text Available This paper studies the vibrational behavior and far-field sound radiation of a submerged stiffened conical shell at low frequencies. The solution for the dynamic response of the conical shell is presented in the form of a power series. A smeared approach is used to model the ring stiffeners. Fluid loading is taken into account by dividing the conical shell into narrow strips which are considered to be local cylindrical shells. The far-field sound pressure is solved by the Element Radiation Superposition Method. Excitations in two directions are considered to simulate the loading on the surface of the conical shell. These excitations are applied along the generator and normal to the surface of the conical shell. The contributions from the individual circumferential modes on the structural responses of the conical shell are studied. The effects of the external fluid loading and stiffeners are discussed. The results from the analytical models are validated by numerical results from a fully coupled finite element/boundary element model.

  6. [Submerged cultivation and chemical composition of Hericium erinaceus mycelium].

    Science.gov (United States)

    Avtonomova, A V; Bakanov, A V; Shuktueva, M I; Vinokurov, V A; Popova, O V; Usov, A I; Krasnopol'skaia, L M

    2012-01-01

    Submerged cultivation of Hericium erinaceus in various media was studied. The yield of the biomass was shown to depend mainly on the carbon source, whereas the content of water soluble polysaccharides depended mainly on the nitrogen source. The optimal medium composition provided the biomass yield of 21-23 g/l in 7 days. The biomass was characterized by the content of total protein, lipids and carbohydrates. In addition, the amino acid composition of the biomass was determined and shown to meet all the requirements of FAO/WHO concerning the amounts of essential amino acids (with exception of tryptophane). Oleinic and linoleic acids were identified as the main components of the fatty acids. Two water soluble polysaccharide fractions differing in solubility in aqueous ethanol were isolated and shown to contain rhamnose, fucose, xylose, glucose and galactose in different proportions. Vitamins B1, B2, B6, PP and E, ergosterol and coenzyme Q were also detected in the biomass of H. erinaceus.

  7. Underwater Photosynthesis of Submerged Plants – Recent Advances and Methods

    Science.gov (United States)

    Pedersen, Ole; Colmer, Timothy D.; Sand-Jensen, Kaj

    2013-01-01

    We describe the general background and the recent advances in research on underwater photosynthesis of leaf segments, whole communities, and plant dominated aquatic ecosystems and present contemporary methods tailor made to quantify photosynthesis and carbon fixation under water. The majority of studies of aquatic photosynthesis have been carried out with detached leaves or thalli and this selectiveness influences the perception of the regulation of aquatic photosynthesis. We thus recommend assessing the influence of inorganic carbon and temperature on natural aquatic communities of variable density in addition to studying detached leaves in the scenarios of rising CO2 and temperature. Moreover, a growing number of researchers are interested in tolerance of terrestrial plants during flooding as torrential rains sometimes result in overland floods that inundate terrestrial plants. We propose to undertake studies to elucidate the importance of leaf acclimation of terrestrial plants to facilitate gas exchange and light utilization under water as these acclimations influence underwater photosynthesis as well as internal aeration of plant tissues during submergence. PMID:23734154

  8. Immunomodulatory properties of Grifola frondosa in submerged culture.

    Science.gov (United States)

    Wu, Ming-Jiuan; Cheng, Tso-Lin; Cheng, Su-Yun; Lian, Tzi-Wei; Wang, Lisu; Chiou, Shu-Yuan

    2006-04-19

    Maitake (Grifola frondosa) is a popular mushroom in Asia for its tasty flavor and immune-stimulating property. The aim of the study is to investigate the innate immunity augmentation effects of different extracts of mycelia and culture filtrate from G. frondosa in submerged cultures. The hot water extract of mycelia showed the strongest cytokine induction effect as a function of its concentration in human whole blood culture. The most potent fractions of hot water extract, Fr. I and II, were mainly composed of polysaccharides with molecular masses of 43-140 and 13-38 kDa, respectively. These fractions (0.025 mg/mL) showed marked activity in enhancing phagocytosis of human polymorphonuclear neutrophils (PMN). In parallel, the expression of CD11b, an early marker of PMN activation, was also up-regulated dose dependently. This result suggested that complement receptor 3 was primed by these fractions. In addition to activation of phagocytes, these bioactive fractions also increased human peripheral blood natural killer cell cytotoxicity. These results imply that the relatively low molecular mass polysaccharides isolated from mycelia of G. frondosa can enhance innate immunity in vitro and therefore may serve as biological response modifiers.

  9. The use of bottle caps as submerged aerated filter medium.

    Science.gov (United States)

    Damasceno de Oliveira, Laurence; Motlagh, Amir Mohaghegh; Goel, Ramesh; de Souza Missagia, Beatriz; Alves de Abreu Filho, Benício; Lautenschlager, Sandro Rogério

    2014-01-01

    In this study, a submerged aerated filter (SAF) using bottle caps as a support medium was evaluated. The system was fed with effluent from an upflow anaerobic sludge blanket system at ETE 2-South wastewater treatment plant, under different volumetric organic load rates (VOLRs). The population of a particular nitrifying microbial community was assessed by fluorescent in situ hybridization with specific oligonucleotide probes. The system showed an average removal of chemical oxygen demand (COD) equal to 76% for VOLRs between 2.6 and 13.6 kg COD m(-3)_media.day(-1). The process of nitrification in conjunction with the removal of organic matter was observed from applying VOLRs lower than 5.5 kg COD m(-3)_media.day(-1) resulting in 78% conversion of NH4(+)-N. As the applied organic load was reduced, an increase in the nitrifying bacteria population was observed compared with total 4'-6-diamidino-2-phenylindole (DAPI) stained cells. Generally, SAF using bottle caps as a biological aerated filter medium treating wastewater from an anaerobic system showed promising removal of chemical oxygen demand (COD) and conversion of NH4(+)-N.

  10. Stainless steel submerged arc weld fusion line toughness

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)

    1995-04-01

    This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.

  11. Submersible Unmanned Aerial Vehicle: Configuration Design and Analysis Based on Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Wang Qinyang

    2017-01-01

    Full Text Available Submersible aerial vehicle is capable of both flying in the air and submerging in the water. Advanced Research Project Agency (DARPA outlined a challenging set of requirements for a submersible aircraft and solicited innovative research proposals on submersible aircraft since 2008. In this paper, a conceptual configuration design scheme of submersible unmanned aerial vehicle is proposed. This submersible UAV lands on the surface of water, then adjusts its own density to entry water. On the contrary, it emerges from water by adjusting its own density and then takes off from the surface of water. Wing of the UAV is whirling wing. It is set along aircraft’s fuselage while submerging for lift reduction. We analysis aerodynamic and hydrodynamic performance of this UAV by CFD method, especially compare the hydrodynamic performance of the whirling wing configuration and normal configuration. It turns out that whirling wing is beneficial for submerging. This result proves that the configuration design scheme proposed in this paper is feasible and suitable for a submersible unmanned aerial vehicle.

  12. Forestry Vehicle

    Science.gov (United States)

    1982-01-01

    Power Pack II provides an economical means of moving a power source into remote roadless forest areas. It was developed by Prof. Miles and his associates, working in cooperation with the University of California's Department of Forestry. The team combined its own design of an all-terrain vehicle with a suspension system based on the NASA load equalization technology. Result is an intermediate-sized unit which carries a power source and the powered tools to perform a variety of forest management tasks which cannot be done economically with current equipment. Power Pack II can traverse very rough terrain and climb a 60 degree slope; any one of the wheels can move easily over an obstacle larger than itself. Work is being done on a more advanced Power Pack III.

  13. Early Human Dispersals and Submerged Landscapes : comment on news feature "Migration: value of submerged early sites" in Nature's May 2012 special issue "Peopling the Planet"

    NARCIS (Netherlands)

    Flemming, Nicholas; Bailey, Geoffrey N.; Sakellariou, Dimitris; Arias, Pablo; Canals, M.; Chiocci, Francesco Latino; Cohen, K.M.; Erlandson, Jon; Faught, Michael K.; Flatman, Joe; Fischer, Anders; Galili, Ehud; Harff, Jan; Lericolais, Gilles; Lűth, Friedrich

    2012-01-01

    Your articles on human dispersal in the late Pleistocene epoch (Nature 485, 23; 2012) overlook the significance of now-submerged archaeological sites on the continental shelf during this period (126,000–11,000 years ago). It is wrong to assume that these were completely destroyed by the sea and that

  14. Differential Response of Floating and Submerged Leaves of Longleaf Pondweed to Silver Ions

    Directory of Open Access Journals (Sweden)

    Nisha Shabnam

    2017-06-01

    Full Text Available In this study, we have investigated variations in the potential of floating and submerged leaves of longleaf pondweed (Potamogeton nodosus to withstand silver ion (Ag+-toxicity. Both floating and submerged leaves changed clear colorless AgNO3 solutions to colloidal brown in the presence of light. Transmission electron microscopy revealed the presence of distinct crystalline Ag-nanoparticles (Ag-NPs in these brown solutions. Powder X-ray diffraction pattern showed that Ag-NPs were composed of Ag0 and Ag2O. Photosystem (PS II efficiency of leaves declined upon exposure to Ag+ with a significantly higher decline in the submerged leaves than in the floating leaves. Similarly, Ag+ treatment caused a significant reduction in the carboxylase activity of the ribulose bisphosphate carboxylase/oxygenase in leaves. The reduction in this carboxylase activity was significantly higher in the submerged than in the floating leaves. Ag+ treatment also resulted in a significant decline in the levels of non-enzymatic and enzymatic antioxidants; the decline was significantly lower in the floating than in submerged leaves. X-ray photoelectron spectroscopy revealed the presence of Ag2O in these leaves. Inductively coupled plasma mass spectrometry analysis revealed a three-fold higher Ag content in the submerged than in floating leaves. Our study demonstrates that floating leaves of longleaf pondweed have a superior potential to counter Ag+-toxicity compared with submerged leaves, which could be due to superior potential of floating leaves to reduce Ag+ to less/non-toxic Ag0/Ag2O-nanoparticles/nanocomplexes. We suggest that modulating the genotype of longleaf pondweed to bear higher proportion of floating leaves would help in cleaning fresh water bodies contaminated with ionic forms of heavy metals.

  15. Multi-Objective Optimization of Submerged Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Saurav Datta

    2010-06-01

    Full Text Available Submerged arc welding (SAW is an important metal fabrication technology specially applied to join metals of large thickness in a single pass. In order to obtain an efficient joint, several process parameters of SAW need to be studied and precisely selected to improve weld quality. Many methodologies were proposed in the past research to address this issue. However, a good number of past work seeks to optimize SAWprocess parameters with a single response only. In practical situations, not only is the influence of process parameters and their interactive effects on output responses are to be critically examined but also an attempt is to be made to optimize more than one response, simultaneously. To this end, the present study considers four process control parameters viz. voltage (OCV, wire feed rate, traverse speed and electrode stick-out. The selected weld quality characteristics related to features of bead geometry are depth of penetration, reinforcement and bead width. In the present reporting, an integrated approach capable of solving the simultaneous optimization of multi-quality responses in SAW was suggested. In the proposed approach, the responses were transformed into their individual desirability values by selecting appropriate desirability function. Assuming equal importance for all responses, these individual desirability values were aggregated to calculate the overall desirability values. Quadratic Response Surface Methodology (RSM was applied to establish a mathematical model representing overall desirability as a function involving linear, quadratic and interaction effect of process control parameters. This model was optimized finally within the experimental domain using PSO (Particle Swarm Optimization algorithm. A confirmatory test showed a satisfactory result. A detailed methodology of RSM, desirability function (DF and a PSO-based optimization approach was illustrated in the paper.

  16. Fallout plume of submerged oil from Deepwater Horizon

    Science.gov (United States)

    Valentine, David L.; Fisher, G. Burch; Bagby, Sarah C.; Nelson, Robert K.; Reddy, Christopher M.; Sylva, Sean P.; Woo, Mary A.

    2014-01-01

    The sinking of the Deepwater Horizon in the Gulf of Mexico led to uncontrolled emission of oil to the ocean, with an official government estimate of ∼5.0 million barrels released. Among the pressing uncertainties surrounding this event is the fate of ∼2 million barrels of submerged oil thought to have been trapped in deep-ocean intrusion layers at depths of ∼1,000–1,300 m. Here we use chemical distributions of hydrocarbons in >3,000 sediment samples from 534 locations to describe a footprint of oil deposited on the deep-ocean floor. Using a recalcitrant biomarker of crude oil, 17α(H),21β(H)-hopane (hopane), we have identified a 3,200-km2 region around the Macondo Well contaminated by ∼1.8 ± 1.0 × 106 g of excess hopane. Based on spatial, chemical, oceanographic, and mass balance considerations, we calculate that this contamination represents 4–31% of the oil sequestered in the deep ocean. The pattern of contamination points to deep-ocean intrusion layers as the source and is most consistent with dual modes of deposition: a “bathtub ring” formed from an oil-rich layer of water impinging laterally upon the continental slope (at a depth of ∼900–1,300 m) and a higher-flux “fallout plume” where suspended oil particles sank to underlying sediment (at a depth of ∼1,300–1,700 m). We also suggest that a significant quantity of oil was deposited on the ocean floor outside this area but so far has evaded detection because of its heterogeneous spatial distribution. PMID:25349409

  17. Submergence Causes Similar Carbohydrate Starvation but Faster Post-Stress Recovery than Darkness in Alternanthera philoxeroides Plants.

    Directory of Open Access Journals (Sweden)

    Xiao Qi Ye

    Full Text Available Carbon assimilation by submerged plants is greatly reduced due to low light levels. It is hypothesized that submergence reduces carbohydrate contents and that plants recover from submergence in the same way as darkness-treated plants. To test this hypothesis, the responses of plants to submergence and darkness were studied and compared. Plants of a submergence-tolerant species, Alternanthera philoxeroides, were exposed to well drained and illuminated conditions, complete submergence conditions or darkness conditions followed by a recovery growth period in a controlled experiment. The biomass maintenance and accumulation, carbohydrate content dynamics and respiration rate in the plants were assessed to quantify the carbohydrate utilization rate and regrowth. The submerged plants maintained higher chlorophyll contents, more green leaf tissue and more biomass; recovered more quickly; and accumulated more carbohydrates and biomass than darkness-treated plants. The respiration rate was continuously reduced in the same pattern under both stress conditions but was maintained at a significantly lower level in the submerged plants; the total soluble sugar and total fructan contents were decreased at approximately the same rate of decrease, reaching similar low levels, in the two stress treatments. The A. philoxeroides plants were more tolerant of submergence than darkness. The faster recovery of desubmerged plants could not be explained by the similar carbohydrate contents at the start of recovery. Other types of carbon reserves besides carbohydrates or other mechanisms such as higher post-stress photosynthetic performance might be involved.

  18. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems.DESCRIPTION: The Vehicle Development Laboratory is...

  19. Solitary and cnoidal wave scattering by a submerged horizontal plate in shallow water

    Directory of Open Access Journals (Sweden)

    Masoud Hayatdavoodi

    2017-06-01

    Full Text Available Solitary and cnoidal wave transformation over a submerged, fixed, horizontal rigid plate is studied by use of the nonlinear, shallow-water Level I Green-Naghdi (GN equations. Reflection and transmission coefficients are defined for cnoidal and solitary waves to quantify the nonlinear wave scattering. Results of the GN equations are compared with the laboratory experiments and other theoretical solutions for linear and nonlinear waves in intermediate and deep waters. The GN equations are then used to study the nonlinear wave scattering by a plate in shallow water. It is shown that in deep and intermediate depths, the wave-scattering varies nonlinearly by both the wavelength over the plate length ratio, and the submergence depth. In shallow water, however, and for long-waves, only the submergence depth appear to play a significant role on wave scattering. It is possible to define the plate submergence depth and length such that certain wave conditions are optimized above, below, or downwave of the plate for different applications. A submerged plate in shallow water can be used as a means to attenuate energy, such as in wave breakers, or used for energy focusing, and in wave energy devices.

  20. [Influence of Submerged Plants on Microbial Community Structure in Sediment of Hongze Lake].

    Science.gov (United States)

    Zhang, Ding-yu; Zhang, Ting-xi; Dong, Dan-ping; Li, De-fang; Wang, Guo-xiang

    2016-05-15

    Phospholipid fatty acids (PLFAs) method was applied to analyze the influence of submerged plants on sediment microbial community structure, in order to investigate the changes of sediment microbial community structure for different kinds of the submerged plants in different growth periods. Particularly, Potamogeton crispus L., Potamogeton pectinatus L and the mixed group were chosen as the typical submerged plants in Hongze Lake for investigation in this paper. The results indicated that the change of total PLFAs in different periods was significant, on the contrary, the PLFA change for different groups in the same period was insignificant. The values of G⁺ PLFA/G⁻ PLFA in the submerged plant group were also highly related to the different growth periods, which demonstrated that the root function of the submerged plant had a severe impact on the microbial community in sediment. Furthermore, some environmental factors, such as Temperature, pH, TOC and DO, were correlated to characteristic phospholipid of PLFAs in sediment, which means the environmental factors could also affect the microbial community structure.

  1. Suspension of Egg Hatching Caused by High Humidity and Submergence in Spider Mites.

    Science.gov (United States)

    Ubara, Masashi; Osakabe, Masahiro

    2015-08-01

    We tested the effects of high humidity and submergence on egg hatching of spider mites. In both the high humidity and submergence treatments, many Tetranychus and Panonychus eggs did not hatch until after the hatching peak of the lower humidity or unsubmerged controls. However, after humidity decreased or water was drained, many eggs hatched within 1-3 h. This was observed regardless of when high humidity or submergence treatments were implemented: either immediately after oviposition or immediately before hatching was due. Normal eyespot formation was observed in most eggs in the high humidity and submergence treatments, which indicates that spider mite embryos develop even when eggs are underwater. Therefore, delays in hatching are not caused by delayed embryonic development. A delay in hatching was always observed in Panonychus citri (McGregor) but was more variable in Tetranychus urticae Koch and Tetranychus kanzawai Kishida. The high humidity and submergence treatments affected but did not suppress larval development in these species. In contrast, many Oligonychus eggs died following the high humidity treatments. In Tetranychus and Panonychus spider mites, suspension of egg hatching may mitigate the adverse effects of rainfall. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Individual and combined suppressive effects of submerged and floating-leaved macrophytes on algal blooms.

    Science.gov (United States)

    Seto, Mayumi; Takamura, Noriko; Iwasa, Yoh

    2013-02-21

    Shallow lakes and ponds are often characterised either by clear water with abundant submerged macrophytes or by turbid water with abundant phytoplankton. Blooms of toxic filamentous blue-green algae (cyanobacteria) often dominate the phytoplankton community in eutrophic lakes, which threatens ecological functions and biodiversity of freshwater ecosystems. We studied a simple lake model in order to evaluate individual and combined suppressive effects of rooted submerged and rooted floating-leaved macrophytes on algal blooms. Floating-leaved plants are superior competitors for light, whereas submerged plants absorb and reduce available phosphorus in a water column that rooted floating-leaved plants exploit to a lesser extent. We found that mixed vegetation that includes both submerged and floating-leaved plants is more resistant than vegetation comprised by a single plant type to algal invasion triggered by phosphorus loading. In addition, competitive exclusion of submerged plants by floating-leaved plants may promote an algal bloom. These predictions were confirmed by the decision tree analysis of field data from 35 irrigation ponds in Hyogo Prefecture, Japan. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Constructed tropical wetlands with integrated submergent-emergent plants for sustainable water quality management.

    Science.gov (United States)

    Tanaka, Norio; Jinadasa, K B S N; Werellagama, D R I B; Mowjood, M I M; Ng, W J

    2006-01-01

    Improvement of primary effluent quality by using an integrated system of emergent plants (Scirpus grossus in the leading subsurface flow arrangement) and submergent plants (Hydrilla verticillata in a subsequent channel) was investigated. The primary effluent was drawn from a septic tank treating domestic sewage from a student dormitory at the University of Peradeniya, Sri Lanka. Influent and effluent samples were collected once every 2 weeks from May 2004 through July 2005 and analyzed to determine water quality parameters. Both the emergent and submergent plants were harvested at predetermined intervals. The results suggested that harvesting prolonged the usefulness of the system and the generation of a renewable biomass with potential economic value. The mean overall pollutant removal efficiencies of the integrated emergent and submergent plant system were biological oxygen demand (BOD5), 65.7%; chemical oxygen demand (COD), 40.8%; ammonium (NH4+-N), 74.8%; nitrate (NO3--N), 38.8%; phosphate (PO43-), 61.2%; total suspended solids (TSS), 65.8%; and fecal coliforms, 94.8%. The submergent plant subsystem improved removal of nutrients that survived the emergent subsystem operated at low hydraulic retention times. The significant improvement in effluent quality following treatment by the submergent plant system indicates the value of incorporating such plants in wetland systems.

  4. Characteristics and Limitations of Submerged GPS L1 Observations

    Science.gov (United States)

    Steiner, Ladina; Geiger, Alain

    2017-04-01

    Extensive amount of water stored in snow covers has a high impact on flood development during snow melting periods. Early assessment of these parameters in mountain environments enhance early-warning and thus prevention of major impacts. Sub-snow GNSS techniques are lately suggested to determine liquid water content, snow water equivalent or considered for avalanche rescue. This technique is affordable, flexible, and provides accurate and continuous observations independent on weather conditions. However, the characteristics of GNSS observations for applications within a snow-pack still need to be further investigated. The magnitude of the main interaction processes involved for the GPS wavelength propagating through different layers of snow, ice or water is theoretically examined. Liquid water exerts the largest influence on GPS signal propagation through a snow-pack. Therefore, we focus on determining the characteristics of GNSS observables under water. An experiment was set-up to investigate the characteristics and limitations of submerged GPS observations using a pool, a level control by communicating pipes, a geodetic and a low-cost GPS antenna, and a water level sensor. The GPS antennas were placed into the water. The water level was increased daily by a step of two millimeters up to thirty millimeters above the antenna. Based on this experiment, the signal penetration depth, satellite availability, the attenuation of signal strength and the quality of solutions are analyzed. Our experimental results show an agreement with the theoretically derived attenuation parameter and signal penetration depth. The assumption of water as the limiting parameter for GPS observations within a snow-pack can be confirmed. Higher wetness in a snow-pack leads to less transmission, higher refraction, higher attenuation and thus a decreased penetration depth as well as a reduced quality of the solutions. In consequence, GPS applications within a snow-pack are heavily impacted by

  5. Torsion vehicle model test for automotive vehicle

    Science.gov (United States)

    Nor, M. K. Mohd; Ho, C. S.; Ma'at, N.

    2017-04-01

    Torsion vehicle model test of Simple Structural Surfaces (SSS) model for automotive vehicle sedan is proposed in this paper to demonstrate the importance of providing continuous load path within the vehicle structures. The proposed approach is relatively easy to understand as compared to Finite Element Method (FEM). The results prove that the proposed vehicle model test is capable to show that a satisfactory load paths can five a sufficient structural stiffness within the vehicle structure. It is clearly observed that the global torsion stiffness reduces significantly when only one panel is removed from the complete SSS model. The results also five a food agreement with respect to the theoretical hypothesis as the structure is less stiff in torsion in an open section condition. The SSS model and the corresponding torsion test is obviously useful to give an overview of vehicle structural integrity. It can be potentially integrated with FEM to speed up the design process of automotive vehicle.

  6. Survival after submergence in the pupae of five species of blow flies (Diptera: Calliphoridae).

    Science.gov (United States)

    Singh, D; Greenberg, B

    1994-09-01

    Survival of pupae of known ages after 1 to 5 d of submersion under water was assessed by determining the emergence of Protophormia terraenovae (Robineau-Desvoidy), Calliphora vicina (Robineau-Desvoidy), Cochliomyia macellaria (F.), Phormia regina (Meigen), and Phaenicia sericata (Meigen). Survival after 1 d of submergence was < 14% in the white puparial stage, 0-100% in pharate adults nearing eclosion, and approximately 100% in pupae between these two stages. This pattern inversely tracks O2 consumption during metamorphosis. Twenty-five percent of the pupae of three species (P. terraenovae, P. regina, and P. sericata) produced normal adults after 4 d of submersion, but none after 5 d. Among survivors, the pupation period was extended by the duration of submersion. Pupae of C. vicina were least able to withstand drowning. These data are potentially useful in estimating duration of submergence of a corpse in forensic investigations where the corpse becomes submerged after the larvae have developed and pupariated.

  7. Bioaccumulation of heavy metals by submerged macrophytes: looking for hyperaccumulators in eutrophic lakes.

    Science.gov (United States)

    Xing, Wei; Wu, Haoping; Hao, Beibei; Huang, Wenmin; Liu, Guihua

    2013-05-07

    To directly select submerged macrophytes with high accumulation capability from the field, 24 eutrophic lakes along the middle and lower reaches of the Yangtze River were investigated in the study. These eutrophic lakes have large amounts of heavy metals in both water and sediments because of human activities. The results showed that Najas marina is a hyperaccumulator of As and Cd, Ceratophyllum demersum is a hyperaccumulator of Co, Cr, and Fe, and Vallisneria natans is a hyperaccumulator of Pb. Strong positive correlations were found between concentrations of heavy metals in tissues of submerged macrophytes, probably because of coaccumulation of heavy metals. However, for most heavy metals, no significant correlations were found between submerged macrophytes and their surrounding environments. In conclusion, N. marina, C. demersum, and V. natans are good candidate species for removing heavy metals from eutrophic lakes.

  8. Factors involved in spatiotemporal dynamics of submerged macrophytes in a Portuguese coastal lagoon under Mediterranean climate

    Science.gov (United States)

    Antunes, Cristina; Correia, Otília; Marques da Silva, Jorge; Cruces, Anabela; Freitas, Maria da Conceição; Branquinho, Cristina

    2012-09-01

    Submerged macrophytes are key in coastal ecosystems, with important structural and functional roles. Thus, the characterization of the submerged aquatic vegetation dynamics is of prime importance for assessing the ecological status of coastal ecosystems. The main aim of this study was to assess the spatial and temporal dynamics of submerged macrophytes biomass in a temporarily open coastal lagoon in Melides, Portugal, and to evaluate the physiological performance of the dominant macrophyte in the system. This lagoon is subject to several disturbances such as the dramatic changes in water physicochemical parameters over time, since temporarily opens to the sea occur renewing the lagoon water content. Moreover it is under a Mediterranean climate with the inherently high temporal variability of precipitation and high temperatures during the summer. Our study shows that the submerged macrophyte community was dominated initially by Ruppia cirrhosa and then replaced by Potamogeton pectinatus, which showed a marked temporal and spatial pattern with extremely high values of biomass in August and in the inner part of the lagoon. The spatial and temporal biomass patterns in submerged macrophytes were mainly related with water level, salinity, pH and transparency. The physiological performance of R. cirrhosa was lower when there was greater biomass accumulation and in extremely shallow waters, whereas physiological vigor seemed to be greater at moderate temperatures and in areas with higher salinity and dissolved oxygen. The data from this study can be used to predict submerged biomass macrophyte responses to extreme water quality changes and to feed a decision support system for the best period to promote the seasonal artificial breaching of the sandy barrier.

  9. Elevation dynamics in a restored versus a submerging salt marsh in Long Island Sound

    Science.gov (United States)

    Anisfeld, Shimon C.; Hill, Troy D.; Cahoon, Donald R.

    2016-01-01

    Accelerated sea-level rise (SLR) poses the threat of salt marsh submergence, especially in marshes that are relatively low-lying. At the same time, restoration efforts are producing new low-lying marshes, many of which are thriving and avoiding submergence. To understand the causes of these different fates, we studied two Long Island Sound marshes: one that is experiencing submergence and mudflat expansion, and one that is undergoing successful restoration. We examined sedimentation using a variety of methods, each of which captures different time periods and different aspects of marsh elevation change: surface-elevation tables, marker horizons, sediment cores, and sediment traps. We also studied marsh hydrology, productivity, respiration, nutrient content, and suspended sediment. We found that, despite the expansion of mudflat in the submerging marsh, the areas that remain vegetated have been gaining elevation at roughly the rate of SLR over the last 10 years. However, this elevation gain was only possible thanks to an increase in belowground volume, which may be a temporary response to waterlogging. In addition, accretion rates in the first half of the twentieth century were much lower than current rates, so century-scale accretion in the submerging marsh was lower than SLR. In contrast, at the restored marsh, accretion rates are now averaging about 10 mm yr−1 (several times the rate of SLR), much higher than before restoration. The main cause of the different trajectories at the two marshes appeared to be the availability of suspended sediment, which was much higher in the restored marsh. We considered and rejected alternative hypotheses, including differences in tidal flooding, plant productivity, and nutrient loading. In the submerging marsh, suspended and deposited sediment had relatively high organic content, which may be a useful indicator of sediment starvation.

  10. Electric and hybrid vehicles

    Science.gov (United States)

    1979-01-01

    Report characterizes state-of-the-art electric and hybrid (combined electric and heat engine) vehicles. Performance data for representative number of these vehicles were obtained from track and dynamometer tests. User experience information was obtained from fleet operators and individual owners of electric vehicles. Data on performance and physical characteristics of large number of vehicles were obtained from manufacturers and available literature.

  11. Strong growth limitation of a floating plant (Lemna gibba) by the submerged macrophyte (Elodea nuttallii) under laboratory conditions

    NARCIS (Netherlands)

    Szabo, S.; Scheffer, M.; Roijackers, R.M.M.; Waluto, B.; Zambrano, L.

    2010-01-01

    1. The asymmetric competition for light and nutrients between floating and submerged aquatic plants is thought to be key in explaining why dominance by either of these groups can be stable and difficult to change. 2. Although the shading effect of floating plants on submerged plants has been well

  12. Effect of temperature and nutrients on the competition between free-floating Salvinia natans and submerged Elodea nuttallii in mesocosms

    NARCIS (Netherlands)

    Netten, J.J.C.; Arts, G.H.P.; Gylstra, R.; Nes, van E.H.; Scheffer, M.; Roijackers, R.M.M.

    2010-01-01

    In many aquatic ecosystems, free-floating plants compete with submerged plants for nutrients and light. Being on top of the water surface free-floating plants are superior competitors for light. Submerged plants can take up nutrients from the sediment and the water column, hereby reducing these

  13. Biological control of phytoplankton by the subtropical submerged macrophytes Egeria densa and Potamogeton illinoensis: a mesocosm study

    NARCIS (Netherlands)

    Vanderstukken, M.; Mazzeo, N.; Colen, W.; Declerck, S.A.J.; Muylaert, K.

    2011-01-01

    1. In temperate regions, submerged macrophytes can hamper phytoplankton blooms. Such an effect could arise directly, for instance via allelopathy, or indirectly, via competition for nutrients or the positive interaction between submerged macrophytes and zooplankton grazing. However, there is some

  14. Effect of heat input on dilution and heat affected zone in submerged ...

    Indian Academy of Sciences (India)

    Submerged arc welding (SAW) is a fusion joining process, known for its high deposition capabilities. This process is useful in joining thick section components used in various industries. Besides joining, SAW can also be used for surfacing applications. Heat Affected Zone (HAZ) produced within the base metal as a result of ...

  15. Effect of heat input on dilution and heat affected zone in submerged ...

    Indian Academy of Sciences (India)

    Effect of heat input on dilution and heat affected zone in submerged arc welding process. HARI OM1,∗ and SUNIL PANDEY2. 1Department of Mechanical Engineering, YMCA University of Science and. Technology, Sector 06, Faridabad 121 006, India. 2Department of Mechanical Engineering, Indian Institute of Technology ...

  16. Environmental cracking behavior of submerged arc-welded supermartensitic stainless steel weldments

    Science.gov (United States)

    Srinivasan, P. Bala; Sharkawy, S. W.; Dietzel, W.

    2004-04-01

    Supermartensitic stainless steel welds produced by submerged are welding were assessed for their microstructure and properties. Slow strain rate tests conducted on these specimens revealed that both the parent material and the weld metals are susceptible to cracking under conditions of hydrogen (H) charging.

  17. Possibilities of Application of Carbon-Fluorine Containing Additions in Submerged-Arc Welding

    Science.gov (United States)

    Kozyrev, N. A.; Kryukov, N. E.; Kryukov, R. E.; Igushev, V. F.; Kovalskii, I. I.

    2015-09-01

    The paper provides results of comparative analysis of the effect of carbonaceous components introduced into welding fluxes on molten metal - slag interaction. A positive influence of carbonaceous additives on gas content and mechanical properties of welds is demonstrated. Carbon and fluorine containing additives are emphasized to be promising for automatic submerged arc welding.

  18. Modification of the submerged coil to prevent microbial carryover error in thermal death studies.

    Science.gov (United States)

    Keller, Susanne E; Shazer, Arlette G; Fleischman, Gregory J; Chirtel, Stuart; Anderson, Nathan; Larkin, John

    2008-04-01

    A submerged coil unit generates death rate data for foodborne pathogens through precise computer-controlled sequential sampling rather than the usual manually timed, labor-intensive single sampling associated with other approaches. Our work with Yersinia pseudotuberculosis and Listeria monocytogenes Scott A using the submerged coil unit indicated non-log-linear death rates with large degrees of tailing. Varying degrees of cell adhesion to the surface of the exit port resulted in carryover that was likely the primary cause of these non-log-linear kinetics. This carryover also resulted in erroneously high measured levels of thermal resistance for both organisms. To address the carryover problem, modifications were made to the exit port of the submerged coil unit to ensure continuous and uniform heat treatment. These modifications resulted in a 2-fold decrease in measured D-values for L. monocytogenes Scott A and a 10-fold decrease in measured D-values for Y. pseudotuberculosis. D-values measured with the modified machine for L. monocytogenes Scott A were similar to those found in the literature. Slight tailing in survival curves persisted with the modified method, particularly for Y. pseudotuberculosis. These results indicate that kinetic data for microbial death rates obtained using an unmodified submerged coil unit must be viewed with suspicion in light of the significant potential for carryover.

  19. Modelling of wave propagation over a submerged sand bar using SWASH

    Digital Repository Service at National Institute of Oceanography (India)

    Jishad, M.; Vu, T.T.T.; JayaKumar, S.

    A non-hydrostatic numerical model "SWASH" (Simulating WAves till SHore) is used to study the wave propagation over a submerged sand bar in a wave flume The SWASH model is calibrated and further used to validate the wave propagation for two different...

  20. Captive bubble and sessile drop surface characterization of a submerged aquatic plant, Hydrilla verticillata

    Science.gov (United States)

    The surface energy parameters of the invasive aquatic weed, Hydrilla verticillata, were determined using contact angle measurements using two different methods. The abaxial and adaxial surfaces of the leaves and stem were characterized for the weed while submerged in water using captive air and octa...

  1. Surprising spectra of root-associated fungi in submerged aquatic plants.

    Science.gov (United States)

    Kohout, Petr; Sýkorová, Zuzana; Ctvrtlíková, Martina; Rydlová, Jana; Suda, Jan; Vohník, Martin; Sudová, Radka

    2012-04-01

    Similarly to plants from terrestrial ecosystems, aquatic species harbour wide spectra of root-associated fungi (RAF). However, comparably less is known about fungal diversity in submerged roots. We assessed the incidence and diversity of RAF in submerged aquatic plants using microscopy, culture-dependent and culture-independent techniques. We studied RAF of five submerged isoetid species collected in four oligotrophic freshwater lakes in Norway. Levels of dark septate endophytes (DSE) colonization differed among the lakes and were positively related to the organic matter content and negatively related to pH. In total, we identified 41 fungal OTUs using culture-dependent and culture-independent techniques, belonging to Mucoromycotina, Chytridiomycota, Glomeromycota, Ascomycota as well as Basidiomycota. Sequences corresponding to aquatic hyphomycetes (e.g. Nectria lugdunensis, Tetracladium furcatum and Varicosporium elodeae) were obtained. Eight arbuscular mycorrhizal taxa belonging to the orders Archaeosporales, Diversisporales and Glomerales were also detected. However, the vast majority of the fungal species detected (e.g. Ceratobasidium sp., Cryptosporiopsis rhizophila, Leptodontidium orchidicola, and Tuber sp.) have previously been known only from roots of terrestrial plants. The abundance and phylogenetic distribution of mycorrhizal as well as nonmycorrhizal fungi in the roots of submerged plants have reshaped our views on the fungal diversity in aquatic environment. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  2. PERFORMANCE OF NEWLY CONFIGURED SUBMERGED MEMBRANE BIOREACTOR FOR AEROBIC INDUSTRIAL WASTEWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    I Gede Wenten

    2012-02-01

    Full Text Available The application of membrane to replace secondary clarifier of conventional activated sludge, known as membrane bioreactor, has led to a small footprint size of treatment with excellent effluent quality. The use of MBR eliminates almost all disadvantages encountered in conventional wastewater treatment plant such as low biomass concentration and washout of fine suspended solids. However, fouling remains as a main drawback. To minimize membrane fouling, a new configuration of submerged membrane bioreactor for aerobic industrial wastewater treatment has been developed. For the new configuration, a bed of porous particle is applied to cover the submerged ends-free mounted ultrafiltration membrane. Membrane performance was assessed based on flux productivity and selectivity. By using tapioca wastewater containing high organic matter as feed solution, reasonably high and stable fluxes around 11 l/m2.h were achieved with COD removal efficiency of more than 99%. The fouling analysis also shows that the newly configured ends-free membrane bioreactor exhibits lower irreversible resistance compared with the submerged one. In addition, the performance of pilot scale system, using a membrane module  with 10 m2 effective area and reactor tank with 120 L volume, was also assessed. The flux achieved from the pilot scale system around 8 l/m2.h with COD removal of more than 99%. Hence, this study has demonstrated the feasibility of the newly configured submerged ends-free MBR at larger scale.

  3. Underwater exploration of submerged towns near Tranquebar (Tarangambadi) on Tamilnadu coast

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, S.R.

    to the transgression of the sea. The foot of the medieval habitation deposit north of the temple is of great archaeological importance. Innumerable coins, mostly of copper and a few of silver, lead and gold were found indicating wreck or structure submergence....

  4. Analytical model for stage-discharge estimation in meandering compound channels with submerged flexible vegetation

    Science.gov (United States)

    Shan, Yuqi; Liu, Xingnian; Yang, Kejun; Liu, Chao

    2017-10-01

    For overbank flows, submerged flexible vegetation on floodplains increases channel resistance and decreases channel conveyance capability. This study presents an analytical model for estimating the stage-discharge relationship in a meandering compound channel with dense, submerged, flexible vegetation on floodplains under high flow conditions. The mean velocity within a canopy was linked to the depth-averaged velocity, and a relationship between the two velocities was proposed. The governing equation was deduced in curvilinear coordinates, and the lateral shear stresses were found to be negligible, as validated by our experimental measurements in a large-scale meandering channel. Then, analytical solutions of subarea discharges and total discharge were derived by ignoring lateral shear stresses. Measurements from two flume experiments and one field study were used to verify the proposed model. The field case involved a natural river with both submerged and emergent grass on the floodplains. Good agreement between predictions and measurements indicated that the model accurately predicted subarea discharges and the stage-discharge relationships in a meandering compound channel with submerged vegetation. Finally, the predictions of this model were sensitive to the secondary flow parameters in the main channel but insensitive to those on the floodplains.

  5. Microbial community dynamics in a submerged fixed bed bioreactor during biological treatment of saline urban wastewater

    NARCIS (Netherlands)

    Cortés-Lorenzo, C.; Sipkema, D.; Rodríguez-Díaz, M.; Fuentes, S.; Juárez-Jiménez, B.; Rodelas, B.; Smidt, H.; González-López, J.

    2014-01-01

    The influence of salt (NaCl) on bacterial and archaeal communities in a submerged fixed bed bioreactor system for the treatment of urban wastewater was determined by DGGE and 454 pyrosequencing of PCR-amplified 16S ribosomal RNA gene fragments. Cluster analysis of DGGE fingerprints showed

  6. Effects of surrounding land use on metal accumulation in environments and submerged plants in subtropical ponds.

    Science.gov (United States)

    Liu, Hui; Bu, Hongmei; Liu, Guihua; Wang, Zhixiu; Liu, Wenzhi

    2015-12-01

    Ponds are widely used as stormwater treatment facilities to retain contaminants, including metals, and to improve water quality throughout the world. However, there is still a limited understanding of the effects of surrounding land use on metal accumulation in pond environments and organisms. To address this gap, we measured the concentrations of nine metals (i.e., Al, Ba, Ca, K, Li, Mg, Na, Se, and Sr) in water, sediments, and submerged plants collected from 37 ponds with different surrounding land uses in southwestern China and assessed the metal accumulation capacity of four dominant submerged plant species. Our results showed that Al, Ca, and K concentrations in the water were above drinking water standards. In the sediments, the average concentrations of Ca and Sr were higher than the corresponding soil background values. Ceratophyllum demersum L. could accumulate more K in aboveground biomass than Myriophyllum spicatum L. and Potamogeton maackianus A. Benn. The K concentration in submerged plants was positively influenced by the corresponding metal concentration in the water and negatively influenced by water temperature. Among the nine studied metals, only the water K concentration in ponds receiving agricultural runoff was significantly higher than that for ponds receiving urban and forested runoff. This result suggests that surrounding land use types have no significant effect on metal accumulation in sediments and submerged plants in the studied ponds. A large percentage of the metals in these ponds may be derived from natural sources such as the weathering of rocks.

  7. Heavy metals in water, sediments and submerged macrophytes in ponds around the Dianchi Lake, China.

    Science.gov (United States)

    Wang, Zhixiu; Yao, Lu; Liu, Guihua; Liu, Wenzhi

    2014-09-01

    Through retaining runoff and pollutants such as heavy metals from surrounding landscapes, ponds around a lake play an important role in mitigating the impacts of human activities on lake ecosystems. In order to determine the potential for heavy metal accumulation of submerged macrophytes, we investigated the concentrations of 10 heavy metals (i.e., As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in water, sediments, and submerged macrophytes collected from 37 ponds around the Dianchi Lake in China. Our results showed that both water and sediments of these ponds were polluted by Pb. Water and sediments heavy metal concentrations in ponds received urban and agricultural runoff were not significantly higher than those in ponds received forest runoff. This result indicates that a large portion of heavy metals in these ponds may originate from atmospheric deposition and weathering of background soils. Positive relationships were found among heavy metal concentrations in submerged macrophytes, probably due to the coaccumulation of heavy metals. For most heavy metals, no significant relationships were found between submerged macrophytes and their water and sediment environments. The maximum concentrations of Cr, Fe and Ni in Ceratophyllum demersum were 4242, 16,429 and 2662mgkg(-1), respectively. The result suggests that C. demersum is a good candidate species for removing heavy metals from polluted aquatic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Corrosion monitoring for underground and submerged concrete structures - examples and interpretation issues

    NARCIS (Netherlands)

    Polder, R.B.; Peelen, W.H.A.; Leegwater, G.

    2008-01-01

    Since about 1980 Corrosion Monitoring Systems have been used in many concrete structures in aggressive environmentworldwide. While these systemswork properly in aboveground environment, some questions have arisen for submerged conditions, e.g. the outer sides of tunnels, piers in seawater or

  9. A comparative study of the lipase yield by solid state and submerged ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... A comparative study of lipase enzyme yields by solid state fermentation (SSF) and submerged fermentation (SmF) was performed here. Three fungal colonies were isolated from biopharmaceutical oil waste collected from “Oushadhi” (The Pharmaceutical Corporation (IM) Kerala Ltd). The pure colonies.

  10. Wave forces limit the establishment of submerged macrophytes in large shallow lakes

    NARCIS (Netherlands)

    Zuidam, van B.G.; Peeters, E.T.H.M.

    2015-01-01

    We studied the effect of waves on submerged macrophytes and hypothesized that exposure to large wave forces can hamper seedling establishment. In an indoor experiment in cylindrical mesocosms we tested whether large wave forces indeed inhibited the establishment of Chara globularis and Potamogeton

  11. Wave attenuation by submerged vegetation: combining the effect of organism traits and tidal current

    NARCIS (Netherlands)

    Paul, M.; Bouma, T.J.; Amos, C.L.

    2012-01-01

    Accurate wave height prediction along the shore plays an important role in coastal protection and management. To account for the effect of submerged vegetation in wave-attenuation models, it is important to understand how the interaction between vegetation characteristics and hydrodynamic forcing

  12. Clonal variation in the thermal response of the submerged aquatic macrophyte Potamogeton pectinatus

    NARCIS (Netherlands)

    Pilon, J.; Santamaria, L.

    2002-01-01

    Broadly distributed plants have to cope with dramatic differences across latitude in the prevailing environmental temperature. We investigated the effect of water temperature on plant morphology, biomass accumulation and oxygen-exchange for five clones of the submerged aquatic macrophyte Potamogeton

  13. Over-expression of Sub1 A, a submergence tolerance gene from ...

    African Journals Online (AJOL)

    Sub1A, an ethylene-response-factor-like (ERE-like) gene, mediates the extinguished submergence tolerance of rice. To gain further insight into the function of Sub1A in other species, we transformed tobacco plants with the gene under the control of the ubiquitin promoter. Compared to the wild-type plants, transgenic plants ...

  14. Deep water marine algal flora of the submerged banks off west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ambiye, V.; Untawale, A.G.

    A survey of submerged banks off India viz Cora Divh, Sessostris and Bassas de-Pedro resulted in obtaining information on the rich and diverse marine algal flora from various depths ranging from 18-70 m. A programme of onboard dredging was undertaken...

  15. A survey of estuarine submerged aquatic vegetation in the northern Gulf coast

    Science.gov (United States)

    Carter, J.

    2003-01-01

    The status of submerged aquatic vegetation along the northern Gulf of Mexico is of concern because of its role in the ecology and economy of the coast. Recent studies by U.S. Geological Survey scientists help assess the factors that contribute to SAV distribution and health.

  16. Transient Marangoni waves due to impulsive motion of a submerged body

    CERN Document Server

    Shu, Jian-Jun

    2014-01-01

    The Oseen problem in a viscous fluid is formulated for studying the transient free-surface and Marangoni waves generated by the impulsive motion of a submerged body beneath a surface with surfactants. Wave asymptotics and wavefronts for large Reynolds numbers are obtained by employing Lighthill's two-stage scheme. The results obtained show explicitly the effects of viscosity and surfactants on Kelvin wakes.

  17. Competition between free-floating and submerged macrophytes in a future of climate change

    NARCIS (Netherlands)

    Netten, J.J.C.

    2011-01-01


    This research was about the asymmetric competition between free-floating and submerged macrophytes in shallow freshwater ecosystems. I studied the effect of climate change on the dominance of free-floating macrophytes in temperate regions. The research approach was a combination of outdoor

  18. The mechanism of improved aeration due to gas films on leaves of submerged rice.

    Science.gov (United States)

    Verboven, Pieter; Pedersen, Ole; Ho, Quang Tri; Nicolai, Bart M; Colmer, Timothy D

    2014-10-01

    Some terrestrial wetland plants, such as rice, have super-hydrophobic leaf surfaces which retain a gas film when submerged. O2 movement through the diffusive boundary layer (DBL) of floodwater, gas film and stomata into leaf mesophyll was explored by means of a reaction-diffusion model that was solved in a three-dimensional leaf anatomy model. The anatomy and dark respiration of leaves of rice (Oryza sativa L.) were measured and used to compute O2 fluxes and partial pressure of O2 (pO2 ) in the DBL, gas film and leaf when submerged. The effects of floodwater pO2 , DBL thickness, cuticle permeability, presence of gas film and stomatal opening were explored. Under O2 -limiting conditions of the bulk water (pO2  gas film significantly increases the O2 flux into submerged leaves regardless of whether stomata are fully or partly open. With a gas film, tissue pO2 substantially increases, even for the slightest stomatal opening, but not when stomata are completely closed. The effect of gas films increases with decreasing cuticle permeability. O2 flux and tissue pO2 decrease with increasing DBL thickness. The present modelling analysis provides a mechanistic understanding of how leaf gas films facilitate O2 entry into submerged plants. © 2014 John Wiley & Sons Ltd.

  19. Acclimation of a terrestrial plant to submergence facilitates gas exchange under water

    NARCIS (Netherlands)

    Mommer, L.; Pedersen, O.; Visser, E.J.W.

    2004-01-01

    Flooding imposes stress upon terrestrial plants since it severely hampers gas exchange rates between the shoot and the environment. The resulting oxygen deficiency is considered to be the major problem for submerged plants. Oxygen microelectrode studies have, however, shown that aquatic plants

  20. A comparative study of the lipase yield by solid state and submerged ...

    African Journals Online (AJOL)

    A comparative study of lipase enzyme yields by solid state fermentation (SSF) and submerged fermentation (SmF) was performed here. Three fungal colonies were isolated from biopharmaceutical oil waste collected from “Oushadhi” (The Pharmaceutical Corporation (IM) Kerala Ltd). The pure colonies were then used as ...

  1. Impact of submerged macrophytes including charophytes on phyto- and zooplankton communities: allelopathy versus other mechanisms

    NARCIS (Netherlands)

    Van Donk, E.; Van de Bund, W.J.

    2002-01-01

    Submerged macrophytes are crucial for the stabilization of the clear water state in shallow, mesotrophic and eutrophic lakes. Especially, charophytes often play an important role because they are typically rapid colonizers and because charophyte meadows are believed to have a particularly strong

  2. Differential response to climatic variation of free-floating and submerged macrophytes in ditches

    NARCIS (Netherlands)

    Netten, J.J.C.; Zuidam, van J.P.; Kosten, S.; Peeters, E.T.H.M.

    2011-01-01

    1. Experimental studies have indicated in freshwater ecosystems that a shift in dominance from submerged to free-floating macrophytes may occur with climate change because of increased water surface temperatures and eutrophication. Field evidence is, however, rare. 2. Here, we analysed long-term (26

  3. Ethylene response factor BnERF2-like (ERF2.4 from Brassica napus L. enhances submergence tolerance and alleviates oxidative damage caused by submergence in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yanyan Lv

    2016-06-01

    Full Text Available Ethylene response factor proteins play an important role in regulating a variety of stress responses in plants, but their exact functions in submergence stress are not well understood. In this study, we isolated BnERF2.4 from Brassica napus L. to study its function in submergence tolerance. The expression of the BnERF2.4 gene in B. napus and the expression of antioxidant enzyme genes in transgenic Arabidopsis were analyzed by quantitative RT-PCR. The expression of BnERF2.4 was induced by submergence in B. napus and the overexpression of BnERF2.4 in Arabidopsis increased the level of tolerance to submergence and oxidative stress. A histochemical method detected lower levels of H2O2, O2•− and malondialdehyde (MDA in transgenic Arabidopsis. Compared to the wild type, transgenic lines also had higher soluble sugar content and higher activity of antioxidant enzymes, which helped to protect plants against the oxidative damage caused by submergence. It was concluded that BnERF2.4 increased the tolerance of plants to submergence stress and may be involved in regulating soluble sugar content and the antioxidant system in defense against submergence stress.

  4. Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

    Directory of Open Access Journals (Sweden)

    Jessica E M van der Wal

    Full Text Available Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

  5. Crestal bone loss around submerged and nonsubmerged dental implants: A systematic review.

    Science.gov (United States)

    Al Amri, Mohammad D

    2016-05-01

    To my knowledge, there is no systematic review of crestal bone loss (CBL) around submerged and nonsubmerged dental implants. The purpose of this review was to systematically assess CBL around submerged and nonsubmerged dental implants. The addressed focused question was, "Does crestal and subcrestal placement of dental implants influence crestal bone levels?" Databases were searched from 1986 through October 2015 using different combinations of the following keywords: crestal, sub-crestal, bone loss, dental implant, submerged, and nonsubmerged. Reference lists of potentially relevant original and review articles were hand-searched to identify any further studies. Letters to the editor, case reports, commentaries, studies on platform-switched implants, and studies published in languages other than English were excluded. In total, 13 studies (6 human and 7 animal), which were performed at universities, were included. In the human studies, the number of participants ranged from 8 to 84 individuals. The follow-up period ranged from 1 to 5 years. CBL at the test sites ranged from 0.17 mm to 0.9 mm and at control sites from 0.02 mm to 1.4 mm. Five human studies reported no significant difference in CBL around implants placed at the test and control sites. All animal studies were performed in dogs with a mean age ranging from 1 to approximately 2 years. The follow-up period ranged from 2 to 6 months. Four animal studies reported no significant difference in CBL around submerged and nonsubmerged implants. No significant difference in CBL was found around submerged and nonsubmerged dental implants. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. Improvement of Photosynthesis by Sub1 QTL in Rice Under Submergence: Probed by Chlorophyll Fluorescence OJIP Transients

    Directory of Open Access Journals (Sweden)

    Panda Debabrata

    2011-09-01

    Full Text Available The influence of submergence on the photosynthetic activity in rice plants either possessing or not possessing Sub1 QTL i.e. Swarna and Swarna Sub1 cultivars (cv. were evaluated under simulated complete submergence. The leaf photosynthetic rate and stomatal conductance decreased in both the cv. during the progression of submergence as compared to control plant but significant varietal differences was observed after 1 day (d of submergence. Submergence also alters the photo-system (PS II activity, as reflected in a decrease in the values of Fo, Fm and the Fv/Fm ratio and degradation of chlorophyll, more in Swarna than that of Swarna Sub1. Under complete submergence the shape of the OJIP transient also changed in rice leaves with decrease in maximal fluorescence (P=Fm intensity, resulted lowering of variable fluorescence levels. The decrease was more pronounced in Swarna compared to the Swarna Sub1 cv. Thus, Swarna Sub1 improves photosynthetic activity showing more photosynthetic rate compared to Swarna under submergence because, of less degradation of chlorophyll, higher stomatal conductance, and efficient PS II activity.

  7. The Electric Vehicle Development

    DEFF Research Database (Denmark)

    Wang, Jingyu; Liu, Yingqi; Kokko, Ari

    2014-01-01

    In order to respond to the energy crisis and environment problem, countries carry out their research and promotion about electric vehicles. As the ten cities one thousand new energy buses started in 2009, the new energy vehicles have been greatly developed in China, while the development...... of electric vehicles is not that good. This paper selects four cities-Los Angeles, Kanagawa, Hamburg, Amsterdam-that promote electric vehicles successfully and deeply analyzes the development of electric vehicles in these four cities and analyzes the factors that affect the development of electric vehicles...... in three aspects-city environment, government and stakeholders. Then the paper discusses the promotion ways and role of government and consumer. Finally, the paper offers some suggestions to promote electric vehicles in China: focusing on feasibility and adaptability of electric vehicles, playing...

  8. Bridge vehicle impact assessment.

    Science.gov (United States)

    2011-12-01

    Bridges in New York State have been experiencing close to 200 bridge hits a year. These : accidents are attributed to numerous factors including: improperly stored equipment on trucks; : violation of vehicle posting signs; illegal commercial vehicles...

  9. LATCH usability in vehicles.

    Science.gov (United States)

    2012-04-01

    This project investigated the usability of Lower Anchors and Tethers for CHildren (LATCH) hardware by measuring LATCH implementations in 98 2011 or 2010 model-year vehicles. ISO and SAE LATCH usability rating systems were used to assess all vehicles ...

  10. Submerging vehicles : an account of descriptive and experimental research undertaken for the Minister of Social Affairs and Public Health.

    NARCIS (Netherlands)

    Vis, A.A.

    1973-01-01

    This report is a translation of the dutch document "auto's te water". This report from the Netherlands concerns investigations of cars that crash into water. The investigation was conducted in two sections, descriptive and experimental research. In the latter, investigation is made of the

  11. Electric Vehicle Charging Modeling

    OpenAIRE

    Grahn, Pia

    2014-01-01

    With an electrified passenger transportation fleet, carbon dioxide emissions could be reduced significantly depending on the electric power production mix. Increased electric power consumption due to electric vehicle charging demands of electric vehicle fleets may be met by increased amount of renewable power production in the electrical systems. With electric vehicle fleets in the transportation system there is a need for establishing an electric vehicle charging infrastructure that distribu...

  12. ROV, Remote Operated Vehicle

    OpenAIRE

    Patiris, Ioannis

    2015-01-01

    The purpose of this thesis is to show the basic principles of a Remote Operated Vehicle. The aim is also to document in detail how a small scale remote operated vehicle is constructed from the start. This thesis provides theoretical information about remote operated vehicles, as well as ex-plains the construction of hobbyist Remote Operated Vehicle as I carried it out. In the theoretical part information about the history, classification and the cables used in modern Re-mote Operated Vehi...

  13. Costs of swimming measured at optimum speed: scale effects, differences between swimming styles, taxonomic groups and submerged and surface swimming.

    Science.gov (United States)

    Videler, J J; Nolet, B A

    1990-01-01

    1. Data on swimming energy expenditure of 30 submerged and nine surface swimmers, covering different swimming styles and taxonomic groups, are selected from the literature. 2. The costs of transport at the optimum speed are compared and related to body mass and Re numbers. 3. Fish and turtles use relatively less and most surface swimmers slightly more energy than the other submerged swimmers; man and mink are poorly adapted to swimming. 4. The metabolic rate in W at optimum speed is approximately equal to the body mass in kg for fish and turtles and three times the mass figure for the other submerged swimmers.

  14. Electric Vehicle Technician

    Science.gov (United States)

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  15. MRV - Modular Robotic Vehicle

    Science.gov (United States)

    Ridley, Justin; Bluethmann, Bill

    2015-01-01

    The Modular Robotic Vehicle, or MRV, completed in 2013, was developed at the Johnson Space Center in order to advance technologies which have applications for future vehicles both in space and on Earth. With seating for two people, MRV is a fully electric vehicle modeled as a "city car", suited for busy urban environments.

  16. Road-rail vehicle

    NARCIS (Netherlands)

    Evers, J.J.M.

    2002-01-01

    A transport vehicle equipped with a number of first wheel sets, having wheels provided with tires, to which steering means and driving means, if any, are coupled to enable the transport vehicle to be moved over a road surface. The transport vehicle further comprises at least one second wheel set,

  17. Automotive vehicle sensors

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.

    1995-09-01

    This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.

  18. Electric vehicles: Driving range

    Science.gov (United States)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  19. Procurement Policy for Armored Vehicles

    National Research Council Canada - National Science Library

    Jolliffe, Richard B; Burton, Bruce A; Carros, Deborah L; Schaefer, Beth K; Truong, Linh; Palmer, Kevin A; Chun, Judy M; Smith, Jessica M; Abraham, Amanda M; Peters, Anthony R

    2007-01-01

    ...., and Armor Holdings, Inc., for armored vehicles. This report addresses armored vehicles, specifically the Buffalo Mine Protected Clearance Vehicle, the Cougar, the Joint Explosive Ordnance Disposal Rapid Response Vehicle (JERRV...

  20. Ariane transfer vehicle scenario

    Science.gov (United States)

    Deutscher, Norbert; Cougnet, Claude

    1990-10-01

    ESA's Ariane Transfer Vehicle (ATV) is a vehicle design concept for the transfer of payloads from Ariane 5 launch vehicle orbit insertion to a space station, on the basis of the Ariane 5 program-developed Upper Stage Propulsion Module and Vehicle Equipment Bay. The ATV is conceived as a complement to the Hermes manned vehicle for lower cost unmanned carriage of logistics modules and other large structural elements, as well as waste disposal. It is also anticipated that the ATV will have an essential role in the building block transportation logistics of any prospective European space station.

  1. Space vehicle chassis

    Science.gov (United States)

    Judd, Stephen; Dallmann, Nicholas; Seitz, Daniel; Martinez, John; Storms, Steven; Kestell, Gayle

    2017-07-18

    A modular space vehicle chassis may facilitate convenient access to internal components of the space vehicle. Each module may be removable from the others such that each module may be worked on individually. Multiple panels of at least one of the modules may swing open or otherwise be removable, exposing large portions of the internal components of the space vehicle. Such chassis architectures may reduce the time required for and difficulty of performing maintenance or modifications, may allow multiple space vehicles to take advantage of a common chassis design, and may further allow for highly customizable space vehicles.

  2. EAARL-B Submerged Topography–Saint Croix, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII XYZ point cloud data for a portion of the submerged environs of Saint Croix, U.S. Virgin Islands, was produced from remotely sensed, geographically referenced...

  3. EAARL-B Submerged Topography–—Saint Thomas, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — ASCII XYZ point cloud data for a portion of the submerged environs of Saint Thomas, U.S. Virgin Islands, was produced from remotely sensed, geographically referenced...

  4. Seed weight and germination behavior of the submerged plant Potamogeton pectinatus in the arid zone of northwest China

    National Research Council Canada - National Science Library

    Li, Zhongqiang; Lu, Wei; Yang, Lei; Kong, Xianghong; Deng, Xuwei

    2015-01-01

    .... This study examined within‐species variation in seed weight and germination attributes and the effects of environmental factors on seed traits of the submerged plant P otamogeton pectinatus in the arid zone of northwest China...

  5. Medium selection for exopolysaccharide and biomass production in submerged cultures of culinary-medicinal mushrooms from Turkey

    NARCIS (Netherlands)

    Kizilcik, M.; Yamaç, M.; Griensven, van L.J.L.D.

    2010-01-01

    The present study investigates the exopolysaccharide (EPS) and biomass production of 18 strains of 15 species of culinary-medicinal higher Basidiomycetes in submerged culture under four different media. Gloeophyllum abietinum and Schizophyllum commune produced the highest EPS and biomass

  6. Surviving floods: leaf gas films improve O2 and CO2 exchange, root aeration, and growth of completely submerged rice

    DEFF Research Database (Denmark)

    Pedersen, Ole; Rich, Sarah Meghan; Colmer, Timothy David

    2009-01-01

    that the improved gas exchange was not caused by differences in diffusive boundary layers adjacent to submerged leaves with or without gas films; instead, reduced resistance to gas exchange was probably due to the enlarged water–gas interface (cf. aquatic insects). When gas films were removed artificially......When completely submerged, the leaves of some species retain a surface gas film. Leaf gas films on submerged plants have recently been termed 'plant plastrons', analogous with the plastrons of aquatic insects. In aquatic insects, surface gas layers (i.e. plastrons) enlarge the gas–water interface...... to promote O2 uptake when under water; however, the function of leaf gas films has rarely been considered. The present study demonstrates that gas films on leaves of completely submerged rice facilitate entry of O2 from floodwaters when in darkness and CO2 entry when in light. O2 microprofiles showed...

  7. EAARL-B coastal topography: Fire Island, New York, pre-Hurricane Sandy, 2012: seamless (bare earth and submerged)

    Science.gov (United States)

    Wright, C. Wayne; Kranenburg, Christine J.; Klipp, Emily S.; Troche, Rodolfo J.; Fredericks, Alexandra M.; Masessa, Melanie L.; Nagle, David B.

    2014-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived seamless (bare-earth and submerged) topography datasets were produced by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida.

  8. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Science.gov (United States)

    Arrichiello, Filippo; Antonelli, Gianluca; Aguiar, Antonio Pedro; Pascoal, Antonio

    2013-01-01

    The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV) localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the performance of an

  9. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Directory of Open Access Journals (Sweden)

    Filippo Arrichiello

    2013-11-01

    Full Text Available The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the

  10. XRD and DTA Analysis of Developed Agglomerated Fluxes for Submerged Arc Welding

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2013-01-01

    Full Text Available A unique study of structural and chemical analysis of crystalline phases in developed agglomerated fluxes was carried out. Thirty-two fluxes were developed by using a mixture of oxides, halides, carbonates, silicates, and ferroalloys for submerged arc welding. The present paper focuses on only ten (out of thirty-two fluxes which were analyzed by X-ray diffraction (XRD to know the different types of oxides formed and changed in oxidation number of metallic centers after sintering process at around 850∘C. To know the effect of temperature over phase transformation and melting of different compounds, differential thermal analysis (DTA was carried out from 1000 to 1400∘C. This study aims to know the quantity of ions present (percentage and melting behavior of developed agglomerated fluxes for submerged arc welding process.

  11. Two-flow simulation of the natural light field within a canopy of submerged aquatic plants

    Science.gov (United States)

    Ackleson, S. G.; Klemas, V.

    1986-01-01

    A two-flow model is developed to simulate a light field composed of both collimated and diffuse irradiance within natural waters containing a canopy of bottom-adhering plants. To account for the effects of submerging a canopy, the transmittance and reflectance terms associated with each plant structure (leaves, stems, fruiting bodies, etc.) are expressed as functions of the ratio of the refractive index of the plant material to the refractive index of the surrounding media and the internal transmittance of the plant stucture. Algebraic solutions to the model are shown to yield plausible physical explanations for unanticipated variations in volume reflectance spectra. The effect of bottom reflectance on the near-bottom light field is also investigated. These indicate that within light-limited submerged aquatic plant canopies, substrate reflectance may play an important role in determining the amount of light available to the plants and, therefore, canopy productivity.

  12. Acclimation of a terrestrial plant to submergence facilitates gas exchange under water

    DEFF Research Database (Denmark)

    Mommer, L.; Pedersen, O.; Visser, E. J. W.

    2004-01-01

    Flooding imposes stress upon terrestrial plants since it severely hampers gas exchange rates between the shoot and the environment. The resulting oxygen deficiency is considered to be the major problem for submerged plants. Oxygen microelectrode studies have, however, shown that aquatic plants...... maintain relatively high internal oxygen pressures under water, and even may release oxygen via the roots into the sediment, also in dark. Based on these results, we challenge the dogma that oxygen pressures in submerged terrestrial plants immediately drop to levels at which aerobic respiration is impaired....... The present study demonstrates that the internal oxygen pressure in the petioles of Rumex palustris plants under water is indeed well above the critical oxygen pressure for aerobic respiration, provided that the air-saturated water is not completely stagnant. The beneficial effect of shoot acclimation...

  13. Wave energy absorption by a submerged air bag connected to a rigid float

    DEFF Research Database (Denmark)

    Kurniawan, Adi; Chaplin, J. R.; Hann, M. R.

    2017-01-01

    A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements are gene......A new wave energy device features a submerged ballasted air bag connected at the top to a rigid float. Under wave action, the bag expands and contracts, creating a reciprocating air flow through a turbine between the bag and another volume housed within the float. Laboratory measurements...... are generally in good agreement with numerical predictions. Both show that the trajectory of possible combinations of pressure and elevation at which the device is in static equilibrium takes the shape of an S. This means that statically the device can have three different draughts, and correspondingly three...

  14. [Applied study of the submerged macrophytes bed-immobilized bacteria in drinking water restoration].

    Science.gov (United States)

    Chen, Qi-Chun; Li, Zheng-Kui; Wang, Yi-Chao; Wu, Kai; Fan, Nian-Wen

    2012-01-01

    The effect of submerged macrophytes bed-immobilized bacteria technology which applied in drinking water restoration was studied. Ammonifying bacteria, nitrobacteria, nitrosobacteria and denitrifying bacteria which isolated from Taihu Labe was immobilized to the porous carries, combined with the submerged macrophytes bed technology, we applied the new equipment in water restoration of gonghu bay, this equipment has good ability to resist storm, the denitrifying bacteria number increased from 5.4 x 10(2)-2.7 x 10(3) to 3.9 x 10(5)-9.1 x 10(5), N2O flux of experimental plot was 3-24 microg x (m2 x h)(-1), it's more than the contrast group obviously, TN concentration reduced 19% - 74%, while NO3- concentration reduced 24% -81% after the equipment running a period of time; The experimental data of 120 days showed that this technology is suitable for drinking water restoration, as it can control eutrophication.

  15. Ultrasound imaging measurement of submerged topography in the muddy water physical model

    Science.gov (United States)

    Xiao, Xiongwu; Guo, Bingxuan; Li, Deren; Zou, Xianjian; Zhang, Peng; liu, Jian-chen; Zang, Yu-fu

    2015-08-01

    The real-time, accurate measurement of submerged topography is vital for the analysis of riverbed erosion and deposition. This paper describes a novel method of measuring submerged topography in the B-scan image obtained using an ultrasound imaging device. Results show the distribution of gray values in the image has a process of mutation. This mutation process can be used to adaptively track the topographic lines between riverbed and water, based on the continuity of topography in the horizontal direction. The extracted topographic lines, of one pixel width, are processed by a wavelet filtering method. Compared with the actual topography, the measurement accuracy is within 1 mm. It is suitable for the real-time measurement and analysis of all current model topographies with the advantage of good self-adaptation. In particular, it is visible and intuitive for muddy water in the movable-bed model experiment.

  16. Onshore and nearshore explorations along the Maharashtra Coast: With a view to locating ancient ports and submerged sites

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.; Gaur, A.S.

    and Nearshore Explorations along the Maharashtra Coast: with a View to Locating Ancient Ports and Submerged Sites Sila Tripati and A.S. Gaur Marine Archaeology Centre National Institute of Oceanography Dona Paula Goa 403 004 Abstract Coastal explorations... migrations by exploring and excavating defunct and submerged ports as well as sunken ships. A systematic attempt has been made by the National Institute of Oceanography (NIO) to explore and study the ancient ports and their locations all along the coast...

  17. Contribution of seedling vigour and anoxia/hypoxia-responsive genes to submergence tolerance in Vietnamese lowland rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Hien Thi Thu Vu

    2016-09-01

    Full Text Available A direct-seeded rice cultivation system has been widely adopted in Asian countries. Optimum germination and vigorous seedling growth under submergence are key traits for the practice of direct seeding. We studied the post-germination seedling vigour in Vietnamese lowland rice accessions based on three bio-parameters, shoot elongation growth under five-day submergence in water-filled test-tubes, seedling recovery rate five days after transferring submerged seedlings to pots with soil and seedling survival rate 21 days after sowing seeds in nursery beds and immediate incubation under submergence. A large diversity was found in seedling vigour thus estimated among the accessions. Significantly high correlations were observed among all three bio-parameters, verifying the contribution of seedling vigour to the manifestation of submergence tolerance at this critical stage of rice development. To examine the roles of anoxia/hypoxia-responsive genes, the expression of 17 candidate genes was studied by reverse transcription polymerase chain reaction (RT-PCR and compared between selected vigorous and non-vigorous groups of accessions. Transcripts of all but two genes showed marked accumulation in submerged seedlings. No differences, however, were found between the two contrasting groups. The observed common and coordinate expression of anoxia/hypoxia-induced genes suggests that they might assume roles in attaining baseline tolerance against submergence stress. It was also suggested that some unknown genetic factors are operating in determining cultivar/genotype-specific levels of submergence tolerance as assessed by post-germination seedling vigour.

  18. A new mechanism of macrophyte mitigation: how submerged plants reduce malathion's acute toxicity to aquatic animals.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2014-08-01

    A growing body of evidence suggests that aquatic plants can mitigate the toxicity of insecticides to sensitive aquatic animals. The current paradigm is that this ability is driven primarily by insecticide sorption to plant tissues, especially for hydrophobic compounds. However, recent work shows that submerged plants can strongly mitigate the toxicity of the relatively hydrophilic insecticide malathion, despite the fact that this compound exhibits a slow sorption rate to plants. To examine this disparity, we tested the hypothesis that the mitigating effect of submerged plants on malathion's toxicity is driven primarily by the increased water pH from plant photosynthesis causing the hydrolysis of malathion, rather than by sorption. To do this, we compared zooplankton (Daphnia magna) survival across five environmentally relevant malathion concentrations (0, 1, 4, 6, or 36 μg L(-1)) in test containers where we chemically manipulated water pH in the absence of plants or added the submerged plant (Elodea canadensis) but manipulated plant photosynthetic activity via shading or no shading. We discovered that malathion was equally lethal to Daphnia at all concentrations tested when photosynthetically inactive (i.e. shaded) plants were present (pH at time of dosing=7.8) or when pH was chemically decreased (pH=7.7). In contrast, when photosynthetically active (i.e. unshaded) plants were present (pH=9.8) or when pH was chemically increased (pH=9.5), the effects of 4 and 6 μg L(-1) of malathion on Daphnia were mitigated strongly and to an equal degree. These results demonstrate that the mitigating effect of submerged plants on malathion's toxicity can be explained entirely by a mechanism of photosynthesizing plants causing an increase in water pH, resulting in rapid malathion hydrolysis. Our findings suggest that current ecotoxicological models and phytoremediation strategies may be overlooking a critical mechanism for mitigating pesticides. Copyright © 2014 Elsevier Ltd

  19. Geothermal Investigations of California Submerged Lands and Spherical Flow in Naturally Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Northup, William F.; Everitts, D.J.; Eaton, C.F.; Welday, E.E.; Martin, Roger C.; Ershaghi, Iraj; Wilde, P.; Oldson, J.C.; Case, C.W.

    1976-01-01

    A large portion of California State-owned land is the tidal and submerged land along the coastline and around the islands that extends seaward for three geographical miles. Other large areas of State-owned lands form the beds of lakes and navigable rivers. Some evidence, such as the proximity of hot springs, indicates there may be important geothermal potential on these lands. The purpose of this project is to develop methods, tools, and interpretive techniques to explore for and evaluate geothermal resources on submerged lands. Presently, the state of the art is primitive because there has been little interest or effort in assessing the resource potential of submerged lands, and the limited work carried out thus far has been for scientific purposes. There has been a moderate amount of water temperature measuring for oceanographic or limnologic studies and fairly reliable techniques exist. There have been limited measurements of the temperature, thermal gradient, and heat flow in bottom sediment of the ocean area off California and from the lakes. Probably less than a dozen data points exist for State-owned land. This work was done using large equipment, such as piston corers with outrigger-mounted thermistors arrayed along the core barrels. To achieve penetration, such equipment requires heavy weights, strong cable, heavy duty winches, large crews and oceanographic research-type vessels or large barges, and this entails considerable expenses and logistical problems. Clearly, many hundreds, or thousands of data points are required for a remotely reliable evaluation of the resources. The first problem is to assess existing methods and develop others that will enable economical and efficient exploration for geothermal resources on submerged lands.

  20. Submergence rice cultivation in southern Bangladesh: farmers opinion and adaptations practices

    Directory of Open Access Journals (Sweden)

    AKM Abdul Ahad Biswas

    2015-12-01

    Full Text Available Rice productivity in coastal Bangladesh is lower than the national average and total coastal area is considered to be submergence-prone and higher vulnerable in July to January cropping season. The selected study areas are Kalapara and Patuakhali Sadar Upazila that are too vulnerable to agriculture practices. Field survey was conducted during 01st June to 30th July, 2015 to investigate the impact of submergence on Aman rice cultivation (ARC, existing adopted local adaptation practices with impacts and options to address the submergence problem. Primary data was collected through Focus Group Discussion (FGD, Individual Interview and Key Informant Interview methods and secondary data was collected from different secondary sources. A well-structured pretested questionnaire schedule was developed keeping in mind the objectives and variables under this study. After cyclone SIDR and AILA devastation, the rate of traditional ARC is decreasing every year and in 2015 it was 26.51%. Recently farmers have adopted new cropping practices and strategies like modern ARC in Aman season as single crop; Boro-Aus-Aman season as triple crop and Aus-Aman season as double crop are practicing. Approximately all farmers have adopted to grow stress tolerant rice varieties (STRV; farmer’s curiosities to familiar with and to have the STRV are encouraging. Farmers were fully adopted BRRIdhan52 rice cultivation with positive perceptions of higher yield and lower production cost. Therefore it can be concluded that the intensity of adoption of adaptation and mitigation measures are significantly influenced positively by the STRV yield capability; farmer’s participation in intervention programs; livelihood diversification; frequency of extension personnel contact; submergence and inundation characteristics; tolerance attributes of STRV and availability of STRV cultivation information.International Journal of Environment Vol.4(4 2015: 100-113

  1. Inulinase Production by a Mexican Semi-Desert Xerophylic Penicillium citrinum Strain under Submerged Culture

    OpenAIRE

    Adriana C. Flores-Gallegos; Jesús Morlett-Chávez; Aguilar, Cristóbal N.; Raúl Rodríguez-Herrera

    2012-01-01

    The aim of the study was to produce inulinase under submerged culture (SmC) by a xerophylic fungal strain isolated from the Mexican semi-dessert and to verify its potential as an industrial inulinase producer. This enzyme can be obtained from microorganisms that live in close association with inulin plant store tissues. Inulin is a widespread plant polyfructan that serves as a storage polysaccharide in several plants and its depolymerization involves the action of inulinase. Inulinases are cl...

  2. Modern morphological engineering techniques for improving productivity of filamentous fungi in submerged cultures

    OpenAIRE

    Antecka, Anna; Bizukojc, Marcin; Ledakowicz, Stanislaw

    2016-01-01

    Morphological engineering techniques have recently gained popularity as they are used for increasing the productivity of a variety of metabolites and enzymes in fungi growing in submerged cultures. Their action is mainly associated with the changes they evoke in fungal morphology. Traditional morphological engineering approaches include manipulation of spore concentration, pH-shifting and mechanical stress exerted by stirring and aeration. As the traditional methods proved to be insufficient,...

  3. A filtration model applied to submerged anaerobic MBRs (SAnMBRs)

    OpenAIRE

    Robles Martínez, Ángel; Ruano García, María Victoria; Ribes Bertomeu, José; SECO TORRECILLAS, AURORA; Ferrer, J.

    2013-01-01

    The aim of this study was to develop a model able to correctly reproduce the filtration process of submerged anaerobic MBRs (SAnMBRs). The proposed model was calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. Three suspended components were contemplated in the model: total solids concentration; dry mass of cake on the membrane surface; and dry mass of irreversible fouling on the membrane surface. The model addressed the following phys...

  4. Mathematical modelling of filtration in submerged anaerobic MBRs (SAnMBRs): long-term validation

    OpenAIRE

    Robles Martínez, Ángel; Ruano García, María Victoria; Ribes Bertomeu, José; SECO TORRECILLAS, AURORA; Ferrer, J.

    2013-01-01

    The aim of this study was the long-term validation of a model capable of reproducing the filtration process occurring in a submerged anaerobic membrane bioreactor (SAnMBR) system. The proposed model was validated using data obtained horn a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. The validation was carried out using both lightly and heavily fouled membranes operating at different bulk concentrations, gas sparging intensities and transmembrane fluxes. Acr...

  5. Design methodology for submerged anaerobic membrane bioreactors (AnMBR): A case study

    OpenAIRE

    Ferrer, J.; Pretel, R.; Durán Pinzón, Freddy; Giménez, JB; Robles Martínez, Ángel; Ruano García, María Victoria; Serralta Sevilla, Joaquín; Ribes Bertomeu, José; SECO TORRECILLAS, AURORA

    2015-01-01

    The main objective of this study is to propose guidelines for designing submerged anaerobic MBR (AnMBR) technology for municipal wastewater treatment. The design methodology was devised on the basis of simulation and experimental results from an AnMBR plant featuring industrial-scale hollow-fibre membranes. The proposed methodology aims to minimise both capital expenditure and operating expenses, and the key parameters considered were: hydraulic retention time, solids retention ti...

  6. Corncob hydrolysate, an efficient substrate for Monascus pigment production through submerged fermentation.

    Science.gov (United States)

    Zhou, Zhongxin; Yin, Zheng; Hu, Xiaoqing

    2014-01-01

    Monascus pigment has traditionally been produced by the fermentation of Monascus using rice powder or glucose as a culture substrate. Submerged fermentation can produce stable Monascus pigment yield and control the accumulation of the by-product, citrinin, which can then be more easily removed. To reduce the cost of Monascus submerged fermentation, the feasibility of corncob hydrolysate as an alternative substrate was investigated. Results showed that, when compared with a conventional glucose medium, the corncob hydrolysate medium produced an equivalent pigment yield without stimulating citrinin accumulation. Furthermore, the corncob hydrolysate medium and cultivation conditions were optimized to enhance pigment production and decrease citrinin synthesis. When Monascus sp. was cultured under dark conditions in the presence of caprylic acid, pigment production was increased to 25.8 ± 0.8 UA500 /mL, which was higher than that achieved in a glucose medium (24.0 ± 0.9 UA500 /mL), and those obtained in previously reported Monascus submerged fermentations using the same yield unit; on the other hand, citrinin accumulation was decreased to 26.2 ± 1.9 µg/L, which was significantly lower than that generated in the glucose control (44.3 ± 2.2 µg/L) and in those previously reported fermentations. Thus, corncob hydrolysate was proved to be an efficient alternative substrate for Monascus pigment production through submerged fermentation, which showed significant advantages over a conventional glucose substrate. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  7. Natural variation of submergence tolerance among Arabidopsis thaliana accessions

    DEFF Research Database (Denmark)

    Vashisht, D.; Hesselink, A.; Pierik, R.

    2011-01-01

    in the dark. Survival curves were plotted to estimate median lethal times as a measure of tolerance. Flooding-associated survival parameters, such as root and shoot oxygen content, initial carbohydrate content and petiole elongation under water, were also measured. • There was a significant variation....... • Arabidopsis accessions show considerable variation in the ability to tolerate complete submergence, making it a good species in which to identify and characterize genes and to study mechanisms that contribute to survival under water....

  8. Competition between free-floating and submerged macrophytes in a future of climate change

    OpenAIRE

    Netten, J.J.C.

    2011-01-01

    This research was about the asymmetric competition between free-floating and submerged macrophytes in shallow freshwater ecosystems. I studied the effect of climate change on the dominance of free-floating macrophytes in temperate regions. The research approach was a combination of outdoor mesocosm experiments, a laboratory experiment, a database analysis and a literature review. In Chapter 2a I explored the possibility to use inexpensive open-top chambers (OTCs) as passive artificial warmin...

  9. Growth and yield of rice submergence stress conditions in two types of swampy lowland of South Sumatera

    Science.gov (United States)

    Gribaldi, Nurlaili, Danial, E.; Rahim, S. E.

    2017-09-01

    This study aims to determine the best fertilizer treatment at vegetative stage for the growth and yield of rice submergence stress conditions on two types of swampy lowland. The experimental design used in this research was spilt-plot design with three replications. The main plot was fertilization treatment consisting of P1 = base fertilization, P2 = fertilizer before being submerged, P3 = fertilizer after being submerged + PPC Micro, P4 = fertilization before and after being submerged. The subplots are varieties of rice, V1 = Inpara 5, V2 = IR 64. The subplot was rice variety which consisted of V1 = Inpara 5, V2 = IR 64. The results showed fertilization treatment can increase rice production growth and submergence stress conditions, varieties of Inpara 5 added with fertilization before flooded can suppress a decrease in grain yield for 16 % in the shallow-backswamp and 6 % in middle-backswamps or with each production of 2.9 and 5.1 tons per hectare, varieties of Inpara 5 which is giving fertilization before flooded, tends to be a good treatment to be developed in rice submergence cultivation both in the the shallow-backswamp and middle-backswamps.

  10. Experimental studies of the stress state of the surface layer of detailat treatment with submerged jets

    Directory of Open Access Journals (Sweden)

    Олександр Олександрович Анділахай

    2015-03-01

    Full Text Available In the instrument and electrical industry was the use of the method of abrasive machining submerged jet, which is the most promising method for abrasive blasting of small parts of low stiffness. This method eliminates the main drawback сhip plants - abrasion channel nozzles or injection nozzles, but the state of the surface layer of machined parts are poorly understood and to make maximum use of the potential to provide the required quality parameters. The study of the state of the surfaces of parts resulting from abrasive blasting traditional methods, dedicated work, which define quality indicators: microhardness depth residual stress, as well as their nature (compressive, tensile. However, known from the literature values correspond to the conditions of surface treatment of parts in a fixed state with an abrasive material through the feed nozzle, and therefore the dynamics of the interaction of a single abrasive grain and significantly different parts. The process in question, and different modes of processing characteristics of the abrasive grains. In the paper, a series of experimental studies designed to assess the state of machined surfaces of parts as a result of abrasion submerged jets. It is established that during the treatment the non-oriented disorderly traces overlay the abrasive grains on the treated surface, thereby forming a tight skin layer thickness of 4 - 5 micrometers. Processed surface gets cold working, as evidenced by the study of microhardness before and after abrasive machining in a free state submerged jets

  11. Cellulase production by Aspergillus niger in biofilm, solid-state, and submerged fermentations.

    Science.gov (United States)

    Gamarra, Norma N; Villena, Gretty K; Gutiérrez-Correa, Marcel

    2010-06-01

    Cellulase production by Aspergillus niger was compared in three different culture systems: biofilm, solid-state, and submerged fermentation. Biofilm and solid-state fermentations were carried out on perlite as inert support, and lactose was used as a carbon source in the three culture systems. In cryo-scanning electron microscopy, biofilm and solid-state cultures gave similar morphological patterns and confirmed that both spore first attachment and hyphal adhered growth are helped by the production of an adhesive extracellular matrix. Biofilm cultures produced higher cellulase activities than those in submerged and solid-state cultures (1,768, 1,165, and 1,174 U l(-1), respectively). Although biofilm cultures grew less than the other cultures, they produced significantly higher cellulase yields (370, 212, and 217 U g(-1) lactose, respectively) and volumetric productivities (24, 16, and 16 U l(-1) h(-1), respectively). Likewise, endoglucanase and xylanase activities were higher in biofilm cultures. Under the conditions tested, it seems that fungal attached growth on perlite may favor better enzyme production. Biofilms are efficient systems for cellulase production and may replace solid-state fermentation. Biofilm fermentation holds promise for further optimization and development. The results of this work reveal that fungal biofilms may be used for the commercial production of cellulase employing the technology developed for submerged fermentation at high cell densities.

  12. Production of Pleurotus sajor-caju strain PS-2001 biomass in submerged culture.

    Science.gov (United States)

    Confortin, Fernanda Grison; Marchetto, Rosane; Bettin, Fernanda; Camassola, Marli; Salvador, Mirian; Dillon, Aldo José Pinheiro

    2008-10-01

    Mushrooms or fruiting bodies of many basidiomycetes are commonly produced in solid-state fermentation, generally after 20-60 days of growth. However, it is also possible to produce biomass from these fungi, in submerged fermentation in shorter time. This work was aimed at evaluating biomass production with the basidiomycete Pleurotus sajor-caju, in a submerged process and to determine the proportion of chemical components of this biomass. Initially, an optimization of the culture medium was done to produce a faster growth of microbial mass by changing the concentrations of ammonium sulfate, soy protein and yeast extract. Using the optimized culture medium, values of approximately 5.5 g L(-1) of biomass in a medium with 10 g L(-1) of glucose were attained. When the optimized culture medium was tested in a 5-L stirred tank bioreactor, using 10 g L(-1) of glucose or sucrose as carbon source, values of 8.18 and 5.94 g L(-1) of biomass concentration were obtained, respectively. In the medium with glucose, high yields (0.82 g g(-1)) and productivity of 0.085 g L(-1) h(-1) were obtained. The exopolysaccharide content (1.58 g dry matter L(-1)) in the culture was higher in the fermentation with sucrose. The nutritional composition of the biomass obtained in the submerged fermentation was similar to that of the fruiting body in terms of quantities of total carbohydrates, ash and calories, but total fat and protein were higher.

  13. Investigation of scour adjacent to submerged geotextiles used for shore protection

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, Alicia M.; Herrington, Thomas O.; Smith, Ernest R.

    2018-01-03

    This study presents the results of an experimental investigation of morphology change in the vicinity of submerged geotextiles placed within the surf zone. The study was motivated by the emerging use of submerged geotextile tubes for shore protection, shoreline stabilization, and surf amenity enhancement and the need to understand the mechanisms responsible for scour in the vicinity of these structures to preserve their structural integrity and reduce their structural failure. A movable bed physical model experiment was conducted at the U.S. Army Engineer Research and Development Center’s Large-scale Sediment Transport Facility (LSTF) to develop empirical formulations to predict the mean scour depth adjacent to geotextiles under oblique wave-breaking conditions as a function of the maximum Keulegan-Carpenter, Shields, and Reynolds numbers. The observed scour in the vicinity of the geotextiles was also compared to a previous study of scour in the vicinity of submerged cylinders. Formulations developed by Cataño-Lopera and García (2006) relating the Keulegan-Carpenter, Shields, and Reynolds numbers to the scour depth were used to predict the scour observed during the LSTF experiment. Results show that the formulations of Cataño-Lopera and García (2006) over-predict the observed scour when calculated using the maximum Keulegan-Carpenter, Shields, and Reynolds numbers. New, modified expressions of Cataño-Lopera and García (2006) were developed for use in oblique random wave fields.

  14. Effect of piano-key shape inlet on critical submergence at a vertical pipe intake

    Science.gov (United States)

    Shemshi, R.; Kabiri-Samani, A.

    2012-11-01

    Intake vortices are the result of angular momentum conservation at the flow constriction, where angular velocity increases with a decrease in the cross sectional area. The common solution for avoiding air-entrainment and swirl is to provide sufficient submergence to the intake. If the required approach flow conditions can not be met to avoid swirl and air entrainment, other approaches for preventing vortices at water intakes are considered. There are several means of avoiding air-entrainment, where the most cost-effective option is often determined by a physical model study. Among the most economical and common measures of reducing the effect of air-entrainment and swirl strength, is the optimized shape of inlet for instance by installing a Piano-Key inlet over the pipe intake. If Piano-Key inlet is used, then, its' optimum geometry should be studied experimentally. Since there is not any realized guidance for the use of Piano-Key inlets in pipe intakes, hence, a comprehensive set of model experiments have been carried out using Piano-Key inlets with different dimensions, with respect to the vertical pipe intakes, and four different pipe diameters of (D=) 75, 100, 125 and 150 mm. Results showed that by employing a Piano-Key inlet over the vertical pipe intake, the critical submergence reduces significantly. Fianally, according to the results, the effect of Piano-Key inlet geometry on critical submergence were evaluated in the form of realized relationships which would be of practical interest for design engineers.

  15. 3-D flow and scour near a submerged wing dike: ADCP measurements on the Missouri River

    Science.gov (United States)

    Jamieson, E.C.; Rennie, C.D.; Jacobson, R.B.; Townsend, R.D.

    2011-01-01

    Detailed mapping of bathymetry and three-dimensional water velocities using a boat-mounted single-beam sonar and acoustic Doppler current profiler (ADCP) was carried out in the vicinity of two submerged wing dikes located in the Lower Missouri River near Columbia, Missouri. During high spring flows the wing dikes become submerged, creating a unique combination of vertical flow separation and overtopping (plunging) flow conditions, causing large-scale three-dimensional turbulent flow structures to form. On three different days and for a range of discharges, sampling transects at 5 and 20 m spacing were completed, covering the area adjacent to and upstream and downstream from two different wing dikes. The objectives of this research are to evaluate whether an ADCP can identify and measure large-scale flow features such as recirculating flow and vortex shedding that develop in the vicinity of a submerged wing dike; and whether or not moving-boat (single-transect) data are sufficient for resolving complex three-dimensional flow fields. Results indicate that spatial averaging from multiple nearby single transects may be more representative of an inherently complex (temporally and spatially variable) three-dimensional flow field than repeated single transects. Results also indicate a correspondence between the location of calculated vortex cores (resolved from the interpolated three-dimensional flow field) and the nearby scour holes, providing new insight into the connections between vertically oriented coherent structures and local scour, with the unique perspective of flow and morphology in a large river.

  16. Screening of phytase producers and optimization of culture conditions for submerged fermentation.

    Science.gov (United States)

    Coban, Hasan B; Demirci, Ali

    2014-04-01

    Phytase (myo-inositol-hexakisphosphate phosphohydrolase) is an enzyme, which breaks down phytate to inositol and orthophosphoric acid. Phytase has been used as feed additive, and in some medical applications for years. To date, phytase production has been usually performed as a solid-state fermentation with small production volumes. Therefore, the aim of this study was to increase the phytase activity in submerged fermentations by screening several microorganism strains based on the literature to select the most productive phytase producer and optimizing growth parameters such as temperature, pH, and aeration level using response surface methodology (RSM). As a result, among the four different microorganisms evaluated, Aspergillus ficuum (NRRL 3135) was selected as the most productive strain. Optimum temperature, pH, and aeration values were determined as 33 °C, 4.5, and 0.9 vvm, respectively, for A. ficuum in 2-l batch submerged phytase productions. Under these conditions, phytase activity was measured as 2.27 U/ml. Therefore, this is a unique study showing the production of phytase with A. ficuum successfully in submerged fermentation as opposed to the traditional solid-state fermentation.

  17. Mathematical investigation of tsunami-like long waves interaction with submerge dike of different thickness

    Science.gov (United States)

    Zhiltsov, Konstantin; Kostyushin, Kirill; Kagenov, Anuar; Tyryshkin, Ilya

    2017-11-01

    This paper presents a mathematical investigation of the interaction of a long tsunami-type wave with a submerge dike. The calculations were performed by using the freeware package OpenFOAM. Unsteady two-dimensional Navier-Stokes equations were used for mathematical modeling of incompressible two-phase medium. The Volume of Fluid (VOF) method is used to capture the free surface of a liquid. The effects caused by long wave of defined amplitude motion through a submerged dike of varying thickness were discussed in detail. Numerical results show that after wave passing through the barrier, multiple vortex structures were formed behind. Intensity of vortex depended on the size of the barrier. The effectiveness of the submerge barrier was estimated by evaluating the wave reflection and transmission coefficients using the energy integral method. Then, the curves of the dependences of the reflection and transmission coefficients were obtained for the interaction of waves with the dike. Finally, it was confirmed that the energy of the wave could be reduced by more than 50% when it passed through the barrier.

  18. Antioxidant Properties of the Edible Basidiomycete Armillaria mellea in Submerged Cultures

    Directory of Open Access Journals (Sweden)

    Ming-Yeou Lung

    2011-09-01

    Full Text Available Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from dried mycelia (MEM and mycelia-free broth (MEB and hot water extracts from dried mycelia (HWEM by A. mellea submerged cultures show good antioxidant properties as evidenced by low EC50 values (< 10 mg/mL. Total flavonoid is mainly found in hot water extracts; however, total phenol is rich in methanol and hot water extracts from mycelia. Ascorbic acid and total phenol contents are well correlated with the reducing power and the scavenging effect on superoxide anions. Total flavonoid content is dependent on the antioxidant activity and the chelating effect on ferrous ions. Total antioxidant component contents are closely related to the antioxidant activity and the scavenging superoxide anion ability. Results confirm that extracts with good antioxidant properties from fermenting products by A. mellea are potential good substitutes for synthetic antioxidants and can be applied to antioxidant-related functional food and pharmaceutical industries.

  19. Antioxidant Properties of the Edible Basidiomycete Armillaria mellea in Submerged Cultures

    Science.gov (United States)

    Lung, Ming-Yeou; Chang, Yu-Cheng

    2011-01-01

    Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from dried mycelia (MEM) and mycelia-free broth (MEB) and hot water extracts from dried mycelia (HWEM) by A. mellea submerged cultures show good antioxidant properties as evidenced by low EC50 values (Total flavonoid is mainly found in hot water extracts; however, total phenol is rich in methanol and hot water extracts from mycelia. Ascorbic acid and total phenol contents are well correlated with the reducing power and the scavenging effect on superoxide anions. Total flavonoid content is dependent on the antioxidant activity and the chelating effect on ferrous ions. Total antioxidant component contents are closely related to the antioxidant activity and the scavenging superoxide anion ability. Results confirm that extracts with good antioxidant properties from fermenting products by A. mellea are potential good substitutes for synthetic antioxidants and can be applied to antioxidant-related functional food and pharmaceutical industries. PMID:22072892

  20. Scale resolving computation of submerged wall jets on flat wall with different roughness heights

    Science.gov (United States)

    Paik, Joongcheol; Bombardelli, Fabian

    2014-11-01

    Scale-adaptive simulation is used to investigate the response of velocity and turbulence in submerged wall jets to abrupt changes from smooth to rough beds. The submerged wall jets were experimentally investigated by Dey and Sarkar [JFM, 556, 337, 2006] at the Reynolds number of 17500 the Froude number of 4.09 and the submergence ratio of 1.12 on different rough beds that were generated by uniform sediments of different median diameters The SAS is carried out by means of a second-order-accurate finite volume method in space and time and the effect of bottom roughness is treated by the approach of Cebeci (2004). The evolution of free surface is captured by employing the two-phase volume of fluid (VOF) technique. The numerical results obtained by the SAS approach, incorporated with the VOF and the rough wall treatment, are in good agreement with the experimental measurements. The computed turbulent boundary layer grows more quickly and the depression of the free surface is more increased on the rough wall than those on smooth wall. The size of the fully developed zone shrinks and the decay rate of maximum streamwise velocity and Reynolds stress components are faster with increase in the wall roughness. Supported by NSF and NRF of Korea.

  1. Improved production, purification and bioactivity of a polysaccharide from submerged cultured Ganoderma lucidum.

    Science.gov (United States)

    Zhou, Huabin; Liu, Gaoqiang; Huang, Furu; Wu, Xiangting; Yang, Hailong

    2014-12-01

    Polysaccharides from Ganoderma lucidum showed multiple biological activities, such as immuno-modulating, antitumor, antioxidant, and hepatoprotective activity, etc. Adlay oil was added into the media to enhance polysaccharide production by submerged culture of G. lucidum in this work. The results revealed the optimal concentration of adlay oil was 1.5 % for polysaccharide production of G. lucidum. Analysis of the polysaccharide components confirmed that no novel components were biosynthesized by the addition of adlay oil. The main fraction of extracellular polysaccharide, GLEP-2, was isolated from the submerged culture broth of G. lucidum by ethanol precipitation, filtration, DEAE cellulose-52 and Sepharose CL-6B chromatography. GLEP-2, which was composed of glucose, galactose, mannose, arabinose, and rhamnose in a ratio of 332:55:32:13:3 respectively, had an average molecular weight of ~2.08 × 10(4) Da. The bioactivity tests demonstrated that GLEP-2 enhanced the T lymphocyte proliferation significantly at a concentration of 200 μg/mL and B lymphocyte proliferation at lower concentrations of 50 μg/mL. The results suggest polysaccharides from the submerged culture of G. lucidum are potential candidates for further development and possible commercial applications, especially in the pharmaceutical and functional foods industries.

  2. Oral administration of submerged cultivated Grifola frondosa enhances phagocytic activity in normal mice.

    Science.gov (United States)

    Wang, Lisu; Ha, Choi-Lan; Cheng, Tso-Lin; Cheng, Su-Yun; Lian, Tzi-Wei; Wu, Ming-Jiuan

    2008-02-01

    Grifola frondosa fruiting body (Maitake) has been used as a dietary supplement due to its antitumour and immunomodulatory properties. The aim of this study was to evaluate the immunomodulatory effects of orally administered submerged cultivated G. frondosa mixture, including both mycelium and culture broth, in a healthy murine model. Composition analyses showed that submerged cultivated G. frondosa mixture contained only 32.48% carbohydrate, which was less than half of fruiting bodies. The content of adenosine, a potential immunomodulatory agent in medicinal mushrooms, was 2.8 mg g(-1). After feeding 8-week-old female BALB/cByJ mice with AIN-93G diet containing 0% (C), 1% (G1), 3% (G3) or 5% (G5) (wt/wt) G. frondosa mixture for 31 days, neither body weight nor the outward appearance of organs showed any significant difference among different diet groups. Splenocyte subpopulation, mitogen-activated cytokine release and splenic NK activity were not affected by G. frondosa administration, either. On the other hand, the phagocytic activity was enhanced in leucocytes of groups G3 and G5, without exerting detectable levels of serum proinflammatory cytokines. These results suggested that oral administration of submerged cultivated G. frondosa mixture may enhance host innate immunity against foreign pathogens without eliciting adverse inflammatory response.

  3. Dynamic Behaviour of Submerged Floating Tunnels under Seismic Loadings with Different Cable Configurations

    Directory of Open Access Journals (Sweden)

    Endah Wahyuni

    2012-05-01

    Full Text Available The paper presents the dynamic behavior of a Submerged Floating Tunnel (SFT in the Seribu Archipelago crossing under seismic loadings by using the different cable configurations. The SFT is a tubular structure submerged in the water at a fixed depth, which features several advantages from the structural and environmental impact points of view. In particular, the structural system is suited for waterway crossings in seismicity zones. Its interaction with the water provides additional damping and inertia to the system. To evaluate the SFT structural response of seismic loadings, a response spectrum analyses were carried out, in which the ground multi-support excitation is considered. The investigation of the different cable system configurations were also carried out. Both static and dynamic analyses were carried to find the optimal configuration of the structural system. Although the paper has had a definitive conclusion yet, the results gave useful indications of responses of Submerged Floating Tunnels subjected to earthquake. The SFT with two cable diagonals perpendicular with SFT’s body (called Model C shows the optimal structural configuration compared with others.

  4. Oblique wave motion over multiple submerged porous bars near a vertical wall

    Science.gov (United States)

    Zhao, Yang; Liu, Yong; Li, Huajun; Chang, Anteng

    2017-08-01

    This study examines oblique wave motion over multiple submerged porous bars in front of a vertical wall. Based on linear potential theory, an analytical solution for the present problem is developed using matched eigenfunction expansions. A complex dispersion relation is adopted to describe the wave elevation and energy dissipation over submerged porous bars. In the analytical solution, no limitations on the bar number, bar size, and spacing between adjacent bars are set. The convergence of the analytical solution is satisfactory, and the correctness of the analytical solution is confirmed by an independently developed multi-domain BEM (boundary element method) solution. Numerical examples are presented to examine the reflection and transmission coefficients of porous bars, C R and C T , respectively, for engineering applications. The calculation results show that when the sum of widths for all the porous bars is fixed, increasing the bar number can significantly improve the sheltering function of the bars. Increasing the bar height can cause more wave energy dissipation and lower C R and C T . The spacing between adjacent bars and the spacing between the last bar and the vertical wall are the key parameters affecting C R and C T . The proposed analytical method may be used to analyze the hydrodynamic performance of submerged porous bars in preliminary engineering designs.

  5. Improving cellulase production in submerged fermentation by the expression of a Vitreoscilla hemoglobin in Trichoderma reesei.

    Science.gov (United States)

    Lin, Jie; Zhang, Xiamei; Song, Bingran; Xue, Wei; Su, Xiaoyun; Chen, Xiuzhen; Dong, Zhiyang

    2017-11-15

    Trichoderma reesei is well known as an industrial workhorse fungus in cellulase production. The low dissolved oxygen supply in the highly viscous medium of T. reesei remains a major bottleneck that hampers growth and cellulase production in submerged fermentation. Vitreoscilla hemoglobin (VHb) has been demonstrated to improve metabolism and protein production in different heterologous hosts under hypoxic conditions, but the use of VHb in T. reesei remains uninvestigated. This study examines the effect of VHb in improving T. reesei performance in submerged fermentation. The VHb gene (vgb)-expressing cassette was successfully transformed into the TU-6 strain, integrated into the genome of T. reesei, and functionally expressed with biological activity, which was confirmed by carbon monoxide difference analysis. Compared to the parent strain, the expression of VHb increased the glucose consumption rate of the transformant. Moreover, in cellulase-inducing medium total protein secretion of the VHb expressing strain was 2.2-fold of the parental strain and the filter paper cellulase activity was increased by 58% under oxygen-limiting conditions. In summary, our results demonstrate that VHb has beneficial effects on improving total protein secretion and cellulase activity of T. reesei in submerged fermentation.

  6. Enhanced effects of biotic interactions on predicting multispecies spatial distribution of submerged macrophytes after eutrophication.

    Science.gov (United States)

    Song, Kun; Cui, Yichong; Zhang, Xijin; Pan, Yingji; Xu, Junli; Xu, Kaiqin; Da, Liangjun

    2017-10-01

    Water eutrophication creates unfavorable environmental conditions for submerged macrophytes. In these situations, biotic interactions may be particularly important for explaining and predicting the submerged macrophytes occurrence. Here, we evaluate the roles of biotic interactions in predicting spatial occurrence of submerged macrophytes in 1959 and 2009 for Dianshan Lake in eastern China, which became eutrophic since the 1980s. For the four common species occurred in 1959 and 2009, null species distribution models based on abiotic variables and full models based on both abiotic and biotic variables were developed using generalized linear model (GLM) and boosted regression trees (BRT) to determine whether the biotic variables improved the model performance. Hierarchical Bayesian-based joint species distribution models capable of detecting paired biotic interactions were established for each species in both periods to evaluate the changes in the biotic interactions. In most of the GLM and BRT models, the full models showed better performance than the null models in predicting the species presence/absence, and the relative importance of the biotic variables in the full models increased from less than 50% in 1959 to more than 50% in 2009 for each species. Moreover, co-occurrence correlation of each paired species interaction was higher in 2009 than that in 1959. The findings suggest biotic interactions that tend to be positive play more important roles in the spatial distribution of multispecies assemblages of macrophytes and should be included in prediction models to improve prediction accuracy when forecasting macrophytes' distribution under eutrophication stress.

  7. Development and validation of phytotoxicity tests with emergent and submerged aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.S. [Carolina Ecotox, Inc., Durham, NC (United States); Powell, R.L. [Monsanto Co., St. Louis, MO (United States); Nelson, M.K. [National Biological Service, Columbia, MO (United States)

    1995-12-31

    Toxicity testing procedures have recently been developed for assessment of contaminant effects on emergent and submerged aquatic macrophytes commonly found in freshwater wetlands. These tests have potential application in risk assessments for contaminated wetlands as well as for new chemical substances. The objective of this study was to evaluate and modify, if necessary, these methods and to validate them, using two benchmark chemicals, in a contract laboratory setting. Oryza sativa (domestic rice) was used as a surrogate emergent vascular plant, while Ceratophylium demersum (coontail) and Myriophyllum heterophyllum (variable-leaf milfoil) were the representative submerged vascular plants. Subsequent to evaluating culturing techniques and testing conditions, toxicity tests were conducted using boron and metribuzin. The test procedure for the emergent plants involves a two-week pro-exposure period followed by a two-week aqueous exposure. Five types of sediment, including both natural and artificial sediments, were evaluated for use with rice. Fresh weight and chlorophyll a content were the selected test endpoints. The submerged plants were exposed for two weeks, and the response variables evaluated included length, weight (fresh and dry), and root number. The sensitivity of these tests were comparable to the results obtained for the same two chemicals using the green alga, Selenastrum capricornutum, and the duckweed, Lemna gibba, with the exception that rice was less sensitive to metribuzin than the other species.

  8. Thruster Modelling for Underwater Vehicle Using System Identification Method

    Directory of Open Access Journals (Sweden)

    Mohd Shahrieel Mohd Aras

    2013-05-01

    Full Text Available Abstract This paper describes a study of thruster modelling for a remotely operated underwater vehicle (ROV by system identification using Microbox 2000/2000C. Microbox 2000/2000C is an XPC target machine device to interface between an ROV thruster with the MATLAB 2009 software. In this project, a model of the thruster will be developed first so that the system identification toolbox in MATLAB can be used. This project also presents a comparison of mathematical and empirical modelling. The experiments were carried out by using a mini compressor as a dummy depth pressure applied to a pressure sensor. The thruster model will thrust and submerge until it reaches a set point and maintain the set point depth. The depth was based on pressure sensor measurement. A conventional proportional controller was used in this project and the results gathered justified its selection.

  9. Electric Vehicle Propulsion System

    OpenAIRE

    Keshri, Ritesh Kumar

    2014-01-01

    Electric vehicles are being considered as one of the pillar of eco-friendly solutions to overcome the problem of global pollution and radiations due to greenhouse gases. Present thesis work reports the improvement in overall performance of the propulsion system of an electric vehicle by improving autonomy and torque-speed characteristic. Electric vehicle propulsion system consists of supply and traction system, and are coordinated by the monitoring & control system. Case of light electric veh...

  10. Wave Transformation and Attenuation near the Submerged Breakwater and Vegetation: Field investigation and Numerical simulation

    Science.gov (United States)

    Shin, S.; Kim, I.; Hur, D.; Lee, W.; Kim, J.; Lee, J. L.; Lee, H. S.; Kim, H. G.

    2016-12-01

    The large scale decreasing of beach width in the Anmok beach had occurred due to the coastal erosion caused by the short-term events, such as unexpected high waves and storms. Hence, the city officials decided the installation of hard construction, and the first submerged breakwater, which is a structure that parallels the beach and support as a wave absorber, was constructed on this beach in September 2014. In order to deduce the correlation equation of the transmitted wave heights (TWH) after the breakwater installed, we have observed the transmitted wave height at four sites nearby the breakwater, two wave gauges were mounted on the front side of the breakwater, and the others were placed in the behind side of it. We found that the TWH using the formula suggested by Takayama et al. (1985) for the submerged breakwaters (crown elevation: D.L. (-)0.5 m, crown width: 18.5 m, bottom width: 22.8 m) was 0.501, whereas the value which was measured by the wave gauge showed 0.547. Therefore, we suggested a formula for estimating the TWH based on the field observation data. 3D numerical model (LES-WASS-3D) was employed to estimate hydrodynamic chracteristics near the submerged breakwater. The results showed that the predicted TWH agreed well with the field field observation data results. In order to consider evironmet-friendly measure, the model also simulated the wave transformation and attenuation phenomina near the area of submerged vegetation. The model was already verified in two-dimensional laboratory experiments. In this study, the numerical model is used to predict the three-dimensional wave transformation and attenucation through the underwater vegetation. The results are compared with those in the case of submerged breakwater. This research was partially supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2016R1A2B4015419) and Korean Institute of Marine Science and Technology

  11. Routing Vehicles with Ants

    Science.gov (United States)

    Tan, Wen Fang; Lee, Lai Soon; Majid, Zanariah Abdul; Seow, Hsin Vonn

    Routing vehicles involve the design of an optimal set of routes for a fleet of vehicles to serve a number of customers with known demands. This research develops an Ant Colony Optimization for the vehicle routing with one central depot and identical vehicles. The procedure simulates the behavior of real ants that always find the shortest path between their nest and a food source through a form of communication, pheromone trail. Finally, preliminary results on the learning of the algorithm testing on benchmark data set will be presented in this paper.

  12. Electric vehicle propulsion alternatives

    Science.gov (United States)

    Secunde, R. R.; Schuh, R. M.; Beach, R. F.

    1983-01-01

    Propulsion technology development for electric vehicles is summarized. Analytical studies, technology evaluation, and the development of technology for motors, controllers, transmissions, and complete propulsion systems are included.

  13. 75 FR 76692 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Science.gov (United States)

    2010-12-09

    ..., and 571 Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY... passenger vehicles, trucks, buses, trailers, incomplete vehicles, motorcycles, and motor vehicle equipment...

  14. Micro Unmanned Surface Vehicle for Shallow Littoral Data Sampling

    Science.gov (United States)

    Murphy, R. R.; Wilde, G.

    2016-02-01

    This paper describes the creation of an autonomous air boat that can be carried by one person, called a micro unmanned surface vehicle (USV), for sensor sampling in shallow littoral areas such as inlets and creeks. A USV offers advantages over other types of unmanned marine vehicles. Unlike an autonomous underwater vehicle, the Challenge 1.0 air boat can operate in shallow water of less than 15 cm depth and maintain network connectivity for control and data sampling. A USV does not require a tether, like a remotely operated marine vehicle (ROV), which would limit the distance and mobility. However, a USV operating in shallow littoral areas poses several challenges. Navigation is a challenge since rivers and bays may have semi-submerged obstacles and there may be no depth maps; the approach taken in the Challenge 1.0 project is to let the operator specify a safe area of the water by visual inspection and then the USV autonomously creates a path to optimally sample the collision free area. Navigation is also a challenge because of platform dynamics-the USV we describe is a non-holonomic vehicle; this paper explores spiral paths rather than boustrophedon paths. Another challenge is the quality of sensing. Water-based sensing is noisy and thus a reading at a single point may not reflect the overall value. In practice, areas are sampled rather than a single point, but the noise in the point values within the sampled area produce a survey with widely varying numbers and are difficult for humans to interpret. This paper implements an inverse distance weighting interpolation algorithm to produce a visual "heatmap" that reliably portrays the smoothed data.

  15. Green Vehicle Guide

    Science.gov (United States)

    ... about MPG math Discover fuel-saving tips Promote green vehicles Your mileage may vary $ 0 0 , 0 0 0 , 0 0 0 , 0 0 0 GHG metric tons Check out the estimated savings of U.S. consumers who have already purchased new vehicles under the ...

  16. Electric Vehicle Battery Challenge

    Science.gov (United States)

    Roman, Harry T.

    2014-01-01

    A serious drawback to electric vehicles [batteries only] is the idle time needed to recharge their batteries. In this challenge, students can develop ideas and concepts for battery change-out at automotive service stations. Such a capability would extend the range of electric vehicles.

  17. Optimal vehicle control

    NARCIS (Netherlands)

    Alirezaei, M.; Kanarachos, S.A.; Scheepers, B.T.M.; Maurice, J.P.

    2013-01-01

    The Integrated Vehicle Safety Department of TNO (Dutch Organization for Applied Scientific Research) investigates the application of modern control methods in the Integrated Vehicle Dynamics Control (IVDC) field, as a strategic research topic of the Beyond Safe framework. The aim of IVDC is to

  18. Light Vehicle Preventive Maintenance.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to instruct students in the performance of preventive maintenance on motor vehicles. Instructional materials are presented in three chapters as follows: (1) Major Maintenance Areas (maintenance system, tires, batteries, cooling systems, and vehicle lubrication; (2)…

  19. Advanced Tracking of Vehicles

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Li, K.-J.; Pakalnis, Stardas

    2005-01-01

    With the continued advances in wireless communications, geo-location technologies, and consumer electronics, it is becoming possible to accurately track the time-varying location of each vehicle in a population of vehicles. This paper reports on ongoing research that has as it objective to develo...

  20. Tropic Testing of Vehicles

    Science.gov (United States)

    2014-08-27

    a ground crawling vehicle to negotiate one pass over fine-grained soil (clays and silts). Experimental VCI is not determined for clean sands. Soil...1. Vegetation Data a. Stem diameter at breast height (DBH) (inches) b. Vegetation type c. Mode of tree failure 2. Vehicle

  1. Vehicle usage verification system

    NARCIS (Netherlands)

    Scanlon, W.G.; McQuiston, Jonathan; Cotton, Simon L.

    2012-01-01

    EN)A computer-implemented system for verifying vehicle usage comprising a server capable of communication with a plurality of clients across a communications network. Each client is provided in a respective vehicle and with a respective global positioning system (GPS) by which the client can

  2. Energy harvesting water vehicle

    KAUST Repository

    Singh, Devendra

    2018-01-04

    An efficient energy harvesting (EEH) water vehicle is disclosed. The base of the EEH water vehicle is fabricated with rolling cylindrical drums that can rotate freely in the same direction of the water medium. The drums reduce the drag at the vehicle-water interface. This reduction in drag corresponds to an increase in speed and/or greater fuel efficiency. The mechanical energy of the rolling cylindrical drums is also transformed into electrical energy using an electricity producing device, such as a dynamo or an alternator. Thus, the efficiency of the vehicle is enhanced in two parallel modes: from the reduction in drag at the vehicle-water interface, and from capturing power from the rotational motion of the drums.

  3. Automated Vehicles Symposium 2014

    CERN Document Server

    Beiker, Sven; Road Vehicle Automation 2

    2015-01-01

    This paper collection is the second volume of the LNMOB series on Road Vehicle Automation. The book contains a comprehensive review of current technical, socio-economic, and legal perspectives written by experts coming from public authorities, companies and universities in the U.S., Europe and Japan. It originates from the Automated Vehicle Symposium 2014, which was jointly organized by the Association for Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Burlingame, CA, in July 2014. The contributions discuss the challenges arising from the integration of highly automated and self-driving vehicles into the transportation system, with a focus on human factors and different deployment scenarios. This book is an indispensable source of information for academic researchers, industrial engineers, and policy makers interested in the topic of road vehicle automation.

  4. Automated Vehicles Symposium 2015

    CERN Document Server

    Beiker, Sven

    2016-01-01

    This edited book comprises papers about the impacts, benefits and challenges of connected and automated cars. It is the third volume of the LNMOB series dealing with Road Vehicle Automation. The book comprises contributions from researchers, industry practitioners and policy makers, covering perspectives from the U.S., Europe and Japan. It is based on the Automated Vehicles Symposium 2015 which was jointly organized by the Association of Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Ann Arbor, Michigan, in July 2015. The topical spectrum includes, but is not limited to, public sector activities, human factors, ethical and business aspects, energy and technological perspectives, vehicle systems and transportation infrastructure. This book is an indispensable source of information for academic researchers, industrial engineers and policy makers interested in the topic of road vehicle automation.

  5. Hydrogen vehicle fueling station

    Energy Technology Data Exchange (ETDEWEB)

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A. [Los Alamos National Lab., NM (United States)] [and others

    1995-09-01

    Hydrogen fueling stations are an essential element in the practical application of hydrogen as a vehicle fuel, and a number of issues such as safety, efficiency, design, and operating procedures can only be accurately addressed by a practical demonstration. Regardless of whether the vehicle is powered by an internal combustion engine or fuel cell, or whether the vehicle has a liquid or gaseous fuel tank, the fueling station is a critical technology which is the link between the local storage facility and the vehicle. Because most merchant hydrogen delivered in the US today (and in the near future) is in liquid form due to the overall economics of production and delivery, we believe a practical refueling station should be designed to receive liquid. Systems studies confirm this assumption for stations fueling up to about 300 vehicles. Our fueling station, aimed at refueling fleet vehicles, will receive hydrogen as a liquid and dispense it as either liquid, high pressure gas, or low pressure gas. Thus, it can refuel any of the three types of tanks proposed for hydrogen-powered vehicles -- liquid, gaseous, or hydride. The paper discusses the fueling station design. Results of a numerical model of liquid hydrogen vehicle tank filling, with emphasis on no vent filling, are presented to illustrate the usefulness of the model as a design tool. Results of our vehicle performance model illustrate our thesis that it is too early to judge what the preferred method of on-board vehicle fuel storage will be in practice -- thus our decision to accommodate all three methods.

  6. Connected vehicles and your privacy.

    Science.gov (United States)

    2016-01-01

    Connected vehicles communicate wirelessly with other vehicles and our roads, : sharing important safety and mobility information and generating new data about : how, when, and where vehicles travel. The unprecedented level of data generated : will be...

  7. Wave transmission over permeable submerged breakwaters; Transmision del oleaje en rompeolas sumergidos permeables

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-y-Zurvia-Flores, Jaime Roberto; Fragoso-Sandoval, Lucio [Instituto Politecnico Nacional(Mexico)

    2008-10-15

    The permeable submerged breakwaters represent a coastal protection alternative, where some degree of wave energy transmission is acceptable. Such would be the case of tourist beach protection in Mexico. In previous researches, like those performed by D'Angremond et al. (1996), Seabrook and Hall (1998), and Briganti et al. (2003), the empirical formulas developed, give only some limited information over the spatial distribution of wave energy over the structure. Therefore, a decision was made to conduct a study on a reduced physical model of a permeable submerged breakwater based on the results presented by those researchers and with possible applications. Therefore this paper presents the development of a study of wave transmission over permeable submerged breakwaters performed in a reduced physical model of different sections of a submerged rockfill breakwater of the trapezoidal type. This was done in a narrow wave flume with a hydraulic irregular wave generator controlled by a computer that was used to generate and to reproduce different types of irregular waves to be used in the tests. It also has a wave meter with four sensors, and they are connected to a computer in order to process the wave data. The main objective of the study was to determine in an experimental way the influence of the several parameters of submerged breakwater over the wave transmission coefficient. Our experimental results were comparable to those obtained by D'Angremond et al. (1996) and Seabrook and Hall (1998). The results show that the sumerged breakwater parameters of most influence over the wave transmission coefficient were relative submergence and the relative width crest of the sumerged breakwater, and that the formula by Seabrook and Hall correlates best with our results. [Spanish] Los rompeolas sumergidos permeables representan actualmente una alternativa de proteccion de costas, donde un cierto grado de transmision de energia del oleaje es aceptable, como seria el

  8. Insight into cordycepin biosynthesis of Cordyceps militaris: Comparison between a liquid surface culture and a submerged culture through transcriptomic analysis.

    Science.gov (United States)

    Suparmin, Ahmad; Kato, Tatsuya; Dohra, Hideo; Park, Enoch Y

    2017-01-01

    Cordyceps militaris produces cordycepin, which is known to be a bioactive compound. Currently, cordycepin hyperproduction of C. militaris was carried out in a liquid surface culture because of its low productivity in a submerged culture, however the reason was not known. In this study, 4.92 g/L of cordycepin was produced at the 15th day of C. militaris NBRC 103752 liquid surface culture, but only 1 mg/L was produced in the submerged culture. RNA-Seq was used to clarify the gene expression profiles of the cordycepin biosynthetic pathways of the submerged culture and the liquid surface culture. From this analysis, 1036 genes were shown to be upregulated and 557 genes were downregulated in the liquid surface culture compared with the submerged culture. Specifically, adenylosuccinate synthetase and phosphoribosylaminoimidazole-succinocarboxamide (SAICAR) synthase in purine nucleotide metabolism were significantly upregulated in the liquid surface culture. Thick mycelia formation in the liquid surface culture was found to induce the expression of hypoxia-related genes (GABA shunt, glutamate synthetase precursor, and succinate-semialdehyde dehydrogenase). Cytochrome P450 oxidoreductases containing heme were also found to be significantly enriched, suggesting that a hypoxic condition might be created in the liquid surface culture. These results suggest that hypoxic conditions are more suitable for cordycepin production in the liquid surface culture compared with the submerged culture. Our analysis paves the way for unraveling the cordycepin biosynthesis pathway and for improving cordycepin production in C. militaris.

  9. Monitoring the effects of floods on submerged macrophytes in a large river.

    Science.gov (United States)

    Ibáñez, Carles; Caiola, Nuno; Rovira, Albert; Real, Montserrat

    2012-12-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton to a macrophyte-dominated system. Macrophytes started to spread at the end of the 1990s and since 2002 artificial floods (flushing flows) of short duration (1-2 days) are released from the Riba-roja dam once or twice a year in order to reduce macrophyte density. The aim of this study was to analyse the spatiotemporal trends of the submerged macrophytes in two stretches of the lower Ebro River using high-resolution hydroacoustic methods, in order to elucidate the effects of artificial floods and natural floods on its distribution and abundance. Results showed that the mean cover in the two studied stretches (Móra and Ginestar) was not reduced after a flushing flow (from 36.59% to 55.85% in Móra, and from 21.18% to 21.05% in Ginestar), but it was greatly reduced after the natural flood (down to 9.79% in Móra and 2.04% in Ginestar); surprisingly the cover increased in Móra after the artificial flood. In order to increase the efficiency of floods in controlling macrophyte spreading, the magnitude and frequency of them should largely increase, as well as the suspended sediment load, approaching as much as possible to the original flood pattern before dam construction. Hydroacoustic methods combined with geostatistics and interpolation in GIS can accurately monitor spatiotemporal trends of submerged macrophytes in large rivers. This is the first article to apply this monitoring system to submerged macrophytes in rivers. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Simple relationships to predict attributes of fish assemblages in patches of submerged macrophytes

    Directory of Open Access Journals (Sweden)

    Fernando Mayer Pelicice

    Full Text Available Submerged macrophytes play an important role in structuring habitats and, therefore, in determining patterns of aquatic biodiversity. Because these plants are widespread in shallow areas of many Neotropical reservoirs, the present work investigated if variables related to habitat structure, measured in patches of submerged macrophytes (Egeria densa and E. najas, can be used to predict fish assemblage attributes (fish density and species richness. Based on patch characteristics at fine spatial extents (macrophyte patches within reservoir arms, we considered plant biomass, volume and proportional volume (i.e. percentage of macrophyte volume in the water column as potential predictors. Fish and macrophytes were sampled with a 1-m² throw trap in littoral habitats of Rosana Reservoir, Paranapanema River, and simple correlation analyses were performed. Fish richness and abundance were highly correlated with all variables (R = 0.53 to 0.90, a relationship consistently observed in all sites. When compared to biomass, plant volume and proportional volume did not yield stronger correlations. We observed stronger correlations when E. densa and E. najas patches were analyzed separately (mono-specificity, probably because particular effects of each macrophyte on habitat structuring were removed (e.g. unnoticed morphological differences or unknown effects on habitat quality. The high R values observed in all pairwise relationships are uncommon in ecological studies, highlighting the predictive potential of variables related to habitat structure. These results suggest that, at small spatial extents, macrophyte biomass may represent an interesting predictor of fish density and richness in reservoirs with extensive colonization of submerged plants.

  11. Accuracy verification and analysis of SEA method for calculating radiation noise pressure of submerged cylindrical shell

    Directory of Open Access Journals (Sweden)

    ZHANG Kai

    2017-08-01

    Full Text Available Statistical Energy Analysis(SEAis an effective method for solving high frequency structural vibration and acoustic radiation problems. When we use it to analyze submerged structures, it is necessary to consider the actions of fluid as'heavy fluid' relative to structures, which differs from when it is used in the air. The simple model of a submerged cylindrical shell is used to calculate at a higher frequency using FEM/BEM. The SEA and FEM method are then used to calculate the radiation sound pressure level, verifying the accuracy of the SEA prediction for submerged structures. The classified method of subsystems and the effect of the error of the internal loss factor on the accuracy of the results are explored. The calculated results of SEA and FEM/BEM are very different below 400 Hz, and basically the same above 400 Hz. The error caused by the division of different subsystems is about 5 dB. The error in the calculation results caused by the error of the internal loss factor is 2-3 dB. It is possible to use SEA to calculate the radiated noise of an underwater cylindrical shell when the modal density is high enough.For the cylindrical shell, dividing the subsystems along the circumference is not reliable at a low frequency, as it may lead to inaccurate calculation results. At a high frequency, it is more accurate to divide the subsystems along the circumference than the axle. For subsystems with high energy, the internal loss factor has a greater effect on the simulation results, so a more accurate way should be taken to determine the internal loss factor of subsystems with high energy.

  12. Nitrogen fertilizer management for tidal submergence tolerant landrace rice (Oryza sativa L. cultivars

    Directory of Open Access Journals (Sweden)

    M.A.A. Mamun

    2017-12-01

    Full Text Available In tidal submergence ecosystem, nitrogen (N is a crucial nutrient for improved and sustainable rice production. Therefore, a series of on-farm and on-station field experiments were conducted to develop a suitable N management practice for tidal submergence tolerant landrace aman rice. In on-farm, urea deep placement (UDP through urea super granule before panicle initiation (PI stage was compared with no fertilizer application. Similarly, five N fertilizer management practices viz. (i. two splits of prilled urea (PU, (ii. UDP at 10 DAT, (iii. UDP before PI, (iv. full dose PU before PI and (v. No urea (control were compared at on-station trial. Tidal submergence tolerance aman rice varieties (Rajashail, Kutiagni, Sadamota and Lalmota were used as testing materials. In on farm experiment, aman cultivars produced 2.0–2.5 t ha−1 grain without N fertilizer. But, cultivated Rajashail, Kutiagni, Sadachikon, Sadapajam, Lalmota and Sadamota gave 3.0–3.5 t ha−1 grain yield with the UDP before PI in tidal prone areas. Though UDP required fertilizer and application cost but it gave profit upto 22,000 BDT ha−1 (Bangladeshi Taka. In on-station experiment, UDP before PI stage significantly increased rice yield and economic return although it was comparable to two splits of PU and top dressing of PU before PI stage. However, UDP at 10 DAT increased straw yield but failed to increase grain yield even compared to control. It could be concluded that UDP before PI stage of rice is an effective method for increasing rice yield and farm income in tidal prone areas.

  13. Vehicle frame measurement device

    Energy Technology Data Exchange (ETDEWEB)

    Sarauer, A.J.

    1987-08-04

    This patent describes a vehicle frame and body measurement apparatus for use in realigning the structure of a damaged unibody vehicle the device having a longitudinal axis utilized in a horizontal plane the apparatus comprising means for measuring the vehicle body and frame comprising, (a) means for supporting a damaged motor vehicle in a fixed position, (b) an elongated rail on each side of the supporting means spaced apart a distance greater than the width of the supporting means and the width of the vehicle, (c) a vertical upright of a length exceeding the height of the motor vehicle slidably supported by each of the rails and having a vertical axis substantially perpendicular to the horizontal plane of the vehicle, (d) a vertically adjustable horizontal bar attached to each of the uprights, substantially perpendicular to both the longitudinal axis of the rails and the vertical axis of the uprights, (e) means for affixing the horizontal bar to the uprights so that the bar is vertically adjustable, the affixing means being provided with releasable means to permit adjustable horizontal extension of the horizontal bar and (f) at least one extendable measuring means attached to each vertical upright at its junction with its associated horizontal rail and adjustably extending along the horizontal rail, the free end of the measuring means having to releasably affix it to the rail.

  14. The rise and fall of sunspot group 18962 - A case of magnetic submergence

    Science.gov (United States)

    Zirin, H.

    1985-01-01

    Normal sunspot groups emerge from below the surface as a big arch; the footpoints form a dipole that moves apart and the fields eventually diffuse and disappear. BBSO 18962 was a small dipole with elements which, after spreading apart in the first day of existence, drew back together and disappeared below the surface. It is proposed that the flux loop was pulled back down by magnetic tension and submerged. The circumstances suggest that this behavior may not be uncommon. It implies that some dipoles do not decouple from subsurface fields.

  15. Submerged reef systems on the central western continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Almeida, F.

    reef system, now submerged. It is inferred that the reefs began forming and continued advancing shoreward as a result of a rise in sea level. The occurrence of reefs below the clay leads to the proposition that sudden climatic changes increased... in the adjoining northern and southern parts of the shelf. It is evident from Figs.1 and 4 that there is a definite correlation between the echogram and sonograph data. As these ridges mostly consist of dead corals and coralline limestone, they are believed...

  16. Technical note: Cascade of submerged reservoirs as a rainfall-runoff model

    Science.gov (United States)

    Kurnatowski, Jacek

    2017-09-01

    The rainfall-runoff conceptual model as a cascade of submerged linear reservoirs with particular outflows depending on storages of adjoining reservoirs is developed. The model output contains different exponential functions with roots of Chebyshev polynomials of the first kind as exponents. The model is applied to instantaneous unit hydrograph (IUH) and recession curve problems and compared with the analogous results of the Nash cascade. A case study is performed on a basis of 46 recession periods. Obtained results show the usefulness of the model as an alternative concept to the Nash cascade.

  17. Moving of Inline Cleaning Units Along Submerged Crossing in Main Pipelines

    Directory of Open Access Journals (Sweden)

    Toropov Sergey

    2016-01-01

    Full Text Available The article analyzes the forces acting on the inline cleaning units of new design, operating on a bailer principle. In this case all cleaning products are collected in the internal cavity of the cleaning unit, which eliminates the formation of the ground plug and can significantly reduce the friction of the cleaning unit on the inner surface of the pipeline. The moving of the cleaning units of the given design within the space of a curved steel pipeline is investigated, the solution of the obtained equations and their analysis related to pipeline submerged crossing are shown.

  18. Wirelessly powered submerged-light illuminated photobioreactors for efficient microalgae cultivation

    DEFF Research Database (Denmark)

    Murray, Alexandra Marie; Fotidis, Ioannis; Isenschmid, Alex

    2017-01-01

    A novel submerged-light photobioreactor (SL-PBR) with free-floating, wireless internal light sources powered by near-field resonant inductive coupling was investigated using a quick (Chlorella vulgaris) and a slow (Haematococcus pluvialis) growing microalgal species. During testing of the SL......-PBR, the yield on photons was 1.18 and 1.15 g biomass mol− 1 photons for C. vulgaris and H. pluvialis, respectively. At the same time, a conventional, externally illuminated PBR with the same internal light intensity produced yields of 0.78 and 0.05 g biomass mol− 1 photons for C. vulgaris and H. pluvialis...

  19. Global sensitivity analysis of a filtration model for submerged anaerobic membrane bioreactors (AnMBR)

    OpenAIRE

    Robles Martínez, Ángel; Ruano García, María Victoria; Ribes Bertomeu, José; SECO TORRECILLAS, AURORA; Ferrer, J.

    2014-01-01

    The results of a global sensitivity analysis of a filtration model for submerged anaerobic MBRs (AnMBRs) are assessed in this paper. This study aimed to (1) identify the less- (or non-) influential factors of the model in order to facilitate model calibration and (2) validate the modelling approach (i.e. to determine the need for each of the proposed factors to be included in the model). The sensitivity analysis was conducted using a revised version of the Morris screening method. The dynamic...

  20. Existence of equilibrium states of hollow elastic cylinders submerged in a fluid

    Directory of Open Access Journals (Sweden)

    M. B. M. Elgindi

    1992-01-01

    Full Text Available This paper is concerned with the existence of equilibrium states of thin-walled elastic, cylindrical shell fully or partially submerged in a fluid. This problem obviously serves as a model for many problems with engineering importance. Previous studies on the deformation of the shell have assumed that the pressure due to the fluid is uniform. This paper takes into consideration the non-uniformity of the pressure by taking into account the effect of gravity. The presence of a pressure gradient brings additional parameters to the problem which in turn lead to the consideration of several boundary value problems.

  1. Advanced control system for optimal filtration in submerged anaerobic MBRs (SAnMBRs)

    OpenAIRE

    Robles Martínez, Ángel; Ruano García, María Victoria; Ribes Bertomeu, José; Ferrer, J.

    2013-01-01

    The main aim of this study was to develop an advanced controller to optimise filtration in submerged anaerobic MBRs (SAnMBRs). The proposed controller was developed, calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes with variable influent flow and load. This 2-layer control system is designed for membranes operating sub-critically and features a lower layer (on/off and PID controllers) and an upper layer (knowledge-based controller). ...

  2. Submerged fermentation of Lactobacillus rhamnosus YS9 for γ-aminobutyric acid (GABA production

    Directory of Open Access Journals (Sweden)

    Qian Lin

    2013-01-01

    Full Text Available γ-Aminobutyric acid (GABA is a major inhibitory neurotransmitter in central nervous system, and its application in drugs and functional foods has attracted great attention. To enhance production of y-aminobutyric acid, Lactobacillus rhamnosus YS9, a strain isolated from Chinese traditional fermented food pickled vegetable, was grown under submerged fermentation. Its cultivation conditions were investigated. When culture pH condition was adjusted to the optimal pH of glutamate decarboxylase activity, culture of Lb. rhamnosus YS9 in medium supplemented with 200 mM of monosodium glutamate and 200 µM of pyridoxal phosphate (PLP, produced 187 mM of GABA.

  3. Interactions between piscivores, zooplanktivores and zooplankton in submerged macrophytes : Preliminary observations from enclosure and pond experiments

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Perrow, M.R.; Landkildehus, F.

    1997-01-01

    behavioural changes of zooplanktivores has received little attention, even though this may be an important mechanism in enhancing the stability of submerged macrophytes in shallow lakes. Preliminary observations from an unreplicated large-scale field enclosure experiment and a replicated pond experiment...... and the presence of zooplanktivores typically changed the habitat selection of cladoceran zooplankton. In the case of piscivore/zooplanktivore interactions, the risk of predation was enough to generate clear responses even where the losses to predation were low. However, only in the enclosure experiment...

  4. Wave power absorption by a submerged balloon fixed to the sea bed

    DEFF Research Database (Denmark)

    Kurniawan, Adi; Greaves, Deborah

    2016-01-01

    The possibility of absorbing wave energy using a submerged balloon fixed to the sea bed is investigated. The balloon is in the form of a fabric encased within an array of meridional tendons which terminate at a point at the top of the balloon and at some radius at the bottom. The expansion...... and contraction of the balloon in waves pump air via a turbine into and out of a chamber of constant volume. A more refined model than that used by Kurniawan and Greaves [Proc. 2nd Offshore Energy and Storage Symposium , 2015] predicts a similarly broad-banded response, but the maximum absorption is less than...

  5. Production and partial characterization of alkaline feruloyl esterases by Fusarium oxysporum during submerged batch cultivation

    DEFF Research Database (Denmark)

    Topakas, E.; Christakopoulos, Paul

    2004-01-01

    Production of feruloyl esterases (FAEs) by Fusarium oxysporum was enhanced by optimization of initial pH of the culture medium, the type and concentration of nitrogen and carbon source. Submerged batch cultivation in a laboratory bioreactor (17 1) produced activity at 82 nkat g(-1) dry substrate...... (corn cobs) which compared favorably to those reported for the other microorganisms. Use of de-esterified corn cobs as carbon source decreased FAE production by 5.5-fold compared to untreated corn cobs even though ferulic acid (FA) was added to the concentration found in alkali-extracts of corn cobs...

  6. Cell growth and catecholase production for Polyporus versicolor in submerged culture

    Energy Technology Data Exchange (ETDEWEB)

    Carroad, P.A.; Wilke, C.R.

    1977-04-01

    Cell growth and catecholase production for Polyporus versicolor (ATCC 12679) were studied in mechanically agitated submerged culture, as functions of temperature. The exponential-phase growth rate exhibited a maximum at 28/sup 0/C. Over the range of 20/sup 0/C to approximately 30/sup 0/C, both cell mass and enzyme yield factors were constant. At higher temperatures (30 to 40/sup 0/C) cell mass yield factor decreased and enzyme yield factor increased. Specific respiration rate of P. versicolor was determined. Thermal deactivation of catecholase was investigated between 30 and 50/sup 0/C, and deactivation rates were fit to an Arrhenius rate expression.

  7. Cell growth and catecholase production for Polyporus versicolor in submerged culture.

    Science.gov (United States)

    Carroad, P A; Wilke, C R

    1977-04-01

    Cell growth and catecholase production for Polyporus veriscolor (ATCC 12679) were studied in mechanically agitated submerged culture, as functions of temperature. The exponential-phase growth rate exhibited a maximum at 28 degrees C. Over the range of 20 degrees C to approximately 30 degrees C, both cell mass and enzyme yield factors were constant. At higher temperatures (30 to 40 degrees C) cell mass yield factor decreased and enzyme yield factor increased. Specific respiration rate of P. versicolor was determined. Thermal deactivation of catecholase was investigated between 30 and 50 degrees C, and deactivation rates were fit to an Arrhenius rate expression.

  8. Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces

    OpenAIRE

    Mayser, Matthias J; Bohn, Holger F; Meike Reker; Wilhelm Barthlott

    2014-01-01

    Some plants and animals feature superhydrophobic surfaces capable of retaining a layer of air when submerged under water. Long-term air retaining surfaces (Salvinia-effect) are of high interest for biomimetic applications like drag reduction in ship coatings of up to 30%. Here we present a novel method for measuring air volumes and air loss under water. We recorded the buoyancy force of the air layer on leaf surfaces of four different Salvinia species and on one biomimetic surface using a hig...

  9. Temporal changes of diatoms in marine biofilm developed on acrylic panels submerged in a tropical coast

    Science.gov (United States)

    Satheesh, Sathianeson; Wesley, Samuel Godwin

    2012-12-01

    The colonization of diatom groups on the acrylic panels submerged in Kudankulam coastal waters, east coast of India, was studied for one year from October 2004 to August 2005. Results showed temporal variability in the abundance of dominant diatom groups. Diatoms belonging to 19 genera colonized the panels. Navicula and Nitzschia were the dominant diatoms observed throughout the present study. The abundance of diatoms on test panels increased with the length of exposure. Significant variations in the abundance of Navicula and Nitzschia were observed between the sampling months. Temporal changes in biofilm diatom community composition in this study attain significance from the view point of macrofouling community recruitment on marine structures.

  10. Monitoring Corals and Submerged Aquatic Vegetation in Western Pacific Using Satellite Remote Sensing Integrated with Field Data

    Science.gov (United States)

    Roelfsema, C. M.; Phinn, S. R.; Lyons, M. B.; Kovacs, E.; Saunders, M. I.; Leon, J. X.

    2013-12-01

    Corals and Submerged Aquatic Vegetation (SAV) are typically found in highly dynamic environments where the magnitude and types of physical and biological processes controlling their distribution, diversity and function changes dramatically. Recent advances in the types of satellite image data and the length of their archives that are available globally, coupled with new techniques for extracting environmental information from these data sets has enabled significant advances to be made in our ability to map and monitor coral and SAV environments. Object Based Image Analysis techniques are one of the most significant advances in information extraction techniques for processing images to deliver environmental information at multiple spatial scales. This poster demonstrates OBIA applied to high spatial resolution satellite image data to map and monitor coral and SAV communities across a variety of environments in the Western Pacific that vary in their extent, biological composition, forcing physical factors and location. High spatial resolution satellite imagery (Quickbird, Ikonos and Worldview2) were acquired coincident with field surveys on each reef to collect georeferenced benthic photo transects, over various areas in the Western Pacific. Base line maps were created, from Roviana Lagoon Solomon island (600 km2), Bikini Atoll Marshall Island (800 Km2), Lizard Island, Australia (30 km2) and time series maps for geomorphic and benthic communities were collected for Heron Reef, Australia (24 km2) and Eastern Banks area of Moreton Bay, Australia (200 km2). The satellite image data were corrected for radiometric and atmospheric distortions to at-surface reflectance. Georeferenced benthic photos were acquired by divers or Autonomous Underwater Vehicles, analysed for benthic cover composition, and used for calibration and validation purposes. Hierarchical mapping from: reef/non-reef (1000's - 10000's m); reef type (100's - 1000's m); 'geomorphic zone' (10's - 100's m); to

  11. ELECTROMAGNETIC BIOSPHERE POLLUTION BY MOTOR TRANSPORT (VEHICLES, ELECTRIC VEHICLES, HYBRID VEHICLES)

    National Research Council Canada - National Science Library

    S. Selivanov; V. Filenko; А. Bazhynov; E. Budianskaya

    2009-01-01

    The physics of the electromagnetic field is considered. The analysis of electromagnetic radiation on the human-being, the origin of which is the vehicle the electric vehicle, the hybrid vehicle is being considered...

  12. Blast resistant vehicle seat

    Science.gov (United States)

    Ripley, Edward B

    2013-02-12

    Disclosed are various seats for vehicles particularly military vehicles that are susceptible to attack by road-bed explosive devices such as land mines or improvised explosive devices. The seats often have rigid seat shells and may include rigid bracing for rigidly securing the seat to the chassis of the vehicle. Typically embodiments include channels and particulate media such as sand disposed in the channels. A gas distribution system is generally employed to pump a gas through the channels and in some embodiments the gas is provided at a pressure sufficient to fluidize the particulate media when an occupant is sitting on the seat.

  13. A Joint Vehicle-Vehicle/Vehicle-Roadside Communication Protocol for Highway Traffic Safety

    OpenAIRE

    Bin Hu; Hamid Gharavi

    2011-01-01

    A joint vehicle-vehicle/vehicle-roadside communication protocol is proposed for cooperative collision avoiding in Vehicular Ad Hoc Networks (VANETs). In this protocol, emergency warning messages are simultaneously transmitted via Vehicle-to-Vehicle (V2V) and Vehicle-to-Roadside (V2R) communications in order to achieve multipath diversity routing. In addition, to further improve communication reliability and achieve low latency, a Multi-Channel (MC) technique based on two nonove...

  14. Studies of Physcomitrella patens reveal that ethylene-mediated submergence responses arose relatively early in land-plant evolution

    KAUST Repository

    Yasumura, Yuki

    2012-10-18

    Colonization of the land by multicellular green plants was a fundamental step in the evolution of life on earth. Land plants evolved from fresh-water aquatic algae, and the transition to a terrestrial environment required the acquisition of developmental plasticity appropriate to the conditions of water availability, ranging from drought to flood. Here we show that extant bryophytes exhibit submergence-induced developmental plasticity, suggesting that submergence responses evolved relatively early in the evolution of land plants. We also show that a major component of the bryophyte submergence response is controlled by the phytohormone ethylene, using a perception mechanism that has subsequently been conserved throughout the evolution of land plants. Thus a plant environmental response mechanism with major ecological and agricultural importance probably had its origins in the very earliest stages of the colonization of the land. © 2012 Blackwell Publishing Ltd.

  15. Electric vehicle energy impacts.

    Science.gov (United States)

    2017-05-01

    The objective of this research project was to evaluate the impacts of electric vehicles (EVs) and : renewable wind and solar photovoltaic (PV) power generation on reducing petroleum imports : and greenhouse gas emissions to Hawaii. In 2015, the state...

  16. Ground Vehicle Fleet Health

    National Research Council Canada - National Science Library

    Chappell, Isaac; Holzer, Jenny; Koehn, Phillip; Macheret, Jenya; Sparrow, Dave

    2007-01-01

    ...), the Army Materiel Systems Analysis Activity (AMSAA) Sample Data Collection (SDC) and the Army's reported mission capable rates to determine if there was evidence of deterioration in the Army's combat or tactical vehicle fleets...

  17. Abandoned vehicles - Reminder

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  18. Abandonned vehicles - REMINDER

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  19. Abandoned vehicles REMINDER

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  20. Aerodynamics of Small Vehicles

    Science.gov (United States)

    Mueller, Thomas J.

    In this review we describe the aerodynamic problems that must be addressed in order to design a successful small aerial vehicle. The effects of Reynolds number and aspect ratio (AR) on the design and performance of fixed-wing vehicles are described. The boundary-layer behavior on airfoils is especially important in the design of vehicles in this flight regime. The results of a number of experimental boundary-layer studies, including the influence of laminar separation bubbles, are discussed. Several examples of small unmanned aerial vehicles (UAVs) in this regime are described. Also, a brief survey of analytical models for oscillating and flapping-wing propulsion is presented. These range from the earliest examples where quasi-steady, attached flow is assumed, to those that account for the unsteady shed vortex wake as well as flow separation and aeroelastic behavior of a flapping wing. Experiments that complemented the analysis and led to the design of a successful ornithopter are also described.

  1. Connected vehicle applications : environment.

    Science.gov (United States)

    2016-01-01

    The U.S. Department of Transportation has developed a number of connected vehicle environmental : applications, including the Applications for the Environment Real-Time Information Synthesis (AERIS) : research program applications and road weather ap...

  2. Vehicle Technologies Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-09-05

    Overview of the Vehicle Technologies Program including external assessment and market view; internal assessment, program history and progress; program justification and federal role; program vision, mission, approach, strategic goals, outputs, and outcomes; and performance goals.

  3. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  4. Hybrid vehicle control

    Science.gov (United States)

    Shallvari, Iva; Velnati, Sashidhar; DeGroot, Kenneth P.

    2015-07-28

    A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

  5. TRACKED VEHICLE Rev 75

    Energy Technology Data Exchange (ETDEWEB)

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parameters of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.

  6. Vehicle Dynamics and Control

    CERN Document Server

    Rajamani, Rajesh

    2012-01-01

    Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system applications covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire-road friction coefficient estimation, rollover prevention, and hybrid electric vehicle. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics. A special effort has been made to explain the several different tire models commonly used in literature and to interpret them physically. In the second edition of the book, chapters on roll dynamics, rollover prevention and hybrid electric vehicles have been added, and the chapter on electronic stability co...

  7. Handbook of Intelligent Vehicles

    CERN Document Server

    2012-01-01

    The Handbook of Intelligent Vehicles provides a complete coverage of the fundamentals, new technologies, and sub-areas essential to the development of intelligent vehicles; it also includes advances made to date, challenges, and future trends. Significant strides in the field have been made to date; however, so far there has been no single book or volume which captures these advances in a comprehensive format, addressing all essential components and subspecialties of intelligent vehicles, as this book does. Since the intended users are engineering practitioners, as well as researchers and graduate students, the book chapters do not only cover fundamentals, methods, and algorithms but also include how software/hardware are implemented, and demonstrate the advances along with their present challenges. Research at both component and systems levels are required to advance the functionality of intelligent vehicles. This volume covers both of these aspects in addition to the fundamentals listed above.

  8. How connected vehicles work.

    Science.gov (United States)

    2011-01-01

    Connected vehicles have the potential to transform the way Americans travel through the creation : of a safe, interoperable wireless communications networka system that includes cars, buses, : trucks, trains, traffic signals, cell phones, and othe...

  9. Growth and physiological responses of submerged plant Vallisneria natans to water column ammonia nitrogen and sediment copper

    Directory of Open Access Journals (Sweden)

    Zhengjie Zhu

    2016-04-01

    Full Text Available Background. The decline of submerged plant populations due to high heavy metal (e.g., Cu levels in sediments and ammonia nitrogen (ammonia-N accumulation in the freshwater column has become a significant global problem. Previous studies have evaluated the effect of ammonia-N on submerged macrophytes, but few have focused on the influence of sediment Cu on submerged macrophytes and their combined effects. Methods. In this paper, we selected three levels of ammonia-N (0, 3, and 6 mg L−1 and sediment Cu (25.75 ± 6.02 as the control, 125.75 ± 6.02, and 225.75 ± 6.02 mg kg−1, to investigate the influence of sediment Cu and ammonia-N on submerged Vallisneria natans. We measured the relative growth rate (RGR, above- and below- ground biomass, chlorophyll, non-protein thiol (NP-SH, and free proline. Results and Discussion. The below-ground biomass of V. natans decreased with increasing Cu sediment levels, suggesting that excessive sediment Cu can result in significant damage to the root of V. natans. Similarly, the above-ground biomass significantly decreased with increasing ammonia-N concentrations, indicating that excessive water ammonia-N can cause significant toxicity to the leaf of V. natans. In addition, high ammonia-N levels place a greater stress on submerged plants than sediment Cu, which is indicated by the decline of RGR and chlorophyll, and the increase of (NP-SH and free proline. Furthermore, high sediment Cu causes ammonia-N to impose greater injury on submerged plants, and higher sediment Cu levels (Cu ≥ 125.75 mg kg−1 led to the tolerant values of ammonia-N for V. natans decreasing from 6 to 3 mg L−1. This study suggests that high sediment Cu restricts the growth of plants and intensifies ammonia-N damage to V. natans.

  10. Vehicle Routing in Practice

    OpenAIRE

    Hasle, Geir

    2010-01-01

    Solving the Vehicle Routing Problem (VRP) is a key to efficiency in transportation and supply chain management. The VRP is a computationally hard problem that comes in many guises. The VRP literature contains thousands of papers, and VRP research is regarded as one of the great successes of OR. In industry and the public sector, vehicle routing tools provide substantial savings every day. An industry of routing tool vendors has emerged. Exact optimization methods of today cannot consistently ...

  11. HYBRID VEHICLE CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Dvadnenko

    2016-06-01

    Full Text Available The hybrid vehicle control system includes a start–stop system for an internal combustion engine. The system works in a hybrid mode and normal vehicle operation. To simplify the start–stop system, there were user new possibilities of a hybrid car, which appeared after the conversion. Results of the circuit design of the proposed system of basic blocks are analyzed.

  12. Adaptive Vehicle Traction Control

    OpenAIRE

    Lee, Hyeongcheol; Tomizuka, Masayoshi

    1995-01-01

    This report presents two different control algorithms for adaptive vehicle traction control, which includes wheel slip control, optimal time control, anti-spin acceleration and anti-skid control, and longitudinal platoon control. The two control algorithms are respectively based on adaptive fuzzy logic control and sliding mode control with on-line road condition estimation. Simulations of the two control methods are conducted using a complex nonlinear vehicle model as well as a simple linear ...

  13. ALPHA-AMYLASE PRODUCTION FROM Aspergillus oryzae M BY SUBMERGED FERMENTATION

    Directory of Open Access Journals (Sweden)

    Suleimenova

    2016-08-01

    Full Text Available The main goal of present study was implementation of the Aspergillus oryzae M strain improved technology using earlier developed method of microorganism selection. 8 pure strains of Aspergillus fungi were screened for the production of extra cellular alpha-amylase using agar medium with starch as a substrate and incubated for 72h at 30 ºС. Zone of clearance was observed for screening of the amylolytic fungi (in mm. Aspergillus oryzae M has demonstrated the highest zone of clearance. Aspergillus oryzae M was cultivated for 42 days in submerged conditions of growth using new method of fungal cultivation. This method based on immobilizing enzymes producers on solid career in submerged conditions of growth gives the way to improve quality of filtrates, which remain clear, does not require additional filtering and easily separated from the mycelium. Moreover, it allows to prolong the process of fungal cultivation and to maintain high enzymatic activity for a long period of time. Presented method allowed increasing alpha-amylase production from 321 U/ml (before immobilization to 502 U/ml (after immobilization.

  14. Laser Submerged Arc Welding (LUPuS) with Solid State Lasers

    Science.gov (United States)

    Reisgen, Uwe; Olschok, Simon; Jakobs, Stefan

    The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The newly developed hybrid welding process allows the welding of plates with a thickness larger than 20 mm in a single pass and the welding of thicker plates with the double-sided single pass technique. In this special hybrid process, the use of CO2-lasers causes problems when forward sliding flux of slag meets the laser beam path and forms an uncontrollable plasma plume in the beam path. This plasma then shields the work piece from the laser power and thus provokes the collapse of the laser keyhole and leads to process instability. The substitution of the CO2-laser with a modern solid-state laser significantly improves the performance and the stability of the hybrid process. This contribution will demonstrate the latest results and improvements by means of welding results gained with steel plates with a thickness of up to 40mm.

  15. Study the Effect of SiO2 Based Flux on Dilution in Submerged Arc Welding

    Science.gov (United States)

    kumar, Aditya; Maheshwari, Sachin

    2017-08-01

    This paper highlights the method for prediction of dilution in submerged arc welding (SAW). The most important factors of weld bead geometry are governed by the weld dilution which controls the chemical and mechanical properties. Submerged arc welding process is used generally due to its very easy control of process variables, good penetration, high weld quality, and smooth finish. Machining parameters, with suitable weld quality can be achieved with the different composition of the flux in the weld. In the present study Si02-Al2O3-CaO flux system was used. In SiO2 based flux NiO, MnO, MgO were mixed in various proportions. The paper investigates the relationship between the process parameters like voltage, % of flux constituents and dilution with the help of Taguchi’s method. The experiments were designed according to Taguchi L9 orthogonal array, while varying the voltage at two different levels in addition to alloying elements. Then the optimal results conditions were verified by confirmatory experiments.

  16. Simulation of flow pattern at rectangular lateral intake with different dike and submerged vane scenarios

    Directory of Open Access Journals (Sweden)

    Hojat Karami

    2017-07-01

    Full Text Available A comprehensive understanding of the sediment behavior at the entrance of diversion channels requires complete knowledge of three-dimensional (3D flow behavior around such structures. Dikes and submerged vanes are typical structures used to control sediment entrainment in the diversion channel. In this study, a 3D computational fluid dynamic (CFD code was calibrated with experimental data and used to evaluate flow patterns, the diversion ratio of discharge, the strength of secondary flow, and dimensions of the vortex inside the channel in various dike and submerged vane installation scenarios. Results show that the diversion ratio of discharge in the diversion channel is dependent on the width of the flow separation plate in the main channel. A dike perpendicular to the flow with a narrowing ratio of 0.20 doubles the ratio of diverted discharge in addition to reducing suspended sediment input to the basin, compared with a no-dike situation, by creating the outer arch conditions. A further increase in the narrowing ratio decreases the diverted discharge. In addition, increasing the longitudinal distance between consecutive vanes (Ls increases the velocity gradient between the vanes and leads to a more severe erosion of the bed, near the vanes.

  17. Submerged pedology: the soils of minor islands in the Venice lagoon

    Directory of Open Access Journals (Sweden)

    Mohammad Washa

    2015-12-01

    Full Text Available Minor islands of the Venice lagoon are part of a delicate ecosystem, with equilibrium that depends on multiple factors deriving from both the aqueous and the terrestrial compartment, and represent useful indicators of the lagoon ecosystem status. Over centuries, some islands emerged, some others disappeared, others are being submerged in consequence of sea level rise, or are dismantled by marine erosion. Ecological survey and soil sampling evidenced rather homogeneous environment and soil characters, likely due to the same genesis from HTM during centuries, and to environmental conditions such as moisture and brackish groundwater. Four of the examined soils are Inceptisols, while the others present limited horizon differentiation, and are Entisols. All the profiles reflect udic or aquic conditions, and some of them are submerged for most time. Most soils are moderately alkaline (7.9 250 g/kg; organic carbon content at surface is within the normal range (8 17 g/kg and carbonates. Moreover, the textural class is generally silty-loam with increasing clay content with depth. Currently, the soils examined present hydromorphic pedofeatures, which are the result of the most important pedogenic process in the lagoon. Alternating reduction/oxidation processes would increase as a consequence of sea level rise, determining reducing conditions at bottom, and conversely enhancing salt concentration uppermost, with negative consequences for both pedogenic evolution and vegetation survival.

  18. Turbulence-induced noise of a submerged cylinder using a permeable FW–H method

    Directory of Open Access Journals (Sweden)

    Woen-Sug Choi

    2016-05-01

    Full Text Available Among underwater noise sources around submerged bodies, turbulence-induced noise has not been well investigated because of the difficulty of predicting it. In computational aeroacoustics, a number of studies has been conducted using the Ffowcs Williams–Hawkings (FW–H acoustic analogy without consideration of quadrupole source term due to the unacceptable calculation cost. In this paper, turbulence-induced noise is predicted, including that due to quadrupole sources, using a large eddy simulation (LES turbulence model and a developed formulation of permeable FW–H method with an open source computational fluid dynamics (CFD tool-kit. Noise around a circular cylinder is examined and the results of using the acoustic analogy method with and without quadrupole noise are compared, i.e. the FW–H method without quadrupole noise versus the permeable FW–H method that includes quadrupole sources. The usability of the permeable FW–H method for the prediction of turbulence-noise around submerged bodies is shown.

  19. Video monitoring of sandbar-shoreline response to an offshore submerged structure at a microtidal beach

    Science.gov (United States)

    Bouvier, Clément; Balouin, Yann; Castelle, Bruno

    2017-10-01

    In early 2013, an 800-m long and 12-m wide submerged breakwater with its crest in 2-m depth was implemented at the wave-dominated barred beach of Sète, SE France, to fight against erosion and submersion hazards. Daily video images from April 2011 to April 2016 covering an alongshore distance of 3.5 km are used to analyse the response of both the sandbar(s) and the shoreline to the structure implementation. Results show that the breakwater had a profound impact on the nearshore system, both shoreward of the structure and well away from it alongshore. A progressive rotation and linearisation of the sandbar was observed shoreward of the submerged breakwater. This resulted in the splitting of the sandbar adjacent to the structure during a net offshore sandbar migration event driven by a severe storm in December 2013. The typical formation of a salient or tombolo was not observed. Instead, shoreline coupled to the sandbar geometry, which resulted in a slight seaward migration of the shoreline in front of the structure. Overall, this study highlights that the role of the sandbar is critical to shoreline response to the implementation of breakwaters on barred beaches.

  20. Response of sago pondweed, a submerged aquatic macrophyte, to herbicides in three laboratory culture systems

    Science.gov (United States)

    Fleming, W.J.; Ailstock, M.S.; Momot, J.J.; Norman, C.M.; Gorsuch, Joseph W.; Lower, William R.; Wang, Wun-cheng; Lewis, M.A.

    1991-01-01

    The phytotoxicity of atrazine, paraquat, glyphosate, and alachlor to sago pondweed (Potamogeton pectinatus), a submerged aquatic macrophyte, was tested under three types of laboratory culture conditions. In each case, tests were conducted in static systems, the test period was four weeks, and herbicide exposure was chronic, resulting from a single addition of herbicide to the test vessels at the beginning of the test period. The three sets of test conditions employed were(1) axenic cultures in 125-mL flasks containing a nutrient media and sucrose; (2) a microcosm system employing 18.9-L buckets containing a sand, shell, and peat substrate; and (3) an algae-free system employing O.95-L jars containing reconstituted freshwater and a nutrient agar substrate. The primary variable measured was biomass production. Plants grew well in all three test systems, with biomass of untreated plants increasing by a factor of about 5 to 6.5 during the four-week test period. Biomass production in response to herbicide exposure differed significantly among culture systems, which demonstrates the need for a standardized testing protocol for evaluating the effects of toxics on submerged aquatic plants.

  1. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Mo Shuqing

    2017-01-01

    Full Text Available Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN, total phosphorus (TP and chlorophyll a (Chl a concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.

  2. Fulvic acid degradation using nanoparticle TiO2 in a submerged membrane photocatalysis reactor.

    Science.gov (United States)

    Fu, Jian-feng; Ji, Min; An, Ding-nian

    2005-01-01

    The degradation of fulvic acid (FA) by nanoparticle TiO2 in a submerged membrane photocatalysis (SMPC) reactor was studied. In this reactor, photocatalytic oxidation and membrane separation co-occured. The continuous air supplier provided O2 for the photocatalytical reaction and mixed the solution through an airflow controller. The particle TiO2 could automatically settle due to gravity without particle agglomeration so it could be easily separated by microfiltration (MF) membrane. It was efficient to maintain high flux of membranes. The effects of operational parameters on the photocatalytic oxidation rate of FA were investigated. Results indicated that photocatalyst at 0.5 g/L and airflow at 0.06 m3/h were the optimum condition for the removal of fulvic acid, the removal efficiency was higher in acid media than that in alkaline media. The effects of different filtration duration on permeate flux rate of MF with P25 powder and with nanoparticle TiO2 were compared. Experimental results indicated that the permeate flux rate of MF was improved and the membrane fouling phenomenon was reduced with the addition of nanoparticle TiO2 catalyst compared with conventional P25 powder. Therefore, this submerged membrane photocatalysis reactor can faciliate potential application of photocatalytic oxidation process in drinking water treatment.

  3. Investigation of submerged waterjet cavitation through surface property and flow information in ambient water

    Science.gov (United States)

    Kang, Can; Liu, Haixia; Zhang, Tao; Li, Qing

    2017-12-01

    To illuminate primary factors influencing the morphology of the surface impinged by submerged waterjet, experiments were performed at high jet pressures from 200 to 320 MPa. The cavitation phenomenon involved in the submerged waterjet was emphasized. Copper specimens were used as the targets enduring the impingement of high-pressure waterjets. The microhardness of the specimen was measured. Surface morphology was observed using an optical profiling microscope. Pressure fluctuations near the jet stream were acquired with miniature pressure transducers. The results show that microhardness increases with jet pressure and impingement time, and the hardening effect is restricted within a thin layer underneath the target surface. A synthetic effect is testified with the plastic deformation and cavities on the specimen surfaces. Characteristics of different cavitation erosion stages are illustrated by surface morphology. At the same jet pressure, the smallest standoff distance is not corresponding to the highest mass removal rate. Instead, there is an optimal standoff distance. With the increase of jet pressure, overall mass removal rate rises as well. Low-frequency components are predominant in the pressure spectra and the dual-peak pattern is typical. As the streamwise distance from the nozzle is enlarged, pressure amplitudes associated with cavitation bubble collapse are improved.

  4. Alpha-terpineol promotes triterpenoid production of Antrodia cinnamomea in submerged culture.

    Science.gov (United States)

    Lu, Zhen-Ming; Geng, Yan; Li, Hua-Xiang; Sun, Qing; Shi, Jin-Song; Xu, Zheng-Hong

    2014-09-01

    Antrodia cinnamomea is a medicinal mushroom producing potent bioactive triterpenoids. However, triterpenoids of A. cinnamomea in submerged culture are much less than those in fruiting bodies. Here we evaluated effects of different extracts from a host-related species, Cinnamomum camphora, on the mycelial growth and triterpenoid production of A. cinnamomea in submerged culture. The hot water extract of the stem showed the strongest promotion of the mycelial growth. The petroleum ether extract of the stem (PES) (0.05 g L(-1)) showed the greatest stimulatory effect on content and production of triterpenoids. A total of 39 compounds including terpenoids, phenolic and aromatic compounds were identified in the PES by GC-MS analysis. Furthermore, the effects of seven compounds contained in the PES on the mycelial growth and triterpenoid production of A. cinnamomea were evaluated. Among them, α-terpineol (0.5 mg L(-1)) showed the greatest stimulatory effect on the triterpenoid content (23.31 mg g(-1)) and triterpenoid production (91.33 mg L(-1)) of A. cinnamomea. Results of LC-MS analysis showed that α-terpineol (0.5 mg L(-1)) stimulated the syntheses of six triterpenoids in the mycelia of A. cinnamomea. This indicates that α-terpineol can act as an elicitor for triterpenoid biosynthesis in A. cinnamomea. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Sustainable operation of submerged Anammox membrane bioreactor with recycling biogas sparging for alleviating membrane fouling.

    Science.gov (United States)

    Li, Ziyin; Xu, Xindi; Xu, Xiaochen; Yang, FengLin; Zhang, ShuShen

    2015-12-01

    A submerged anaerobic ammonium oxidizing (Anammox) membrane bioreactor with recycling biogas sparging for alleviating membrane fouling has been successfully operated for 100d. Based on the batch tests, a recycling biogas sparging rate at 0.2m(3)h(-1) was fixed as an ultimate value for the sustainable operation. The mixed liquor volatile suspended solid (VSS) of the inoculum for the long operation was around 3000mgL(-1). With recycling biogas sparging rate increasing stepwise from 0 to 0.2m(3)h(-1), the reactor reached an influent total nitrogen (TN) up to 1.7gL(-1), a stable TN removal efficiency of 83% and a maximum specific Anammox activity (SAA) of 0.56kg TNkg(-1) VSSd(-1). With recycling biogas sparging rate at 0.2 m(3) h(-1) (corresponding to an aeration intensity of 118m(3)m(-2)h(-1)), the membrane operation circle could prolong by around 20 times compared to that without gas sparging. Furthermore, mechanism of membrane fouling was proposed. And with recycling biogas sparging, the VSS and EPS content increasing rate in cake layer were far less than the ones without biogas sparging. The TN removal performance and sustainable membrane operation of this system showed the appealing potential of the submerged Anammox MBR with recycling biogas sparging in treating high-strength nitrogen-containing wastewaters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Stage–discharge relationship for a pipe overflow structure in both free and submerged flow

    Directory of Open Access Journals (Sweden)

    Gilles Isenmann

    2016-01-01

    Full Text Available Many facilities for urban drainage systems are equipped with a pipe overflow structure that can often be treated as a circular broad-crested weir. Thus it is possible to evaluate the overflow discharge through this device by measuring the water levels in the upstream tank and at the outlet of the pipe. In the present study, computational fluid dynamics (CFD is used to determine a relationship between the discharge and the water levels upstream and downstream of the orifice for a range of diameters between 200 and 600 mm and a relative head up to 2. Over 50 numerical simulations are performed to take into account all the operating conditions of the system: free flow, submerged flow and pressurized flow. A regression is applied to the resulting data in order to obtain an orifice equation valid in both free-flow and submerged-flow regimes. Specific formulas, derived from Bernoulli's theorem, are also given for pressurized flows. The proposed methodology is applied to two examples.

  7. Evaluation of some biotechnological parameters influencing the Pleurotus ostreatus biomass production by submerged cultivation

    Directory of Open Access Journals (Sweden)

    Vicenţiu-Bogdan HORINCAR

    2015-12-01

    Full Text Available The submerged culture of mushrooms represents a future for biotechnological processes at industrial level, in order to obtain biomass with economical value (food and ingredients, nutraceuticals and pharmaceuticals. Pleurotus ostreatus is well known worldwide for its culinary and medicinal value. The aim of the present study was to evaluate the most important biotechnological parameters that have influence on the biomass production of P. ostreatus, by cultivation in submerged conditions. Applying the Plackett-Burman experimental design, the significant parameters influencing the P. ostreatus biomass production were found to be the concentration of dextrose and yeast extract and time of cultivation. The best results in terms of maximising the biomass production (25.71 g·L-1 were obtained when the “+1” level of each independent variables was used in the Plackett-Burman experimental design. Analysis of variance (ANOVA exhibited a high correlation coefficient (R2 value of 0.9908, which certifies that the mathematical model was relevant for the biotechnological process.

  8. Comparative study on the treatment of raw and biologically treated textile effluents through submerged nanofiltration.

    Science.gov (United States)

    Chen, Qing; Yang, Ying; Zhou, Mengsi; Liu, Meihong; Yu, Sanchuan; Gao, Congjie

    2015-03-02

    Raw and biologically treated textile effluents were submerged filtrated using lab-fabricated hollow fiber nanofiltration membrane with a molecular weight cut-off of about 650 g/mol. Permeate flux, chemical oxygen demand (COD) reduction, color removal, membrane fouling, and cleaning were investigated and compared by varying the trans-membrane pressure (TMP) and volume concentrating factor (VCF). It was found that both raw and biologically treated textile effluents could be efficiently treated through submerged nanofiltration. The increase of TMP resulted in a decline in water permeability, COD reduction, color removal, and flux recovery ratio, while the increase of VCF resulted in both increased COD reduction and color removal. Under the TMP of 0.4 bar and VCF of 5.0, fluxes of 1.96 and 2.59 l/m(2)h, COD reductions of 95.7 and 94.2%, color removals of 99.0, and 97.3% and flux recovery ratios of 91.1 and 92.9% could be obtained in filtration of raw and biologically treated effluents, respectively. After filtration, the COD and color contents of the raw effluent declined sharply from 1780 to 325 mg/l and 1.200 to 0.060 Abs/cm, respectively, while for the biologically treated effluent, they decreased from 780 to 180 mg/l and 0.370 to 0.045 Abs/cm, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Microparticle-enhanced Aspergillus ficuum phytase production and evaluation of fungal morphology in submerged fermentation.

    Science.gov (United States)

    Coban, Hasan B; Demirci, Ali; Turhan, Irfan

    2015-06-01

    Phytase can be used in animal's diets to increase the absorption of several divalent ions, amino acids and proteins and to decrease the excessive phosphorus release in manure to prevent negative effects on the environment. This study aimed to enhance the current submerged fungal phytase productions with a novel fermentation technique by evaluating the effect of the various microparticles on Aspergillus ficuum phytase production. It was observed that microparticles prevented bulk fungal pellet growth, decreased average fungal pellet size and significantly increased phytase activity in the submerged fermentation. Microbial structure imaging results showed that the average fungal pellet radius decreased from 800 to 500 and 200 µm by addition of 15 g/L aluminum oxide and talcum, respectively, in shake-flask fermentation. Also, addition of 15 g/L of talcum and aluminum oxide increased phytase activity to 2.01 and 2.93 U/ml, respectively, compared to control (1.02 U/ml) in shake-flask fermentation. Additionally, phytase activity reached 6.49 U/ml within 96 h of fermentation with the addition of 15 g/L of talcum, whereas the maximum phytase activity was only 3.45 U/ml at 120 h of fermentation for the control in the 1-L working volume bioreactors. In conclusion, microparticles significantly increased fungal phytase activity and production yield compared to control fermentation.

  10. Comparison of GC-MS and NMR for metabolite profiling of rice subjected to submergence stress.

    Science.gov (United States)

    Barding, Gregory A; Béni, Szabolcs; Fukao, Takeshi; Bailey-Serres, Julia; Larive, Cynthia K

    2013-02-01

    Natural disasters such as drought, extreme temperatures, and flooding can severely impact crop production. Understanding the metabolic response of crops threatened with these disasters provides insights into biological response mechanisms that can influence survival. In this study, a comparative analysis of GC-MS and (1)H NMR results was conducted for wild-type and tolerant rice varieties stressed by up to 3 days of submergence and allowed 1 day of postsubmergence recovery. Most metabolomics studies are conducted using a single analytical platform. Each platform, however, has inherent advantages and disadvantages that can influence the analytical coverage of the metabolome. In this work, a more thorough analysis of the plant stress response was possible through the use of both (1)H NMR and GC-MS. Several metabolites, such as S-methyl methionine and the dipeptide alanylglycine, were only detected and quantified by (1)H NMR. The high dynamic range of NMR, as compared with that of the GC-TOF-MS used in this study, provided broad coverage of the metabolome in a single experiment. The sensitivity of GC-MS facilitated the quantitation of sugars, organic acids, and amino acids, some of which were not detected by NMR, and provided additional insights into the regulation of the TCA cycle. The combined metabolic information provided by (1)H NMR and GC-MS was essential for understanding the complex biochemical and molecular response of rice plants to submergence.

  11. Adsorption of Arsenite by Six Submerged Plants from Nansi Lake, China

    Directory of Open Access Journals (Sweden)

    Zhibin Zhang

    2014-01-01

    Full Text Available Nansi Lake is the largest and the most important freshwater lake in north China for the South-North Water Transfer Project. Due to long-time and large-scale fish farming of history, the excess fish food and excretion usually release pentavalent arsenic, which is converted into trivalent arsenic (As (III in the lake sediment and released into lake water. Adsorption of arsenite using six submerged plants (Mimulicalyx rosulatus, Potamogeton maackianus, Hydrilla, Watermifoil, Pteris vittata, and Potamogeton crispus as adsorbing materials was investigated. The experimental data obtained have been analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models and the pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetics models. According to the results, the As (III equilibrium data agreed well with the Freundlich isotherm model. The adsorption capacity of the plants was in the following order: Potamogeton crispus > Pteris vittata > Potamogeton maackianus > Mimulicalyx rosulatus > Hydrilla > Watermifoil. The sorption system with the six submerged plants was better described by pseudo-second-order than by first-order kinetics. Moreover, the adsorption with Potamogeton crispus could follow intraparticle diffusion (IPD model. The initial adsorption and rate of IPD using Potamogeton crispus and Pteris vittata were higher than those using other plants studied.

  12. Effects of internal mass distribution and its isolation on the acoustic characteristics of a submerged hull

    Science.gov (United States)

    Peters, Herwig; Kinns, Roger; Kessissoglou, Nicole

    2014-03-01

    The primary aim of machinery isolation in marine vessels is to isolate structural vibration of the onboard machinery from the hull and to reduce far-field radiation of underwater noise. A substantial proportion of the total submarine mass is on flexible mounts that isolate supported masses from the hull at frequencies above the mounting system resonant frequency. This reduces the dynamically effective mass of the hull and affects the signature of the marine vessel due to propeller excitation. A fully coupled finite element/boundary element (FE/BE) model has been developed to investigate the effect of mass distribution and isolation in a submerged hull. The finite element model of the structure includes internal structures to represent the machinery and other flexibly mounted components. Changes in the radiated sound power demonstrate the effect of machinery isolation on the acoustic signature of the submerged hull due to the external propeller forces. Results are also presented to show how the arrangement of flexible mounts for a large internal structure can influence the radiation due to machinery forces.

  13. Unusual energy properties of leaky backward Lamb waves in a submerged plate.

    Science.gov (United States)

    Nedospasov, I A; Mozhaev, V G; Kuznetsova, I E

    2017-05-01

    It is found that leaky backward Lamb waves, i.e. waves with negative energy-flux velocity, propagating in a plate submerged in a liquid possess extraordinary energy properties distinguishing them from any other type of waves in isotropic media. Namely, the total time-averaged energy flux along the waveguide axis is equal to zero for these waves due to opposite directions of the longitudinal energy fluxes in the adjacent media. This property gives rise to the fundamental question of how to define and calculate correctly the energy velocity in such an unusual case. The procedure of calculation based on incomplete integration of the energy flux density over the plate thickness alone is applied. The derivative of the angular frequency with respect to the wave vector, usually referred to as the group velocity, happens to be close to the energy velocity defined by this mean in that part of the frequency range where the backward mode exists in the free plate. The existence region of the backward mode is formally increased for the submerged plate in comparison to the free plate as a result of the liquid-induced hybridization of propagating and nonpropagating (evanescent) Lamb modes. It is shown that the Rayleigh's principle (i.e. equipartition of total time-averaged kinetic and potential energies for time-harmonic acoustic fields) is violated due to the leakage of Lamb waves, in spite of considering nondissipative media. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Scour around a submerged cylinder and marine hydrokinetic (MHK) device in live-bed conditions

    Science.gov (United States)

    Beninati, Maria Laura; Volpe, Michael; Krane, Michael; Fontaine, Arnold

    2013-11-01

    Experiments are presented to explore how sediment scour around a single Marine Hydrokinetic (MHK) turbine varies with flow speed. Three Reynolds numbers, based on support structure diameter were used to induce live-bed scour conditions. Based on results from previous studies on submerged cylinders, differences in scour patterns between a single cylinder and MHK device can be determined. In the case of MHK energy, many devices are submerged in the flow. Thus, it is important to analyze the impact of both the support structure and the addition of the rotating blades. The experiments were performed in the small-scale testing platform in the hydraulic flume facility at Bucknell University. For each test case, bed form topology was measured after a three-hour time interval using a traversing two-dimensional bed profiler. During the experiment, scour depth measurements at the front face of the cylindrical support structure were taken to estimate the scour rate. Measurements of the bed form were taken across the width of the test section. Results show that the scour hole dimensions increase in the presence of the MHK device. These dimensions also increase with increasing Reynolds number.

  15. Mowing Submerged Macrophytes in Shallow Lakes with Alternative Stable States: Battling the Good Guys?

    Science.gov (United States)

    Kuiper, Jan J.; Verhofstad, Michiel J. J. M.; Louwers, Evelien L. M.; Bakker, Elisabeth S.; Brederveld, Robert J.; van Gerven, Luuk P. A.; Janssen, Annette B. G.; de Klein, Jeroen J. M.; Mooij, Wolf M.

    2017-04-01

    Submerged macrophytes play an important role in maintaining good water quality in shallow lakes. Yet extensive stands easily interfere with various services provided by these lakes, and harvesting is increasingly applied as a management measure. Because shallow lakes may possess alternative stable states over a wide range of environmental conditions, designing a successful mowing strategy is challenging, given the important role of macrophytes in stabilizing the clear water state. In this study, the integrated ecosystem model PCLake is used to explore the consequences of mowing, in terms of reducing nuisance and ecosystem stability, for a wide range of external nutrient loadings, mowing intensities and timings. Elodea is used as a model species. Additionally, we use PCLake to estimate how much phosphorus is removed with the harvested biomass, and evaluate the long-term effect of harvesting. Our model indicates that mowing can temporarily reduce nuisance caused by submerged plants in the first weeks after cutting, particularly when external nutrient loading is fairly low. The risk of instigating a regime shift can be tempered by mowing halfway the growing season when the resilience of the system is highest, as our model showed. Up to half of the phosphorus entering the system can potentially be removed along with the harvested biomass. As a result, prolonged mowing can prevent an oligo—to mesotrophic lake from becoming eutrophic to a certain extent, as our model shows that the critical nutrient loading, where the lake shifts to the turbid phytoplankton-dominated state, can be slightly increased.

  16. Detection of the Three Gorges Dam influence on the Changjiang (Yangtze River) submerged delta

    Science.gov (United States)

    Dai, Zhijun; Liu, James T.; Wei, Wen; Chen, Jiyu

    2014-10-01

    While most large river-deltas in the world are facing the risk of subsidence and erosion in the Anthropocene, it is suspected that the Changjiang submerged delta (CSD) could be subjected to the impacts of the world's largest dam, the Three Gorges Dam (TGD). Here we firstly indicate that the CSD went through high accumulation (1958-1978) slight accumulation (1978-1997), slight erosion (1997-2002) and high accumulation (2002-2009), despite the 70% reduction of the sediment load from upstream since the operation of the TGD in 2003. Meanwhile, at the depocenter of the submerged delta, the accumulation maintained a high rate of 10 cm/yr during 1958-2009. This suggests on a longer term, the distal sediment source from the upstream had little effect on the CSD. Within this time frame the changes in the partition of sediment load among the branching channels of the Changjiang Estuary could likely control the shifting of the depocenter of the CSD on a decadal time scale. Episodic extreme floods and storm surges also increased the magnitude of deposition and erosion of the CSD on short-term scales. A re-evaluation of the impacts of TGD on the CSD is urgently needed.

  17. Oxygen, pH, and Eh microprofiles around submerged macrophyte Vallisneria natans response to growing stages

    Science.gov (United States)

    Dong, B.; Wang, G. X.; Yu, H. G.

    2017-08-01

    The periphyton, attached to the surfaces of submerged plants, has important effects on plant growth and development in eutrophic waters. Periphyton complicates the microenvironment of diffusive boundary layer around submerged plants. We researched periphyton characteristics, oxygen (O2), pH, and Eh microprofiles at various growing stages of Vallisneria natans. The results suggested that during the growing period of V. natans, O2 concentration and pH decreased from 0 to 2 mm above the leaf surface, whereas the Eh increased. As V. natans grew, O2 and pH gradually increased until they peaked during stable growing stages, while the Eh decreased. However, during the decline stage, O2 and pH gradually decreased, and Eh increased. To summarise, O2 and pH showed a unimodal pattern in response to the life cycle of V. natans, with the maximum levels during the stable growth stage and the minimum levels during the rapid growth and decline stages. Our study demonstrated that V. natans growth induced steep gradients in O2 concentrations, pH, and Eh at the DBL by increasing the layer’s thickness, macrophyte photosynthetic capacity, and periphyton biomass in eutrophic waters.

  18. Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol

    Directory of Open Access Journals (Sweden)

    Carla Eliana Todero Ritter

    2013-01-01

    Full Text Available The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problems with rheology and oxygen transfer. The submerged fermentations containing media composed of 0, 0.25, 0.5, 0.75, and 1% (w/v sorbitol and cellulose that were added at different times during the cultivation; 0.2% (w/v soy bran; 0.1% (w/v wheat bran; and a solution of salts. The highest filter paper activity (FPA ( IU·mL−1 was obtained on the seventh day in the medium containing 0.5% (w/v sorbitol and 0.5% (w/v cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day ( IU·mL−1 in the medium containing 0.75% (w/v sorbitol and 0.75% (w/v cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75% (w/v sorbitol and 0.25% (w/v cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems.

  19. Benthic Macrofauna Associated with Submerged Bottoms of a Tectonic Estuary in Tropical Eastern Pacific

    Directory of Open Access Journals (Sweden)

    Carlos E. Guevara-Fletcher

    2011-01-01

    Full Text Available The composition and distribution of the main associations of submerged macrobenthos of Bahía Málaga (Colombian pacific coast, were studied in relation to the distribution of hard and soft substrates and some abiotic factors. Eight localities were sampled during six months: three in the external border of the estuary and five in the inner part. In total, 728 organisms were registered, belonging to 207 species, 132 genera, 86 families, and 14 orders of six invertebrate groups (Porifera, Cnidaria, Polychaeta, Mollusca, Crustacea, and Echinodermata. The submerged bottoms presented soft and hard substrates, with rocks and thick sand in five sites, soft bottoms with fine sand in one, and soft bottoms with slime and clay in two. The temperature and salinity values were higher in the external localities, while dissolved oxygen and pH were higher in the internal localities. The localities with hard substrates presented the highest richness of species while the soft substrates, were characterized by a paucity of species and individuals. The similarity classification analyses showed two groups: one characterized by having 61 species in common and high richness with 113 exclusive species. The other group with low diversity and richness values, 37 species in common and 23 exclusive species.

  20. Degradation and metabolism of tetrabromobisphenol A (TBBPA) in submerged soil and soil-plant systems.

    Science.gov (United States)

    Sun, Feifei; Kolvenbach, Boris Alexander; Nastold, Peter; Jiang, Bingqi; Ji, Rong; Corvini, Philippe Francois-Xavier

    2014-12-16

    Contamination by tetrabromobisphenol A (TBBPA), the most widely used brominated flame retardant, is a matter of environmental concern. Here, we investigated the fate and metabolites of (14)C-TBBPA in a submerged soil with an anoxic-oxic interface and planted or not with rice (Oryza sativa) and reed (Phragmites australis) seedlings. In unplanted soil, TBBPA dissipation (half-life 20.8 days) was accompanied by mineralization (11.5% of initial TBBPA) and the substantial formation (60.8%) of bound residues. Twelve metabolites (10 in unplanted soil and 7 in planted soil) were formed via four interconnected pathways: oxidative skeletal cleavage, O-methylation, type II ipso-substitution, and reductive debromination. The presence of the seedlings strongly reduced (14)C-TBBPA mineralization and bound-residue formation and stimulated debromination and O-methylation. Considerable radioactivity accumulated in rice (21.3%) and reed (33.1%) seedlings, mainly on or in the roots. While TBBPA dissipation was hardly affected by the rice seedlings, it was strongly enhanced by the reed seedlings, greatly reducing the half-life (11.4 days) and increasing monomethyl TBBPA formation (11.3%). The impact of the interconnected aerobic and anaerobic transformation of TBBPA and wetland plants on the profile and dynamics of the metabolites should be considered in phytoremediation strategies and environmental risk assessments of TBBPA in submerged soils.

  1. Submerged Membrane Bioreactor (sMBR: a promising alternative to wastewater treatment for water reuse

    Directory of Open Access Journals (Sweden)

    Eduardo Lucas Subtil

    2013-12-01

    Full Text Available Treatment technology for wastewater treatment and reuse encompasses a vast number of options, and the Submerged Membrane Bioreactor is regarded as a key element for the role it can play in water reuse schemes. Thus, this study aimed to present and discuss the current status of sMBR implementation, as well as to present the results of a pilot plant with submerged flat sheet membranes treating wastewater from the residence halls and the restaurant of the University of São Paulo. The pilot plant was operated under stationary conditions over a period of 90 days with a concentration of 3422 ± 693 mg TSS/L. The results showed that the system can produce an effluent with low concentrations of color, turbidity, COD and BOD5 with values of 25 uC, 0.29 NTU, 5.5 mg O2/L and 24 mg O2/L, respectively. Furthermore, the ultrafiltration membranes used were able to reduce the density of pathogen indicators, with removal of 7 and 6 log of thermotolerant coliforms and E. coli respectively, resulting with concentrations of 9,3 ± 21,0 e 1,8 ± 4,0 MPN/100 mL, respectively.

  2. Sleep related vehicle accidents.

    Science.gov (United States)

    Horne, J A; Reyner, L A

    1995-03-04

    To assess the incidence, time of day, and driver morbidity associated with vehicle accidents where the most likely cause was the driver falling asleep at the wheel. Two surveys were undertaken, in southwest England and the midlands, by using police databases or on the spot interviews. Drivers involved in 679 sleep related vehicle accidents. Of all vehicle accidents to which the police were summoned, sleep related vehicle accidents comprised 16% on major roads in southwest England, and over 20% on midland motorways. During the 24 hour period there were three major peaks: at around 0200, 0600, and 1600. About half these drivers were men under 30 years; few such accidents involved women. Sleep related vehicle accidents are largely dependent on the time of day and account for a considerable proportion of vehicle accidents, especially those on motorways and other monotonous roads. As there are no norms for the United Kingdom on road use by age and sex for time of day with which to compare these data, we cannot determine what the hourly exposure v risk factors are for these subgroups. The findings are in close agreement with those from other countries.

  3. Production of polyhydroxyalkanoates (PHAs) from waste materials and by-products by submerged and solid-state fermentation.

    Science.gov (United States)

    Castilho, Leda R; Mitchell, David A; Freire, Denise M G

    2009-12-01

    Polyhydroxyalkanoates are biodegradable polymers produced by prokaryotic organisms from renewable resources. The production of PHAs by submerged fermentation processes has been intensively studied over the last 30 years. In recent years, alternative strategies have been proposed, such as the use of solid-state fermentation or the production of PHAs in transgenic plants. This paper gives an overview of submerged and solid-state fermentation processes used to produce PHAs from waste materials and by-products. The use of these low-cost raw materials has the potential to reduce PHA production costs, because the raw material costs contribute a significant part of production costs in traditional PHA production processes.

  4. Submerged biological contractors, the SBC process. Procesos S. B. C. contactores biologicos sumergidos. Tercera generacion de biodiscos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Cudinach, R.

    1994-01-01

    The third generation of rotating filters are introduced. Like their predecessors, they include aeration which allows them to deal with extremely high organic and hydraulic loads, simultaneously activating the bio disc bodies. Finally, in this new version, most of the disc is submerged in the medium to be purified of biomass (over 30.000 ppm) to produce efficient purification at lower investment cost. The model can be submerged up to 70-90% and has a diameter of up to 5.5 m at 1 rpm.

  5. Numerical simulation for submerged body fitted with hydrofoil by boundary element method; Kyokai yosoho ni yoru yokutsuki bossuitai mawari no nagare keisan

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, S.; Kasahara, Y.; Ashidate, I. [NKK Corp., Tokyo (Japan)

    1996-12-31

    In a high-speed boat of a type using hydrofoils, lifting force increases in proportion to square of its length, while displacement is proportional to the third power. Therefore, an idea has come up that speed of a large boat may be increased by combining the hydrofoils with a submerged body. In other words, the idea is to levitate a ship by using composite support consisting of buoyancy of the submerged body and lifting force caused by the hydrofoils. Insufficiency of the lifting force may be complemented by the buoyancy of the submerged body which increases in an equivalent rate as that in the displacement. However, combining a submerged body with hydrofoils render a problem that lifting force for hydrofoils decreases because of interactions among the submerged body, hydrofoils, and free surface. Therefore, assuming a model of a submerged body with a length of 85 m cruising at 40 kt, analysis was given on decrease in lifting force for hydrofoils due to interactions between the submerged and lifting body and free surface by using the boundary element method. As a result, it was verified that the lifting force for the hydrofoils decreases as a result of creation of a flow that decreases effective angle of attach of the hydrofoils. It was also made clear that making the submerging depth greater reduces the decrease in the lifting force. 9 refs., 14 figs., 1 tab.

  6. Electric/Hybrid Vehicle Simulation

    Science.gov (United States)

    Slusser, R. A.; Chapman, C. P.; Brennand, J. P.

    1985-01-01

    ELVEC computer program provides vehicle designer with simulation tool for detailed studies of electric and hybrid vehicle performance and cost. ELVEC simulates performance of user-specified electric or hybrid vehicle under user specified driving schedule profile or operating schedule. ELVEC performs vehicle design and life cycle cost analysis.

  7. Accident externality and vehicle size

    OpenAIRE

    Jonsson, Lina; Lindberg, Gunnar

    2009-01-01

    Vehicle mass is a crucial factor for the distribution of injuries between occupants in involved vehicles in a two-vehicle crash. A larger vehicle mass protects the occupants in the vehicle while on the same time inflicts a higher injury risk on the occupants in the collision partner. This mass externality can be internalized to reach a situation where the drivers choose vehicle mass based on the social optimum instead of a private optimum that ignores the negative effects that a large vehicle...

  8. Advokaadi kutse-eetika reason d’etre / Ain Alvin

    Index Scriptorium Estoniae

    Alvin, Ain, 1959-

    2014-01-01

    Advokaadi kohustus on kutsetegevuses järgida lisaks seadusele kutse-eetika nõudeid, häid kombeid ja südametunnistust. Mida sellised kohustused sisuliselt tähendavad, millest tuleneb vajadus kutse-eetika kutseühendusesisese reguleerimise järele ja milline on kutse-eetika normide sisu?

  9. ELECTROMAGNETIC BIOSPHERE POLLUTION BY MOTOR TRANSPORT (VEHICLES, ELECTRIC VEHICLES, HYBRID VEHICLES

    Directory of Open Access Journals (Sweden)

    S. Selivanov

    2009-01-01

    Full Text Available The physics of the electromagnetic field is considered. The analysis of electromagnetic radiation on the human-being, the origin of which is the vehicle the electric vehicle, the hybrid vehicle is being considered. The monitoring of electromagnetic radiation of vehicles is carried out.

  10. ELECTROMAGNETIC BIOSPHERE POLLUTION BY MOTOR TRANSPORT (VEHICLES, ELECTRIC VEHICLES, HYBRID VEHICLES)

    OpenAIRE

    S. Selivanov; V. Filenko; А. Bazhynov; E. Budianskaya

    2009-01-01

    The physics of the electromagnetic field is considered. The analysis of electromagnetic radiation on the human-being, the origin of which is the vehicle the electric vehicle, the hybrid vehicle is being considered. The monitoring of electromagnetic radiation of vehicles is carried out.

  11. Methane oxidation associated to submerged brown-mosses buffers methane emissions from Siberian polygonal peatlands

    Science.gov (United States)

    Liebner, Susanne; Zeyer, Josef; Knoblauch, Christian

    2010-05-01

    Circumpolar peatlands store roughly 18 % of the globally stored carbon in soils [based on 1, 2]. Also, northern wetlands and tundra are a net source of methane (CH4), an effective greenhouse gas (GHG), with an estimated annual CH4 release of 7.2% [3] or 8.1% [4] of the global total CH4 emission. Although it is definite that Arctic tundra significantly contributes to the global methane emissions in general, regional variations in GHG fluxes are enormous. CH4 fluxes of polygonal tundra within the Siberian Lena Delta, for example, were reported to be low [5, 6], particularly at open water polygonal ponds and small lakes [7] which make up around 10 % of the delta's surface. Low methane emissions from polygonal ponds oppose that Arctic permafrost thaw ponds are generally known to emit large amounts of CH4 [8]. Combining tools of biogeochemistry and molecular microbiology, we identified sinks of CH4 in polygonal ponds from the Lena Delta that were not considered so far in GHG studies from Arctic wetlands. Pore water CH4 profiling in polygonal ponds on Samoylov, a small island in the central part of the Lena Delta, revealed a pronounced zone of CH4 oxidation near the vegetation surface in submerged layers of brown-mosses. Here, potential CH4 oxidation was an order of magnitude higher than in non-submerged mosses and in adjacent bulk soil. We could additionally show that this moss associated methane oxidation (MAMO) is hampered when exposure of light is prevented. Shading of plots with submerged Scorpidium scorpioides inhibited MAMO leading to higher CH4 concentrations and an increase in CH4 fluxes by a factor of ~13. Compared to non-submerged mosses, the submerged mosses also showed significantly lower δ13C values indicating that they use carbon dioxide derived from methane oxidation for photosynthesis. Applying stable isotope probing of DNA, type II methanotrophs were identified to be responsible for the oxidation of CH4 in the submerged Scorpidium scorpioides. Our

  12. China's Launch Vehicle Operations

    Science.gov (United States)

    Bai, Jingwu

    2002-01-01

    China's Launch Vehicle technologies have been started since 1950s. With the efforts made by several-generation Chinese Space people, the Long March (LM) Launch Vehicles, China's main space transportation tools, have undergone a development road from conventional propellants to cryogenic propellants, from stage-by-stage to strap-on, from dedicated-launch to multiple-launch, from satellite-launching to space capsule-launching. The LM Launch Vehicles are capable of sending various payloads to different orbits with low cost and high reliability. Till now, the LM Launch Vehicles have conducted 67 launch missions, putting 76 spacecraft into the given orbits since the successful mission made by LM-1 in 1970. Especially, they have performed 22 international commercial satellite-launching missions, sending 27 foreign satellites successfully. The footprints of LM Launch Vehicles reflect the development and progress of Chinese Space Industry. At the beginning of the 21st century, with the development of launch vehicle technology and the economic globalization, it is an inexorable trend that Chinese space industry must participate in the international cooperation and competition. Being faced with both opportunities and challenges, Chinese Space Industry should promote actively the commercial launch service market to increase service quality and improve the comprehensive competition capabilities. In order to maintain the sustaining development of China's launch vehicle technology and to meet the increasing needs in the international commercial launch service market, Chinese space industry is now doing research work on developing new-generation Chinese launchers. The new launchers will be large-scale, powerful and non-contamination. The presence of the new-generation Chinese launchers will greatly speed up the development of the whole space-related industries in China, as well as other parts of the world. In the first part, this paper gives an overview on China Aerospace Science

  13. VEHICLES LICENSED IN SWITZERLAND

    CERN Multimedia

    Service des Relations avec les Pays-Hôtes

    2000-01-01

    1.\tVehicle licensinga)\tTime limitsVehicles must have a Swiss registration document and Swiss number plates: -\tif the owner has been residing in Switzerland for more than one year without a break of more than three consecutive months and has been using it for more than one month on Swiss territory, or -\tif the vehicle itself has been on Swiss territory for more than one year without a break of more than three consecutive months. b)\tTechnical details Vehicles belonging to non-Swiss members of the personnel who hold a carte de légitimation issued by the Swiss Federal Department of Foreign Affairs (hereinafter referred to as 'DFAE') and who were not permanently resident in Switzerland before taking up their appointment may be licensed in Switzerland with virtually no restrictions provided that their owner produces: -\tthe vehicle registration document and number plates of the country in which the car was previously registered, or -\ta manufacturer's certi...

  14. Distributed Propulsion Vehicles

    Science.gov (United States)

    Kim, Hyun Dae

    2010-01-01

    Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. are enabling a high degree of integration of the airframe and propulsion system in aircraft design. The National Aeronautics and Space Administration (NASA) has been investigating a number of revolutionary distributed propulsion vehicle concepts to increase aircraft performance. The concept of distributed propulsion is to fully integrate a propulsion system within an airframe such that the aircraft takes full synergistic benefits of coupling of airframe aerodynamics and the propulsion thrust stream by distributing thrust using many propulsors on the airframe. Some of the concepts are based on the use of distributed jet flaps, distributed small multiple engines, gas-driven multi-fans, mechanically driven multifans, cross-flow fans, and electric fans driven by turboelectric generators. This paper describes some early concepts of the distributed propulsion vehicles and the current turboelectric distributed propulsion (TeDP) vehicle concepts being studied under the NASA s Subsonic Fixed Wing (SFW) Project to drastically reduce aircraft-related fuel burn, emissions, and noise by the year 2030 to 2035.

  15. Wall-Friction Support of Vertical Loads in Submerged Sand and Gravel Columns

    Energy Technology Data Exchange (ETDEWEB)

    Walton, O. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vollmer, H. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hepa, V. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-25

    Laboratory studies of the ‘floor-loads’ under submerged vertical columns of sand and/or gravel indicate that such loads can be approximated by a buoyancy-corrected Janssen-silo-theory-like relationship. Similar to conditions in storage silos filled with dry granular solids, most of the weight of the sand or gravel is supported by wall friction forces. Laboratory measurements of the loads on the floor at the base of the water-filled columns (up to 25-diameters tall) indicate that the extra floor-load from the addition of the granular solid never exceeded the load that would exist under an unsupported (wide) bed of submerged sand or gravel that has a total depth corresponding to only two column-diameters. The measured floorloads reached an asymptotic maximum value when the depth of granular material in the columns was only three or four pipe-diameters, and never increased further as the columns were filled to the top (e.g. up to heights of 10 to 25 diameters). The floor-loads were stable and remained the same for days after filling. Aggressive tapping (e.g. hitting the containing pipe on the outside, manually with a wrench up and down the height and around the circumference) could increase (and occasionally decrease) the floor load substantially, but there was no sudden collapse or slumping to a state without significant wall friction effects. Considerable effort was required, repeatedly tapping over almost the entire column wall periphery, in order to produce floor-loads that corresponded to the total buoyancy-corrected weight of granular material added to the columns. Projecting the observed laboratory behavior to field conditions would imply that a stable floor-load condition, with only a slightly higher total floor pressure than the preexisting hydrostatic-head, would exist after a water-filled bore-hole is filled with sand or gravel. Significant seismic vibration (either a large nearby event or many micro-seismic events over an extended period) would likely

  16. On-line study of fungal morphology during submerged growth in a small flow-through cell

    DEFF Research Database (Denmark)

    Spohr, Anders Bendsen; Dam Mikkelsen, C.; Carlsen, Morten

    1998-01-01

    A flow-through cell is designed to measure the growth kinetics of hyphae of Aspergillus oryzae grown submerged in a well controlled environment. The different stages of the growth process are characterized, from the spore to the fully developed hyphal element with up to 60 branches and a total...

  17. 77 FR 5529 - Commercial Lease of Submerged Lands for Renewable Energy Development on the Outer Continental Shelf

    Science.gov (United States)

    2012-02-03

    ... Bureau of Ocean Energy Management Commercial Lease of Submerged Lands for Renewable Energy Development on.... SUMMARY: The Bureau of Ocean Energy Management (BOEM) will use Form 0008 to issue commercial renewable..., ``Renewable Energy and Alternate Uses of Existing Facilities on the Outer Continental Shelf,'' BOEM stated...

  18. Aspergillus oryzae in solid-state and submerged fermentations. Progress report on a multi-disciplinary project

    NARCIS (Netherlands)

    Biesebeke, te R.; Ruijter, G.; Rahardjo, Y.S.P.; Hoogschagen, M.J.; Heerikhuisen, M.; Levin, A.; Driel, van K.G.A.; Schutyser, M.A.I.; Dijksterhuis, J.; Yang Zhu, Yang; Weber, F.J.; Vos, de W.M.; Hondel, van den K.A.; Rinzema, A.; Punt, P.J.

    2002-01-01

    We report the progress of a multi-disciplinary research project on solid-state fermentation (SSF) of the filamentous fungus Aspergillus oryzae. The molecular and physiological aspects of the fungus in submerged fermentation (SmF) and SSF are compared and we observe a number of differences correlated

  19. Aspergillus oryzae in solid-state and submerged fermentations. Progress report on a multi-disciplinary project

    NARCIS (Netherlands)

    te Biesebeke, Rob; Ruijter, George; Rahardjo, Yovita S P; Hoogschagen, Marisca J; Heerikhuisen, Margreet; Levin, Ana; van Driel, Kenneth G A; Schutyser, Maarten A I; Dijksterhuis, Jan; Zhu, Yang; Weber, Frans J; de Vos, Willem M; van den Hondel, Kees A M J J; Rinzema, Arjen; Punt, Peter J

    We report the progress of a multi-disciplinary research project on solid-state fermentation (SSF) of the filamentous fungus Aspergillus oryzae. The molecular and physiological aspects of the fungus in submerged fermentation (SmF) and SSF are compared and we observe a number of differences correlated

  20. Aspergillus oryzae in solid-state and submerged fermentations: Progress report on a multi-disciplinary project

    NARCIS (Netherlands)

    Biesebeke, R. te; Ruijter, G.; Rahardjo, Y.S.P.; Hoogschagen, M.J.; Heerikhuisen, M.; Levin, A.; Driel, K.G.A. van; Schutyser, M.A.I.; Dijksterhuis, J.; Zhu, Y.; Weber, F.J.; Vos, W.M. de; Hondel, K.A.M.J.J. van den; Rinzema, A.; Punt, P.J.

    2002-01-01

    We report the progress of a multi-disciplinary research project on solid-state fermentation (SSF) of the filamentous fungus Aspergillus oryzae. The molecular and physiological aspects of the fungus in submerged fermentation (SmF) and SSF are compared and we observe a number of differences correlated

  1. Effect of inorganic nutrients on relative contributions of fungi and bacteria to carbon flow from submerged decomposing leaf litter

    Science.gov (United States)

    Vladislav Gulis; Keller Suberkropp

    2003-01-01

    The relative contributions of fungi and bacteria to carbon flow from submerged decaying plant litter at different levels of inorganic nutrients (N and P) were studied. We estimated leaf mass loss, fungal and bacterial biomass and production, and microbial respiration and constructed partial carbon budgets for red maple leaf disks precolonized in a stream and then...

  2. Fingerprint of a submerged-arc furnace : Optimising energy consumption through data mining, dynamic modelling and computational fluid dynamics

    NARCIS (Netherlands)

    Scheepers, E.

    2008-01-01

    This study imparts a scientific perception of a phosphorous-producing submerged arc furnace never seen before; a proverbial fingerprint that can improve problem identification, disturbance diagnostics, process prediction, dynamic modelling and model predictive control of this type of furnace. It

  3. Ethylene regulates fast apoplastic acidification and expansin A transcription during submergence-induced petiole elongation in Rumex palustris

    NARCIS (Netherlands)

    Vreeburg, RAM; Benschop, JJ; Peeters, AJM; Colmer, TD; Ammerlaan, AHM; Staal, M; Elzenga, TM; Staals, RHJ; Darley, CP; McQueen-Mason, SJ; Voesenek, LACJ

    The semi-aquatic dicot Rumex palustris responds to complete submergence by enhanced elongation of young petioles. This elongation of petiole cells brings leaf blades above the water surface, thus reinstating gas exchange with the atmosphere and increasing survival in flood-prone environments. We

  4. Quantitative assessment of ammonia-oxidizing bacterial communities in the epiphyton of submerged macrophytes in shallow lakes

    NARCIS (Netherlands)

    Coci, M.; Nicol, G.W.; Pilloni, G.N.; Schmid, M.; Kamst-van Agterveld, M.P.; Bodelier, P.L.E.; Laanbroek, H.J.

    2010-01-01

    In addition to the benthic and pelagic habitats, the epiphytic compartment of submerged macrophytes in shallow freshwater lakes offers a niche to bacterial ammonia-oxidizing communities. However, the diversity, numbers, and activity of epiphytic ammonia-oxidizing bacteria have long been overlooked.

  5. Submerged Conidiation and Product Formation by Aspergillus niger at Low Specific Growth Rates Are Affected in Aerial Developmental Mutants

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R.; Nielsen, Kristian Fog; Arentshorst, Mark

    2011-01-01

    . fwnA encodes the polyketide synthase responsible for melanin biosynthesis during aerial differentiation, and we show that conidial melanin synthesis in submerged retentostat cultures and aurasperone B production are fwnA dependent. The scl-1 and scl-2 strains are two UV mutants generated in the Δfwn...

  6. Submergence-induced morphological, anatomical, and biochemical responses in a terrestrial species affect gas diffusion resistance and photosynthetic performance

    NARCIS (Netherlands)

    Mommer, L; Pons, TL; Wolters-Arts, M; Venema, JH; Visser, EJW

    Gas exchange between the plant and the environment is severely hampered when plants are submerged, leading to oxygen and energy deficits. A straightforward way to reduce these shortages of oxygen and carbohydrates would be continued photosynthesis under water, but this possibility has received only

  7. Production and Characterization of Lipases by Two New Isolates of Aspergillus through Solid-State and Submerged Fermentation

    Science.gov (United States)

    Colla, Luciane Maria; Ficanha, Aline M. M.; Rizzardi, Juliana; Bertolin, Telma Elita; Reinehr, Christian Oliveira; Costa, Jorge Alberto Vieira

    2015-01-01

    Due to the numerous applications of lipases in industry, there is a need to study their characteristics, because lipases obtained from different sources may present different properties. The aim of this work was to accomplish the partial characterization of lipases obtained through submerged fermentation and solid-state fermentation by two species of Aspergillus. Fungal strains were isolated from a diesel-contaminated soil and selected as good lipases producers. Lipases obtained through submerged fermentation presented optimal activities at 37°C and pH 7.2 and those obtained through solid-state fermentation at 35°C and pH 6.0. The enzymes produced by submerged fermentation were more temperature-stable than those obtained by solid-state fermentation, presenting 72% of residual activity after one hour of exposition at 90°C. Lipases obtained through submerged fermentation had 80% of stability in acidic pH and those obtained through solid-state fermentation had stability greater than 60% in alkaline pH. PMID:26180809

  8. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

  9. 49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.455 External corrosion control: Buried or... against external corrosion, including the following: (1) It must have an external protective coating...

  10. Thermophilic treatment of acidified and partially acidified wastewater using an anaerobic submerged MBR: Factors affecting long-term operational flux.

    NARCIS (Netherlands)

    Jeison, D.; Lier, van J.B.

    2007-01-01

    The long-term operation of two thermophilic anaerobic submerged membrane bioreactors (AnSMBRs) was studied using acidified and partially acidified synthetic wastewaters. In both reactors, cake formation was identified as the key factor governing critical flux. Even though cake formation was observed

  11. Electric vehicle station equipment for grid-integrated vehicles

    Science.gov (United States)

    Kempton, Willett; Kiamilev, Fouad; McGee, Rodney; Waite, Nick

    2017-09-05

    Methods, systems, and apparatus transferring power between the grid and an electric vehicle are disclosed. The apparatus may include at least one vehicle communication port for interfacing with electric vehicle equipment (EVE) and a processor coupled to the at least one vehicle communication port to establish communication with the EVE, receive EVE attributes from the EVE, and transmit electric vehicle station equipment (EVSE) attributes to the EVE. Power may be transferred between the grid and the electric vehicle by maintaining EVSE attributes, establishing communication with the EVE, and transmitting the EVSE maintained attributes to the EVE.

  12. Smart Vehicle System

    Science.gov (United States)

    Pahadiya, Pallavi; Gupta, Rajni

    2010-11-01

    An approach to overcome the accidental problem happens in the night, while the driver is drunk or feels sleepy. This system controls the speed of the vehicle at steep turns. It is designed, to provide the information to the driver, whether the next turn is right/left, is there any traffic jam or land sliding in the coming way. It also assists during heavy rains and mist conditions. It may be implemented by using computer or by using a dedicated microcontroller. If we have a group of vehicles connected with the system then we can locate them by using the cameras, at different places. Information regarding any vehicle can be transmitted anywhere using Internet provided at the monitoring system, so as to prevent accidents or provide information during any calamity.

  13. Dynamics of aerospace vehicles

    Science.gov (United States)

    Schmidt, David K.

    1991-01-01

    The focus of this research was to address the modeling, including model reduction, of flexible aerospace vehicles, with special emphasis on models used in dynamic analysis and/or guidance and control system design. In the modeling, it is critical that the key aspects of the system being modeled be captured in the model. In this work, therefore, aspects of the vehicle dynamics critical to control design were important. In this regard, fundamental contributions were made in the areas of stability robustness analysis techniques, model reduction techniques, and literal approximations for key dynamic characteristics of flexible vehicles. All these areas are related. In the development of a model, approximations are always involved, so control systems designed using these models must be robust against uncertainties in these models.

  14. Rail vehicle dynamics

    CERN Document Server

    Knothe, Klaus

    2017-01-01

    This book on the dynamics of rail vehicles is developed from the manuscripts for a class with the same name at TU Berlin. It is directed mainly to master students with pre-knowledge in mathematics and mechanics and engineers that want to learn more. The important phenomena of the running behaviour of rail vehicles are derived and explained. Also recent research results and experience from the operation of rail vehicles are included. One focus is the description of the complex wheel-rail contact phenomena that are essential to understand the concept of running stability and curving. A reader should in the end be able to understand the background of simulation tools that are used by the railway industry and universities today.

  15. Affordable Vehicle Avionics Overview

    Science.gov (United States)

    Cockrell, James J.

    2015-01-01

    Public and private launch vehicle developers are reducing the cost of propulsion for small commercial launchers, but conventional high-performance, high-reliability avionics remain the disproportionately high cost driver for launch. AVA technology performs as well or better than conventional launch vehicle avionics, but with a fraction of the recurring costs. AVA enables small launch providers to offer affordable rides to LEO to nano-satellites as primary payloads meaning, small payloads can afford to specify their own launch and orbit parameters

  16. Bubble Formation at a Submerged Orifice for Aluminum Foams Produced by Gas Injection Method

    Science.gov (United States)

    Fan, Xueliu; Chen, Xiang; Liu, Xingnan; Zhang, Huiming; Li, Yanxiang

    2013-02-01

    The bubble formation at a submerged orifice in the process of aluminum foams produced by gas injection method is investigated. The experimental results show that the increase of the gas flow rate and the orifice diameter can lead to increasing of the bubble size. The large orifice can make the frequency of bubble formation decrease by slowing down the increase of the gas chamber pressure when the gas flow rate increases. The effect of the gas chamber volume on the bubble size can be ignored in the experiment when it expands from 1 to 125 cm3. A theoretical model of bubble formation, expansion, and detachment under constant flow conditions is established to predict the bubble size. The theoretical predictions for air-aluminum melt systems are consistent with the experimental results.

  17. A waveless free surface flow past a submerged triangular obstacle in presence of surface tension

    Directory of Open Access Journals (Sweden)

    Hakima Sekhri

    2016-07-01

    Full Text Available We consider the Free surface flows passing a submerged triangular obstacle at the bottom of a channel. The problem is characterized by a nonlinear boundary condition on the surface of unknown configuration. The analytical exact solutions for these problems are not known. Following Dias and Vanden Broeck [6], we computed numerically the solutions via a series truncation method. These solutions depend on two parameters: the Weber number $\\alpha$ characterizing the strength of the surface tension and the angle $\\beta$ at the base characterizing the shape of the apex. Although free surface flows with surface tension admit capillary waves, it is found that solution exist only for values of the Weber number greater than $\\alpha_0$ for different configurations of the triangular obstacle.

  18. Treatment of space loss caused by submerged maxillary second primary molar

    Directory of Open Access Journals (Sweden)

    Karacay S

    2007-03-01

    Full Text Available Submersion is a clinical term describing a tooth depressed below the occlusal plane. In this case report, we present the treatment of a patient who had totally submerged primary maxillary second molar, which caused impaction of the second premolar and space loss in the maxillary arch due to tipping of adjacent teeth. A 12-year-old girl was referred to the pediatric dentistry clinic. The intra-oral examination revealed that right maxillary second primary molar was localized buccal side of posterior maxillary alveolar process, being almost completely covered by gingiva and adjacent teeth inclined closing the space of the related teeth completely. Periapical radiograph demonstrated that maxillary second premolar was impacted. Based on clinical and radiographic findings, maxillary primary second molar was extracted. Headgear was used for the distalization of maxillary right first molar in order to create space for the impacted second premolar. Eruption begun spontaneously 6 months later.

  19. Parameter optimization of flux-aided backing-submerged arc welding by using Taguchi method

    Science.gov (United States)

    Pu, Juan; Yu, Shengfu; Li, Yuanyuan

    2017-07-01

    Flux-aided backing-submerged arc welding has been conducted on D36 steel with thickness of 20 mm. The effects of processing parameters such as welding current, voltage, welding speed and groove angle on welding quality were investigated by Taguchi method. The optimal welding parameters were predicted and the individual importance of each parameter on welding quality was evaluated by examining the signal-to-noise ratio and analysis of variance (ANOVA) results. The importance order of the welding parameters for the welding quality of weld bead was: welding current > welding speed > groove angle > welding voltage. The welding quality of weld bead increased gradually with increasing welding current and welding speed and decreasing groove angle. The optimum values of the welding current, welding speed, groove angle and welding voltage were found to be 1050 A, 27 cm/min, 40∘ and 34 V, respectively.

  20. Aerobic and anaerobic ethanol production by Mucor circinelloides during submerged growth

    DEFF Research Database (Denmark)

    Lübbehüsen, Tina Louise; Nielsen, Jens; Mcintyre, Mhairi

    2004-01-01

    The dimorphic organism Mucor circinelloides is currently being investigated as a potential host for heterologous protein production. The production of ethanol on pentose and hexose sugars was studied in submerged batch cultivations to further the general knowledge of Mucor physiology, with a view...... to the minimisation or elimination of the by-product ethanol for future process design. Large amounts of ethanol were produced during aerobic growth on glucose under non-oxygen limiting conditions, which is indicative of M. circinelloides being a Crabtree-positive organism. Ethanol production on galactose or xylose...... was less significant. The response of the organism to increased ethanol concentrations, both as the sole carbon source and in the presence of a sugar, was investigated in terms of biomass formation and morphology....

  1. Analysis of single hyphal growth and fragmentation in submerged cultures using a population model

    DEFF Research Database (Denmark)

    Krabben, Preben; Nielsen, Søren; Michelsen, Michael Locht

    1997-01-01

    Descriptions of population dynamics in submerged cultures are important when studying the mechanisms of growth and fragmentation of filamentous microorganisms. Population models are traditionally formulated as population balance equations. Population models of filamentous morphology are difficult...... to solve because of random fragmentation, which introduces an integral term into the population balance equations. Balances for the systemic properties, e.g. concentration of hyphal elements, substrate concentration, average total hyphal length, and average number of growing tips, are set up. Based...... on these balances one can solve the inverse problem, i.e. determination of kinetic parameters directly from measurements of the hyphal morphology. Both a Monte Carlo method and a discretization method have been used to calculate the steady-state population distribution. The two methods are compared and the Monte...

  2. Production of surfactin from rice mill polishing residue by submerged fermentation using Bacillus subtilis MTCC 2423.

    Science.gov (United States)

    Gurjar, Jigar; Sengupta, Bina

    2015-08-01

    Rice mill polishing residue (RMPR), an abundant and cheap agro residue, was used as substrate for microbial growth of Bacillus subtilis MTCC 2423 by submerged fermentation process to produce surfactin. Nutrients present in the residue were sufficient to sustain the growth of the microorganism. Multi stage foam fractionation followed by acid precipitation was used to concentrate and recover the product. Recoverable yield of surfactin was 4.17 g/kg residue. Product recovered in the foamate accounted for 69% of the total yield. The residual broth containing ∼ 30% surfactin exhibited biological oxygen demand and chemical oxygen demand values of 23 and 69 mg/L respectively. The microbial growth data was correlated using three parameter sigmoid models. Surfactin synthesized had a predominance of molecular weight 1076 Da. Foam separation of copper using surfactin resulted in a maximum removal of 72.5%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Modification of Surf Zone Turbulence and the Undertow by a Submerged Canopy

    Science.gov (United States)

    Mandel, T.; Koseff, J. R.; Rosenzweig, I.; Suckale, J.; Zarama, F. J.

    2016-02-01

    As sea level rise and stronger storm events threaten our coastlines, coastal vegetation has come under consideration as a potentially resilient, financially viable tool to mitigate flooding and erosion. However, the actual role of this "green infrastructure" in the near-shore region is not fully understood. In order to evaluate the role of vegetation in coastal protection, a series of experiments were conducted in a simulated laboratory surf zone. We examine the impact of canopy location and submergence on the undertow profile, turbulent kinetic energy, and Reynolds stress for varying Reynolds number and Keulegan-Carpenter number, and compare these results to theoretical formulations that utilize a depth-averaged undertow and highly simplified eddy viscosity.

  4. Transition States for Submerged Superhydrophobic Surfaces: Partially-Pinned Air-Water Interface

    Science.gov (United States)

    Tafreshi, Hooman; Hemeda, Ahmed; VCU Team

    2015-11-01

    The pressure at which a superhydrophobic surface transitions from the Cassie state to the Wenzel state is often referred to as the critical pressure. Our mathematical simulations have shown that the Cassie-to-Wenzel transition is a gradual process that takes place over a range of pressures as oppose to an event that happens at a certain pressure. During the transition period, the air-water interface may go through a series pinned, partially-pinned, and de-pinned states that depend on the geometry of the surface asperities. This in turn indicates that the drag-reduction effect produced by a submerged superhydrophobic surface can vary with the hydrostatic pressure, and is highly dependent on sharpness of the surface asperities. The study reported here reviews our recent discoveries in simulating the wetted area and drag reduction effect of superhydrophobic surfaces with different microstructures. National Science Foundation CMM 1029924 and CBET 1402655 programs.

  5. EXOPOLYSACCHARIDE PRODUCTION AND ITS BIOACTIVITIES OF THE EDIBLE PLEUROTUS OSTREATUS IN SUBMERGED CULTURE

    Directory of Open Access Journals (Sweden)

    IWAN SASKIAWAN

    2009-01-01

    Full Text Available Submerged cultures were used to study the influence of various carbon sources on the mycelial biomass and exopolysaccharide production of Pleurotus ostreatus. The antimicrobial and antioxidant activity of the exopolysaccharide were also determined. The yield of mycelial biomass of 7.06 g/l, 5.12 g/l, 4.66 g/l, and 2.96 g/l was obtained by utilization of maltose, glucose, lactose and starch as a carbon source, respectively. Furthermore, in the medium containing maltose, lactose, glucose, and starch produce 100.05 mg/l, 97.73 mg/l, 78.63 mg/l, and 70.45 mg/l of exopolysaccharide, respectively. The assay of antimicrobial and antioxidant activity showed that the exopolysaccharide is more active to inhibit the growth of B. subtilis rather than those of E. coli and S. cerevisiae. Furthermore, the exopolysaccharide was also indicated to have antioxidant activity.

  6. High strength domestic wastewater treatment with submerged forward osmosis membrane bioreactor.

    Science.gov (United States)

    Aftab, Bilal; Khan, Sher Jamal; Maqbool, Tahir; Hankins, Nicholas P

    2015-01-01

    Forward osmosis membranes are less prone to fouling with high rejection of salts, and the osmotic membrane bioreactor (OMBR) can be considered as an innovative membrane technology for wastewater treatment. In this study, a submerged OMBR having a cellulose triacetate membrane, with the active layer facing the feed solution configuration, was operated at different organic loading rates (OLRs), i.e., 0.4, 1.2 and 2.0 kg-COD/(m(3)·d) with chemical oxygen demand (COD) concentrations of 200 mg/L, 600 mg/L and 1,000 mg/L, respectively, to evaluate the performance on varying wastewater strengths. High organic content with sufficient amount of nutrients enhanced the biomass growth. High OLR caused more extrapolymeric substances production and less dewaterability. However, no significant differences in fouling trends and flux rates were observed among different OLR operational conditions.

  7. Coconut oil induced production of a surfactant-compatible lipase from Aspergillus tamarii under submerged fermentation.

    Science.gov (United States)

    Das, Arijit; Bhattacharya, Sourav; Shivakumar, Srividya; Shakya, Sujina; Sogane, Swathi Shankar

    2017-02-01

    Filamentous fungi are efficient producers of lipases. The present study focuses on identification of a potent lipolytic fungus and enhancement of lipase production through optimization of nutritional and cultural conditions under submerged fermentation. Molecular characterization of the fungus by 18S rDNA sequencing revealed its identity as Aspergillus tamarii with 98% homology. Maximum lipase production was noted in mineral salts medium supplemented with coconut oil (2.5%, v/v). A combination of ammonium chloride (2%, w/v) and tryptone (2%, w/v) facilitated maximum lipase production at pH 5 of the production medium. A carbon: nitrogen ratio of 1:4 led to significant (p oil stain removal activity of a commercially available detergent by 2.2-fold. The current findings suggest the potentiality of this fungal lipase to be used in detergent formulation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Reduction of the radiating sound of a submerged finite cylindrical shell structure by active vibration control.

    Science.gov (United States)

    Kim, Heung Soo; Sohn, Jung Woo; Jeon, Juncheol; Choi, Seung-Bok

    2013-02-06

    In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. Three Macro Fiber Composites (MFCs) were used as actuators and sensors. One MFC was used as an exciter. The optimum control algorithm was designed based on the reduced system equations. The active control performance was then evaluated using the lab scale underwater cylindrical shell structure. Structural vibration and structure-borne noise of the underwater cylindrical shell structure were reduced significantly by activating the optimal controller associated with the MFC actuators. The results provide that active vibration control of the underwater structure is a useful means to reduce structure-borne noise in water.

  9. Cryogenic grinding of electrospun poly-ε-caprolactone mesh submerged in liquid media.

    Science.gov (United States)

    Knotek, Petr; Pouzar, Miloslav; Buzgo, Matej; Krizkova, Barbora; Vlcek, Milan; Mickova, Andrea; Plencner, Martin; Navesnik, Jakub; Amler, Evzen; Belina, Petr

    2012-08-01

    In this paper, the treatment of poly-ε-caprolactone (PCL) nano/micro-mesh system by cryogenic grinding and subsequent characterization of obtained product is described. The PCL nano/micro-mesh layer submerged in appropriate liquid was cryogenically ground and obtained particles were characterized employing mainly laser diffraction and scanning electron microscopy (SEM). In the ground sample, different types of particles (fibrous particles, fibrous fragments, agglomerates with and without an internal fibrous structure, lamellae and nanoparticles) were identified, described and quantified. Parameters of cryogenic grinding (weight of sample, type of liquid medium, and influence of sample storage) were optimized to maximize the yield of particles with desired features. The potential of the system for cell scaffolding was demonstrated by cultivation of 3T3 fibroblasts on the produced microparticles. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Structural Response of Submerged Air-Backed Plates by Experimental and Numerical Analyses

    Directory of Open Access Journals (Sweden)

    Lloyd Hammond

    2000-01-01

    Full Text Available This paper presents the results of a series of small-scale underwater shock experiments that measured the structural responses of submerged, fully clamped, air-backed, steel plates to a range of high explosive charge sizes. The experimental results were subsequently used to validate a series of simulations using the coupled LS-DYNA/USA finite element/boundary element codes. The modelling exercise was complicated by a significant amount of local cavitation occurring in the fluid adjacent to the plate and difficulties in modelling the boundary conditions of the test plates. The finite element model results satisfactorily predicted the displacement-time history of the plate over a range of shock loadings although a less satisfactory correlation was achieved for the peak velocities. It is expected that the predictive capability of the finite element model will be significantly improved once hydrostatic initialisation can be fully utilised with the LS-DYNA/USA software.

  11. Analysis of filtration characteristics in submerged microfiltration for drinking water treatment.

    Science.gov (United States)

    Lee, Sangho; Park, Pyung-Kyu; Kim, Jae-Hyuk; Yeon, Kyung-Min; Lee, Chung-Hak

    2008-06-01

    Hollow fiber membranes have been widely employed for water and wastewater treatments. Nevertheless, understanding the filtration characteristics of hollow fiber membranes is complicated by the axial distributions of transmembrane pressure (TMP) and flux, which are key factors for both fouling control and module design. In this study, model equations to account for different fouling mechanisms were derived to analyze the performance of submerged hollow fiber systems with different conditions in terms of feed water characteristics and membrane material. A series of experiments with synthetic feed and raw water were carried out using hydrophilic and hydrophobic membrane modules. The model successfully fits the experimental results for synthetic feed as well as raw water. The major fouling mechanisms for filtration of raw water using hydrophilic and hydrophobic membranes are identified as cake formation and standard blocking, respectively. The model calculations indicate that the distributions of flux and cake (fouling) resistance are sensitive to the fiber length of the membrane.

  12. Global sensitivity analysis of a filtration model for submerged anaerobic membrane bioreactors (AnMBR).

    Science.gov (United States)

    Robles, A; Ruano, M V; Ribes, J; Seco, A; Ferrer, J

    2014-04-01

    The results of a global sensitivity analysis of a filtration model for submerged anaerobic MBRs (AnMBRs) are assessed in this paper. This study aimed to (1) identify the less- (or non-) influential factors of the model in order to facilitate model calibration and (2) validate the modelling approach (i.e. to determine the need for each of the proposed factors to be included in the model). The sensitivity analysis was conducted using a revised version of the Morris screening method. The dynamic simulations were conducted using long-term data obtained from an AnMBR plant fitted with industrial-scale hollow-fibre membranes. Of the 14 factors in the model, six were identified as influential, i.e. those calibrated using off-line protocols. A dynamic calibration (based on optimisation algorithms) of these influential factors was conducted. The resulting estimated model factors accurately predicted membrane performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Biosynthesis of fructo-oligosaccharides by Sporotrichum thermophile during submerged batch cultivation in high sucrose media

    DEFF Research Database (Denmark)

    Katapodis, P.; Kalogeris, E.; Kekos, D.

    2004-01-01

    found to be the predominant compatible solutes. The fungus accumulated glutamic acid, arginine, alanine, leucine and lysine, in order to balance the outer osmotic pressure. Fatty acid analysis of the membrane lipids showed a relatively high percentage of unsaturated lipids, which is known......Biosynthesis of fructo-oligosaccharides (FOS) was observed during growth of the thermophilic fungus Sporotrichum thermophile on media containing high sucrose concentrations. Submerged batch cultivation with the optimum initial sucrose concentration of 250 g/l allowed the production of 12.5 g FOS....../l. The FOS mixture obtained was composed of three sugars, which were isolated by size-exclusion chromatography. They were characterized by acid hydrolysis and HPLC as 1-kestose, 6-kestose and neokestose. The mechanism of osmotic adaptation of S. thermophile was investigated and sugars and amino acids were...

  14. Dynamic fouling behaviors of submerged nonwoven bioreactor for filtration of activated sludge with different SRT.

    Science.gov (United States)

    Chuang, Shun-Hsing; Lin, Po-Kuen; Chang, Wei-Chin

    2011-09-01

    The flux variations and resistances accumulated during filtration of activated sludge with sludge retention time (SRT) of 15, 30, and 60 days were analyzed to investigate the dynamic fouling behavior in a submerged nonwoven bioreactor. Different SRT values varied sludge condition and particle size distribution in the supernatants, which caused dissimilar fouling characteristics. Short-term fouling of the nonwoven bioreactor during filtration of activated sludge with SRT of 15 days was fully reversible, and the resistance percentages of solutes, colloids, and suspended solids were 6%, 27%, and 67%, respectively. On the other hand, significant increases of colloid resistance, such as with the filtration of activated sludge with SRT of 30 and 60 days, were related to the occurrence of irreversible fouling. The phenomenon of pore blocking by particles or colloids with size analogous to the pore of nonwoven fabric was a decisive factor leading to irreversible fouling in the large-pore materials. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. The role of cable stiffness in the dynamic behaviours of submerged floating tunnel

    Directory of Open Access Journals (Sweden)

    Muhammad Naik

    2017-01-01

    Full Text Available Submerged floating tunnel (SFT is a new solution for the transportation infrastructure through sea straits, fjords, and inland waters and can be a good alternative to long span suspension bridges and immersed tunnels. The mooring cables/anchors are main structural components to provide restoring capacity to the SFT. The time domain dynamic problem of SFT moored by vertical and inclined mooring cables/anchors is formulated. The dynamic analysis of SFT subjected to hydrodynamic and seismic excitations is performed. As the cable stiffness determines the deformation ability of SFT, therefore it becomes crucial to evaluate the effect of mooring cable stiffness on the response of SFT. The displacements and internal forces of SFT clearly specify that the vertical/tension leg mooring cables provide very small stiffness as compared to inclined mooring cables. In order to keep the SFT displacements within an acceptable limit, the effect of cable stiffness should be properly evaluated for practical design of SFT.

  16. Reduction of the Radiating Sound of a Submerged Finite Cylindrical Shell Structure by Active Vibration Control

    Directory of Open Access Journals (Sweden)

    Seung-Bok Choi

    2013-02-01

    Full Text Available In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. Three Macro Fiber Composites (MFCs were used as actuators and sensors. One MFC was used as an exciter. The optimum control algorithm was designed based on the reduced system equations. The active control performance was then evaluated using the lab scale underwater cylindrical shell structure. Structural vibration and structure-borne noise of the underwater cylindrical shell structure were reduced significantly by activating the optimal controller associated with the MFC actuators. The results provide that active vibration control of the underwater structure is a useful means to reduce structure-borne noise in water.

  17. Water surface elevations recorded by submerged pressure transducers along the upper Willamette River, Oregon, Spring, 2015

    Science.gov (United States)

    Lind, Greg D.; Wellman, Roy E.; Mangano, Joseph F.

    2017-01-01

    Water-surface elevations were recorded by submerged pressure transducers in Spring, 2015 along the upper Willamette River, Oregon, between Eugene and Corvallis. The water-surface elevations were surveyed by using a real-time kinematic global positioning system (RTK-GPS) at each pressure sensor location. These water-surface elevations were logged over a small range of discharges, from 4,600 cubic feet per second to 10,800 cubic feet per second at Harrisburg, OR. These datasets were collected for equipment calibration and validation for the National Aeronautics and Space Administration’s (NASA) Surface Water and Ocean Topography (SWOT) satellite mission. This is one of multiple datasets that will be released for this effort.

  18. Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65

    Science.gov (United States)

    Hashemi, S. H.; Mohammadyani, D.

    2011-01-01

    The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

  19. Examination of histological samples from submerged carrion to aid in the determination of postmortem submersion interval.

    Science.gov (United States)

    Humphreys, Michael Keith; Panacek, Edward; Green, William; Albers, Elizabeth

    2013-03-01

    The use of histology in the as a tool for estimating postmortem intervals has rarely been explored but it has the potential for offering medical examiners an additional means for estimating the postmortem submersion interval (PMSI) during a death investigation. This study used perinatal piglets as human analogs which were submerged in freshwater for various time intervals. Each piglet was extracted from the water and underwent a necropsy examination during which histological samples were collected. The samples revealed that the necrotic tissue decomposed relatively predictably over time and that this decompositional progression may have the potential to be used via a scoring system to determine or aid in determining the PMSI. This method for calculating PMSI allows for normalization between piglets of various mass and body types. It also prevents any contamination of the remains via algae growth and animal activity that may exacerbate and possibly exaggerate PMSI calculation.

  20. Effects of relative submergence and bed slope on sediment incipient motion under decelerating flows

    Directory of Open Access Journals (Sweden)

    Bolhassani Ramin

    2015-12-01

    Full Text Available This paper presents the results of an experimental study to quantify the effects of bed slope and relative submergence on incipient motion of sediment under decelerating flows. Experiments were conducted in an experimental tilting-flume of 8 m long 0.4 m wide and 0.6 m deep with glass-walls. Three uniform sediments with median grain sizes of 0.95, 1.8 and 3.8 mm and three bed slopes of 0.0075, 0.0125 and 0.015 were used under decelerating flow. The main conclusion is that the Shields diagram, which is commonly used to evaluate the critical shear stress, is not suitable to predict the critical shear stress under decelerating flows.

  1. Freshwater lichens on submerged stones and alder roots in the Polish lowlands

    Directory of Open Access Journals (Sweden)

    Mariusz Hachułka

    2013-12-01

    Full Text Available The article presents the results of the studies of lichens in streams and spring areas of the escarpment zone of Wzniesienia Łódzkie Heights in Central Poland. The boulders, stones and roots of Alnus glutinosa, situated in 3 inundated zones in the streams: submerged zone, fluvial mesic zone and fluvial xeric zone, were examined in the streams. The studies have shown 23 species connected with these streams. Six species of freshwater lichens: Verrucaria aquatilis, V. hydrela, Hydropunctaria rheitrophila, V. margacea, V. praetermissa and V. madida, occupied stones in 3 different zones. Verrucaria aquatilis and Hydropunctaria rheitrophila colonized also secondary substrates – the bark of alder roots incrusted with sand grains and silt.

  2. Effect of operating conditions on speciation and bioavailability of trace metals in submerged anaerobic membrane bioreactors.

    Science.gov (United States)

    Thanh, Pham Minh; Ketheesan, Balachandran; Zhou, Yan; Stuckey, David C

    2017-11-01

    This study investigated the effect of changes in pH (7, 6.5 and 6), hydraulic retention time (HRT) (6h, 4h, and 2h), solids retention time (SRT) (100d and 25d) on the speciation of trace metals (TMs) in submerged anaerobic membrane bioreactors (SAMBRs). The results showed that the metal retention capacity of SAMBRs reduced when the pH, HRT and SRT were reduced i.e. up to 21.9%, 39.1%, and 17.1%, respectively, but it was also found that the speciation of these TMs generally shifted towards highly bioavailable fractions i.e. Soluble and Exchangeable. The degree of shifting in speciation depended on the affinity of the TMs for anaerobic sludge and their sensitivity to the changes. TMs with the most and the least significant changes in speciation were Fe and Mn, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Dissipation of Electrical Energy in Submerged Arc Furnaces Producing Silicomanganese and High-Carbon Ferromanganese

    Science.gov (United States)

    Steenkamp, Joalet Dalene; Hockaday, Christopher James; Gous, Johan Petrus; Nzima, Thabo Witness

    2017-09-01

    Submerged-arc furnace technology is applied in the primary production of ferroalloys. Electrical energy is dissipated to the process via a combination of arcing and resistive heating. In processes where a crater forms between the charge zone and the reaction zone, electrical energy is dissipated mainly through arcing, e.g., in coke-bed based processes, through resistive heating. Plant-based measurements from a device called "Arcmon" indicated that in silicomanganese (SiMn) production, at times up to 15% of the electrical energy used is transferred by arcing, 30% in high-carbon ferromanganese (HCFeMn) production, compared with 5% in ferrochromium and 60% in ferrosilicon production. On average, the arcing is much less at 3% in SiMn and 5% in HCFeMn production.

  4. Effect of Submergence and Apron Length on Spillway Scour: Case Study

    Directory of Open Access Journals (Sweden)

    Seungho Hong

    2015-10-01

    Full Text Available Large-scale water resources systems are often managed by an integrated set of hydraulic structures that are vulnerable to wider ranges of discharge and tailwater elevation than envisioned in their original design due to climate change and additional project objectives such as fostering healthy ecosystems. The present physical model study explored the performance of a spillway structure on the Kissimmee River, operated by the South Florida Water Management District, under extreme conditions of drought and flooding with accompanying low and high tailwater levels for both gate-controlled and uncontrolled spillway flow conditions. Maximum scour depths and their locations for two different riprap apron lengths downstream of the spillway stilling basin were measured along with the complex flow fields prior to scour. Effects of tailwater submergence, type of spillway flow and riprap apron length on scour results are interpreted in terms of the measured turbulent kinetic energy and velocity distributions near the bed.

  5. Soft tissue decomposition of submerged, dismembered pig limbs enclosed in plastic bags.

    Science.gov (United States)

    Pakosh, Caitlin M; Rogers, Tracy L

    2009-11-01

    This study examines underwater soft tissue decomposition of dismembered pig limbs deposited in polyethylene plastic bags. The research evaluates the level of influence that disposal method has on underwater decomposition processes and details observations specific to this scenario. To our knowledge, no other study has yet investigated decomposing, dismembered, and enclosed remains in water environments. The total sample size consisted of 120 dismembered pig limbs, divided into a subsample of 30 pig limbs per recovery period (34 and 71 days) for each treatment. The two treatments simulated non-enclosed and plastic enclosed disposal methods in a water context. The remains were completely submerged in Lake Ontario for 34 and 71 days. In both recovery periods, the non-enclosed samples lost soft tissue to a significantly greater extent than their plastic enclosed counterparts. Disposal of remains in plastic bags therefore results in preservation, most likely caused by bacterial inhibition and reduced oxygen levels.

  6. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.

    Science.gov (United States)

    Wang, Chaoying; Li, Changxiao; Wei, Hong; Xie, Yingzan; Han, Wenjiao

    2016-01-01

    Responses of bald cypress (Taxodium distichum) and pond cypress (Taxodium ascendens) saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR) were studied. Water treatments of periodic deep submergence (DS) and moderate submergence (MS) in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles) compared to a control (i.e. shallow submergence, abbreviated as SS). Results showed that pond cypress had no significant change in net photosynthetic rate (Pn) in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH) and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.

  7. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.

    Directory of Open Access Journals (Sweden)

    Chaoying Wang

    Full Text Available Responses of bald cypress (Taxodium distichum and pond cypress (Taxodium ascendens saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR were studied. Water treatments of periodic deep submergence (DS and moderate submergence (MS in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles compared to a control (i.e. shallow submergence, abbreviated as SS. Results showed that pond cypress had no significant change in net photosynthetic rate (Pn in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.

  8. Algae mediate submerged macrophyte response to nutrient and dissolved inorganic carbon loading: a mesocosm study on different species.

    Science.gov (United States)

    Xie, Dong; Yu, Dan; You, Wen-Hua; Wang, Li-Gong

    2013-10-01

    Nutrient and dissolved inorganic carbon are two important factors that influence the development and species composition of submerged macrophyte communities in shallow lake ecosystems. Yet little is known about their potential interactive effects on the submerged macrophytes and competition outcome of macrophyte-phytoplankton. We performed a mesocosm experiment to investigate the growth and photosynthetic performance of three submerged macrophytes in relation to phytoplankton/epiphyton with nutrient and bicarbonate enrichment. During the experimental period (42 d), increase in nutrient loading in water column resulted in a substantial burst of phytoplankton and epiphyton growth and increased light attenuation. When combined with nutrient loading, bicarbonate enrichment also resulted in a heavily phytoplankton- and epiphyton-dominated state, although bicarbonate enrichment per se does not cause the phytoplankton and epiphyton growth. However, increase in nutrient loading in water column had significant negative impact on individual performances (growth and photosynthesis) of the three submerged macrophytes and bicarbonate enrichment increased the effect of eutrophication on two dissected-leaf macrophytes (M. spicatum and E. nuttallii). Furthermore, our results also suggest that species-specific photosynthetic performances occurred when submerged macrophytes in an environment with high abundance of phytoplankton/epiphyton. This study highlighted that increase in nutrient loading and bicarbonate in water column is likely to interactively impact both abiotic and biotic properties of a freshwater ecosystem. The interactions of these two factors could select macrophyte species that are able to resist the shading from phytoplankton/epiphyton, making these species more dominant in natural freshwater ecosystems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Multiple mitigation mechanisms: Effects of submerged plants on the toxicity of nine insecticides to aquatic animals.

    Science.gov (United States)

    Brogan, William R; Relyea, Rick A

    2017-01-01

    Understanding the processes that regulate contaminant impacts in nature is an increasingly important challenge. For insecticides in surface waters, the ability of aquatic plants to sorb, or bind, hydrophobic compounds has been identified as a primary mechanism by which toxicity can be mitigated (i.e. the sorption-based model). However, recent research shows that submerged plants can also rapidly mitigate the toxicity of the less hydrophobic insecticide malathion via alkaline hydrolysis (i.e. the hydrolysis-based model) driven by increased water pH resulting from photosynthesis. However, it is still unknown how generalizable these mitigation mechanisms are across the wide variety of insecticides applied today, and whether any general rules can be ascertained about which types of chemicals may be mitigated by each mechanism. We quantified the degree to which the submerged plant Elodea canadensis mitigated acute (48-h) toxicity to Daphnia magna using nine commonly applied insecticides spanning three chemical classes (carbamates: aldicarb, carbaryl, carbofuran; organophosphates: malathion, diazinon, chlorpyrifos; pyrethroids: permethrin, bifenthrin, lambda-cyhalothrin). We found that insecticides possessing either high octanol-water partition coefficients (log K ow ) values (i.e. pyrethroids) or high susceptibility to alkaline hydrolysis (i.e. carbamates and malathion) were all mitigated to some degree by E. canadensis, while the plant had no effect on insecticides possessing intermediate log K ow values and low susceptibility to hydrolysis (i.e. chlorpyrifos and diazinon). Our results provide the first general insights into which types of insecticides are likely to be mitigated by different mechanisms based on known chemical properties. We suggest that current models and mitigation strategies would be improved by the consideration of both mitigation models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Influence of keratinized tissue on spontaneous exposure of submerged implants: classification and clinical observations

    Directory of Open Access Journals (Sweden)

    G. Mendoza

    2014-10-01

    Full Text Available Aim: The reasons for spontaneous early exposure (SEE of dental implants during healing have not been established yet. The objective of this study was to assess whether the width of keratinized tissue (KT and other site-related conditions could be associated with implants’ SEE. Materials and methods: Data from 500 implants placed in 138 non-smoking patients, between September 2009 and June 2010, were evaluated. Implants were submerged and allowed to heal for 3 to 6 months. At baseline, the following conditions were documented: the presence of keratinized tissue width > 2 mm; the type of implant site (i.e. fresh extraction socket or edentulous alveolar ridge; concomitant use of guided tissue regeneration. During the healing period, the occurrence of partial or total implants SEE was recorded; thus, a mixed-effects logistic regression analysis was performed to investigate the association between implant site conditions and implant exposure. Results: One hundred and eighty-five implants (37.0% remained submerged after healing and were classified as Class I, whereas 215 (43.0% showed partial spontaneous early exposure (SEE at the first week after implant placement (Class II, and 100 implants (20.0% developed more extensive exposures (Class III. The variables, baseline width of KT (p = 0.18, fresh extraction socket (p = 0.88 and guided tissue regeneration (GTR plus bone substitutes (p = 0.42, were not found to be correlated with implants` SEE, with an odds ratio (OR of 1.29 (95% confidence interval: -0.12–0.63, 1.03 (95% confidence interval: -0.46–0.53 and 1.22 (95% confidence interval: -0.29–0.68, respectively. Conclusion: It was not possible to establish an association between SEE and some implant-related factors; therefore, further investigations focused on the reasons associated to implants’ SEE are needed.

  11. The optimization of Marasmius androsaceus submerged fermentation conditions in five-liter fermentor.

    Science.gov (United States)

    Meng, Fanxin; Xing, Gaoyang; Li, Yutong; Song, Jia; Wang, Yanzhen; Meng, Qingfan; Lu, Jiahui; Zhou, Yulin; Liu, Yan; Wang, Di; Teng, Lirong

    2016-01-01

    Using desirability function, four indexes including mycelium dry weight, intracellular polysaccharide, adenosine and mannitol yield were uniformed into one expected value (Da) which further served as the assessment criteria. In our present study, Plackett-Burman design was applied to evaluate the effects of eight variables including initial pH, rotating speed, culture temperature, inoculum size, ventilation volume, culture time, inoculum age and loading volume on Da value during Marasmius androsaceus submerged fermentation via a five-liter fermentor. Culture time, initial pH and rotating speed were found to influence Da value significantly and were further optimized by Box-Behnken design. Results obtained from Box-Behnken design were analyzed by both response surface regression (Design-Expert.V8.0.6.1 software) and artificial neural network combining the genetic algorithm method (Matlab2012a software). After comparison, the optimum M. androsaceus submerged fermentation conditions via a five-liter fermentor were obtained as follows: initial pH of 6.14, rotating speed of 289.3 rpm, culture time of 6.285 days, culture temperature of 26 °C, inoculum size of 5%, ventilation volume of 200 L/h, inoculum age of 4 days, and loading volume of 3.5 L/5 L. The predicted Da value of the optimum model was 0.4884 and the average experimental Da value was 0.4760. The model possesses well fitness and predictive ability.

  12. Diversification of gene expression during formation of static submerged biofilms by Escherichia coli

    Directory of Open Access Journals (Sweden)

    Olga Besharova

    2016-10-01

    Full Text Available Many bacteria primarily exist in nature as structured multicellular communities, so called biofilms. Biofilm formation is a highly regulated process that includes the transition from the motile planktonic to sessile biofilm lifestyle. Cellular differentiation within a biofilm is a commonly accepted concept but it remains largely unclear when, where and how exactly such differentiation arises. Here we used fluorescent transcriptional reporters to quantitatively analyze spatio-temporal expression patterns of several groups of genes during the formation of submerged Escherichia coli biofilms in an open static system. We first confirm that formation of such submerged biofilms as well as pellicles at the liquid-air interface requires the major matrix component, curli, and flagella-mediated motility. We further demonstrate that in this system, diversification of gene expression leads to emergence of at least three distinct subpopulations of E. coli, which differ in their levels of curli and flagella expression, and in the activity of the stationary phase sigma factor σS. Our study reveals mutually exclusive expression of curli fibers and flagella at the single cell level, with high curli levels being confined to dense cell aggregates/microcolonies and flagella expression showing an opposite expression pattern. Interestingly, despite the known σS-dependence of curli induction, there was only a partial correlation between the σS activity and curli expression, with subpopulations of cells having high σS activity but low curli expression and vice versa. Finally, consistent with different physiology of the observed subpopulations, we show striking differences between the growth rates of cells within and outside of aggregates.

  13. Submerged macrophytes mitigate direct and indirect insecticide effects in freshwater communities.

    Directory of Open Access Journals (Sweden)

    William R Brogan

    Full Text Available Understanding how ecological interactions mitigate the impacts of perturbations such as pesticides in biological communities is an important basic and applied question for ecologists. In aquatic ecosystems, new evidence from microcosm experiments suggests that submerged macrophytes can buffer cladocerans from pulse exposures to the widely used insecticide malathion, and that mitigation increases with macrophyte density. However, whether these results scale up to more complex aquatic communities where ecological interactions such as competition can alter toxicity is unknown. Further, macrophyte abilities to mitigate different insecticide exposure scenarios (i.e. single versus repeated pulses have never been tested. To address these gaps, we performed a factorial mesocosm experiment examining the influence of four macrophyte treatments (0, 10, 50, or 100 Elodea Canadensis shoots planted per mesocosm crossed with three malathion exposure scenarios (no insecticide, single pulse, repeated pulses on aquatic communities containing zooplankton, phytoplankton, periphyton, two snail species, and larval amphibians. In the absence of macrophytes, single malathion pulses caused short-term declines in cladoceran abundance followed by their rapid recovery, which precluded any indirect effects (i.e. trophic cascades. However, repeated malathion pulses caused cladoceran extinctions, resulting in persistent phytoplankton blooms and reduced abundance of one snail species. In contrast, with macrophytes present, even at low density, malathion had no effect on any taxa. We also discovered novel effects of macrophytes on the benthic food web. In the two highest macrophyte treatments, we observed trends of reduced periphyton biomass, decreased abundance of one snail species, and decreased amphibian time to and mass at metamorphosis. To our knowledge, this is the first evidence of negative submerged macrophyte effects on amphibians, a taxa of global conservation concern

  14. Control of sediment entry into an intake canal by using submerged vanes

    Science.gov (United States)

    Sruthi, T. K.; Ranjith, K. B.; Chandra, Venu

    2017-08-01

    River flow which is entering into an intake canal carries lot of sediment due to centrifugal action at river-intake junction and results in various problems. The present work aims to control sediment entry into an intake canal by modifying flow pattern using submerged vanes. Experiments are conducted in a 57.5 cm wide rectangular laboratory model filled with sediment, d50=0.28mm, for a constant discharge of 0.025m3/s and flow depth (H) of 8cm. A rigid bed trapezoidal channel (side slopes, 1H: 1V) of bed width 15 cm, diverting at an angle of 45° from river model is used as an intake channel. Submerged vanes of width 0.18H and 1mm thick are arranged in single and double rows at a spacing (Vs) of 8cm and 12cm. The angle of attack (θ) of vane with respect to flow direction in river model varies as 15°, 300 and 450. A total of seven vanes are arranged as a crest of wave with a central vane height of 0.625 H and decreasing gradually to 0.438H on either side. In single row vane arrangement, for `Vs'=8 cm and `θ'=15°, 30° and 450, the sediment entry (S) reduces to 43%, 47% and 57% of sediment entry without vanes (So) and it is 40%, 44% and 48% of `So' for `Vs'= 12cm. Further `S' reduces to 38%, 39% and 47% of `So', by adding a second row of vanes at a lateral spacing and `Vs' of 8cm. It is observed that `S' decreases with an increase of `Vs' as well as with addition of a second row of vanes and increases with an increase of `θ'.

  15. Adaptive significance of the formation of multi-species fish spawning aggregations near submerged capes.

    Directory of Open Access Journals (Sweden)

    Mandy Karnauskas

    Full Text Available BACKGROUND: Many fishes are known to spawn at distinct geomorphological features such as submerged capes or "promontories," and the widespread use of these sites for spawning must imply some evolutionary advantage. Spawning at these capes is thought to result in rapid offshore transport of eggs, thereby reducing predation levels and facilitating dispersal to areas of suitable habitat. METHODOLOGY/PRINCIPAL FINDINGS: To test this "off-reef transport" hypothesis, we use a hydrodynamic model and explore the effects of topography on currents at submerged capes where spawning occurs and at similar capes where spawning does not occur, along the Mesoamerican Barrier Reef. All capes modeled in this study produced eddy-shedding regimes, but specific eddy attributes differed between spawning and non-spawning sites. Eddies at spawning sites were significantly stronger than those at non-spawning sites, and upwelling and fronts were the products of the eddy formation process. Frontal zones, present particularly at the edges of eddies near the shelf, may serve to retain larvae and nutrients. Spawning site eddies were also more predictable in terms of diameter and longevity. Passive particles released at spawning and control sites were dispersed from the release site at similar rates, but particles from spawning sites were more highly aggregated in their distributions than those from control sites, and remained closer to shore at all times. CONCLUSIONS/SIGNIFICANCE: Our findings contradict previous hypotheses that cape spawning leads to high egg dispersion due to offshore transport, and that they are attractive for spawning due to high, variable currents. Rather, we show that current regimes at spawning sites are more predictable, concentrate the eggs, and keep larvae closer to shore. These attributes would confer evolutionary advantages by maintaining relatively similar recruitment patterns year after year.

  16. Adaptive significance of the formation of multi-species fish spawning aggregations near submerged capes.

    Science.gov (United States)

    Karnauskas, Mandy; Chérubin, Laurent M; Paris, Claire B

    2011-01-01

    Many fishes are known to spawn at distinct geomorphological features such as submerged capes or "promontories," and the widespread use of these sites for spawning must imply some evolutionary advantage. Spawning at these capes is thought to result in rapid offshore transport of eggs, thereby reducing predation levels and facilitating dispersal to areas of suitable habitat. To test this "off-reef transport" hypothesis, we use a hydrodynamic model and explore the effects of topography on currents at submerged capes where spawning occurs and at similar capes where spawning does not occur, along the Mesoamerican Barrier Reef. All capes modeled in this study produced eddy-shedding regimes, but specific eddy attributes differed between spawning and non-spawning sites. Eddies at spawning sites were significantly stronger than those at non-spawning sites, and upwelling and fronts were the products of the eddy formation process. Frontal zones, present particularly at the edges of eddies near the shelf, may serve to retain larvae and nutrients. Spawning site eddies were also more predictable in terms of diameter and longevity. Passive particles released at spawning and control sites were dispersed from the release site at similar rates, but particles from spawning sites were more highly aggregated in their distributions than those from control sites, and remained closer to shore at all times. Our findings contradict previous hypotheses that cape spawning leads to high egg dispersion due to offshore transport, and that they are attractive for spawning due to high, variable currents. Rather, we show that current regimes at spawning sites are more predictable, concentrate the eggs, and keep larvae closer to shore. These attributes would confer evolutionary advantages by maintaining relatively similar recruitment patterns year after year.

  17. Air–water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Markus Moosmann

    2017-08-01

    Full Text Available Underwater air retention of superhydrophobic hierarchically structured surfaces is of increasing interest for technical applications. Persistent air layers (the Salvinia effect are known from biological species, for example, the floating fern Salvinia or the backswimmer Notonecta. The use of this concept opens up new possibilities for biomimetic technical applications in the fields of drag reduction, antifouling, anticorrosion and under water sensing. Current knowledge regarding the shape of the air–water interface is insufficient, although it plays a crucial role with regards to stability in terms of diffusion and dynamic conditions. Optical methods for imaging the interface have been limited to the micrometer regime. In this work, we utilized a nondynamic and nondestructive atomic force microscopy (AFM method to image the interface of submerged superhydrophobic structures with nanometer resolution. Up to now, only the interfaces of nanobubbles (acting almost like solids have been characterized by AFM at these dimensions. In this study, we show for the first time that it is possible to image the air–water interface of submerged hierarchically structured (micro-pillars surfaces by AFM in contact mode. By scanning with zero resulting force applied, we were able to determine the shape of the interface and thereby the depth of the water penetrating into the underlying structures. This approach is complemented by a second method: the interface was scanned with different applied force loads and the height for zero force was determined by linear regression. These methods open new possibilities for the investigation of air-retaining surfaces, specifically in terms of measuring contact area and in comparing different coatings, and thus will lead to the development of new applications.

  18. Biosorption of arsenic in drinking water by submerged plant: Hydrilla verticilata.

    Science.gov (United States)

    Nigam, Shubha; Gopal, Krishna; Vankar, Padma S

    2013-06-01

    To evaluate the biosorption efficacy of submerged aquatic plant Hydrilla verticilata for arsenic uptake from drinking water. H. verticillata, a submerged aquatic plant was utilized successfully for arsenic uptake from aqueous solution. Batch studies with various parameters viz. pH, sorbent dose, contact time, initial metal ion concentration, and temperature were carried out. Data were utilized to plot Lagergren graph along with pseudo-second-order graphs for kinetic studies to estimate the removal efficacy and to determine the nature of reaction. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) have been performed for characterization of metals on biomass. The study showed 96.35 % maximum absorption of arsenic by H. verticilata at initial concentration of 100 ppb with 0.5 g of biomass/100 ml for 5 h contact time at pH 6.0 with 150 rpm agitation rate. Data followed Langmuir isotherm showing sorption to be monolayer on homogeneous surface of biosorbent. The negative values of ΔG° indicated spontaneous nature; whereas ΔH° indicates exothermic nature of system and negative value of ∆S° entropy change correspond to a decrease in the degree of freedom to the adsorbed species followed by pseudo-second-order adsorption kinetics. FTIR and SEM results showed apparent changes in functional group regions after metal chelation and the changes in surface morphology of biosorbent. This is a comparatively more effective, economic, easily available, and environmentally safe source for arsenic uptake from solution due to its high biosorption efficacy than other biosorbents already used.

  19. AIRBORNE LASER BATHYMETRY FOR DOCUMENTATION OF SUBMERGED ARCHAEOLOGICAL SITES IN SHALLOW WATER

    Directory of Open Access Journals (Sweden)

    M. Doneus

    2015-04-01

    Full Text Available Knowledge of underwater topography is essential to the understanding of the organisation and distribution of archaeological sites along and in water bodies. Special attention has to be paid to intertidal and inshore zones where, due to sea-level rise, coastlines have changed and many former coastal sites are now submerged in shallow water. Mapping the detailed inshore topography is therefore important to reconstruct former coastlines, identify sunken archaeological structures and locate potential former harbour sites. However, until recently archaeology has lacked suitable methods to provide the required topographical data of shallow underwater bodies. Our research shows that airborne topo-bathymetric laser scanner systems are able to measure surfaces above and below the water table over large areas in high detail using very short and narrow green laser pulses, even revealing sunken archaeological structures in shallow water. Using an airborne laser scanner operating at a wavelength in the green visible spectrum (532 nm two case study areas in different environmental settings (Kolone, Croatia, with clear sea water; Lake Keutschach, Austria, with turbid water were scanned. In both cases, a digital model of the underwater topography with a planimetric resolution of a few decimeters was measured. While in the clear waters of Kolone penetration depth was up to 11 meters, turbid Lake Keutschach allowed only to document the upper 1.6 meters of its underwater topography. Our results demonstrate the potential of this technique to map submerged archaeological structures over large areas in high detail providing the possibility for systematic, large scale archaeological investigation of this environment.

  20. Enhanced submerged Aspergillus ficuum phytase production by implementation of fed-batch fermentation.

    Science.gov (United States)

    Coban, Hasan B; Demirci, Ali

    2014-12-01

    Phytase is an important feed and food additive, which is both used in animal and human diets. Phytase has been used to increase the absorption of several divalent ions, amino acids, and proteins in the bodies and to decrease the excessive phosphorus release in the manure to prevent negative effects on the environment. To date, microbial phytase has been mostly produced in solid-state fermentations with insignificant production volumes. There are only a few studies in the literature that phytase productions were performed in submerged bench-top reactor scale. In our previous studies, growth parameters (temperature, pH, and aeration) and important fermentation medium ingredients (glucose, Na-phytate, and CaSO4) were optimized. This study was undertaken for further enhancement of phytase production with Aspergillus ficuum in bench-top bioreactors by conducting fed-batch fermentations. The results showed that addition of 60 g of glucose and 10 g of Na-phytate at 96 h of fermentation increased phytase activity to 3.84 and 4.82 U/ml, respectively. Therefore, the maximum phytase activity was further enhanced with addition of glucose and Na-phytate by 11 and 40 %, respectively, as compared to batch phytase fermentations. It was also reported that phytase activity increased higher in early log stage additions than late log stage additions because of higher microbial activity. In addition, the phytase activity in fed-batch fermentation did not drop significantly as compared to the batch fermentation. Overall, this study shows that fungal phytase can be successfully produced in submerged fed-batch fermentations.

  1. Coastline shifts and probable ship landing site submerged off ancient Locri-Epizefiri, southern Italy

    Science.gov (United States)

    Tennent, J.M.; Stanley, J.-D.; Hart, P.E.; Bernasconi, M.P.

    2009-01-01

    A geophysical survey provides new information on marine features located seaward of Locri-Epizefiri (Locri), an ancient Greek settlement on the Ionian coastal margin in southern Italy. The study supplements previous work by archaeologists who long searched for the site's harbor and recently identified what was once a marine basin that is now on land next to the city walls of Locri. Profiles obtained offshore, between the present coast and outer shelf, made with a high-resolution, seismic subbottom-profiling system, record spatial and temporal variations of buried Holocene deposits. Two of these submerged features are part of a probable now-submerged ship landing facility. The offshore features can be linked to coastline displacements that occurred off Locri: a sea-to-land shift before Greek settlement, followed by a shoreline reversal from the archaeological site back to sea, and more recently, a return landward. The seaward directed coastal shift that occurred after Locri's occupation by Greeks was likely caused by land uplift near the coastal margin and tectonic seaward shift of the coast, as documented along this geologically active sector of the Calabrian Arc. The seismic survey records an angular, hook-shaped, low rise that extends from the present shore and is now buried on the inner shelf. The rise, enclosing a core lens of poorly stratified to transparent acoustic layers, bounds a broad, low-elevation zone positioned immediately seaward of the shoreline. Close proximity of the raised feature to the low-elevation area suggests it may have been a fabricated structure that functioned as a wave-break for a ship-landing site. The study indicates that the basin extended offshore as a function of the coastline's seaward migration during and/or after Greek occupation of Locri.

  2. Drinking water treatment using a submerged internal-circulation membrane coagulation reactor coupled with permanganate oxidation.

    Science.gov (United States)

    Zhang, Zhongguo; Liu, Dan; Qian, Yu; Wu, Yue; He, Peiran; Liang, Shuang; Fu, Xiaozheng; Li, Jiding; Ye, Changqing

    2017-06-01

    A submerged internal circulating membrane coagulation reactor (MCR) was used to treat surface water to produce drinking water. Polyaluminum chloride (PACl) was used as coagulant, and a hydrophilic polyvinylidene fluoride (PVDF) submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure (TMP), zeta potential (ZP) of the suspended particles in raw water, and KMnO 4 dosing on water flux and the removal of turbidity and organic matter were systematically investigated. Continuous bench-scale experiments showed that the permeate quality of the MCR satisfied the requirement for a centralized water supply, according to the Standards for Drinking Water Quality of China (GB 5749-2006), as evaluated by turbidity (water flux, the removal of turbidity, TOC and dissolved organic carbon (DOC) in the raw water also increased with increasing TMP in the range of 0.01-0.05MPa. High ZP induced by PACl, such as 5-9mV, led to an increase in the number of fine and total particles in the MCR, and consequently caused serious membrane fouling and high permeate turbidity. However, the removal of TOC and DOC increased with increasing ZP. A slightly positive ZP, such as 1-2mV, corresponding to charge neutralization coagulation, was favorable for membrane fouling control. Moreover, dosing with KMnO 4 could further improve the removal of turbidity and DOC, thereby mitigating membrane fouling. The results are helpful for the application of the MCR in producing drinking water and also beneficial to the research and application of other coagulation and membrane separation hybrid processes. Copyright © 2016. Published by Elsevier B.V.

  3. Air-water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy.

    Science.gov (United States)

    Moosmann, Markus; Schimmel, Thomas; Barthlott, Wilhelm; Mail, Matthias

    2017-01-01

    Underwater air retention of superhydrophobic hierarchically structured surfaces is of increasing interest for technical applications. Persistent air layers (the Salvinia effect) are known from biological species, for example, the floating fern Salvinia or the backswimmer Notonecta. The use of this concept opens up new possibilities for biomimetic technical applications in the fields of drag reduction, antifouling, anticorrosion and under water sensing. Current knowledge regarding the shape of the air-water interface is insufficient, although it plays a crucial role with regards to stability in terms of diffusion and dynamic conditions. Optical methods for imaging the interface have been limited to the micrometer regime. In this work, we utilized a nondynamic and nondestructive atomic force microscopy (AFM) method to image the interface of submerged superhydrophobic structures with nanometer resolution. Up to now, only the interfaces of nanobubbles (acting almost like solids) have been characterized by AFM at these dimensions. In this study, we show for the first time that it is possible to image the air-water interface of submerged hierarchically structured (micro-pillars) surfaces by AFM in contact mode. By scanning with zero resulting force applied, we were able to determine the shape of the interface and thereby the depth of the water penetrating into the underlying structures. This approach is complemented by a second method: the interface was scanned with different applied force loads and the height for zero force was determined by linear regression. These methods open new possibilities for the investigation of air-retaining surfaces, specifically in terms of measuring contact area and in comparing different coatings, and thus will lead to the development of new applications.

  4. Air–water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy

    Science.gov (United States)

    Schimmel, Thomas; Barthlott, Wilhelm; Mail, Matthias

    2017-01-01

    Underwater air retention of superhydrophobic hierarchically structured surfaces is of increasing interest for technical applications. Persistent air layers (the Salvinia effect) are known from biological species, for example, the floating fern Salvinia or the backswimmer Notonecta. The use of this concept opens up new possibilities for biomimetic technical applications in the fields of drag reduction, antifouling, anticorrosion and under water sensing. Current knowledge regarding the shape of the air–water interface is insufficient, although it plays a crucial role with regards to stability in terms of diffusion and dynamic conditions. Optical methods for imaging the interface have been limited to the micrometer regime. In this work, we utilized a nondynamic and nondestructive atomic force microscopy (AFM) method to image the interface of submerged superhydrophobic structures with nanometer resolution. Up to now, only the interfaces of nanobubbles (acting almost like solids) have been characterized by AFM at these dimensions. In this study, we show for the first time that it is possible to image the air–water interface of submerged hierarchically structured (micro-pillars) surfaces by AFM in contact mode. By scanning with zero resulting force applied, we were able to determine the shape of the interface and thereby the depth of the water penetrating into the underlying structures. This approach is complemented by a second method: the interface was scanned with different applied force loads and the height for zero force was determined by linear regression. These methods open new possibilities for the investigation of air-retaining surfaces, specifically in terms of measuring contact area and in comparing different coatings, and thus will lead to the development of new applications. PMID:28875104

  5. Spectral wave dissipation by submerged aquatic vegetation in a back-barrier estuary

    Science.gov (United States)

    Nowacki, Daniel J.; Beudin, Alexis; Ganju, Neil K.

    2017-01-01

    Submerged aquatic vegetation is generally thought to attenuate waves, but this interaction remains poorly characterized in shallow-water field settings with locally generated wind waves. Better quantification of wave–vegetation interaction can provide insight to morphodynamic changes in a variety of environments and also is relevant to the planning of nature-based coastal protection measures. Toward that end, an instrumented transect was deployed across a Zostera marina (common eelgrass) meadow in Chincoteague Bay, Maryland/Virginia, U.S.A., to characterize wind-wave transformation within the vegetated region. Field observations revealed wave-height reduction, wave-period transformation, and wave-energy dissipation with distance into the meadow, and the data informed and calibrated a spectral wave model of the study area. The field observations and model results agreed well when local wind forcing and vegetation-induced drag were included in the model, either explicitly as rigid vegetation elements or implicitly as large bed-roughness values. Mean modeled parameters were similar for both the explicit and implicit approaches, but the spectral performance of the explicit approach was poor compared to the implicit approach. The explicit approach over-predicted low-frequency energy within the meadow because the vegetation scheme determines dissipation using mean wavenumber and frequency, in contrast to the bed-friction formulations, which dissipate energy in a variable fashion across frequency bands. Regardless of the vegetation scheme used, vegetation was the most important component of wave dissipation within much of the study area. These results help to quantify the influence of submerged aquatic vegetation on wave dynamics in future model parameterizations, field efforts, and coastal-protection measures.

  6. Environmental Evaluation of New Generation Vehicles and Vehicle Components

    Energy Technology Data Exchange (ETDEWEB)

    Schexnayder, S.M.

    2002-02-06

    This report documents assessments that address waste issues and life cycle impacts associated with the vehicle materials and vehicle technologies being developed under the Partnership for a New Generation of Vehicles (PNGV) program. We refer to these vehicles as 3XVs, referring to the PNGV goal that their fuel mileage be three times better than the baseline vehicle. To meet the program's fuel consumption goals, these vehicles substitute lightweight materials for heavier materials such as steel and iron that currently dominate the composition of vehicles, and use engineering and power system changes. Alternative power systems being developed through the PNGV program include batteries for hybrid electric vehicles and fuel cells. With respect to all these developments, it is imperative to learn what effects they will have on the environment before adopting these designs and technologies on a large-scale basis.

  7. Does Driving Range of Electric Vehicles Influence Electric Vehicle Adoption?

    Directory of Open Access Journals (Sweden)

    Seiho Kim

    2017-10-01

    Full Text Available This study aims to determine the influential factors on the market share of electric vehicles through panel data analysis based on time series data from 2011 to 2015 in 31 countries. We selected five significant independent variables that are expected to affect electric vehicle adoption based on literature review. The econometric model in this study suggests that the relative price of electric vehicle compared to internal combustion engine vehicle, driving range, and number of models available in markets are correlated to the market share of electric vehicles. On the other hand, relationship between recharging infrastructure—an important factor for electric vehicle adoption in many studies—and market share of electric vehicles turned out to be insignificant in this study. From a political point of view, we argue that policy makers need to allocate more resources to research and development in order to extend driving range at the early stage of electric vehicle deployment in the markets.

  8. Comparison of solid-state and submerged-state fermentation for the bioprocessing of switchgrass to ethanol and acetate by Clostridium phytofermentans.

    Science.gov (United States)

    Jain, Abhiney; Morlok, Charles K; Henson, J Michael

    2013-01-01

    The conversion of sustainable energy crops using microbiological fermentation to biofuels and bioproducts typically uses submerged-state processes. Alternatively, solid-state fermentation processes have several advantages when compared to the typical submerged-state processes. This study compares the use of solid-state versus submerged-state fermentation using the mesophilic anaerobic bacterium Clostridium phytofermentans in the conversion of switchgrass to the end products of ethanol, acetate, and hydrogen. A shift in the ratio of metabolic products towards more acetate and hydrogen production than ethanol production was observed when C. phytofermentans was grown under solid-state conditions as compared to submerged-state conditions. Results indicated that the end product concentrations (in millimolar) obtained using solid-state fermentation were higher than using submerged-state fermentation. In contrast, the total fermentation products (in weight of product per weight of carbohydrates consumed) and switchgrass conversion were higher for submerged-state fermentation. The conversion of xylan was greater than glucan conversion under both fermentation conditions. An initial pH of 7 and moisture content of 80 % resulted in maximum end products formation. Scanning electron microscopy study showed the presence of biofilm formed by C. phytofermentans growing on switchgrass under submerged-state fermentation whereas bacterial cells attached to surface and no apparent biofilm was observed when grown under solid-state fermentation. To our knowledge, this is the first study reporting consolidated bioprocessing of a lignocellulosic substrate by a mesophilic anaerobic bacterium under solid-state fermentation conditions.

  9. Does Driving Range of Electric Vehicles Influence Electric Vehicle Adoption?

    OpenAIRE

    Seiho Kim; Jaesik Lee; Chulung Lee

    2017-01-01

    This study aims to determine the influential factors on the market share of electric vehicles through panel data analysis based on time series data from 2011 to 2015 in 31 countries. We selected five significant independent variables that are expected to affect electric vehicle adoption based on literature review. The econometric model in this study suggests that the relative price of electric vehicle compared to internal combustion engine vehicle, driving range, and number of models availabl...

  10. TARDEC Ground Vehicle Robotics: Vehicle Dynamic Characterization and Research

    Science.gov (United States)

    2015-09-01

    of Contents I. Introduction II. Physical Vehicle Design Properties a. All-Terrain Vehicle Classification b. UGV Classification c. OEMs in...Vehicle Design Properties The physical components of a vehicle naturally have a large effect on its performance. Body and chassis type have the...Diesel-Electric, Series, Parallel. Power Distribution: RWD, FWD, AWD, open diff, LSD , Torsen diff, differential braking (traction control), drive by

  11. Field of Vision - Vehicles

    Science.gov (United States)

    2017-05-11

    observer to the ground for a 95th percentile male and a 5th percentile female . The dimensions of the vehicle should also be taken. 4. TEST...field of vision Gd ground distance MIL-STD Military Standard SAE Society of Automotive Engineers Sd stadia rod distance from the center of the...

  12. The Electric Vehicle Challenge

    Science.gov (United States)

    Roman, Harry T.

    2010-01-01

    This article describes a design activity that provides students with a solid understanding of the many issues involved with alternate energy system design. In this activity, students will be able to learn about electric vehicles and have the opportunity to design a way to recharge the batteries while the cars are parked in a commuter garage. The…

  13. Hybrid Turbine Electric Vehicle

    Science.gov (United States)

    Viterna, Larry A.

    1997-01-01

    Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

  14. 2008 Combat Vehicles Conference

    Science.gov (United States)

    2008-10-22

    General Michael M. Brogan Combat Vehicles Conference Marine Corps Systems Command 21 October 2008 2 MCSC •LAV •AAV •Tank •HMMWV/ ECV •MRAP PEO LS...34,226 Total 56,649 1985 IOC 1996 M1114 armored HMMWV Limited Production 2006 M1100 series begins fielding scalable armor 2009-10 ECV II

  15. Communication Technologies for Vehicles

    DEFF Research Database (Denmark)

    Vinel, Alexey

    This book constitutes the proceedings of the 8th International Workshop on Communication Technologies for Vehicles, Nets4Cars/Nets4Trains/Nets4Aircraft 2015, held in Sousse, Tunisia, in May 2015. The 20 papers presented in this volume were carefully reviewed and selected from 27 submissions. The ...

  16. Multiple environment unmanned vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Hobart, Clinton G.; Morse, William D.; Bickerstaff, Robert James

    2017-12-19

    A MEUV that is able to navigate aerial, aquatic, and terrestrial environments through the use of different mission mobility attachments is disclosed. The attachments allow the MEUV to be deployed from the air or through the water prior to any terrestrial navigation. The mobility attachments can be removed or detached by and from the vehicle during a mission.

  17. Multiple environment unmanned vehicle

    Science.gov (United States)

    Hobart, Clinton G.; Morse, William D.; Bickerstaff, Robert James

    2017-02-28

    A MEUV that is able to navigate aerial, aquatic, and terrestrial environments through the use of different mission mobility attachments is disclosed. The attachments allow the MEUV to be deployed from the air or through the water prior to any terrestrial navigation. The mobility attachments can be removed or detached by and from the vehicle during a mission.

  18. Motor Vehicle Safety

    Science.gov (United States)

    ... you can do to be safer on the road: Make sure your vehicle is safe and in working order Use car seats for children Wear your seat belt Don't speed or drive aggressively Don't drive impaired Safety also involves being aware of others. Share the ...

  19. Diesel Vehicle Maintenance Competencies.

    Science.gov (United States)

    Braswell, Robert; And Others

    Designed to provide a model set of competencies, this manual presents tasks which were identified by employers, employees, and teachers as important in a postsecondary diesel vehicle maintenance curriculum. The tasks are divided into seven major component areas of instruction: chassis and suspension, diesel engines, diesel fuel, electrical,…

  20. AST Launch Vehicle Acoustics

    Science.gov (United States)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.